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Sample records for owls bubo bubo

  1. Factors influencing territorial occupancy and reproductive success in a Eurasian Eagle-owl (Bubo bubo) population.

    PubMed

    León-Ortega, Mario; Jiménez-Franco, María V; Martínez, José E; Calvo, José F

    2017-01-01

    Modelling territorial occupancy and reproductive success is a key issue for better understanding the population dynamics of territorial species. This study aimed to investigate these ecological processes in a Eurasian Eagle-owl (Bubo bubo) population in south-eastern Spain during a seven-year period. A multi-season, multi-state modelling approach was followed to estimate the probabilities of occupancy and reproductive success in relation to previous state, time and habitat covariates, and accounting for imperfect detection. The best estimated models showed past breeding success in the territories to be the most important factor determining a high probability of reoccupation and reproductive success in the following year. In addition, alternative occupancy models suggested the positive influence of crops on the probability of territory occupation. By contrast, the best reproductive model revealed strong interannual variations in the rates of breeding success, which may be related to changes in the abundance of the European Rabbit, the main prey of the Eurasian Eagle-owl. Our models also estimated the probabilities of detecting the presence of owls in a given territory and the probability of detecting evidence of successful reproduction. Estimated detection probabilities were high throughout the breeding season, decreasing in time for unsuccessful breeders but increasing for successful breeders. The probability of detecting reproductive success increased with time, being close to one in the last survey. These results suggest that reproduction failure in the early stages of the breeding season is a determinant factor in the probability of detecting occupancy and reproductive success.

  2. Factors that influence mercury concentrations in nestling Eagle Owls (Bubo bubo).

    PubMed

    Espín, Silvia; Martínez-López, Emma; León-Ortega, Mario; Calvo, José F; García-Fernández, Antonio Juan

    2014-02-01

    Mercury (Hg) is a global pollutant that bioaccumulates and biomagnifies in food chains, and is associated with adverse effects in both humans and wildlife. The Hg levels detected in blood obtained from Eagle Owl (Bubo bubo) chicks in Southeast Spain (Murcia) can be considered low (mean Hg concentration in blood from 2006 to 2012 was 36.83 ± 145.58 μg/l wet weigh, n=600), and it is therefore unlikely that Hg pollution can negatively affect their breeding. Positive correlation (r=0.339, p<0.001, n=229) was found to exist between the Hg concentrations in the blood and back feathers of the chicks. We provide a regression equation that could be helpful to estimate blood Hg levels when analyzing Hg concentrations in back feathers. Blood Hg concentrations in Eagle Owls have shown positive correlations with Hg levels in rabbit muscles, more evident in nests from the Northern area (r=0.600, p=0.014, n=16), where rabbits are the main prey of Eagle Owls. The best Linear Mixed Model to explain variations in blood Hg concentrations in nestling Eagle Owls includes year and location within the mining area as variables. The variable year is assigned the largest value of relative importance, followed by the location in the ancient mining sites and then the zone. Rainfalls may have an effect on the temporal differences in the blood Hg concentrations of nestling Eagle Owls. Although the studied region is not considered Hg polluted, the Hg levels were higher in Eagle Owls and European Rabbits from areas within the ancient mining sites as compared to those in the entire region. This result shows that spatial differences in Hg concentrations in Eagle Owls may be affected by local contamination, and that the role of diet composition may be less significant.

  3. The Macroanatomy of the Sacral Plexus and Its Nerves in Eurasian Eagle Owls (Bubo bubo).

    PubMed

    Akbulut, Y; Demiraslan, Y; Aslan, K; Coban, A

    2016-10-01

    This study was carried out to reveal the formation of the sacral plexus in the Eurasian Eagle Owls (Bubo bubo) and the nerves originating from this plexus. Five EEOs, three of them were male and two were female, were provided from Wildlife Rescue and Rehabilitation Center of Kafkas University and used as materials. Following the euthanizing of the animals, abdominal cavity was opened. The nerves of plexus sacrales were dissected and photographed. It was detected that the sacral plexus was formed by the ventral ramus of five synsacral nerves. Moreover, it was determined that the roots of the sacral plexus formed three trunks: the truncus cranialis, the truncus medius and the truncus caudalis in fossa renalis. The availability of the n. ischiofemoralis and the availability of n. parafibularis were detected in the EEOs. Five branches were specified as having segregated from the sacral plexus: the n. cutaneus femoralis caudalis, the mutual root of n. fibularis with n. tibialis (n. ischiadicus), the rami musculares, the n. coxalis caudalis and the ramus muscularis. It was observed that the sacral plexus was linked to the lumbar plexus by the n. furcalis, to the pudendus plexus via the n. bigeminus. Consequently, the anatomic structure of the EEO's sacral plexus, the participating synsacral nerves to plexus and the innervation areas of these nerves were revealed.

  4. Complete mitochondrial genome of Eagle Owl (Bubo bubo, Strigiformes; Strigidae) from China.

    PubMed

    Hengjiu, Tian; Jianwei, Ji; Shi, Yang; Zhiming, Zhang; Laghari, Muhammad Younis; Narejo, Naeem Tariq; Lashari, Punhal

    2016-01-01

    In the present study, the complete mitochondrial genome sequence of Bubo bubo using PCR amplification, sequencing and assembling has been obtained for the first time. The total length of the mitochondrial genome was 16,250  bp, with the base composition of 29.88% A, 34.16% C, 14.35% G, and 21.58% T. It contained 37 genes (2 ribosomal RNA genes, 13 protein-coding genes and 22 transfer RNA genes) and a major non-coding control region (D-loop region). The complete mitochondrial genome sequence of Bubo bubo provides an important data set for further investigation on the phylogenetic relationships within Strigiformes.

  5. A curious pellet from a great horned owl (Bubo virginianus)

    USGS Publications Warehouse

    Woodman, N.; Dove, C.J.; Peurach, S.C.

    2005-01-01

    One of the traditional methods of determining the dietary preferences of owls relies upon the identification of bony remains of prey contained in regurgitated pellets. Discovery of a pellet containing a large, complete primary feather from an adult, male Ring-necked Pheasant (Phasianus colchicus) prompted us to examine in detail a small sample of pellets from a Great Horned Owl (Bubo virginianus). Our analyses of feather and hair remains in these pellets documented the presence of three species of birds and two species of mammals, whereas bones in the pellets represented only mammals. This finding indicates an important bias that challenges the reliability of owl pellet studies making use of only osteological remains.

  6. [Successful rehabilitation and release with a subsequent brood of a one-eyed eagle owl (Bubo bubo)].

    PubMed

    Hegemann, Arne; Hegemann, Ernst Dieter; Krone, Oliver

    2007-01-01

    The rehabilitation and release of injured or ill raptors and owls is widespread. The overall aim of this intervention is the successful reintroduction of the bird into the wild population. Though many injuries are treatable, it is thought that vision-impaired birds have no change of survival and their release is refused. Here we report a case study and give a description of the rehabilitation and subsequent release of an injured Eagle Owl (Bubo bubo). The bird was found with an injured eye and a paralysed wing in the district of Soest, North Rhine-Westphalia, Germany. While the paralysis healed, the bird stayed blind in one eye. Nevertheless it was released with a radio-transmitter. The female Eagle Owl could be followed by radio-telemetry for more than half a year after release, by visual and acoustic skills for a full year after release. Although the female was only two years old, it paired successful with a partner, and raised a brood with three offspring. No differences in the behaviour compared to non-handicapped birds could be detected. This one-eyed Eagle Owl demonstrates not only survival, but also successful reproduction following reintegration into the wild population. However, low intraspecific competition in the area might have contributed to the reproductive success of the owl.

  7. Presumptive keratoglobus in a great horned owl (Bubo virginianus).

    PubMed

    Lau, Rachael K; Moresco, Anneke; Woods, Sarah J; Reilly, Christopher M; Hawkins, Michelle G; Murphy, Christopher J; Hollingsworth, Steven R; Hacker, Dennis; Freeman, Kate S

    2016-07-31

    A juvenile to young adult, male, great horned owl (Bubo virginianus,GHOW) was presented to the wildlife rehabilitation hospital at Lindsay Wildlife Museum (WRHLWM) due to trauma to the right patagium from barbed wire entanglement. On presentation, both corneas were irregular, dry, and no movement of the third eyelid was noted. A severe corneal enlargement/globoid appearance was the predominant ophthalmic feature. The fundus was normal in both eyes (OU). Over the course of several days, both corneas developed edema combined with further dessication at the ocular surface associated with diffuse dorsal fluorescein stain uptake. Repeated ophthalmic examinations found normal intraocular pressures and an inability to move the third eyelid over the enlarged corneas. The bird was deemed nonreleasable due to severe wing damage and poor prognosis associated with eye abnormalities and was humanely euthanized. Postmortem CT, enucleation, and histopathology were performed to evaluate the ocular anatomical abnormality and confirm the suspected diagnosis of keratoglobus. This GHOW represents the first reported case of presumptive keratoglobus in a raptor.

  8. Oxidative stress biomarkers in Eurasian eagle owls (Bubo bubo) in three different scenarios of heavy metal exposure.

    PubMed

    Espín, Silvia; Martínez-López, Emma; León-Ortega, Mario; Martínez, José Enrique; García-Fernández, Antonio Juan

    2014-05-01

    The main aim of the present study is the assessment of oxidative stress related to metals in the Eurasian eagle owl (Bubo bubo) from three areas (agricultural and rural area, industrial area, and mining area) of Murcia, Southern Spain. Mean blood metal concentrations were Cd=0.07±0.21, Pb=3.27±5.21, Cu=10.62±4.77, Zn=311.47±67.14, Hg=2.32±3.83 μg/dl wet weight. Although individuals from the mining area had significant higher Pb and Hg concentrations, and significant lower glutathione-S-transferase (GST) and catalase (CAT) activities in red blood cells (RBC); the lack of differences in oxidative damage to membrane lipids (TBARS) among areas suggests that the antioxidant capacity of the different populations is able to deal with oxidant species and maintain TBARS levels in the same amount. Despite the low levels of metals, several oxidative stress biomarkers were correlated with metal concentrations. This study provides threshold concentrations at which metals cause effects on the antioxidant system in Eagle owls. Blood Cd concentrations greater than 0.3 μg/dl produced an inhibition in GPx (32%) and CAT (26%) activity in RBC. However, Cd concentrations higher than 0.02 μg/dl were enough to produce an inhibition of these enzymes. Regarding Pb levels, blood concentrations above 2 μg/dl produced an inhibition of 8% and 10.5% in GPx and CAT activities, respectively, in RBC. A depletion of 16% and 4% in tGSH levels was associated with Pb concentrations higher than 15 and 3 μg/dl, respectively, in individuals from the ancient mine site. In addition, Pb concentrations above 2 and 10 μg/dl produced a TBARS induction of 10% and 28%, respectively, in individuals from both the industrial and the mining area. Finally, Hg concentrations greater than 3 and 10 μg/dl resulted in a TBARS induction of 102% and 190%, respectively, in Eurasian eagle owls from the industrial area. Our findings show that Pb may produce effects on oxidative stress biomarkers in Strigiformes at

  9. Columbid herpesvirus-1 mortality in great horned owls (Bubo virginianus) from Calgary, Alberta.

    PubMed

    Rose, Nicole; Warren, Amy L; Whiteside, Douglas; Bidulka, Julie; Robinson, John H; Illanes, Oscar; Brookfield, Caroline

    2012-03-01

    Four cases of Columbid herpesvirus-1 infection in great horned owls (Bubo virginianus) were identified in Calgary, Alberta. Necropsy findings included severe multifocal hepatic and splenic necrosis, pharyngeal ulceration and necrosis, and gastrointestinal necrosis. Occasional eosinophilic intranuclear viral inclusion bodies were associated with the foci of necrosis and polymerase chain reaction (PCR) testing confirmed a diagnosis of herpesvirus-induced disease. The sequence of a PCR amplicon had 99.7% homology to Columbid herpesvirus-1.

  10. Avulsion of the brachial plexus in a great horned owl (Bubo virginaus)

    USGS Publications Warehouse

    Moore, M.P.; Stauber, E.; Thomas, N.J.

    1989-01-01

    Avulsion of the brachial plexus was documented in a Great Horned Owl (Bubo virginianus). A fractured scapula was also present. Cause of these injuries was not known but was thought to be due to trauma. Differentiation of musculoskeletal injury from peripheral nerve damage can be difficult in raptors. Use of electromyography and motor nerve conduction velocity was helpful in demonstrating peripheral nerve involvement. A brachial plexus avulsion was suspected on the basis of clinical signs, presence of electromyographic abnormalities in all muscles supplied by the nerves of the brachial plexus and absence of median-ulnar motor nerve conduction velocities.

  11. Home range and habitat use by Great Horned Owls (Bubo virginianus) in Southern California

    USGS Publications Warehouse

    Bennett, J.R.; Bloom, P.H.

    2005-01-01

    Great Horned Owls (Bubo virginianus) are a common, widespread species that can be found in a variety of habitats across most of North America, but little is known about their space and habitat requirements. Using radiotelemetry, location data were collected on nine male and five female Great Horned Owls to determine home range and habitat use in southern California. Owls were tracked between January 1997 and September 1998 for periods ranging from 5-17 mo. Seven owls were also followed during 13 all-night observation periods. The mean 95% adaptive kernel home-range size for females was 180 ha (range = 88-282, SE = 36) and that for males was 425 ha (range = 147-1115 ha, SE = 105). Core areas estimated by the 50% adaptive kernel averaged 27 ha (range = 7-44, SE = 7) for females and 61 ha (range = 15-187, SE = 18) for males. Owls were located in areas with varying degrees of human disturbance ranging from almost entirely urban to native oak (Quercus agrifolia) woodland. Oak/sycamore (Quercus agrifolia/Platanus racemosa) woodland and ruderal grassland (Bromus spp., Avena spp., and various other non-native invasives), were used more often than expected based on availability, but we found no correlation between home-range size and any single habitat type or habitat groups. ?? 2005 The Raptor Research Foundation, Inc.

  12. Blood lead levels and δ-ALAD inhibition in nestlings of Eurasian Eagle Owl (Bubo bubo) to assess lead exposure associated to an abandoned mining area.

    PubMed

    Gómez-Ramírez, P; Martínez-López, E; María-Mojica, P; León-Ortega, M; García-Fernández, A J

    2011-01-01

    In order to biomonitor lead contamination in Southeastern Spain, 218 blood samples from 28 to 30-day old Eurasian Eagle Owl chicks (Bubo bubo) born between 2003 and 2007 were analysed. In general, mean lead levels showed that chicks were exposed to background concentrations. However, mean levels in chicks born in an ancient and abandoned mining site ("Sierra Minera Cartagena-La Union") or in their surroundings (Geometric mean (GM) = 5.83 μg/dl, range 0.49-25.61 μg/dl), an area highly polluted by lead and other metals, were significantly higher (p < 0.001) than the rest of the population (GM = 1.66 μg/dl, range = Non detected-18.37 μg/dl). Because δ-ALAD activity is considered the best biomarker for lead exposure and effect in birds, the activity of this enzyme was also evaluated and correlated with lead levels in blood. In this study, low levels of blood lead inhibited δ-ALAD, even when lead concentrations were lower than the limits described by other authors in raptors. Adverse effects caused by this inhibition may occur when blood lead levels were above 15 μg/dl, although only eight chicks presented these concentrations in their blood. Sampling site also influenced enzymatic activity, since it decreased about 60% in the polluted area in relation to the rest. For all these reasons, further research regarding risk assessment for lead exposure in Eagle Owls nesting in the polluted area is advisable. Our results suggest that the Eurasian Eagle Owl can be considered a suitable sentinel animal for monitoring lead contamination and δ-ALAD activity can be used as a sensitive biomarker for lead exposure and effect in this species.

  13. Cross-species amplification of microsatellite markers in the Great Horned Owl Bubo virginianus, Short-eared Owl Asio flammeus and Snowy Owl B. scandiacus for use in population genetics, individual identification and parentage studies

    USGS Publications Warehouse

    Dial, Cody R.; Talbot, Sandra L.; Sage, George K.; Seidensticker, M.T.; Holt, D.W.

    2012-01-01

    Using DNA from blood and feathers, we screened twenty-four microsatellite primer pairs initially developed for six strigid owls, and four primer pairs shown to be polymorphic across avian taxa, for their utility in Great Horned Owl (Bubo virginianus), Short-eared Owl (Asio flammeus), and Snowy Owl (Bubo scandiacus). Eight of these primers reliably amplified polymorphic fragments in Great Horned Owl, eleven in Short-eared owl, and ten in Snowy Owl. Analyses of results from presumably unrelated owls demonstrate the utility of these loci for individual identification, parentage assignment, and population genetics studies.

  14. Validation of a QuECheRS method for analysis of neonicotinoids in small volumes of blood and assessment of exposure in Eurasian eagle owl (Bubo bubo) nestlings.

    PubMed

    Taliansky-Chamudis, A; Gómez-Ramírez, P; León-Ortega, M; García-Fernández, A J

    2017-04-01

    Neonicotinoid pesticides have gained great interest in the last years both for agricultural and domestic use. Since the information on their environmental distribution or the effects derived from exposure to ecosystems and biota is scarce, new analytical techniques are being developed for monitoring studies. In this sense, two extraction techniques based on QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) methodology to detect the neonicotinoids authorised in Spain (acetamiprid, clothianidin, dinotefuran, imidacloprid, thiacloprid, nitenpyram and thiamethoxam) were adapted and compared: a) using acetate buffer (AB); and b) using citrate buffer (CB). For detection and quantification, high performance liquid chromatography coupled with time of flight mass spectrometry (HPLC/TOF-MS) was used. The CB method provided a wide range of recoveries (68-134%) and accuracy (4-9%). The AB method provided good recoveries (59-76%, 59% corresponded to clothianidin) precision (4-11%) linearity (0.987-0.998%) and limit of quantification (2-10ng/mL) for all the compounds. To test the effectiveness of the technique, we analysed 30 blood samples of free-ranging nestlings of Eurasian eagle owl (Bubo bubo). The only compound detected, in one nestling from a dry land farming area, was imidacloprid, with a concentration of 3.28ng/mL. To our knowledge, this is the first study of neonicotinoid pesticides in free-ranging birds of prey using non-destructive samples, providing the first insight for biomonitoring studies. Further studies, including toxicokinetics and toxicodynamics, are recommended to assess the risk for these species.

  15. OPHTHALMIC REFERENCE VALUES AND LESIONS IN TWO CAPTIVE POPULATIONS OF NORTHERN OWLS: GREAT GREY OWLS (STRIX NEBULOSA) AND SNOWY OWLS (BUBO SCANDIACUS).

    PubMed

    Wills, Sarah; Pinard, Chantale; Nykamp, Stephanie; Beaufrère, Hugues

    2016-03-01

    This study established ophthalmic reference values and characterized ocular lesions in two captive populations of boreal owls, including 46 eyes of 23 great grey owls (Strix nebulosa) and 38 eyes from 19 snowy owls (Bubo scandiacus). A complete ophthalmologic exam was conducted, including neuro-ophthalmic reflexes, Schirmer tear test I (STT-I), intraocular pressure (IOP) using rebound tonometry, fluorescein staining, horizontal corneal measurements using Jameson calipers, direct and indirect ophthalmoscopy, and ocular ultrasound biometry. Eyes with an STT of <5 mm/min, outliers, and eyes with severe diseases were excluded from reference value analysis. No statistically significant differences were found between right or left eyes in either species or among individuals in different age groups and sexes. Mean intraocular pressures and Schirmer tear tests were also not statistically significantly different between great grey owls and snowy owls (IOP: 9.6 ± 2.6 mm Hg and 9.1 ± 1.9 mm Hg, respectively, and STT-I: 9.8 ± 2.8 mm/min and 9.8 ± 2.4 mm/min, respectively). However, snowy owls overall had a significantly larger eye than did great grey owls, reflected in corneal diameters (23.4 ± 1 vs. 20.0 ± 0.8 mm, respectively) and sonographic biometry. In both species, the most common ocular lesions included keratitis, cataracts, chorioretinal lesions, and abnormal pecten. Establishment of reference ocular parameters will help wildlife veterinarians and rehabilitators determine an appropriate treatment plan and will aid in correctly identifying the presence of ocular disease.

  16. Rural culture and the conservation of Mackinders eagle owls (Bubo capensis mackinderi) in Kenya.

    PubMed

    Ogada, Darcy L

    2008-06-01

    The author describes her fieldwork studying a population of Mackinders eagle owls that live adjacent to small-scale farms in rural Kenya. Her study investigated the effects of farming practices on the diet and breeding ecology of the owls. She documented local people's attitudes toward owls since owls are taboo throughout Africa. She describes a typical day in the field, the community aspect of her project, her unique experiences studying owls in Kenya, and promotion of owl tourism.

  17. Anticoagulant rodenticides in red-tailed hawks, Buteo jamaicensis, and great horned owls, Bubo virginianus, from New Jersey, USA, 2008-2010.

    PubMed

    Stansley, William; Cummings, Margaret; Vudathala, Daljit; Murphy, Lisa A

    2014-01-01

    Liver samples from red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus) were analyzed for anticoagulant rodenticides. Residues of one or more second generation anticoagulant rodenticides (SGARs) were detected in 81 % of red-tailed hawks and 82 % of great horned owls. The most frequently detected SGAR was brodifacoum, which was detected in 76 % of red-tailed hawks and 73 % of great horned owls. Bromadiolone was detected in 20 % of red-tailed hawks and 27 % of great horned owls. Difenacoum was detected in one great horned owl. No other ARs were detected. There were no significant differences between species in the frequency of detection or concentration of brodifacoum or bromadiolone. There was a marginally significant difference (p = 0.0497) between total SGAR residues in red-tailed hawks (0.117 mg/kg) and great horned owls (0.070 mg/kg). There were no seasonal differences in the frequency of detection or concentration of brodifacoum in red-tailed hawks. The data suggest that SGARs pose a significant risk of poisoning to predatory birds in New Jersey.

  18. Pharmacokinetics of a single dose of intravenous and oral meloxicam in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus).

    PubMed

    Lacasse, Claude; Gamble, Kathryn C; Boothe, Dawn M

    2013-09-01

    Pharmacokinetic data were determined after a single dose of meloxicam in red-tailed hawks (RTH; Buteo jamaicensis) and great horned owls (GHO; Bubo virginianus). In a nonrandomized crossover design, individual birds of each species received 1 dose of intravenous meloxicam (0.5 mg/kg i.v.; n = 7 for each species) followed by a 2-week washout period, and then each received 1 dose of oral meloxicam (0.5 mg/kg PO; n = 5 for each species). Blood samples were collected intermittently after administration, and meloxicam was detected in plasma by high-performance liquid chromatography. Time versus plasma concentration data were subjected to noncompartmental analysis. Red-tailed hawks were determined to have the shortest elimination half-life for meloxicam (0.49 +/- 0.5 hours) of any species documented. Great horned owls also eliminated meloxicam very rapidly (0.78 +/- 0.52 hours). Great horned owls achieved higher plasma concentrations (368 +/- 87 ng/mL) of meloxicam than RTH (182 +/- 167 ng/mL) after oral administration, although RTH had a markedly higher volume of distribution (832 +/- 711 mL/kg) than GHO (137.6 +/- 62.7 mL/kg). The differences in meloxicam pharmacokinetics between these 2 raptor species supports the need for species-dependent studies and underlines the challenges of extrapolating drug dosages between species. Results of this study suggest that the current recommended once-daily dosing interval of oral meloxicam is unlikely to maintain plasma concentrations anticipated to be therapeutic in either RTH or GHO, and practical dosing options are questionable for this nonsteriodal anti-inflammatory drug in these raptor species.

  19. Pathologic and immunohistochemical findings in goshawks (Accipiter gentilis) and great horned owls (Bubo virginianus) naturally infected with West Nile virus.

    PubMed

    Wünschmann, Arno; Shivers, Jan; Bender, Jeff; Carroll, Larry; Fuller, Susan; Saggese, Miguel; van Wettere, Arnaud; Redig, Pat

    2005-06-01

    The carcasses of 25 great horned owls and 12 goshawks were investigated for West Nile virus (WNV) infection by immunohistochemistry (IHC) performed on various organs, including brain, spinal cord, heart, kidney, eye, bone marrow, spleen, liver, lungs, pancreas, intestine, and proventriculus, using a WNV-antigen-specific monoclonal antibody and by WNV-specific reverse transcriptase-polymerase chain reaction (RT-PCR), performed on fresh brain tissue only. WNV infection was diagnosed by IHC in all owls and all goshawks. WNV-specific RT-PCR amplified WNV-RNA in the brain of all goshawks but only 12 owls (48%). Cachexia was a common macroscopic finding associated with WNV infection in owls (76%). Myocarditis was occasionally macroscopically evident in goshawks (33%). Microscopically, inflammatory lesions, including lymphoplasmacytic and histiocytic encephalitis, myocarditis, endophthalmitis, and pancreatitis were present in both species but were more common and more severe in goshawks than in owls. The most characteristic brain lesion in owls was the formation of glial nodules, in particular in the molecular layer of the cerebellum, while encephalitis affecting the periventricular parenchyma of the cerebral cortex was common in the goshawks. In owls, WNV-antigen-positive cells were present usually only in very small numbers per organ. Kidney (80%), heart (39%), and cerebellum (37%) were the organs that most commonly contained WNV antigen in owls. WNV antigen was frequently widely distributed in the organs of infected goshawks, with increased amounts of WNV antigen in the heart and the cerebrum. Spleen (75%), cerebellum (66%), heart (58%), cerebrum (58%), and eye (50%) were often WNV-antigen positive in goshawks. In contrast with the goshawks, WNV antigen was not present in cerebral and retinal neurons of owls. WNV infection appears to be capable of causing fatal disease in great horned owls and goshawks. However, the distribution and severity of histologic lesions, the

  20. S1P-Dependent Trafficking of Intracellular Yersinia pestis through Lymph Nodes Establishes Buboes and Systemic Infection

    PubMed Central

    St. John, Ashley L.; Ang, W.X. Gladys; Huang, Min-Nung; Kunder, Christian A.; Chan, Elizabeth W.; Gunn, Michael D.; Abraham, Soman N.

    2015-01-01

    SUMMARY Pathologically swollen lymph nodes (LNs), or buboes, characterize Yersinia pestis infection, yet how they form and function is unknown. We report that colonization of the draining LN (dLN) occurred due to trafficking of infected dendritic cells and monocytes in temporally distinct waves in response to redundant chemotactic signals, including through CCR7, CCR2, and sphingosine-1-phospate (S1P) receptors. Retention of multiple subsets of phagocytes within peripheral LNs using the S1P receptor agonist FTY720 or S1P1-specific agonist SEW2871 increased survival, reduced colonization of downstream LNs, and limited progression to transmission-associated septicemic or pneumonic disease states. Conditional deletion of S1P1 in mononuclear phagocytes abolished node-to-node trafficking of infected cells. Thus, Y. pestis-orchestrated LN remodeling promoted its dissemination via host cells through the lymphatic system but can be blocked by prevention of leukocyte egress from DLNs. These findings define a novel trafficking route of mononuclear phagocytes and identify S1P as a therapeutic target during infection. PMID:25238098

  1. [Parasite fauna of Austrian owls (Strigiformes)].

    PubMed

    Kutzer, E; Frey, H; Nöbauer, H

    1982-11-01

    During the examination of 182 owls--Asio otus (51), Strix aluco (44), Bubo bubo (34), Nyctea scandiaca (15), Athene noctua (14), Otus scops (9), Tyto alba (4), Aegolius funereus (3), Glaucidium passerinum (2), Asio flammeus (2), indigenous "owls" (4)--5 protozoan species, 3 trematode species, 1 cestode species, 6 nematode species, 3 acanthocephalan species, 2 acaride species and 7 insect species could be discovered. Dermanyssus hirundinis was proved on the Long-eared Owl and Carnus hemapterus on the Barn Owl for the first time. The infestation frequency of endo- and ectoparasites was from medium to intense on an average, whereas the infestation intensity was from small to medium. The highest rates of infestation were found at nematodes. A case of "pseudoparasitism" was detected and the significance of the analyses of stomach-contents as a guarantee of diagnosis was pointed out.

  2. Biological monitoring of heavy metal contaminations using owls.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2012-03-01

    Iron, manganese, copper, lead and cadmium were measured in the livers, muscles, kidneys and bones of Eurasian Eagle Owls (Bubo bubo), Brown Hawk Owls (Nixos scutulata) and Collared Scops Owls (Otus lempiji) from Korea. Iron concentrations by tissue within species did not differ, but there were significant differences among tissues across all species. Manganese and copper concentrations in muscles, kidneys and bones, but not livers, differed among species and also differed among tissues in the three owl species. We suggest that manganese and copper concentrations from this study were far below the level associated with their toxicity. Lead concentrations significantly differed among all species for livers and bones, and among tissues for each species. Cadmium concentrations were significantly different among species for all tissues and among tissues in Eurasian Eagle Owls and Collared Scops Owls. For most samples, lead concentrations in livers and bones, and cadmium in livers and kidneys, were within the background levels for wild birds. For some Eurasian Eagle Owls and Collared Scops Owls, lead concentrations were at an acute exposure level, whilst lead concentrations were at a chronic exposure level in Brown Hawk Owls. Cadmium concentrations were at a chronic exposure level in all three owl species. Acute and chronic poisoning was significantly correlated between indicator tissues. We suggest that lead and cadmium contamination in Eurasian Eagle Owls may reflect a Korean source, Brown Hawk Owls may reflect Korean and wintering sites, and Collared Scops Owls may reflect breeding and/or wintering sites.

  3. Sexing young snowy owls

    USGS Publications Warehouse

    Seidensticker, M.T.; Holt, D.W.; Detienne, J.; Talbot, S.; Gray, K.

    2011-01-01

    We predicted sex of 140 Snowy Owl (Bubo scandiacus) nestlings out of 34 nests at our Barrow, Alaska, study area to develop a technique for sexing these owls in the field. We primarily sexed young, flightless owls (3844 d old) by quantifying plumage markings on the remiges and tail, predicting sex, and collecting blood samples to test our field predictions using molecular sexing techniques. We categorized and quantified three different plumage markings: two types of bars (defined as markings that touch the rachis) and spots (defined as markings that do not touch the rachis). We predicted sex in the field assuming that males had more spots than bars and females more bars than spots on the remiges and rectrices. Molecular data indicated that we correctly sexed 100% of the nestlings. We modeled the data using random forests and classification trees. Both models indicated that the number and type of markings on the secondary feathers were the most important in classifying nestling sex. The statistical models verified our initial qualitative prediction that males have more spots than bars and females more bars than spots on flight feathers P6P10 for both wings and tail feathers T1 and T2. This study provides researchers with an easily replicable and highly accurate method for sexing young Snowy Owls in the field, which should aid further studies of sex-ratios and sex-related variation in behavior and growth of this circumpolar owl species. ?? 2011 The Raptor Research Foundation, Inc.

  4. Owls as biomonitors of environmental contamination

    SciTech Connect

    Sheffield, S.R.

    1995-12-31

    Exposure and effects of environmental contaminants on owls has been largely understudied. Research primarily has focused on two species, the eastern screech owl (Otus asio) and barn owl (Tyto alba). Most of this work has been conducted with captive populations at the Patuxent Wildlife Research Center in Laurel, MD. In the wild, work has been, or is currently being, conducted with great-horned owls (Bubo virginianus) at a Superfund site in Colorado and in agricultural croplands in Iowa, and barn owls at a Superfund site in Texas and in metal-contaminated regions of the Netherlands. As higher order consumers, owls bioconcentrate many different environmental contaminants through their prey. Owls have proven to be sensitive to a wide variety of toxic compounds, including PCB`s, metals, and fluoride. Endpoints examined include reproductive effects, eggshell thickness, residue analyses, cholinesterase inhibition, and induction of liver MFO`s. Much more work remains to be done using owls as biomonitors of environmental contamination, particularly with captive populations, salvaged individuals, raptor rehabilitation center birds, and with wild populations in areas around hazardous waste sites, smelters, landfills, agricultural croplands, and other major sources of environmental contamination.

  5. Owls May Use Faeces and Prey Feathers to Signal Current Reproduction

    PubMed Central

    Penteriani, Vincenzo; del Mar Delgado, Maria

    2008-01-01

    Background Many animals communicate by marking focal elements of their home range with different kinds of materials. Visual signaling has been demonstrated to play a previously unrecognized role in the intraspecific communication of eagle owls (Bubo bubo), in both territorial and parent-offspring contexts. Visual signals may play a role in a variety of circumstances in this crepuscular and nocturnal species. Methodology/Principal Findings Here, we report that a large amount of extremely visible white faeces and prey feathers appear during the breeding season on posts and plucking sites in proximity to the nest, potentially representing a way for eagle owls to mark their territory. We present descriptive and experimental evidence showing that faeces and prey remains could act as previously unrecognized visual signals in a nocturnal avian predator. This novel signaling behavior could indicate the owls' current reproductive status to potential intruders, such as other territorial owls or non-breeding floaters. Faeces and prey feather markings may also advertise an owl's reproductive status or function in mate-mate communication. Conclusions/Significance We speculate that faeces marks and plucking may represent an overlooked but widespread method for communicating current reproduction to conspecifics. Such marking behavior may be common in birds, and we may now be exploring other questions and mechanisms in territoriality. PMID:18714382

  6. Moonlight Makes Owls More Chatty

    PubMed Central

    Penteriani, Vincenzo; Delgado, María del Mar; Campioni, Letizia; Lourenço, Rui

    2010-01-01

    Background Lunar cycles seem to affect many of the rhythms, temporal patterns and behaviors of living things on Earth. Ambient light is known to affect visual communication in animals, with the conspicuousness of visual signals being largely determined by the light available for reflection by the sender. Although most previous studies in this context have focused on diurnal light, moonlight should not be neglected from the perspective of visual communication among nocturnal species. We recently discovered that eagle owls Bubo bubo communicate with conspecifics using a patch of white throat plumage that is repeatedly exposed during each call and is only visible during vocal displays. Methodology/Principal Findings Here we provide evidence that this species uses moonlight to increase the conspicuousness of this visual signal during call displays. We found that call displays are directly influenced by the amount of moonlight, with silent nights being more frequent during periods with no-moonlight than moonlight. Furthermore, high numbers of calling bouts were more frequent at moonlight. Finally, call posts were located on higher positions on moonlit nights. Conclusions/Significance Our results support the idea that moon phase affects the visual signaling behavior of this species, and provide a starting point for examination of this method of communication by nocturnal species. PMID:20098700

  7. Surveying woodland hawks with broadcasts of great horned owl vocalization

    USGS Publications Warehouse

    Mosher, James A.; Fuller, Mark R.

    1996-01-01

    Pre-recorded vocalizations of great horned owls (Bubo virginianus) broadcast into predominantly wooded habitat along roadside survey routes resulted in as many detections of resident red-shouldered hawks (Buteo lineatus) and Cooper's hawks (Accipiter cooperii) as broadcasts of each conspecific calls. Survey results for 3 species, expressed as average number of contacts/route, were directly related to the number of resident pairs located during systematic searches conducted on foot across the study area. Regression models based on road-transect counts were significant for predicting abundance of red-shouldered hawks, broad-winged hawks (Buteo platypterus), and Cooper's hawks from our study areas.

  8. Anticoagulant rodenticides in three owl species from Western Canada, 1988-2003.

    PubMed

    Albert, Courtney A; Wilson, Laurie K; Mineau, Pierre; Trudeau, Suzanne; Elliott, John E

    2010-02-01

    Anticoagulant rodenticides are widely used to control rodent infestations. Previous studies have shown that nontarget organisms, such as birds, are at risk for both primary and secondary poisoning. This paper presents rodenticide residue information on the livers from 164 strigiformes which included barn owls (Tyto alba), barred owls (Strix varia), and great horned owls (Bubo virginianus), collected from 1988 to 2003 in the province of British Columbia and the Yukon Territory, Canada. Livers were analyzed for brodifacoum, bromadiolone, chlorophacinone, diphacinone, difethialone, and warfarin. Our results show that, of the 164 owl livers analyzed, 70% had residues of at least one rodenticide, and of these 41% had more than one rodenticide detected. Of the three species of owls examined, barred owls were most frequently exposed (92%, n = 23); brodifacoum and bromadiolone were most often detected, with liver concentrations ranging from 0.001 to 0.927 mg/kg brodifacoum, and 0.002 to 1.012 mg/kg bromadiolone. Six of the owls (three barred owls, two barn owls, and one great horned owl) were diagnosed as having died from anticoagulant poisoning; all six owls had brodifacoum residues in the liver.

  9. Owl predation on snowshoe hares: consequences of antipredator behaviour.

    PubMed

    Rohner, Christoph; Krebs, Charles J

    1996-10-01

    We show evidence of differential predation on snowshoe hares (Lepus americanus) by great horned owls (Bubo virginianus) and ask whether predation mortality is related to antipredator behaviour in prey. We predicted higher predation on (1) young and inexperienced hares, (2) hares in open habitats lacking cover to protect from owl predation, and (3) hares in above average condition assuming that rich food patches are under highest risk of predation. Information on killed hares was obtained at nest sites of owls and by monitoring hares using radio-telemetry. The availability of age classes within the hare population was established from live-trapping and field data on reproduction and survival. Great horned owls preferred juvenile over adult hares. Juveniles were more vulnerable to owl predation before rather than after dispersal, suggesting that displacement or increased mobility were not causes for this increased mortality. Owls killed ratio-collared hares more often in open than in closed forest types, and they avoided or had less hunting success in habitats with dense shrub cover. Also, owls took hares in above average condition, although it is unclear whether samples from early spring are representative for other seasons. In conclusion, these results are consistent with the hypothesis that variation in antipredator behaviours of snowshoe hares leads to differential predation by great horned owls.

  10. Gastrointestinal parasites of owls (Strigiformes) kept in captivity in the Southern region of Brazil.

    PubMed

    da Silva, Aleksandro S; Zanette, Régis A; Lara, Valéria M; Gressler, Luciane T; Carregaro, Adriano B; Santurio, Janio M; Monteiro, Silvia G

    2009-01-01

    The aim of this research was to study the gastrointestinal parasitism in 12 adult owls kept in captivity in the Southern region of Brazil. Cloacal contents of the species Rhinoptynx clamator, Tyto alba, Athene cunicularia, Megascops spp., and Bubo virginianus were evaluated. Feces and urine were collected and analyzed by the zinc sulfate centrifugal-flotation method and stained by the modified Ziehl-Neelsen technique. Eggs of Capillaria spp. and Strongylida, oocysts of Cryptosporidium spp., Eimeria spp., and Isospora spp. were observed. The birds showed no clinical signs, probably due to the mild nature of the infection.

  11. Owls

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.; Millsap, B.A.; Pendleton, Beth Giron

    1990-01-01

    Eight species of owls regularly occur and may breed in one or more of the southeastern states. Several additional northern or western species appear irregularly as accidentals or during years of southward incursions. In the Southeast, the most common and wide- spread owls are the common barn-owl, eastern screech-owl, great horned owl and barred owl; the most restricted is the burrowing owl. The long-eared, short-eared, and northern saw-whet owls are primarily winter visitors in this region, although small and very localized nesting populations of short-eared owls may occur in Virginia. Long-eared owls and northern saw-whet owls may occur in West Virginia and northern saw-whet owls may occur in the highlands of Tennessee and North Carolina. Several owls of the Southeast are Blue-listed as threatened, endangered, or of local concern, including the common barn-owl, eastern screech-owl, burrow'ing owl and short-eared owl. The nesting status of the long-eared owl and northern saw-whet owl are still poorly known. These two owls should be included on stat and regional lists of species of special concern. Important limiting factors for all owls of the Southeast include habitat loss and human related mortality. Management issues center on obtaining a data base useful in predicting the effects of current forest management practices on owl populations and encouraging use of forestry techniques that least impact owls. Research needs include initiating studies of all aspects of the life history and habitat relationships of each owl species.

  12. Diagnostic findings in 132 great horned owls

    USGS Publications Warehouse

    Franson, J.C.; Little, S.E.

    1996-01-01

    We reviewed diagnostic findings for 132 great horned owl (Bubo virginianus) carcasses that were submitted to the National Wildlife Health Center from 1975-93. The carcasses were collected in 24 states but most came from Colorado (N = 21), Missouri (N = 12), Oregon (N = 12), Wyoming (N = 11), Illinois (N = 10), and Wisconsin (N = 9). Forty-two birds were emaciated but presumptive causes of emaciation, including old injuries, chronic lesions in various organs, and exposure to dieldrin, were found in only 16. A greater proportion of juveniles (56%) than adults (29%) were emaciated. Twelve owls were shot and 35 died from other traumatic injuries. Poisonings were diagnosed in 11 birds, including five associated with hydrogen sulfide exposure in oil fields and six cases of agricultural pesticide poisonings. Electrocution killed nine birds and infectious diseases were found in six. Miscellaneous conditions, including egg impaction, drowning, and visceral gout were diagnosed in three of the birds and the cause of death was undetermined in 14 owls. While this review identifies major diagnostic findings in great horned owls, sample bias prevents definitive conclusions regarding actual proportional causes of mortality.

  13. 77 FR 25192 - Wild Bird Conservation Act; Receipt of Application for Approval of a Cooperative Breeding Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-27

    ... Eagle (Aquila nipalensis), Eurasian Eagle Owl (Bubo bubo), Saker Falcon (Falco cherrug), African Fish-eagle (Haliaeetus vocifer), and Southern White- faced Owl (Ptilopsis granti). The applicant wishes to...

  14. Diversity of Quill Mites of the Family Syringophilidae (Acari: Prostigmata) Parasitizing Owls (Aves: Strigiformes) With Remarks on the Host-Parasite Relationships.

    PubMed

    Skoracki, Maciej; Unsoeld, Markus; Marciniak, Natalia; Sikora, Bozena

    2016-07-01

    The quill mite fauna of the family Syringophilidae (Acari: Prostigmata: Cheyletoidea) associated with owls (Aves: Strigiformes) is reviewed. A new genus is proposed, Neobubophilus Skoracki & Unsoeld gen. nov. It differs from closely related Bubophilus (Bubophilus Philips and Norton, 1978) by the absence of leg setae vsII in the both sexes. In addition, four new species are described: (1) Neobubophilus cunicularius Skoracki & Unsoeld sp. nov. from Athene cunicularia (Molina, 1782) (Strigidae) from Paraguay; (2) Neobubophilus atheneus Skoracki & Unsoeld sp. nov. from Athene noctua (Scopoli, 1769) and Athene brama (Temminck, 1821) (Strigidae), both from India; (3) Bubophilus tytonus Skoracki & Unsoeld sp. nov. from Tyto alba affinis (Blyth, 1862) (Tytonidae) from Cameroon, and (4) Megasyringophilus dalmas Skoracki & Unsoeld sp. nov. from Megascops choliba (Vieillot, 1817) (Strigidae) from Venezuela. The following new host species are given: Bubo bubo (Linnaeus, 1758) (Strigidae) from Nepal for Bubophilus ascalaphus (Philips and Norton 1978) and Strix woodfordii (Smith, 1834) (Strigidae) from Tanzania for Bubophilus aluconis (aluconis Nattress and Skoracki 2009). A key for syringophilid genera and species associated with owls is constructed. The host-parasite relationships of syringophilid mites and owls are discussed.

  15. Are red-tailed hawks and great horned owls diurnal-nocturnal dietary counterparts?

    USGS Publications Warehouse

    Marti, C.D.; Kochert, Michael N.

    1995-01-01

    Red-tailed Hawks (Buteo jamaicensis) and Great Homed Owls (Bubo virginianus)are common in North America where they occupy a wide range of habitats, often sympatrically. The two species are similar in size and have been portrayed as ecological counterparts, eating the same prey by day and night. We tested the trophic similarity of the two species by comparing published dietary data from across the United States. Both species ate primarily mammals and birds, and mean proportions of those two prey types did not differ significantly between diets of the two raptors. Red-tailed Hawks ate significantly more reptiles, and Great Homed Owls significantly more invertebrates. Dietary diversity was not significantly different at the level of prey taxonomic class, and diet overlap between the two species averaged 91%. At the prey species level, dietary overlap averaged only 50%, and at that level Red-tailed Hawk dietary diversity was significantly greater than that of Great Horned Owls. Mean prey mass of Red-tailed Hawks was significantly greater than that of Great Homed Owls. Populations of the two species in the western United States differed trophically more than did eastern populations. We conclude that, although the two species are generalist predators, they take largely different prey species in the same localities resulting in distinctive trophic characteristics.

  16. Genetic Signatures of Demographic Changes in an Avian Top Predator during the Last Century: Bottlenecks and Expansions of the Eurasian Eagle Owl in the Iberian Peninsula

    PubMed Central

    Graciá, Eva; Ortego, Joaquín; Godoy, José Antonio; Pérez-García, Juan Manuel; Blanco, Guillermo; del Mar Delgado, María; Penteriani, Vincenzo; Almodóvar, Irene; Botella, Francisco; Sánchez-Zapata, José Antonio

    2015-01-01

    The study of the demographic history of species can help to understand the negative impact of recent population declines in organisms of conservation concern. Here, we use neutral molecular markers to explore the genetic consequences of the recent population decline and posterior recovery of the Eurasian eagle owl (Bubo bubo) in the Iberian Peninsula. During the last century, the species was the object of extermination programs, suffering direct persecution by hunters until the 70’s. Moreover, during the last decades the eagle owl was severely impacted by increased mortality due to electrocution and the decline of its main prey species, the European rabbit (Oryctolagus cuniculus). In recent times, the decrease of direct persecution and the implementation of some conservation schemes have allowed the species’ demographic recovery. Yet, it remains unknown to which extent the past population decline and the later expansion have influenced the current species’ pattern of genetic diversity. We used eight microsatellite markers to genotype 235 eagle owls from ten Spanish subpopulations and analyse the presence of genetic signatures attributable to the recent population fluctuations experienced by the species. We found moderate levels of differentiation among the studied subpopulations and Bayesian analyses revealed the existence of three genetic clusters that grouped subpopulations from central, south-western and south-eastern Spain. The observed genetic structure could have resulted from recent human-induced population fragmentation, a patchy distribution of prey populations and/or the philopatric behaviour and habitat selection of the species. We detected an old population bottleneck, which occurred approximately 10,000 years ago, and significant signatures of recent demographic expansions. However, we did not find genetic signatures for a recent bottleneck, which may indicate that population declines were not severe enough to leave detectable signals on the

  17. Genetic Signatures of Demographic Changes in an Avian Top Predator during the Last Century: Bottlenecks and Expansions of the Eurasian Eagle Owl in the Iberian Peninsula.

    PubMed

    Graciá, Eva; Ortego, Joaquín; Godoy, José Antonio; Pérez-García, Juan Manuel; Blanco, Guillermo; Delgado, María del Mar; Penteriani, Vincenzo; Almodóvar, Irene; Botella, Francisco; Sánchez-Zapata, José Antonio

    2015-01-01

    The study of the demographic history of species can help to understand the negative impact of recent population declines in organisms of conservation concern. Here, we use neutral molecular markers to explore the genetic consequences of the recent population decline and posterior recovery of the Eurasian eagle owl (Bubo bubo) in the Iberian Peninsula. During the last century, the species was the object of extermination programs, suffering direct persecution by hunters until the 70's. Moreover, during the last decades the eagle owl was severely impacted by increased mortality due to electrocution and the decline of its main prey species, the European rabbit (Oryctolagus cuniculus). In recent times, the decrease of direct persecution and the implementation of some conservation schemes have allowed the species' demographic recovery. Yet, it remains unknown to which extent the past population decline and the later expansion have influenced the current species' pattern of genetic diversity. We used eight microsatellite markers to genotype 235 eagle owls from ten Spanish subpopulations and analyse the presence of genetic signatures attributable to the recent population fluctuations experienced by the species. We found moderate levels of differentiation among the studied subpopulations and Bayesian analyses revealed the existence of three genetic clusters that grouped subpopulations from central, south-western and south-eastern Spain. The observed genetic structure could have resulted from recent human-induced population fragmentation, a patchy distribution of prey populations and/or the philopatric behaviour and habitat selection of the species. We detected an old population bottleneck, which occurred approximately 10,000 years ago, and significant signatures of recent demographic expansions. However, we did not find genetic signatures for a recent bottleneck, which may indicate that population declines were not severe enough to leave detectable signals on the species

  18. Pulsed resources at tundra breeding sites affect winter irruptions at temperate latitudes of a top predator, the snowy owl.

    PubMed

    Robillard, A; Therrien, J F; Gauthier, G; Clark, K M; Bêty, J

    2016-06-01

    Irruptive migration is mostly observed in species specialized on pulsed resources and is thought to be a response to unpredictable changes in food supply. We assessed two alternative hypotheses to explain the periodic winter irruptions of snowy owls Bubo scandiacus every 3-5 years in temperate North America: (a) the lack-of-food hypothesis, which states that a crash in small mammal abundance on the Arctic breeding grounds forces owls to move out of the tundra massively to search for food in winter; (b) the breeding-success hypothesis, which states that high abundance of tundra small mammals during the summer allows for high production of young, thus increasing the pool of migrants moving south the following winter. We modeled winter irruptions of snowy owls in relation to summer food resources and geographic location. Winter abundance of owls was obtained from citizen-based surveys from 1994 to 2011 and summer abundance of small mammals was collected in summer at two distant sites in Canada: Bylot Island, NU (eastern High Arctic) and Daring Lake, NWT (central Low Arctic). Winter owl abundance was positively related to prey abundance during the previous summer at both sites and tended to decrease from western to eastern temperate North America. Irruptive migration of snowy owls was therefore best explained by the breeding success hypothesis and was apparently caused by large-scale summer variations in food. Our results, combined with previous findings, suggest that the main determinants of irruptive migration may be species specific even in a guild of apparently similar species.

  19. Diet and trophic characteristics of great horned owls in southwestern Idaho

    USGS Publications Warehouse

    Marti, C.D.; Kochert, Michael N.

    1996-01-01

    We studied the diet of Great Horned Owls (Bubo virginianus) in the Snake River Birds of Prey National Conservation Area in southwestern Idaho for 14 breeding seasons. The diet included 89.2% mammals by number and 91.2% by mass. Kangaroo rats (Dipodomys spp.) were the most common prey overall, but montane voles (Microtus montanus), Peromyscus spp., Great Basin pocket mice (Perognathus parvus) and Townsend's pocket gophers (Thomomys towsendii) were most common at some collection sites. Estimated mean mass of prey was 44.5 g (range 20.5-82.6 g at individual nests), and food-niche breadth (dietary diversity estimated by $1/\\Sigma p_{{\\rm i}}{}^{2}$) was 7.32 (range 1.55-6.85 at individual nests). Lower mean overlap in diet occurred between nests in the same year than between years at the same nest. Species of prey taken were significantly correlated with the general habitat types in which the nest was located. Diets of owls in areas of intensive agriculture overlapped little (42%) with those in rangeland habitats.

  20. Plasma to egg conversion factor for evaluating polychlorinated biphenyl and DDT exposures in great horned owls and bald eagles.

    PubMed

    Strause, Karl D; Zwiernik, Matthew J; Im, Sook Hyeon; Newsted, John L; Kay, Denise P; Bradley, Patrick W; Blankenship, Alan L; Williams, Lisa L; Giesy, John P

    2007-07-01

    The benefits of nondestructive sampling techniques, such as plasma sampling, to directly measure contaminant exposure levels in at-risk or protected raptor populations are many. However, such assays are generally inconsistent with the most certain source of toxicity reference values, which are based on feeding studies and quantified as dietary or "in ovo" (egg-based) concentrations. An accurate conversion factor to translate nondestructive plasma-based contaminant concentrations to comparable egg-based concentrations will prove valuable to risk assessors investigating the potential effects of chemical exposures to raptors. We used databases describing the concentrations of total polychlorinated biphenyls (PCBs) in great horned owls (GHO; Bubo virginianus) and total PCBs and p,p'-dichlorodiphenyldichloroethylene (p,p'-DDE) in bald eagles (Haliaeetus leucocephalus) from the Great Lakes region (Michigan, Wisconsin, USA) to develop a relationship to predict concentrations of PCBs and DDE in eggs. To develop a robust predictive relationship, all of the source data included concentrations of both total PCBs and/or DDE for nestling blood plasma and egg samples collected from within discrete active nesting territories and, in most instances, the same nest. The key characteristics (slope and elevation) of each relationship were tested for differences related to species and geographic region. Predicted variability of relationships were examined and compared to variability associated with natural systems. The results of statistical testing indicate that applying the conversion factors between species (GHO to bald eagle) and among geographic regions yields predicted egg concentrations that are not statistically dissimilar and are within the natural variability observed for residue concentrations among eggs of raptors within species and region.

  1. Owl Pellets.

    ERIC Educational Resources Information Center

    Thompson, Craig D.

    1987-01-01

    Provides complete Project WILD lesson plans for 20-45-minute experiential science learning activity for grades 3-7 students. Describes how students construct a simple food chain through examination of owl pellets. Includes lesson objective, method, background information, materials, procedure, evaluation, and sources of owl pellets and posters.…

  2. Outrageous Owls

    ERIC Educational Resources Information Center

    Walkup, Nancy

    2007-01-01

    The author's encounter with a live owl and her purchase of a Peruvian folk art gourd inspired a new interdisciplinary experience for the author's fourth grade students. In this article, she describes how her students explored owls through clay sculpture. (Contains 2 resources and 1 online resource.)

  3. Lead in hawks, falcons and owls downstream from a mining site on the Coeur D'Alene river, Idaho

    USGS Publications Warehouse

    Henny, C.J.; Blus, L.J.; Hoffman, D.J.; Grove, R.A.

    1994-01-01

    Mining and smelting at Kellogg-Smelterville, Idaho, resulted in high concentrations of lead in Coeur d'Alene (CDA) River sediments and the floodplain downstream, where American Kestrels (Falco sparverius), Northern Harriers (Circus cyaneus), Red-tailed Hawks (Buteo jamaicensis), Great Horned Owls (Bubo virginianus), and Western Screech-owls (Otus kennicotti) nested. Nestling American Kestrels contained significantly higher (P=0.0012) blood lead concentrations along the CDA River (0.24 ?g/g, wet wt) than the nearby reference area (0.087 ?g/g). A 35% inhibition of blood *-aminolevulinic acid dehydratase (ALAD) in nestling Northern Harriers (P=0.0001), 55% in nestling American Kestrels (P=0.0001) and 81% in adult American Kestrels (P=0.0004) provided additional evidence of lead exposure in the CDA River population. In nestling American Kestrels and Northern Harriers, ALAD activity was negatively correlated with lead in blood. An earlier report on Ospreys (Pandion haliaetus) showed slightly less inhibition of ALAD than in American Kestrels, but no significant reduction in hemoglobin or hematocrit and no negative influence on production rates. The adult and nestling American Kestrels along the CDA River contained about twice as much blood lead as Ospreys during the same years (adult 0.46 vs. 0.20 ?g/g, and nestling 0.24 vs. 0.09 ?g/g), but adults showed a 7.5% reduction in hemoglobin (P=0.0356) and nestlings an 8.2% reduction in hemoglobin (P=0.0353) and a 5.8% reduction in hematocrit (P=0.0482). We did not observe raptor deaths related to lead, and although the production rate for American Kestrels was slightly lower along the CDA River, we found no significant negative relation between productivity and lead. Limited data on the other raptors provide evidence of exposure to lead along the CDA River. Several traits of raptors apparently reduce their potential for accumulating critical levels of lead which is primarily stored in bones of prey species.

  4. Snowy owl

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.; Pendleton, Beth Giron; LeFranc, Maurice N.=; Moss, Mary Beth

    1989-01-01

    The snowy owl is a rare to uncommon, irregular winter visitor in the northeastern United States, decreasing southward in abundance except during incursion years, when it is more common and widely distributed. Although snowy owls are recorded in northern New England every winter, major incursions occur at approximately three to four year intervals. Limiting factors include food, habitat and human interference. Research is needed on the population ecology of this species and, perhaps more important, management goals must be directed towards public education emphasizing the value of snowy owls.

  5. Owls On Silent Wings. The Wonder Series.

    ERIC Educational Resources Information Center

    Cooper, Ann C.

    This curriculum guide is all about owls and provides information on the folklore related to owls, present populations, explanations of physical characteristics, exploring owl pellets, burrowing owls, snowy owls, and great horned owls. Included are eight activities using owl cards, owl pellets, puzzles, and origami. This guide aims to increase…

  6. Owl: electronic datasheet generator.

    PubMed

    Appleton, Evan; Tao, Jenhan; Wheatley, F Carter; Desai, Devina H; Lozanoski, Thomas M; Shah, Pooja D; Awtry, Jake A; Jin, Shawn S; Haddock, Traci L; Densmore, Douglas M

    2014-12-19

    Owl ( www.owlcad.org ) is a biodesign automation tool that generates electronic datasheets for synthetic biological parts using common formatting. Data can be retrieved automatically from existing repositories and modified in the Owl user interface (UI). Owl uses the data to generate an HTML page with standard typesetting that can be saved as a PDF file. Here we present the Owl software tool in its alpha version, its current UI, its description of input data for generating a datasheet, its example datasheets, and the vision of the tool's role in biodesign automation.

  7. Mixed-Media Owls

    ERIC Educational Resources Information Center

    Schultz, Kathy

    2010-01-01

    The fun of creating collages is there are unlimited possibilities for the different kinds of materials one can use. In this article, the author describes how her eighth-grade students created an owl using mixed media.

  8. Learning from an Owl.

    ERIC Educational Resources Information Center

    Greeves, Adrian

    1988-01-01

    Describes one creative writing teacher's use of an owl as a focal point for writing activities and how the writing activities aided the students' personal and creative development. Provides samples of student writing. (ARH)

  9. Demographic response of northern spotted owls to barred owl removal

    USGS Publications Warehouse

    Diller, V. Lowell; Hamm, Keith A; Early, Desiree A; Lamphear, David W; Katie Dugger,; Yackulic, Charles B.; Schwarz, Carl J.; Carlson, Peter C.; McDonald, Trent L.

    2016-01-01

    Federally listed as threatened in 1990 primarily because of habitat loss, the northern spotted owl (Strix occidentalis caurina) has continued to decline despite conservation efforts resulting in forested habitat being reserved throughout its range. Recently, there is growing evidence the congeneric invasive barred owl (Strix varia) may be responsible for the continued decline primarily by excluding spotted owls from their preferred habitat. We used a long-term demographic study for spotted owls in coastal northern California as the basis for a pilot barred owl removal experiment. Our demography study used capture–recapture, reproductive output, and territory occupancy data collected from 1990 to 2013 to evaluate trends in vital rates and populations. We used a classic before-after-control-impact (BACI) experimental design to investigate the demographic response of northern spotted owls to the lethal removal of barred owls. According to the best 2-species dynamic occupancy model, there was no evidence of differences in barred or northern spotted owl occupancy prior to the initiation of the treatment (barred owl removal). After treatment, barred owl occupancy was lower in the treated relative to the untreated areas and spotted owl occupancy was higher relative to the untreated areas. Barred owl removal decreased spotted owl territory extinction rates but did not affect territory colonization rates. As a result, spotted owl occupancy increased in the treated area and continued to decline in the untreated areas. Prior to and after barred owl removal, there was no evidence that average fecundity differed on the 2 study areas. However, the greater number of occupied spotted owl sites on the treated areas resulted in greater productivity in the treated areas based on empirical counts of fledged young. Prior to removal, survival was declining at a rate of approximately 0.2% per year for treated and untreated areas. Following treatment, estimated survival was 0.859 for

  10. Owl Pellet Paleontology

    ERIC Educational Resources Information Center

    McAlpine, Lisa K.

    2013-01-01

    In this activity for the beginning of a high school Biology 1 evolution unit, students are challenged to reconstruct organisms found in an owl pellet as a model for fossil reconstruction. They work in groups to develop hypotheses about what animal they have found, what environment it inhabited, and what niche it filled. At the end of the activity,…

  11. Owl Research that's Good for the Birds.

    ERIC Educational Resources Information Center

    Cristol, Daniel A.

    1986-01-01

    Describes and illustrates how to build nest boxes to provide city homes for screech owls to reestablish a healthy ecological balance. Outlines how to conduct a pellet analysis of an owl's diet and how to study screech owl territoriality. (NEC)

  12. All about Owls: Studying Owls, State Birds, and Endangered Species.

    ERIC Educational Resources Information Center

    Rivard, Leonard P.

    1991-01-01

    Activities are included that acquaint students with the parts of birds and the structure of feathers; that identify the prey of owls by opening owl pellets; working with information about threatened and endangered species of birds; and follow-up activities for bird study. A list of state and provincial birds of the United States and Canada and…

  13. Owl Pellets and Crisis Management.

    ERIC Educational Resources Information Center

    Anderson, Tom

    2002-01-01

    Describes a press conference that was used as a "teachable moment" when owl pellets being used for instructional purposes were found to be contaminated with Salmonella. The incident highlighted the need for safe handling of owl pellets, having a crisis management plan, and the importance of conveying accurate information to concerned parents.…

  14. 78 FR 44588 - Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Final...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-07-24

    ... Fish and Wildlife Service Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Final Environmental Impact Statement AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice... final environmental impact statement (Final EIS) for experimental removal of barred owls to...

  15. Blood parasites in owls with conservation implications for the Spotted Owl (Strix occidentalis).

    PubMed

    Ishak, Heather D; Dumbacher, John P; Anderson, Nancy L; Keane, John J; Valkiūnas, Gediminas; Haig, Susan M; Tell, Lisa A; Sehgal, Ravinder N M

    2008-05-28

    The three subspecies of Spotted Owl (Northern, Strix occidentalis caurina; California, S. o. occidentalis; and Mexican, S. o. lucida) are all threatened by habitat loss and range expansion of the Barred Owl (S. varia). An unaddressed threat is whether Barred Owls could be a source of novel strains of disease such as avian malaria (Plasmodium spp.) or other blood parasites potentially harmful for Spotted Owls. Although Barred Owls commonly harbor Plasmodium infections, these parasites have not been documented in the Spotted Owl. We screened 111 Spotted Owls, 44 Barred Owls, and 387 owls of nine other species for haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp.). California Spotted Owls had the greatest number of simultaneous multi-species infections (44%). Additionally, sequencing results revealed that the Northern and California Spotted Owl subspecies together had the highest number of Leucocytozoon parasite lineages (n = 17) and unique lineages (n = 12). This high level of sequence diversity is significant because only one Leucocytozoon species (L. danilewskyi) has been accepted as valid among all owls, suggesting that L. danilewskyi is a cryptic species. Furthermore, a Plasmodium parasite was documented in a Northern Spotted Owl for the first time. West Coast Barred Owls had a lower prevalence of infection (15%) when compared to sympatric Spotted Owls (S. o. caurina 52%, S. o. occidentalis 79%) and Barred Owls from the historic range (61%). Consequently, Barred Owls on the West Coast may have a competitive advantage over the potentially immune compromised Spotted Owls.

  16. Blood parasites in Owls with conservation implications for the Spotted Owl (Strix occidentalis)

    USGS Publications Warehouse

    Ishak, H.D.; Dumbacher, J.P.; Anderson, N.L.; Keane, J.J.; Valkiunas, G.; Haig, S.M.; Tell, L.A.; Sehgal, R.N.M.

    2008-01-01

    The three subspecies of Spotted Owl (Northern, Strix occidentalis courina; California, S. o. occidentalis; and Mexican, S. o. lucida) are all threatened by habitat loss and range expansion of the Barred Owl (S. varia). An unaddressed threat is whether Barred Owls could be a source of novel strains of disease such as avian malaria (Plasmodium spp.) or other blood parasites potentially harmful for Spotted Owls. Although Barred Owls commonly harbor Plasmodium infections, these parasites have not been documented in the Spotted Owl. We screened 111 Spotted Owls, 44 Barred Owls, and 387 owls of nine other species for haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp.). California Spotted Owls had the greatest number of simultaneous multi-species infections (44%). Additionally, sequencing results revealed that the Northern and California Spotted Owl subspecies together had the highest number of Leucocytozoon parasite lineages (n=17) and unique lineages (n=12). This high level of sequence diversity is significant because only one leucocytozoon species (L. danilewskyi) has been accepted as valid among all owls, suggesting that L. danilewskyi is a cryptic species. Furthermore, a Plasmodium parasite was documented in a Northern Spotted Owl for the first time. West Coast Barred Owls had a lower prevalence of infection (15%) when compared to sympatric Spotted Owls (S. o. caurina 52%, S. o. occidentalis 79%) and Barred Owls from the historic range (61%). Consequently, Barred Owls on the West Coast may have a competitive advantage over the potentially immune compromised Spotted Owls. ?? 2008 Ishak et al.

  17. Blood Parasites in Owls with Conservation Implications for the Spotted Owl (Strix occidentalis)

    PubMed Central

    Ishak, Heather D.; Dumbacher, John P.; Anderson, Nancy L.; Keane, John J.; Valkiūnas, Gediminas; Haig, Susan M.; Tell, Lisa A.; Sehgal, Ravinder N. M.

    2008-01-01

    The three subspecies of Spotted Owl (Northern, Strix occidentalis caurina; California, S. o. occidentalis; and Mexican, S. o. lucida) are all threatened by habitat loss and range expansion of the Barred Owl (S. varia). An unaddressed threat is whether Barred Owls could be a source of novel strains of disease such as avian malaria (Plasmodium spp.) or other blood parasites potentially harmful for Spotted Owls. Although Barred Owls commonly harbor Plasmodium infections, these parasites have not been documented in the Spotted Owl. We screened 111 Spotted Owls, 44 Barred Owls, and 387 owls of nine other species for haemosporidian parasites (Leucocytozoon, Plasmodium, and Haemoproteus spp.). California Spotted Owls had the greatest number of simultaneous multi-species infections (44%). Additionally, sequencing results revealed that the Northern and California Spotted Owl subspecies together had the highest number of Leucocytozoon parasite lineages (n = 17) and unique lineages (n = 12). This high level of sequence diversity is significant because only one Leucocytozoon species (L. danilewskyi) has been accepted as valid among all owls, suggesting that L. danilewskyi is a cryptic species. Furthermore, a Plasmodium parasite was documented in a Northern Spotted Owl for the first time. West Coast Barred Owls had a lower prevalence of infection (15%) when compared to sympatric Spotted Owls (S. o. caurina 52%, S. o. occidentalis 79%) and Barred Owls from the historic range (61%). Consequently, Barred Owls on the West Coast may have a competitive advantage over the potentially immune compromised Spotted Owls. PMID:18509541

  18. Rodenticides in British barn owls.

    PubMed

    Newton, I; Wyllie, I; Freestone, P

    1990-01-01

    Out of 145 Barn Owls found dead through accidents (66%), starvation (32%), shooting (2%) and poisoning (<1%), 10% contained residues of rodenticides, difenacoum or brodifacoum, in their livers. Difenacoum was in the range 0.005-0.106 microg g(-1) fresh weight, and brodifacoum was in the range 0.019-0.515 microg g(-1). Minimum levels of detection were about 0.005 microg g(-1) for both chemicals. Mice fed for 1 day on food containing difenacoum and brodifacoum died after 2-11 days. Within these mice residues were present at greater concentration in the liver than in the rest of the carcass. The mean mass of residue in a whole 35g mouse was estimated at 10.17 microg (range 4.73-20.65 microg) for difenacoum and 15.36 microg (range 8.07-26.55) for brodifacoum. Such poisoned mice were fed to Barn Owls for successive periods of 1, 3 and 6 days. All six owls fed on difenacoum-dosed mice survived all three treatments, in which up to an estimated 101.7 microg of difenacoum was consumed, and the coagulation times of their blood returned to near normal in less than 5-23 days. Four of the six owls fed on brodifacoum-dosed mice died 6-17 days after the 1-day treatment, but the survivors also survived the 3-day and 6-day treatments. Those that died had each eaten 3 mice, with a combined weight of about 105g and a total brodifacoum content of about 46.07 microg, which was equivalent to a dose of 0.150-0.182 mg kg(-1) of owl body weight. After death these owls had 0.63-1.25 micro g(-1) of brodifacoum in their livers. Blood from the survivors would not coagulate at 9 days post-treatment, but did so at 16 days in one bird and between 38 and 78 days in the other. It is concluded that: (1) Barn Owls in Britain are now widely exposed to second-generation rodenticides; (2) not all owls exposed to these chemicals are likely to receive a lethal dose; (3) brodifacoum is more toxic to owls than difenacoum; and (4) while there is yet no evidence that rodenticides have had any appreciable

  19. Survey of blood parasites in two forest owls, Northern Saw-whet Owls and Flammulated Owls, of western North America.

    PubMed

    Leppert, Lynda L; Dufty, Alfred M; Stock, Sarah; Oleyar, M David; Kaltenecker, Greg S

    2008-04-01

    Except for a few studies in the eastern United States, little has been published on hemoparasites in owls. We surveyed the blood parasites of 108 Northern Saw-whet Owls (Aegolius acadicus) and 24 Flammulated Owls (Otus flammeolus) in Idaho during autumn migration in 1999 and 2000. We also surveyed 15 Flammulated Owls (FLOW) during breeding season in Utah from 2000. Leucocytozoon ziemanni, Haemoproteus syrnii, Haemoproteus noctuae, and Trypanosoma avium were identified. The overall prevalence of infection was 53% (78/147) and for the combined species, prevalences of Haemoproteus, Leucocytozoon, and Trypanosoma species were 20%, 39%, and 4%, respectively. Northern Saw-whet Owls (NSWO) had an overall prevalence of 51% (55/108), with prevalences of 6%, 47%, and 4% by hemoparasite genus, respectively. Flammulated Owls had an overall prevalence of 59% (23/39), with prevalences of 56%, 18%, and 5% by genus, respectively. This study provides baseline hematozoa information for two boreal owl species.

  20. Barred owls and landscape attributes influence territory occupancy of northern spotted owls.

    PubMed

    Sovern, Stan G; Forsman, Eric D; Olson, Gail S; Biswell, Brian L; Taylor, Margaret; Anthony, Robert G

    2014-11-01

    We used multi-season occupancy analyses to model 2 fates of northern spotted owl territories in relation to habitat amount, habitat fragmentation, and the presence of barred owls in Washington State, USA, 1989-2005. Local colonization is the probability a territory unoccupied by a spotted owl in year i would be occupied in year i + 1, and local extinction is the probability a territory that was occupied by a spotted owl in year i would be unoccupied in year i + 1. We found a negative relationship between local extinction probability and amount of late-seral forest edge. We found a negative relationship between colonization probability and the number of late-seral forest patches (higher fragmentation), and a negative relationship between colonization probability and the amount of non-habitat within 600 m of a spotted owl territory center (Akaike weight = 0.59). The presence of barred owls was positively related to extinction probability and negatively related to detection probability of spotted owls. The negative relationship between presence of barred owls and detectability of spotted owls indicated that spotted owls could be modifying their calling behavior in the presence of barred owls. The positive relationship between barred owl detections and local extinction probability suggests that because of competition with barred owls, spotted owls are being displaced. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.

  1. Comparative ecology of the Flammulated Owl and Northern Saw-whet Owl during fall migration

    USGS Publications Warehouse

    Stock, S.L.; Heglund, P.J.; Kaltenecker, G.S.; Carlisle, J.D.; Leppert, L.

    2006-01-01

    We compared the migration ecology of two owl species that exhibit different migration strategies: the Flammulated Owl (Otus flammeolus) and the Northern Saw-whet Owl (Aegolius acadicus). During fall 1999-2004, we captured 117 Flammulated Owls and 1433 Northern Saw-whet Owls in the southern Boise Mountains of southwestern Idaho. These owl species exhibited contrasting seasonal timing and body condition. Flammulated Owl captures peaked in mid-September and Northern Saw-whet Owl captures peaked in early to mid-October. Flammulated Owls displayed greater body condition than Northern Saw-whet Owls and increasing condition scores during the season, whereas Northern Saw-whet Owls had no apparent seasonal condition patterns. Based on seasonal timing of captures, both species showed unimodal movement patterns characteristic of fall migrants. However, in 1999 both species' capture rates were at least double those in other years of this study. Flammulated Owls' earlier arrival and departure, coupled with superior body condition, were consistent among years and typical of a long-distance migration strategy. In contrast, the Northern Saw-whet Owls' later arrival, more lengthy passage, and variable body condition were more characteristic of a short-distance migrant strategy. Furthermore, Northern Saw-whet Owls' body condition was significantly lower during the irruptive year than during nonirruptive years, supporting the notion that population density affects their migratory condition. ?? 2006 The Raptor Research Foundation, Inc.

  2. Barred owls and landscape attributes influence territory occupancy of northern spotted owls

    PubMed Central

    Sovern, Stan G; Forsman, Eric D; Olson, Gail S; Biswell, Brian L; Taylor, Margaret; Anthony, Robert G

    2014-01-01

    We used multi-season occupancy analyses to model 2 fates of northern spotted owl territories in relation to habitat amount, habitat fragmentation, and the presence of barred owls in Washington State, USA, 1989–2005. Local colonization is the probability a territory unoccupied by a spotted owl in year i would be occupied in year i + 1, and local extinction is the probability a territory that was occupied by a spotted owl in year i would be unoccupied in year i + 1. We found a negative relationship between local extinction probability and amount of late-seral forest edge. We found a negative relationship between colonization probability and the number of late-seral forest patches (higher fragmentation), and a negative relationship between colonization probability and the amount of non-habitat within 600 m of a spotted owl territory center (Akaike weight = 0.59). The presence of barred owls was positively related to extinction probability and negatively related to detection probability of spotted owls. The negative relationship between presence of barred owls and detectability of spotted owls indicated that spotted owls could be modifying their calling behavior in the presence of barred owls. The positive relationship between barred owl detections and local extinction probability suggests that because of competition with barred owls, spotted owls are being displaced. Published 2014. This article is a U.S. Government work and is in the public domain in the USA. PMID:25558093

  3. Avian pox in eastern screech owls and barred owls from Florida.

    PubMed

    Deern, S L; Heard, D J; Fox, J H

    1997-04-01

    Avian pox was diagnosed in two eastern screech owls (Otus asio) and two barred owls (Strix, varia) living in different regions of Florida (USA) between November 1994 and October 1995. Avian poxvirus infection was confirmed by the presence of eosinophilic intracytoplasmic epidermal inclusions (Bollinger bodies) on light microscopy of tissue from all four owls. Additionally, typical poxvirus particles were demonstrated by electron microscopy of a lesion from one of the eastern screech owls. These are the first published case reports of avian pox in eastern screech owls and barred owls.

  4. Role of prey and intraspecific density dependence on the population growth of an avian top predator

    NASA Astrophysics Data System (ADS)

    Fernandez-de-Simon, Javier; Díaz-Ruiz, Francisco; Cirilli, Francesca; Tortosa, Francisco S.; Villafuerte, Rafael; Ferreras, Pablo

    2014-10-01

    Exploring predator-prey systems in diverse ecosystems increases our knowledge about ecological processes. Predator population growth may be positive when conspecific density is low but predators also need areas with prey availability, associated with competition, which increases the risk of suffering losses but stabilises populations. We studied relationships between European rabbits Oryctolagus cuniculus (prey) and adult eagle owls Bubo bubo (predators) in south-western Europe. We assessed models explaining the predator population growth and stability. We estimated the abundance of rabbits and adult eagle owls during three years in eight localities of central-southern Spain. We explored models including rabbit and adult eagle owl abundance, accounting for yearly variations and including the locality as a random variable. We found that population growth of adult eagle owls was positive in situations with low conspecific abundance and tended to be negative but approaching equilibrium in situations of higher conspecific abundance. Population growth was also positively related to previous summer rabbit density when taking into account eagle owl conspecific abundance, possibly indicating that rabbits may support recruitment. Furthermore, abundance stability of adult eagle owls was positively related to previous winter-spring rabbit density, which could suggest predator population stabilisation through quick territory occupation in high-quality areas. These results exemplify the trade-off between prey availability and abundance of adult predators related to population growth and abundance stability in the eagle owl-rabbit system in south-western Europe. Despite rabbits have greatly declined during the last decades and eagle owls locally specialise on them, eagle owls currently have a favourable conservation status. As eagle owls are the only nocturnal raptor with such dependence on rabbits, this could point out that predators may overcome prey decreases in areas with

  5. Transient dynamics of invasive competition: barred owls, spotted owls, habitat, and the demons of competition present.

    PubMed

    Dugger, Katie M; Anthony, Robert G; Andrews, Lawrence S

    2011-10-01

    The recent range expansion of Barred Owls (Strix varia) into the Pacific Northwest, where the species now co-occurs with the endemic Northern Spotted Owl (Strix occidentalis caurina), resulted in a unique opportunity to investigate potential competition between two congeneric, previously allopatric species. The primary criticism of early competition research was the use of current species' distribution patterns to infer past processes; however, the recent expansion of the Barred Owl and the ability to model the processes that result in site occupancy (i.e., colonization and extinction) allowed us to address the competitive process directly rather than inferring past processes through current patterns. The purpose of our study was to determine whether Barred Owls had any negative effects on occupancy dynamics of nesting territories by Northern Spotted Owls and how these effects were influenced by habitat characteristics of Spotted Owl territories. We used single-species, multi-season occupancy models and covariates quantifying Barred Owl detections and habitat characteristics to model extinction and colonization rates of Spotted Owl pairs in southern Oregon, USA. We observed a strong, negative association between Barred Owl detections and colonization rates and a strong positive effect of Barred Owl detections on extinction rates of Spotted Owls. We observed increased extinction rates in response to decreased amounts of old forest at the territory core and higher colonization rates when old-forest habitat was less fragmented. Annual site occupancy for pairs reflected the strong effects of Barred Owls on occupancy dynamics with much lower occupancy rates predicted for territories where Barred Owls were detected. The strong Barred Owl and habitat effects on occupancy dynamics of Spotted Owls provided evidence of interference competition between the species. These effects increase the importance of conserving large amounts of contiguous, old-forest habitat to maintain

  6. A baby owl is found at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A baby owl, possibly a screech owl, shows its fear and resentment of the photographer snapping its picture. The owl was found on the stairs inside Hangar G, Cape Canaveral Air Force Station. It had apparently tried to fly from a nest near the ceiling but couldn't get back to it. Workers called an Audubon rescue center near Orlando, which captured it and will ensure the bird is returned to the wild when it's ready.

  7. A baby owl is found at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A baby owl, possibly a screech owl, displays its wings at the photographer snapping its picture. The owl was found on the stairs inside Hangar G, Cape Canaveral Air Force Station. It had apparently tried to fly from a nest near the ceiling but couldn't get back to it. Workers called an Audubon rescue center near Orlando, which captured it and will ensure the bird is returned to the wild when it's ready.

  8. A baby owl is found at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A baby owl, possibly a screech owl, stares at the photographer snapping its picture. The owl was found on the stairs inside Hangar G, Cape Canaveral Air Force Station. It had apparently tried to fly from a nest near the ceiling but couldn't get back to it. Workers called an Audubon rescue center near Orlando, which captured it and will ensure the bird is returned to the wild when it's ready.

  9. Secondary poisoning of owls by anticoagulant rodenticides

    USGS Publications Warehouse

    Mendenhall, V.M.; Pank, L.F.

    1980-01-01

    Anticoagulants-compounds that prevent clotting of the blood-are extensively used for control of small mammal pests. The potential secondary hazards of 6 anticoagulant rodenticides to birds of prey were examined in this study. Whole rats or mice were killed with each anticoagulant and were fed to 1-3 species of owls. Owls died of hemorrhaging after feeding on rats killed with bromadiolone, brodifacoum, or diphacinone; sublethal hemorrhaging occurred in owls fed rats killed with difenacoum. These results demonstrate potential secondary hazards of 4 anticoagulants to avian predators. No abnormalities were observed in owls fed rats killed with fumarin and chlorophacinone

  10. Competitive interactions and resource partitioning between northern spotted owls and barred owls in western Oregon

    USGS Publications Warehouse

    Wiens, J. David; Anthony, Robert G.; Forsman, Eric D.

    2014-01-01

    The federally threatened northern spotted owl (Strix occidentalis caurina) is the focus of intensive conservation efforts that have led to much forested land being reserved as habitat for the owl and associated wildlife species throughout the Pacific Northwest of the United States. Recently, however, a relatively new threat to spotted owls has emerged in the form of an invasive competitor: the congeneric barred owl (S. varia). As barred owls have rapidly expanded their populations into the entire range of the northern spotted owl, mounting evidence indicates that they are displacing, hybridizing with, and even killing spotted owls. The range expansion by barred owls into western North America has made an already complex conservation issue even more contentious, and a lack of information on the ecological relationships between the 2 species has hampered recovery efforts for northern spotted owls. We investigated spatial relationships, habitat use, diets, survival, and reproduction of sympatric spotted owls and barred owls in western Oregon, USA, during 2007–2009. Our overall objective was to determine the potential for and possible consequences of competition for space, habitat, and food between these previously allopatric owl species. Our study included 29 spotted owls and 28 barred owls that were radio-marked in 36 neighboring territories and monitored over a 24-month period. Based on repeated surveys of both species, the number of territories occupied by pairs of barred owls in the 745-km2 study area (82) greatly outnumbered those occupied by pairs of spotted owls (15). Estimates of mean size of home ranges and core-use areas of spotted owls (1,843 ha and 305 ha, respectively) were 2–4 times larger than those of barred owls (581 ha and 188 ha, respectively). Individual spotted and barred owls in adjacent territories often had overlapping home ranges, but interspecific space sharing was largely restricted to broader foraging areas in the home range

  11. What Do Great Horned Owls Eat?

    ERIC Educational Resources Information Center

    Bandelier, Kenneth J.

    1993-01-01

    Presents an activity to determine the identity of animals that owls ingest. Students dissect and examine the contents of "owl pellets" which are the indigestible parts of animals that are regurgitated after eating. Provides instructions for implementing and extending the activity. (MDH)

  12. The occurrence of second generation anticoagulant rodenticides in non-target raptor species in Norway.

    PubMed

    Langford, Katherine H; Reid, Malcolm; Thomas, Kevin V

    2013-04-15

    Second generation anticoagulant rodenticides (SGARs) are commonly used for rodent pest control in Norway resulting in the potential exposure of non-target raptor species. In this study the occurrence of flocoumafen, difethialone, difenacoum, bromadiolone and brodifacoum was determined in the livers of five species of raptors found dead in Norway between 2009 and 2011. The SGARs brodifacoum, bromadiolone, difenacoum and flocoumafen were detected in golden eagle (Aquila chrysaetos) and eagle owl (Bubo bubo) livers at a total SGAR concentration of between 11 and 255 ng/g in approximately 70% of the golden eagles and 50% of the eagle owls examined in this study. In the absence of specific golden eagle and eagle owl toxicity thresholds for SGARs, a level of >100 ng/g was used as a potential lethal range, accepting that poisoning may occur below this level. Thirty percent (7/24) of the golden eagle and eagle owl livers contained total SGAR residue levels above this threshold. Further estimation of the potential mortality impact on the sampled raptor populations was not possible.

  13. Connect Them Bones! An Interdisciplinary Study of Owl Pellets.

    ERIC Educational Resources Information Center

    Zipko, Stephen J.

    1983-01-01

    Discusses a field/laboratory study of the barn owl in which students collect and dissect owl pellets. Interdisciplinary lessons focus on eco-politics, reconstruction of owl prey skeletons, studies of predator-prey relationships, and construction/installation of nest boxes for owls and other birds. The unit begins and ends with an attitude…

  14. Microsatellite markers characterized in the barn owl (Tyto alba) and of high utility in other owls (Strigiformes: AVES).

    PubMed

    Klein, Akos; Horsburgh, Gavin J; Küpper, Clemens; Major, Agnes; Lee, Patricia L M; Hoffmann, Gyula; Mátics, Róbert; Dawson, Deborah A

    2009-11-01

    We have identified 15 polymorphic microsatellite loci for the barn owl (Tyto alba), five from testing published owl loci and 10 from testing non-owl loci, including loci known to be of high utility in passerines and shorebirds. All 15 loci were sequenced in barn owl, and new primer sets were designed for eight loci. The 15 polymorphic loci displayed two to 26 alleles in 56-58 barn owls. When tested in 10 other owl species (n = 1-6 individuals), between four and nine loci were polymorphic per species. These loci are suitable for studies of population structure and parentage in owls.

  15. The vestibular system of the owl

    NASA Technical Reports Server (NTRS)

    Money, K. E.; Correia, M. J.

    1973-01-01

    Five owls were given vestibular examinations, and two of them were sacrificed to provide serial histological sections of the temporal bones. The owls exhibited a curious variability in the postrotatory head nystagmus following abrupt deceleration; sometimes a brisk nystagnus with direction opposite to that appropriate to the stimulus would occur promptly after deceleration. It was found also that owls can exhibit a remarkable head stability during angular movement of the body about any axis passing through the skull. The vestibular apparatus in the owl is larger than in man, and a prominent crista neglecta is present. The tectorial membrane, the cupula, and the otolithic membranes of the utricle, saccule, and lagena are all attached to surfaces in addition to the surfaces hearing hair cells. These attachments are very substantial in the utricular otolithic membrane and in the cupula.

  16. Great horned owls are released at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Susan Small, director of the Florida Wildlife Hospital, holds a great horned owl before releasing it at Cape Canaveral Air Force Station, Complex 25/29. The owl is one of two found in June on the floor of CCAFS Hangar G, where their nest was located. They were treated at a local veterinary hospital and then taken to the Florida Wildlife Hospital in Melbourne for care and rehabilitation before release.

  17. Great horned owls are released at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    A great horned owl flies to freedom after its release at Cape Canaveral Air Force Station, Complex 25/29. The owl is one of two found in June on the floor of CCAFS Hangar G, where their nest was located. They were treated at a local veterinary hospital and then taken to the Florida Wildlife Hospital in Melbourne for care and rehabilitation before release.

  18. Great horned owls are released at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Eileen Olejarski (left), manager of Florida Wildlife Hospital, holds a great horned owl before releasing it at Cape Canaveral Air Force Station, Complex 25/29. The owl is one of two found in June on the floor of CCAFS Hangar G, where their nest was located. They were treated at a local veterinary hospital and then taken to the Florida Wildlife Hospital in Melbourne for care and rehabilitation before release.

  19. Great horned owls are released at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Eileen Olejarski (left), manager of Florida Wildlife Hospital, and Susan Small, director of the hospital, get ready to release two great horned owls at Cape Canaveral Air Force Station, Complex 25/29. The owls were found in June on the floor of CCAFS Hangar G, where their nest was located. They were treated at a local veterinary hospital and then taken to the Florida Wildlife Hospital in Melbourne for care and rehabilitation before release.

  20. Great horned owls are released at CCAFS

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Eileen Olejarski (left), manager of Florida Wildlife Hospital, and Susan Small, director of the hospital, remove two great horned owls from the vehicle before releasing them at Cape Canaveral Air Force Station, Complex 25/29. The owls were found in June on the floor of CCAFS Hangar G, where their nest was located. They were treated at a local veterinary hospital and then taken to the Florida Wildlife Hospital in Melbourne for care and rehabilitation before release..

  1. Owl: Next Generation System Monitoring

    SciTech Connect

    Schulz, M; White, B S; McKee, S A; Lee, H S; Jeitner, J

    2005-02-16

    As microarchitectural and system complexity grows, comprehending system behavior becomes increasingly difficult, and often requires obtaining and sifting through voluminous event traces or coordinating results from multiple, non-localized sources. Owl is a proposed framework that overcomes limitations faced by traditional performance counters and monitoring facilities in dealing with such complexity by pervasively deploying programmable monitoring elements throughout a system. The design exploits reconfigurable or programmable logic to realize hardware monitors located at event sources, such as memory buses. These monitors run and writeback results autonomously with respect to the CPU, mitigating the system impact of interrupt-driven monitoring or the need to communicate irrelevant events to higher levels of the system. The monitors are designed to snoop any kind of system transaction, e.g., within the core, on a bus, across the wire, or within I/O devices.

  2. Owls and larks in mice.

    PubMed

    Pfeffer, Martina; Wicht, Helmut; von Gall, Charlotte; Korf, Horst-Werner

    2015-01-01

    Humans come in different chronotypes and, particularly, the late chronotype (the so-called owl) has been shown to be associated with several health risks. A number of studies show that laboratory mice also display various chronotypes. In mice as well as in humans, the chronotype shows correlations with the period length and rhythm stability. In addition, some mouse models for human diseases show alterations in their chronotypic behavior, which are comparable to those humans. Thus, analysis of the behavior of mice is a powerful tool to unravel the molecular and genetic background of the chronotype and the prevalence of risks and diseases that are associated with it. In this review, we summarize the correlation of chronotype with free-running period length and rhythm stability in inbred mouse strains, in mice with a compromised molecular clockwork, and in a mouse model for neurodegeneration.

  3. Hypertrophic Cardiomyopathy in Owl Monkeys (Aotus spp.)

    PubMed Central

    Knowlen, Grant G; Weller, Richard E; Perry, Ruby L; Baer, Janet F; Gozalo, Alfonso S

    2013-01-01

    Cardiac hypertrophy is a common postmortem finding in owl monkeys. In most cases the animals do not exhibit clinical signs until the disease is advanced, making antemortem diagnosis of subclinical disease difficult and treatment unrewarding. We obtained echocardiograms, electrocardiograms, and thoracic radiographs from members of a colony of owl monkeys that previously was identified as showing a 40% incidence of gross myocardial hypertrophy at necropsy, to assess the usefulness of these modalities for antemortem diagnosis. No single modality was sufficiently sensitive and specific to detect all monkeys with cardiac hypertrophy. Electrocardiography was the least sensitive method for detecting owl monkeys with hypertrophic cardiomyopathy. Thoracic radiographs were more sensitive than was electrocardiography in this context but cannot detect animals with concentric hypertrophy without an enlarged cardiac silhouette. Echocardiography was the most sensitive method for identifying cardiac hypertrophy in owl monkeys. The most useful parameters suggestive of left ventricular hypertrophy in our owl monkeys were an increased average left ventricular wall thickness to chamber radius ratio and an increased calculated left ventricular myocardial mass. Parameters suggestive of dilative cardiomyopathy were an increased average left ventricular myocardial mass and a decreased average ratio of left ventricular free wall thickness to left ventricular chamber radius. When all 4 noninvasive diagnostic modalities (physical examination, echocardiography, electrocardiography, and thoracic radiography) were used concurrently, the probability of detecting hypertrophic cardiomyopathy in owl monkeys was increased greatly. PMID:23759531

  4. Hypertrophic cardiomyopathy in owl monkeys (Aotus spp.).

    PubMed

    Knowlen, Grant G; Weller, Richard E; Perry, Ruby L; Baer, Janet F; Gozalo, Alfonso S

    2013-06-01

    Cardiac hypertrophy is a common postmortem finding in owl monkeys. In most cases the animals do not exhibit clinical signs until the disease is advanced, making antemortem diagnosis of subclinical disease difficult and treatment unrewarding. We obtained echocardiograms, electrocardiograms, and thoracic radiographs from members of a colony of owl monkeys that previously was identified as showing a 40% incidence of gross myocardial hypertrophy at necropsy, to assess the usefulness of these modalities for antemortem diagnosis. No single modality was sufficiently sensitive and specific to detect all monkeys with cardiac hypertrophy. Electrocardiography was the least sensitive method for detecting owl monkeys with hypertrophic cardiomyopathy. Thoracic radiographs were more sensitive than was electrocardiography in this context but cannot detect animals with concentric hypertrophy without an enlarged cardiac silhouette. Echocardiography was the most sensitive method for identifying cardiac hypertrophy in owl monkeys. The most useful parameters suggestive of left ventricular hypertrophy in our owl monkeys were an increased average left ventricular wall thickness to chamber radius ratio and an increased calculated left ventricular myocardial mass. Parameters suggestive of dilative cardiomyopathy were an increased average left ventricular myocardial mass and a decreased average ratio of left ventricular free wall thickness to left ventricular chamber radius. When all 4 noninvasive diagnostic modalities (physical examination, echocardiography, electrocardiography, and thoracic radiography) were used concurrently, the probability of detecting hypertrophic cardiomyopathy in owl monkeys was increased greatly.

  5. Mycobacterium avium subsp. avium found in raptors exposed to infected domestic fowl.

    PubMed

    Kriz, Petr; Kaevska, Marija; Bartejsova, Iva; Pavlik, Ivo

    2013-09-01

    We report a case of a falcon breeding facility, where raptors (both diurnal and nocturnal) were raised in contact with domestic fowl (Gallus gallus f. domesticus) infected by Mycobacterium avium subsp. avium. Fecal and environmental samples from 20 raptors and four common ravens (Corvus corax) were collected. Mycobacterium a. avium DNA was detected in feces of four raptors (bald eagle [Haliaeetus leucocephalus], eagle owl [Bubo bubo], barn owl [Tyto alba], and little owl [Athene noctua]) using triplex quantitative real-time PCR. As both the flock of domestic fowl and one of the infected raptors had the same origin (zoological collection), they might have had a common source of colonization/infection. However, the detection of M. a. avium in feces of three other raptors may point at transmission of the agent between the birds in the facility. Contact of raptors with domestic fowl infected by M. a. avium may pose a risk for transmission of the infection for them; however, raptors from the falcon breeding facility seemed to be relatively resistant to the infection.

  6. Embryonic and neonatal mortality from salmonellosis in captive bred raptors.

    PubMed

    Battisti, A; Di Guardo, G; Agrimi, U; Bozzano, A I

    1998-01-01

    In a captive breeding center near Rome (Italy), cases of embryonic and neonatal death were recorded during the breeding seasons in the European eagle owl (Bubo bubo), peregrine falcon (Falco peregrinus), buzzard (Buteo buteo), and lanner falcon. (Falco biarmicus). Salmonella havana and S. virchow were isolated. Three pulli, clinically infected with S. havana, were successfully treated with enrofloxacin. From two groups of healthy 3- to 4-wk-old eagle owls, Salmonella sp. group 61 (61:r:-) and S. havana were collected. A strain of S. paratyphi B was detected in a pharyngeal swab and a fecal sample from an adult female goshawk (Accipiter gentilis), affected with pharyngeal trichomoniasis. A S. hadar strain was collected from a healthy 1-yr-old female eagle owl and S. livingstone was isolated from a 1-mo-old female peregrine, dead of an acute respiratory syndrome. Lesions of fibrinous polyserositis and multivisceral congestion were observed. From frozen 1-day-old chicks, on which adult and young raptors were fed, S. havana and S. livingstone isolates with similar biochemical and drug susceptibility patterns to those isolated from raptors were identified. A surveillance program on infectious diseases reduced embryonic and neonatal death rates in the following breeding seasons.

  7. Assessment of Trace Element Concentrations in Birds of Prey in Korea.

    PubMed

    Kim, Jungsoo; Oh, Jong-Min

    2016-07-01

    This study presents liver concentrations of trace elements of cinereous vultures (Aegypius monachus), common buzzards (Buteo buteo), common kestrels (Falco tinnunculus), and Eurasian eagle owls (Bubo bubo) collected in Korea from 2007 to 2008. Iron (Fe), manganese (Mn), copper (Cu), lead (Pb), and cadmium (Cd) concentrations in common kestrel juveniles were greater than in other juveniles of birds of prey. Adult cinereous vultures had greater Fe, Pb, and Cd concentrations than in those of other species, but common kestrels had greater Mn and Cu concentrations than in those of other birds of prey. Zinc concentrations in Eurasian eagle owl juveniles and adults were greater than in juveniles and adults of other species, respectively. In common kestrels, Fe, Cu, Pb, and Cd concentrations were significantly greater in adults than in juveniles. In Eurasian eagle owls, only Pb concentrations were greater in adults than in juveniles. Essential elements, such as Fe, Zn, Mn, and Cu concentrations, were within the range of other birds of prey studies. Seventeen individual birds of prey (30 %) were at a level considered Pb exposed (6-30 µg/g dw). This is a greater proportion than reported earlier in herons, egrets, and other birds from Korea. Elevated Pb concentration might be attributed to ingestion of Pb shot and bullet fragments for cinereous vultures and common buzzards, and urbanization for common kestrels. Cadmium concentrations in birds of prey were within the background concentrations (<3 µg/g dw) for wild birds.

  8. 78 FR 57171 - Experimental Removal of Barred Owls To Benefit Threatened Northern Spotted Owls; Record of...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-17

    ... Alternatives 2 and 3. The Preferred Alternative consists of a demography study conducted on four study areas... action alternatives vary by the number and location of study areas, the type of experimental design... populations. Barred owls displace spotted owls from high-quality habitat (Kelley et al. 2003, p. 51;...

  9. Improving strategies to assess competitive effects of barred owls on northern spotted owls in the Pacific Northwest

    USGS Publications Warehouse

    Wiens, J. David; Weekes, Anne

    2011-01-01

    A scientific study has determined that survey methods designed for spotted owls do not always detect barred owls that are actually present in spotted owl habitat. The researchers suggest that strategies to address potential interactions between spotted owls and barred owls will require carefully designed surveys that account for response behaviors and imperfect detection of both species. Species-specific sampling methods, which are proposed, can be used by forest managers to determine the occurrence and distribution of barred owls with high confidence. This fact sheet provides highlights of the research (Wiens and others, 2011).

  10. Owl Pellet Analysis--A Useful Tool in Field Studies

    ERIC Educational Resources Information Center

    Medlin, G. C.

    1977-01-01

    Describes a technique by which the density and hunting habits of owls can be inferred from their pellets. Owl pellets--usually small, cylindrical packages of undigested bone, hair, etc.--are regurgitated by a roosting bird. A series of activities based on owl pellets are provided. (CP)

  11. F-OWL: An Inference Engine for Semantic Web

    NASA Technical Reports Server (NTRS)

    Zou, Youyong; Finin, Tim; Chen, Harry

    2004-01-01

    Understanding and using the data and knowledge encoded in semantic web documents requires an inference engine. F-OWL is an inference engine for the semantic web language OWL language based on F-logic, an approach to defining frame-based systems in logic. F-OWL is implemented using XSB and Flora-2 and takes full advantage of their features. We describe how F-OWL computes ontology entailment and compare it with other description logic based approaches. We also describe TAGA, a trading agent environment that we have used as a test bed for F-OWL and to explore how multiagent systems can use semantic web concepts and technology.

  12. Measurement of fetal biparietal diameter in owl monkeys (Aotus nancymaae).

    PubMed

    Schuler, A Michele; Brady, Alan G; Tustin, George W; Parks, Virginia L; Morris, Chris G; Abee, Christian R

    2010-09-01

    Owl monkeys are New World primates frequently used in biomedical research. Despite the historical difficulty of breeding owl monkeys in captivity, several productive owl monkey breeding colonies exist currently. The animals in the colony we describe here are not timed-pregnant, and determination of gestational age is an important factor in prenatal care. Gestational age of human fetuses is often determined by using transabdominal measurements of fetal biparietal diameter. The purpose of this study was to correlate biparietal diameter measurements with gestational age in owl monkeys. We found that biparietal diameter can be used to accurately predict gestational age in owl monkeys.

  13. Population trajectory of burrowing owls (Athene cunicularia) in eastern Washington

    USGS Publications Warehouse

    Conway, C.J.; Pardieck, K.L.

    2006-01-01

    Anecdotal evidence suggests that burrowing owls have declined in Washington. The Washington Department of Fish and Wildlife is currently conducting a status review for burrowing owls which will help determine whether they should be listed as threatened or endangered in the state. To provide insights into the current status of burrowing owls (Athene cunicularia), we analyzed data from the North American Breeding Bird Survey using two analytical approaches to determine their current population trajectory in eastern Washington. We used a one-sample t-test to examine whether trend estimates across all BBS routes in Washington differed from zero. We also used a mixed model analysis to estimate the rate of decline in number of burrowing owls detected between 1968 and 2005. The slope in number of burrowing owls detected was negative for 12 of the 16 BBS routes in Washington that have detected burrowing owls. Numbers of breeding burrowing owls detected in eastern Washington declined at a rate of 1.5% annually. We suggest that all BBS routes that have detected burrowing owls in past years in eastern Washington be surveyed annually and additional surveys conducted to track population trends of burrowing owls at finer spatial scales in eastern Washington. In the meantime, land management and regulatory agencies should ensure that publicly managed areas with breeding burrowing owls are not degraded and should implement education and outreach programs to promote protection of privately owned areas with breeding owls.

  14. Modeling interactions betweenspotted owl and barred owl populations in fire-prone forests

    EPA Science Inventory

    Background / Question / Methods Efforts to conserve northern spotted owls (Strix occidentalis caurina) in the eastern Cascades of Washington must merge the challenges of providing sufficient structurally complex forest habitat in a fire-prone landscape with the limitations impos...

  15. Sherry Red Owl, Stands at Dawn Woman

    ERIC Educational Resources Information Center

    Crazy Bull, Cheryl

    2014-01-01

    This article introduces Sherry Red Owl, also known as "Stands at Dawn Woman," because she greets each day as a new opportunity and has spent her life working at new things. She worked at Sinte Gleska University (SGU) during its founding years, taught at an elementary school when few Native teachers were employed in the school systems,…

  16. Kenojuak Ashevak: "Young Owl Takes a Ride."

    ERIC Educational Resources Information Center

    Schwartz, Bernard

    1988-01-01

    Describes a lesson plan used to introduce K-3 students to a Canadian Inuit artist, to the personal and cultural context of the artwork, and to a simple printmaking technique. Includes background information on the artist, instructional strategies, and a print of the artist's "Young Owl Takes a Ride." (GEA)

  17. Introgression and dispersal among spotted owl (Strix occidentalis) subspecies

    PubMed Central

    Funk, W Chris; Forsman, Eric D; Mullins, Thomas D; Haig, Susan M

    2008-01-01

    Abstract Population genetics plays an increasingly important role in the conservation and management of declining species, particularly for defining taxonomic units. Subspecies are recognized by several conservation organizations and countries and receive legal protection under the US Endangered Species Act (ESA). Two subspecies of spotted owls, northern (Strix occidentalis caurina) and Mexican (S. o. lucida) spotted owls, are ESA-listed as threatened, but the California (S. o. occidentalis) spotted owl is not listed. Thus, determining the boundaries of these subspecies is critical for effective enforcement of the ESA. We tested the validity of previously recognized spotted owl subspecies by analysing 394 spotted owls at 10 microsatellite loci. We also tested whether northern and California spotted owls hybridize as suggested by previous mitochondrial DNA studies. Our results supported current recognition of three subspecies. We also found bi-directional hybridization and dispersal between northern and California spotted owls centered in southern Oregon and northern California. Surprisingly, we also detected introgression of Mexican spotted owls into the range of northern spotted owls, primarily in the northern part of the subspecies’ range in Washington, indicating long-distance dispersal of Mexican spotted owls. We conclude with a discussion of the conservation implications of our study. PMID:25567499

  18. Subtle Gardeners: Inland Predators Enrich Local Topsoils and Enhance Plant Growth

    PubMed Central

    Fedriani, José M.; Garrote, Pedro José; Delgado, María del Mar; Penteriani, Vincenzo

    2015-01-01

    Inland vertebrate predators could enrich of nutrients the local top soils in the area surrounding their nests and dens by depositing faeces, urine, and prey remains and, thus, alter the dynamics of plant populations. Surprisingly, and in contrast with convincing evidence from coastal habitats, whether and how this phenomenon occurs in inland habitats is largely uncertain even though these habitats represent a major fraction of the earth's surface. We investigated during two consecutive breeding seasons the potential enrichment of the top-soils associated with inland ground-nesting eagle owls Bubo bubo, as well as its possible consequences in the growth of two common annual grasses in southern Spain. Top-soils associated with owl nests differed strongly and significantly from control top-soils in chemical parameters, mainly fertility-related properties. Specifically, levels of available phosphorus, total nitrogen, organic matter, and available potassium were 49.1, 5.6, 3.1, and 2.7 times higher, respectively, in top-soils associated with owl nests as compared to control top-soils. Germination experiments in chambers indicated that nutrient enrichment by nesting owls enhanced seedling growth in both annual grasses (Phalaris canariensis and Avena sativa), with seedling size being 1.4–1.3 times higher in owl nest top-soils than in control top-soils. Our experimental study revealed that pervasive inland, predatory birds can profoundly enrich the topsoil around their nests and, thus, potentially enhance local vegetation growth. Because diverse inland vertebrate predators are widespread in most habitats they have a strong potential to enhance spatial heterogeneity, impinge on plant communities, and exert an overlooked effect on primary productivity worldwide. PMID:26383647

  19. Causes of owl mortality in Hawaii, 1992-1994

    USGS Publications Warehouse

    Work, T.M.; Hale, J.

    1996-01-01

    Eighty-one barn owls (Tyto alba) and five Hawaiian owls or pueo (Asio flammeus sandwichensis) from Kauai, Oahu, Lanai, Molokai, Maui and Hawaii (USA) were evaluated for cause of death, November 1992 through August 1994. The most common cause of death in barn owls was trauma (50%) followed by infectious disease (28%) and emaciation (22%). Most traumas apparently resulted from vehicular collisions. Trichomoniasis was the predominant infectious disease and appeared to be a significant cause of death in barn owls in Hawaii. Pasteurellosis and aspergillosis were encountered less commonly. No predisposing cause of emaciation was detected. Stomach contents from 28 barn owls contained mainly insects (64%) of the family Tetigoniidae and Gryllidae, and rodents (18%); the remainder had mixtures of rodents and insects or grass. Three pueo died from trauma and one each died from emaciation and pasteurellosis. We found no evidence of organochlorine, organophosphorus, or carbamate pesticides as causes of death in pueo or barn owls.

  20. Causes of owl mortality in Hawaii, 1992 to 1994.

    PubMed

    Work, T M; Hale, J

    1996-04-01

    Eighty-one barn owls (Tyto alba) and five Hawaiian owls or pueo (Asio flammeus sandwichensis) from Kauai, Oahu, Lanai, Molokai, Maui and Hawaii (USA) were evaluated for cause of death, November 1992 through August 1994. The most common cause of death in barn owls was trauma (50%) followed by infectious disease (28%) and emaciation (22%). Most traumas apparently resulted from vehicular collisions. Trichomoniasis was the predominant infectious disease and appeared to be a significant cause of death in barn owls in Hawaii. Pasteurellosis and aspergillosis were encountered less commonly. No predisposing cause of emaciation was detected. Stomach contents from 28 barn owls contained mainly insects (64%) of the family Tetigoniidae and Gryllidae, and rodents (18%); the remainder had mixtures of rodents and insects or grass. Three pueo died from trauma and one each died from emaciation and pasteurellosis. We found no evidence of organochlorine, organophosphorus, or carbamate pesticides as causes of death in pueo or barn owls.

  1. Demography of Northern Spotted Owls in southwestern Oregon

    USGS Publications Warehouse

    Zabel, Cynthia J.; Salmons, Susan E.; Forsman, Eric D.; Destefano, Stephen; Raphael, Martin G.; Gutierrez, R.J.

    1996-01-01

    Northern Spotted Owls (Strix occidentalis caurina) are associated with lower elevation, commercially valuable, late-successional coniferous forests in the Pacific Northwest. Meta-analyses of demographic parameters indicate that Northern Spotted Owl populations are declining throughout their range (Anderson and Burnham 1992, Burnham et al. this volume). Recent research has attempted to determine whether management activities have affected the viability of Spotted Owl populations, and results have led to development of conservation plans for the species (Dawson et al. 1987, Thomas et al. 1990, Murphy and Noon 1992, USDI 1992, Thomas et al. 1993b).In the Recovery Plan for the Northern Spotted Owl (USDI 1992b) threats to the species were identified as small population sizes, declining populations, limited amounts of habitat, continued loss and fragmentation of habitat, geographically isolated populations, and predation and competition from other avian species. Weather and fire are natural processes that also may affect reproductive success of Spotted Owls. Weather may be a factor in the high annual variability in fecundity of Spotted Owls, as has been suggested for other predatory bird species (Newton, 1979, 1986). However, these factors have not been addressed in previous studies of Spotted Owls.Our objectives were to estimate survival, fecundity, and annual rates of population change (l) for resident, territorial female Spotted Owls at two study areas in the coastal mountains of southwestern Oregon. We tested if the amount of rainfall was correlated with reproduction of Spotted Owls. While surveying for Spotted Owls, we documented the increased presence of Barred Owls (Strix varia), a potential competitor of Spotted Owls.

  2. Potential trophic cascades triggered by the barred owl range expansion

    USGS Publications Warehouse

    Holm, Samantha R.; Noon, Barry R.; Wiens, David; Ripple, William J.

    2016-01-01

    Recently, the barred owl (Strix varia) has expanded its range into the Pacific Northwest of the United States resulting in pronounced effects on the demography and behavior of the northern spotted owl (S. occidentalis caurina). The range expansion has brought together historically allopatric species, creating the potential for significant changes in the avian predator community with possible cascading effects on food-web dynamics. The adverse effects of the barred owl on the behavior and demography of the northern spotted owl are well-documented, but little is known about the immediate and long-term effects changes in the predator community may have on native species composition and ecosystem processes. Based on northern spotted owl and barred owl selection for diet and habitat resources, there is a potential for trophic cascades within the region's predator and prey communities, differing responses by their shared and unique prey species, and possible direct and indirect effects on ecosystem processes. We explored the possible ecological consequences of the barred owl range expansion to wildlife communities of the Pacific Northwest based on the theoretical underpinnings of predator–prey relationships, interspecific competition, intraguild predation, and potential cascading trophic interactions. Negative effects on fitness of northern spotted owls because of interspecific competition with barred owls are strong selection forces that may contribute to the regional extinction of the northern spotted owl. In addition, we posit that shared prey species and those uniquely consumed by barred owls, along with other competing native predators, may experience changes in behavior, abundance, and distribution as a result of increased rates of predation by rapidly expanding populations of barred owls.

  3. Translating the Foundational Model of Anatomy into OWL.

    PubMed

    Noy, Natalya F; Rubin, Daniel L

    2008-01-01

    The Foundational Model of Anatomy (FMA) represents the result of manual and disciplined modeling of the structural organization of the human body. It is a tremendous resource in bioinformatics that facilitates sharing of information among applications that use anatomy knowledge. The FMA was developed in Protégé and the Protégé frames language is the canonical representation language for the FMA. We present a translation of the original Protégé frame representation of the FMA into OWL. Our effort is complementary to the earlier efforts to represent FMA in OWL and is focused on two main goals: (1) representing only the information that is explicitly present in the frames representation of the FMA or that can be directly inferred from the semantics of Protégé frames; (2) representing all the information that is present in the frames representation of the FMA, thus producing an OWL representation for the complete FMA. Our complete representation of the FMA in OWL consists of two components: an OWL DL component that contains the FMA constructs that are compatible with OWL DL; and an OWL Full component that imports the OWL DL component and adds the FMA constructs that OWL DL does not allow.

  4. Detecting Burrowing Owl Bloodmeals in Pulex irritans (Siphonaptera: Pulicidae).

    PubMed

    Graham, Christine B; Eisen, Rebecca J; Belthoff, James R

    2016-03-01

    Pulex irritans L. is a cosmopolitan flea species that infests a wide variety of hosts. In North America it generally parasitizes large wild mammals, but in the Pacific Northwest an association has emerged between P. irritans and the western burrowing owl (Athene cunicularia hypugaea). While investigators have recognized this association for decades, it has not been clear if P. irritans feeds on burrowing owls, or if the owls serve exclusively as phoretic hosts. Here we describe using a real-time assay that was originally developed to identify bloodmeals in Ugandan cat fleas (Ctenocephalides felis Bouché) to detect burrowing owl DNA in P. irritans collected from burrowing owls in southern Idaho. Of 50 fleas tested, 12 had no detectable vertebrate bloodmeal. The remaining 38 (76%) contained burrowing owl DNA. The assay did not detect vertebrate DNA in unfed fleas exposed to owl or mouse pelts and is therefore unlikely to detect DNA in fleas from vertebrates that have served exclusively as phoretic hosts. We conclude that P. irritans feeds on burrowing owls. We discuss the potential implications of this finding for burrowing owl conservation and enzootic plague dynamics.

  5. Live trapping of hawks and owls

    USGS Publications Warehouse

    Stewart, R.E.; Cope, J.B.; Robbins, C.S.

    1945-01-01

    1. Hawks of six species (80 individuals) and owls of five species (37 individuals) were trapped for banding from November 1, 1943, to. May 26,1944. 2. In general, pole traps proved better than hand-operated traps or automatic traps using live bait. 3. Verbail pole traps proved very efficient, and were much more humane than padded steel traps because they rarely injured a captured bird. 4: Unbaited Verbail traps took a variety of raptors, in rough proportion to their local abundance, although slightly more of beneficial species were caught than of harmful types. 5. Hawks and owls were retrapped more readily in Verbail traps than in other types tried. 6. The number of song birds caught in Verbail traps was negligible. 7. Crows and vultures were not taken in Verbail traps, but possibly could be caught with bait.

  6. Geographical assemblages of European raptors and owls

    NASA Astrophysics Data System (ADS)

    López-López, Pascual; Benavent-Corai, José; García-Ripollés, Clara

    2008-09-01

    In this work we look for geographical structure patterns in European raptors (Order: Falconiformes) and owls (Order: Strigiformes). For this purpose we have conducted our research using freely available tools such as statistical software and databases. To perform the study, presence-absence data for the European raptors and owl species (Class Aves) were downloaded from the BirdLife International website. Using the freely available "pvclust" R-package, we applied similarity Jaccard index and cluster analysis in order to delineate biogeographical relationships for European countries. According to the cluster of similarity, we found that Europe is structured into two main geographical assemblages. The larger length branch separated two main groups: one containing Iceland, Greenland and the countries of central, northern and northwestern Europe, and the other group including the countries of eastern, southern and southwestern Europe. Both groups are divided into two main subgroups. According to our results, the European raptors and owls could be considered structured into four meta-communities well delimited by suture zones defined by Remington (1968) [Remington, C.L., 1968. Suture-zones of hybrid interaction between recently joined biotas. Evol. Biol. 2, 321-428]. Climatic oscillations during the Quaternary Ice Ages could explain at least in part the modern geographical distribution of the group.

  7. Genetic identification of spotted owls, barred owls, and their hybrids: Legal implications of hybrid identity

    USGS Publications Warehouse

    Haig, Susan M.; Wennerberg, Liv; Mullins, Thomas D.; Forsman, E.D.; Trail, P.

    2004-01-01

    Recent population expansion of Barred Owls ( Strix varia) into western North America has led to concern that they may compete with and further harm the Northern Spotted Owl ( S. occidentalis caurina), which is already listed as threatened under the U.S. Endangered Species Act (ESA). Because they hybridize, there is a legal need under the ESA for forensic identification of both species and their hybrids. We used mitochondrial control-region DNA and amplified fragment-length polymorphism (AFLP) analyses to assess maternal and biparental gene flow in this hybridization process. Mitochondrial DNA sequences (524 base pairs) indicated large divergence between Barred and Spotted Owls (13.9%). Further, the species formed two distinct clades with no signs of previous introgression. Fourteen diagnostic AFLP bands also indicated extensive divergence between the species, including markers differentiating them. Principal coordinate analyses and assignment tests clearly supported this differentiation. We found that hybrids had unique genetic combinations, including AFLP markers from both parental species, and identified known hybrids as well as potential hybrids with unclear taxonomic status. Our analyses corroborated the findings of extensive field studies that most hybrids genetically sampled resulted from crosses between female Barred Owls and male Spotted Owls. These genetic markers make it possible to clearly identify these species as well as hybrids and can now be used for research, conservation, and law enforcement. Several legal avenues may facilitate future conservation of Spotted Owls and other ESA-listed species that hybridize, including the ESA similarity-of-appearance clause (section 4[e]) and the Migratory Bird Treaty Act. The Migratory Bird Treaty Act appears to be the most useful route at this time.

  8. A technique for evisceration as an alternative to enucleation in birds of prey: 19 cases.

    PubMed

    Murray, Maureen; Pizzirani, Stefano; Tseng, Florina

    2013-06-01

    Ocular trauma is common in birds of prey presented to wildlife clinics and rehabilitation centers. Enucleation is the procedure most commonly described for treatment of end-stage ocular disease or chronically painful eyes in birds; however, there are several disadvantages and risks to this procedure. While evisceration has been suggested as an alternative, it has not been described for multiple cases or with long-term follow-up data in birds of prey. This report details an evisceration technique performed in 5 captive birds of prey of 4 different species (1 eastern screech owl [Megascops asio], 1 great horned owl [Bubo virginianus], 2 red-tailed hawks [Buteo jamaicensis], and 1 bald eagle [Haliaeetus leucocephalus]) with long-term follow-up information. In addition, this report describes 14 cases of free-living owls of 3 different species (1 great horned owl, 4 barred owls [Strix varia], and 9 eastern screech owls) on which this technique was performed from 2004 to 2011 and which were subsequently released to the wild. Because of the limited risk of complications and the less-severe disruption of facial symmetry, which may be particularly important in owls that are candidates for release to the wild, evisceration should be considered over enucleation in birds of prey that require surgical intervention for the management of severe sequelae to ocular trauma.

  9. Hunting increases adaptive auditory map plasticity in adult barn owls.

    PubMed

    Bergan, Joseph F; Ro, Peter; Ro, Daniel; Knudsen, Eric I

    2005-10-19

    The optic tectum (OT) of barn owls contains topographic maps of auditory and visual space. Barn owls reared with horizontally displacing prismatic spectacles (prisms) acquire a novel auditory space map in the OT that restores alignment with the prismatically displaced visual map. Although juvenile owls readily acquire alternative maps of auditory space as a result of experience, this plasticity is reduced greatly in adults. We tested whether hunting live prey, a natural and critically important behavior for barn owls, increases auditory map plasticity in adult owls. Two groups of naive adult owls were fit with prisms. The first group was fed dead mice during 10 weeks of prism experience, while the second group was required to hunt live prey for an identical period of time. When the owls hunted live prey, auditory maps shifted substantially farther (five times farther, on average) and the consistency of tuning curve shifts within each map increased. Only a short period of time in each day, during which the two groups experienced different conditions, accounts for this effect. In addition, increased map plasticity correlated with behavioral improvements in the owls' ability to strike and capture prey. These results indicate that the experience of hunting dramatically increases adult adaptive plasticity in this pathway.

  10. Predator facilitation or interference: a game of vipers and owls.

    PubMed

    Embar, Keren; Raveh, Ashael; Hoffmann, Ishai; Kotler, Burt P

    2014-04-01

    In predator-prey foraging games, the prey's reaction to one type of predator may either facilitate or hinder the success of another predator. We ask, do different predator species affect each other's patch selection? If the predators facilitate each other, they should prefer to hunt in the same patch; if they interfere, they should prefer to hunt alone. We performed an experiment in a large outdoor vivarium where we presented barn owls (Tyto alba) with a choice of hunting greater Egyptian gerbils (Gerbillus pyramidum) in patches with or without Saharan horned vipers (Cerastes cerastes). Gerbils foraged on feeding trays set under bushes or in the open. We monitored owl location, activity, and hunting attempts, viper activity and ambush site location, and the foraging behavior of the gerbils in bush and open microhabitats. Owls directed more attacks towards patches with vipers, and vipers were more active in the presence of owls. Owls and vipers facilitated each other's hunting through their combined effect on gerbil behavior, especially on full moon nights when vipers are more active. Owls forced gerbils into the bushes where vipers preferred to ambush, while viper presence chased gerbils into the open where they were exposed to owls. Owls and vipers took advantage of their indirect positive effect on each other. In the foraging game context, they improve each other's patch quality and hunting success.

  11. An Overview of OWL, a Language for Knowledge Representation.

    ERIC Educational Resources Information Center

    Szolovits, Peter; And Others

    This is a description of the motivation and overall organization of the OWL language for knowledge representation. OWL consists of a linguistic memory system (LMS), a memory of concepts in terms of which all English phrases and all knowledge of an application domain are represented; a theory of English grammar which tells how to map English…

  12. The effects of habitat, climate, and Barred Owls on long-term demography of Northern Spotted Owls

    USGS Publications Warehouse

    Dugger, Catherine; Forsman, Eric D.; Franklin, Alan B.; Davis, Raymond J.; White, Gary C.; Schwarz, Carl J.; Burnham, Kenneth P.; Nichols, James D.; Hines, James E.; Yackulic, Charles B.; Doherty, Paul F.; Bailey, Larissa; Clark, Darren A.; Ackers, Steven H.; Andrews, Lawrence S.; Augustine, Benjamin; Biswell, Brian L.; Blakesley, Jennifer; Carlson, Peter C.; Clement, Matthew J.; Diller, Lowell V.; Glenn, Elizabeth M.; Green, Adam; Gremel, Scott A.; Herter, Dale R.; Higley, J. Mark; Hobson, Jeremy; Horn, Rob B.; Huyvaert, Kathryn P.; McCafferty, Christopher; McDonald, Trent; McDonnell, Kevin; Olson, Gail S.; Reid, Janice A.; Rockweit, Jeremy; Ruiz, Viviana; Saenz, Jessica; Sovern, Stan G.

    2016-01-01

    Estimates of species' vital rates and an understanding of the factors affecting those parameters over time and space can provide crucial information for management and conservation. We used mark–recapture, reproductive output, and territory occupancy data collected during 1985–2013 to evaluate population processes of Northern Spotted Owls (Strix occidentalis caurina) in 11 study areas in Washington, Oregon, and northern California, USA. We estimated apparent survival, fecundity, recruitment, rate of population change, and local extinction and colonization rates, and investigated relationships between these parameters and the amount of suitable habitat, local and regional variation in meteorological conditions, and competition with Barred Owls (Strix varia). Data were analyzed for each area separately and in a meta-analysis of all areas combined, following a strict protocol for data collection, preparation, and analysis. We used mixed effects linear models for analyses of fecundity, Cormack-Jolly-Seber open population models for analyses of apparent annual survival (ϕ), and a reparameterization of the Jolly-Seber capture–recapture model (i.e. reverse Jolly-Seber; RJS) to estimate annual rates of population change (λRJS) and recruitment. We also modeled territory occupancy dynamics of Northern Spotted Owls and Barred Owls in each study area using 2-species occupancy models. Estimated mean annual rates of population change (λ) suggested that Spotted Owl populations declined from 1.2% to 8.4% per year depending on the study area. The weighted mean estimate of λ for all study areas was 0.962 (± 0.019 SE; 95% CI: 0.925–0.999), indicating an estimated range-wide decline of 3.8% per year from 1985 to 2013. Variation in recruitment rates across the range of the Spotted Owl was best explained by an interaction between total winter precipitation and mean minimum winter temperature. Thus, recruitment rates were highest when both total precipitation (29 cm) and

  13. Easy Extraction of Terms and Definitions with OWL2TL.

    PubMed

    Judkins, John; Utecht, Joseph; Brochhausen, Mathias

    2016-08-01

    Facilitating good communication between semantic web specialists and domain experts is necessary to efficient ontology development. This development may be hindered by the fact that domain experts tend to be unfamiliar with tools used to create and edit OWL files. This is true in particular when changes to definitions need to be reviewed as often as multiple times a day. We developed "OWL to Term List" (OWL2TL) with the goal of allowing domain experts to view the terms and definitions of an OWL file organized in a list that is updated each time the OWL file is updated. The tool is available online and currently generates a list of terms, along with additional annotation properties that are chosen by the user, in a format that allows easy copying into a spreadsheet.

  14. Easy Extraction of Terms and Definitions with OWL2TL

    PubMed Central

    Judkins, John; Utecht, Joseph; Brochhausen, Mathias

    2016-01-01

    Facilitating good communication between semantic web specialists and domain experts is necessary to efficient ontology development. This development may be hindered by the fact that domain experts tend to be unfamiliar with tools used to create and edit OWL files. This is true in particular when changes to definitions need to be reviewed as often as multiple times a day. We developed "OWL to Term List" (OWL2TL) with the goal of allowing domain experts to view the terms and definitions of an OWL file organized in a list that is updated each time the OWL file is updated. The tool is available online and currently generates a list of terms, along with additional annotation properties that are chosen by the user, in a format that allows easy copying into a spreadsheet. PMID:28035214

  15. Geographic variation and genetic structure in Spotted Owls

    USGS Publications Warehouse

    Haig, Susan M.; Wagner, R.S.; Forsman, E.D.; Mullins, Thomas D.

    2001-01-01

    We examined genetic variation, population structure, and definition of conservation units in Spotted Owls (Strix occidentalis). Spotted Owls are mostly non-migratory, long-lived, socially monogamous birds that have decreased population viability due to their occupation of highly-fragmented late successional forests in western North America. To investigate potential effects of habitat fragmentation on population structure, we used random amplified polymorphic DNA (RAPD) to examine genetic variation hierarchically among local breeding areas, subregional groups, regional groups, and subspecies via sampling of 21 breeding areas (276 individuals) among the three subspecies of Spotted Owls. Data from 11 variable bands suggest a significant relationship between geographic distance among local breeding groups and genetic distance (Mantel r = 0.53, P < 0.02) although multi-dimensional scaling of three significant axes did not identify significant grouping at any hierarchical level. Similarly, neighbor-joining clustering of Manhattan distances indicated geographic structure at all levels and identified Mexican Spotted Owls as a distinct clade. RAPD analyses did not clearly differentiate Northern Spotted Owls from California Spotted Owls. Among Northern Spotted Owls, estimates of population differentiation (FST) ranged from 0.27 among breeding areas to 0.11 among regions. Concordantly, within-group agreement values estimated via multi-response permutation procedures of Jaccarda??s distances ranged from 0.22 among local sites to 0.11 among regions. Pairwise comparisons of FST and geographic distance within regions suggested only the Klamath region was in equilibrium with respect to gene flow and genetic drift. Merging nuclear data with recent mitochondrial data provides support for designation of an Evolutionary Significant Unit for Mexican Spotted Owls and two overlapping Management Units for Northern and California Spotted Owls.

  16. How the owl resolves auditory coding ambiguity

    PubMed Central

    Mazer, James A.

    1998-01-01

    The barn owl (Tyto alba) uses interaural time difference (ITD) cues to localize sounds in the horizontal plane. Low-order binaural auditory neurons with sharp frequency tuning act as narrow-band coincidence detectors; such neurons respond equally well to sounds with a particular ITD and its phase equivalents and are said to be phase ambiguous. Higher-order neurons with broad frequency tuning are unambiguously selective for single ITDs in response to broad-band sounds and show little or no response to phase equivalents. Selectivity for single ITDs is thought to arise from the convergence of parallel, narrow-band frequency channels that originate in the cochlea. ITD tuning to variable bandwidth stimuli was measured in higher-order neurons of the owl’s inferior colliculus to examine the rules that govern the relationship between frequency channel convergence and the resolution of phase ambiguity. Ambiguity decreased as stimulus bandwidth increased, reaching a minimum at 2–3 kHz. Two independent mechanisms appear to contribute to the elimination of ambiguity: one suppressive and one facilitative. The integration of information carried by parallel, distributed processing channels is a common theme of sensory processing that spans both modality and species boundaries. The principles underlying the resolution of phase ambiguity and frequency channel convergence in the owl may have implications for other sensory systems, such as electrolocation in electric fish and the computation of binocular disparity in the avian and mammalian visual systems. PMID:9724807

  17. Reproduction of the owl monkey (Aotus spp.) in captivity.

    PubMed

    Málaga, C A; Weller, R E; Buschbom, R L; Baer, J F; Kimsey, B B

    1997-06-01

    The reproduction performance of captive owl monkeys, a breed used extensively in biomedical research, was observed at the Battelle Primate Facility (BPF). The colony grew through captive breeding, imports from the Peruvian Primatological Project, and others to a peak size of 730. It included seven karyotypes of Aotus sp. Results showed that owl monkeys can breed successfully in a laboratory in numbers sufficient to sustain modest research programs. Reproductive success increases when pairs are compatible, of the same karyotype, and stabilized; however, mated pairs of different karyotype are also productive. Under conditions of controlled lighting and heating, owl monkeys at BPF showed no birth peak nor birth season.

  18. OWL 2 learn profile: an ontology sublanguage for the learning domain.

    PubMed

    Heiyanthuduwage, Sudath R; Schwitter, Rolf; Orgun, Mehmet A

    2016-01-01

    Many experimental ontologies have been developed for the learning domain for use at different institutions. These ontologies include different OWL/OWL 2 (Web Ontology Language) constructors. However, it is not clear which OWL 2 constructors are the most appropriate ones for designing ontologies for the learning domain. It is possible that the constructors used in these learning domain ontologies match one of the three standard OWL 2 profiles (sublanguages). To investigate whether this is the case, we have analysed a corpus of 14 ontologies designed for the learning domain. We have also compared the constructors used in these ontologies with those of the OWL 2 RL profile, one of the OWL 2 standard profiles. The results of our analysis suggest that the OWL 2 constructors used in these ontologies do not exactly match the standard OWL 2 RL profile, but form a subset of that profile which we call OWL 2 Learn.

  19. Modeling co-occurrence of northern spotted and barred owls: accounting for detection probability differences

    USGS Publications Warehouse

    Bailey, Larissa L.; Reid, Janice A.; Forsman, Eric D.; Nichols, James D.

    2009-01-01

    Barred owls (Strix varia) have recently expanded their range and now encompass the entire range of the northern spotted owl (Strix occidentalis caurina). This expansion has led to two important issues of concern for management of northern spotted owls: (1) possible competitive interactions between the two species that could contribute to population declines of northern spotted owls, and (2) possible changes in vocalization behavior and detection probabilities of northern spotted owls induced by presence of barred owls. We used a two-species occupancy model to investigate whether there was evidence of competitive exclusion between the two species at study locations in Oregon, USA. We simultaneously estimated detection probabilities for both species and determined if the presence of one species influenced the detection of the other species. Model selection results and associated parameter estimates provided no evidence that barred owls excluded spotted owls from territories. We found strong evidence that detection probabilities differed for the two species, with higher probabilities for northern spotted owls that are the object of current surveys. Non-detection of barred owls is very common in surveys for northern spotted owls, and detection of both owl species was negatively influenced by the presence of the congeneric species. Our results suggest that analyses directed at hypotheses of barred owl effects on demographic or occupancy vital rates of northern spotted owls need to deal adequately with imperfect and variable detection probabilities for both species.

  20. Herpesviruses and Newcastle disease viruses in white storks (Ciconia ciconia).

    PubMed

    Kaleta, E F; Kummerfeld, N

    1983-01-01

    Three herpesviruses were isolated from white storks (Ciconia ciconia). All isolates reacted in cross-neutralisation tests with homologous antisera and with sera prepared against a herpesvirus from a black stork (Ciconia nigra). These data indicate serologic relatedness of the herpesviruses from both stork species. Antisera prepared against herpesviruses from the domestic chicken (viruses of Marek's disease and infectious laryngotracheitis), turkey, duck and pigeon as well as from the blue-fronted amazon (Amazona aestiva), prairie falcon (Falco mexicanus), eagle owl (Bubo bubo), Lake Victoria cormorant (Phalacrocorax melanoleucos), bobwhite quail (Colinus virginianus) and desmoiselle crane (Anthropoides virgo) did not react with the stork herpesviruses. Neutralising antibodies against stork herpesvirus were detected in the majority of 72 blood samples from white and black storks. In addition, three Newcastle disease viruses (NDV) could be isolated from white storks. One isolate was highly virulent the two others were avirulent for the chicken. Haemagglutination inhibition tests have shown that some storks have antibodies against Paramyxovirus- (PMV)-1 (NDV), PMV-2 and PMV-3. No antibodies could be detected in stork sera against PMV-4, -6 and -7.

  1. First detection of Borrelia burgdorferi-antibodies in free-living birds of prey from Eastern Westphalia, Germany.

    PubMed

    Büker, M; Picozzi, K; Kolb, S; Hatt, J-M

    2013-07-01

    Borrelia (B.) burgdorferi sensu lato, the causative agent of Lyme disease, is the most important arthropod-borne zoonosis-pathogen in the Northern hemisphere. Besides small mammals, birds, primarily Passeriformes and sea birds, play an important role in the transmission, distribution and maintenance of this disease. Previous studies on birds have focused mainly on the detection of Borrelia-infected ticks. However, the presence or absence of an infected tick cannot be taken as an indicator of the infective status of the avian host; to date this area of research has not been explored. In this study, serological analyses of blood collected from free-living birds of prey (n = 29) at the rehabilitation centre in Eastern Westphalia, Germany, highlights that birds of prey are also susceptible to B. burgdorferi and react immunologically to an infection. Increased antibody-levels could be found by using a modified Indirect Immunofluorescent-testing in two common buzzards, Buteo buteo, and two eagle owls, Bubo bubo. Further research regarding the serological diagnostics of B. burgdorferi within the avian host is required. In the future, it should be taken into account that birds of prey can be reservoirs for B. burgdorferi, as well as carriers of infected ticks; although at present their epidemiological importance is still to be confirmed.

  2. Population Characteristics May Reduce the Levels of Individual Call Identity

    PubMed Central

    Delgado, María del Mar; Caferri, Eleonora; Méndez, Maria; Godoy, José A.; Campioni, Letizia; Penteriani, Vincenzo

    2013-01-01

    Individual variability influences the demographic and evolutionary dynamics of spatially structured populations, and conversely ecological and evolutionary dynamics provide the context under which variations at the individual level occur. Therefore, it is essential to identify and characterize the importance of the different factors that may promote or hinder individual variability. Animal signaling is a prime example of a type of behavior that is largely dependent on both the features of individuals and the characteristics of the population to which they belong. After 10 years studying the dynamics of a population of a long-lived species, the eagle owl (Bubo bubo), we investigated the emergence and maintenance of traits that reveal individual identity by focusing on vocal features. We found that individuals inhabiting a high density population characterized by a relative lack of heterogeneity (in terms of prey availability and breeding success) among breeding sites might be selected for reducing the levels of identity. Two non-mutually exclusive hypotheses may explain the structural call patterns we detected: (1) similarity in calls may be principally a consequence of the particular characteristics of the population; and (2) high density may encourage individuals to mimic each other’s vocalizations in a cascade effect, leading to a widespread and unique communication network. PMID:24204869

  3. OWL: A Condor Based Workflow Management System for JWST

    NASA Astrophysics Data System (ADS)

    Pierfederici, F.; Swam, M.; Greene, G.; Kyprianou, M.; Gaffney, N.

    2012-09-01

    The Open Workflow Layer (OWL) is an open source Workflow Management System (WMS) developed at the Space Telescope Science Institute. OWL is being designed for the James Webb Space Telescope (JWST) science data processing using the Hubble Space Telescope (HST) as a test bed. It is however very general and could be applied to many other missions and data processing applications. OWL is a thin Python layer that provides advanced workflow management, GUIs and a data-centric view on top of Condor, a widely used open source batch scheduling system. As such, OWL can transparently take advantage of the many features offered by Condor without having to re-implement them from scratch.

  4. 29. November 1969 'OWL' CAPITAL BETWEEN WINDOWS ON SOUTH WALL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    29. November 1969 'OWL' CAPITAL BETWEEN WINDOWS ON SOUTH WALL OF RIGGS LIBRARY, SECOND LEVEL - Georgetown University, Healy Building, Thirty-seventh & O Streets, Northwest, Washington, District of Columbia, DC

  5. Semantically-Rigorous Systems Engineering Modeling Using Sysml and OWL

    NASA Technical Reports Server (NTRS)

    Jenkins, J. Steven; Rouquette, Nicolas F.

    2012-01-01

    The Systems Modeling Language (SysML) has found wide acceptance as a standard graphical notation for the domain of systems engineering. SysML subsets and extends the Unified Modeling Language (UML) to define conventions for expressing structural, behavioral, and analytical elements, and relationships among them. SysML-enabled modeling tools are available from multiple providers, and have been used for diverse projects in military aerospace, scientific exploration, and civil engineering. The Web Ontology Language (OWL) has found wide acceptance as a standard notation for knowledge representation. OWL-enabled modeling tools are available from multiple providers, as well as auxiliary assets such as reasoners and application programming interface libraries, etc. OWL has been applied to diverse projects in a wide array of fields. While the emphasis in SysML is on notation, SysML inherits (from UML) a semantic foundation that provides for limited reasoning and analysis. UML's partial formalization (FUML), however, does not cover the full semantics of SysML, which is a substantial impediment to developing high confidence in the soundness of any conclusions drawn therefrom. OWL, by contrast, was developed from the beginning on formal logical principles, and consequently provides strong support for verification of consistency and satisfiability, extraction of entailments, conjunctive query answering, etc. This emphasis on formal logic is counterbalanced by the absence of any graphical notation conventions in the OWL standards. Consequently, OWL has had only limited adoption in systems engineering. The complementary strengths and weaknesses of SysML and OWL motivate an interest in combining them in such a way that we can benefit from the attractive graphical notation of SysML and the formal reasoning of OWL. This paper describes an approach to achieving that combination.

  6. Ectoparasites of Burrowing Owls (Athene cunicularia hypugaea) wintering in southern Texas

    USGS Publications Warehouse

    Skoruppa, M.K.; Pearce, B.; Woodin, M.C.; Hickman, G.C.

    2006-01-01

    Fifteen Western Burrowing Owls (Athene cunicularia hypugaea) were captured over two winters (2001-2003) in southern Texas and examined for ectoparasites. Four of the 15 owls (27%) harbored feather lice, and the maximum number of lice found on any individual was ??? three. Two species of feather lice were found: Colpocephalum pectinatum occurred on three of the owls, and Strigiphilus speotyti was found on four owls. No fleas or other ectoparasites were found on any of the Burrowing Owls. The low diversity and numbers of ectoparasites suggest that ectoparasites are not threatening the health of wintering Burrowing Owls in southern Texas.

  7. Insect-foraging in captive owl monkeys (Aotus nancymaae).

    PubMed

    Wolovich, Christy K; Rivera, Jeanette; Evans, Sian

    2010-08-01

    Whereas the diets of diurnal primate species vary greatly, almost all nocturnal primate species consume insects. Insect-foraging has been described in nocturnal prosimians but has not been investigated in owl monkeys (Aotus spp.). We studied 35 captive owl monkeys (Aotus nancymaae) in order to describe their foraging behavior and to determine if there were any age or sex differences in their ability to capture insect prey. Because owl monkeys cooperate in parental care and in food-sharing, we expected social interactions involving insect prey. We found that owl monkeys most often snatched flying insects from the air and immobilized crawling insects against a substrate using their hands. Immatures and adult female owl monkeys attempted to capture prey significantly more often than did adult males; however, there was no difference in the proportion of attempts that resulted in capture. Social interactions involving prey appeared similar to those with provisioned food, but possessors of prey resisted begging attempts more so than did possessors of other food. Owl monkeys attempted to capture prey often (mean = 9.5 +/- 5.8 attempts/h), and we speculate that the protein and lipid content of captured prey is important for meeting the metabolic demands for growth and reproduction.

  8. California spotted owls: Chapter 5 in Managing Sierra Nevada forests

    USGS Publications Warehouse

    Roberts, Suzanne C.; Brooks, Matthew L.

    2012-01-01

    California spotted owls (Strix occidentalis occidentalis) are habitat specialists that are strongly associated with late-successional forests. For nesting and roosting, they require large trees and snags embedded in a stand with a complex forest structure (Blakesley et al. 2005, Gutiérrez et al. 1992, Verner et al. 1992b). In mixedconifer forests of the Sierra Nevada, California spotted owls typically nest and roost in stands with high canopy closure (≥75 percent) [Note: when citing studies, we use terminology consistent with Jennings et al. (1999), however, not all studies properly distinguish between canopy cover and closure and often use the terms interchangeably (see chapter 14 for clarification)] and an abundance of large trees (>24 in (60 cm) diameter at breast height [d.b.h.]) (Bias and Gutiérrez 1992, Gutiérrez et al. 1992, LaHaye et al. 1997, Moen and Gutiérrez 1997, Verner et al. 1992a). The California spotted owl guidelines (Verner et al. 1992b) effectively summarized much of the information about nesting and roosting habitat. Since that report, research on the California spotted owl has continued with much of the new information concentrated in five areas: population trends, barred owl (Strix varia) invasion, climate effects, foraging habitat, and owl response to fire.

  9. Toward instrumentation for ELTs: the OWL case

    NASA Astrophysics Data System (ADS)

    Monnet, Guy; D'Odorico, Sandro

    2004-09-01

    Based on expected Science Drivers for a 60 to 100-m diameter OWL-class telescope, we derive the basic instrumental capabilities that are needed to address them effectively. They come in three flavors -viz. an extremely high-contrast fully diffraction-limited spectro-imager, a cryogenic AO-assisted imager and multi-integral field spectrometer. Their highest priority wavelength range lies in the near-IR. In terms of size and technical requirements, these instruments belong to a quite similar class than instruments currently being developed for the 8-10 m telescopes. This places them hopefully in the feasible category, even if already rather challenging. A big caveat however is that enlarging the imaging field or the spectrometer multiplex would require large clusters of these basic "bricks". The requirements on the adaptive optics correction are stringent and call for a close and careful integration between the telescope adaptive optics systems and the instruments. We also introduce here, as a relevant example of a new observational strategy, an instrument focused on a specific scientific program - the direct measurement of the acceleration of the Universe at different epochs via the Lyα forest in QSO spectra. Being able to host dedicated facilities of this type, used for a specific observing programs in a CERN experiment-like fashion, is deemed essential to ensure that the giant telescopes of the future get and stay at the cutting edge of research in the next decade and beyond. Finally, we comment briefly on the articulation between the development of generic instrument concepts for ELTs in the frame of the European ELT Design Study and their adaptation to the OWL case.

  10. Multidrug-resistant Salmonella enterica Serovar Typhimurium Monophasic Variant 4,12:i:- Isolated from Asymptomatic Wildlife in a Catalonian Wildlife Rehabilitation Center, Spain.

    PubMed

    Molina-López, Rafael A; Vidal, Anna; Obón, Elena; Martín, Marga; Darwich, Laila

    2015-07-01

    Wildlife can act as long-term asymptomatic reservoirs for zoonotic bacteria, such as Salmonella. The prevalence and antimicrobial-susceptibility profiles of Salmonella spp. were assessed in 263 cases in wildlife from 22 animal orders from a wildlife rehabilitation center in Catalonia (NE Spain), September 2013-May 2014. Eleven of 263 tested animals were positive for Salmonella spp., representing an overall prevalence of 4.2%. Prevalences by taxonomic categories were 2% in mammals, 4.7% in birds, and 4.5% in reptiles. By species, one each of European hedgehog (Erinaceus europeus; from a sample of n = 26), Eurasian Eagle Owl (Bubo bubo; n = 2), Barn Owl (Tyto alba; n = 3), Tawny Owl (Strix aluco; n = 20), Egyptian Vulture (Neophron percnopterus; n = 1), Griffon Vulture (Gyps fulvus; n = 1), and Hoopoe (Upupa epops; n = 2), and two each Common Kestrels (Falco tinnunculus; n = 16) and pond sliders (Trachemys scripta; n = 25) were positive for Salmonella. By serotyping, seven of eleven isolates were classified as S. enterica subsp. enterica serovar Typhimurium, and five of seven belonged to the monophasic variant 4,12:i:-. All the monophasic variants were isolated from birds (4/5 in raptors) and showed a multidrug-resistance (MDR) profile to at least ampicillin, streptomycin, sulfonamide, and tetracycline (R-type ASSuT), and up to 12 antibiotics. The large proportion of S. Typhimurium monophasic MDR strains detected in wildlife never treated with antibiotics, especially in raptors, adds more complexity to the epidemiologic control of one of the most frequent serovars involved in human and livestock infection.

  11. Seropositivity and risk factors associated with Toxoplasma gondii infection in wild birds from Spain.

    PubMed

    Cabezón, Oscar; García-Bocanegra, Ignacio; Molina-López, Rafael; Marco, Ignasi; Blanco, Juan M; Höfle, Ursula; Margalida, Antoni; Bach-Raich, Esther; Darwich, Laila; Echeverría, Israel; Obón, Elena; Hernández, Mauro; Lavín, Santiago; Dubey, Jitender P; Almería, Sonia

    2011-01-01

    Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n=610), Strigiformes (n=260), Ciconiiformes (n=156), Gruiformes (n=21), and other orders (n=32), from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1:25) were found in 282 (26.1%, IC(95%:)23.5-28.7) of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus), short-toed snake-eagle (Circaetus gallicus), Bonelli's eagle (Aquila fasciata), golden eagle (Aquila chrysaetos), bearded vulture (Gypaetus barbatus), osprey (Pandion haliaetus), Montagu's harrier (Circus pygargus), Western marsh-harrier (Circus aeruginosus), peregrine falcon (Falco peregrinus), long-eared owl (Asio otus), common scops owl (Otus scops), Eurasian spoonbill (Platalea leucorodia), white stork (Ciconia ciconia), grey heron (Ardea cinerea), common moorhen (Gallinula chloropus); in the International Union for Conservation of Nature (IUCN) "vulnerable" Spanish imperial eagle (Aquila adalberti), lesser kestrel (Falco naumanni) and great bustard (Otis tarda); and in the IUCN "near threatened" red kite (Milvus milvus). The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo) (68.1%, 98 of 144). The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is widespread and can be at a high level in

  12. [Occurrence of parasites in indigenous birds of prey and owls].

    PubMed

    Lierz, M; Göbel, T; Schuster, R

    2002-01-01

    In the present paper a general overview on parasites in birds of prey and owls is given. This part is followed by a study investigating the prevalences and species of parasites in free-ranging birds of prey and owls in Berlin and Brandenburg State, Germany. Over a one year period, 84 birds of prey and owls of the following species were examined for the presence of endo- and ectoparasites: Common Buzzard (Buteo buteo) (n = 32), Kestrel (Falco tinnunculus) (n = 20), Sparrowhawk (Accipiter nisus) (n = 9), Goshawk (Accipiter gentilis) (n = 8), Black Kite (Milvus migrans) (n = 4), Peregrine Falcon (Falco peregrinus) (n = 3), Marsh Harrier (Circus aeruginosus) (n = 1), White-tailed-Sea Eagle (Haliaeetus albicilla) (n = 1), Tawny Owl (Strix aluco) (n = 4), Long-eared Owl (Asio otus) (n = 1) and Barn Owl (Tyto alba) (n = 1). In 97.6% of the cases, ectoparasites (feather mites and hippoboscid flies) were found. Especially eyasses (93.3%) were positive for hippoboscid flies. Trichomonas was detected in 28.6% of all birds of prey and owls examined. A prevalence of 100% was established in the Sparrow Hawks as well as Peregrine Falcons. Leucozytozoon sp. and Hemoproteus sp. as blood parasites were found in 26.9% of the birds in total. Common Buzzards showed the highest prevalence (44.8%). 58.3% of birds examined were positive for endoparasites. Flukes were found in 16.7%, tapeworms in 14.3%, round-worms in 48.8% and acanthocephales in 2.4% of the cases. Interestingly, Tylodelphis clavata (in a Common Buzzard) and Hovorkonema variegatum (in a Goshawk) were found for the first time in raptors. The results of this study underline the importance of a parasitological examination in the process of raptor rehabilitation.

  13. Species richness, relative abundance, and habitat associations of nocturnal birds along the rio grande in Southern texas

    USGS Publications Warehouse

    Skoruppa, M.K.; Woodin, M.C.; Blacklock, G.

    2009-01-01

    The segment of the Rio Grande between International Falcon Reservoir and Del Rio, Texas (distance ca. 350 km), remains largely unexplored ornithologically. We surveyed nocturnal birds monthly during February-June 1998 at 19 stations along the Rio Grande (n = 6) and at upland stock ponds (n = 13) in Webb County, Texas. We conducted 10-min point counts (n = 89) after sunset and before moonset. Four species of owls and five species of nightjars were detected. Nightjars, as a group, were nearly five limes more abundant (mean number/count = 2.63) than owls (mean number = 0.55). The most, common owl, the great horned owl (Bubo virginianus), had a mean number of 0.25/point count. The mean for elf owls (Micrathene whitneyi) was 0.16/point count. The most common nightjars were the common poorwill (Phalaenoptilus nuttallii; 1.21/point count) and lesser nighthawk (Chordeiles acutipennir, 1.16/point count). Survey sites on the river supported more species (mean = 2.2) than did upland stock ponds (mean = 1.4). However, only one species (common pauraque, Nyctidromus albicollis) showed a preference for the river sites. Our results establish this segment of the Rio Grande in southern Texas as an area of high diversity of nightjars in the United States, matched (in numbers of species) only by southeastern Arizona and southwestern New Mexico.

  14. Landscape features influence postrelease predation on endangered black-footed ferrets

    USGS Publications Warehouse

    Poessel, S.A.; Breck, S.W.; Biggins, D.E.; Livieri, T.M.; Crooks, K.R.; Angeloni, L.

    2011-01-01

    Predation can be a critical factor influencing recovery of endangered species. In most recovery efforts lethal and nonlethal influences of predators are not sufficiently understood to allow prediction of predation risk, despite its importance. We investigated whether landscape features could be used to model predation risk from coyotes (Canis latrans) and great horned owls (Bubo virginianus) on the endangered black-footed ferret (Mustela nigripes). We used location data of reintroduced ferrets from 3 sites in South Dakota to determine whether exposure to landscape features typically associated with predators affected survival of ferrets, and whether ferrets considered predation risk when choosing habitat near perches potentially used by owls or near linear features predicted to be used by coyotes. Exposure to areas near likely owl perches reduced ferret survival, but landscape features potentially associated with coyote movements had no appreciable effect on survival. Ferrets were located within 90 m of perches more than expected in 2 study sites that also had higher ferret mortality due to owl predation. Densities of potential coyote travel routes near ferret locations were no different than expected in all 3 sites. Repatriated ferrets might have selected resources based on factors other than predator avoidance. Considering an easily quantified landscape feature (i.e., owl perches) can enhance success of reintroduction efforts for ferrets. Nonetheless, development of predictive models of predation risk and management strategies to mitigate that risk is not necessarily straightforward for more generalist predators such as coyotes. ?? 2011 American Society of Mammalogists.

  15. Hematologic parameters in raptor species in a rehabilitation setting before release.

    PubMed

    Black, Peter A; McRuer, David L; Horne, Leigh-Ann

    2011-09-01

    To be considered for release, raptors undergoing rehabilitation must have recovered from their initial injury in addition to being clinically healthy. For that purpose, a good understanding of reference hematologic values is important in determining release criteria for raptors in a rehabilitation setting. In this study, retrospective data were tabulated from clinically normal birds within 10 days of release from a rehabilitation facility. Hematologic values were compiled from 71 red-tailed hawks (Buteo jamaicensis), 54 Eastern screech owls (Megascops asio), 31 Cooper's hawks (Accipiter cooperii), 30 great-horned owls (Bubo virginianus), 28 barred owls (Strix varia), 16 bald eagles (Haliaeetus leucocephalus), and 12 broad-winged hawks (Buteo platypterus). Parameters collected included a white blood cell count and differential, hematocrit, and total protein concentration. Comparisons were made among species and among previously published reports of reference hematologic values in free-ranging birds or permanently captive birds. This is the first published report of reference values for Eastern screech owls, barred owls, and broad-winged hawks; and the first prerelease reference values for all species undergoing rehabilitation. These data can be used as a reference when developing release criteria for rehabilitated raptors.

  16. Habitat selection by owls in a seasonal semi-deciduous forest in southern Brazil.

    PubMed

    Menq, W; Anjos, L

    2015-11-01

    This paper tested the hypothesis that the structural components of vegetation have impact over the distribution of owl species in a fragment of a semi-deciduous seasonal forest. This paper also determined which vegetation variables contributed to the spatial distribution of owl species. It was developed in the Perobas Biological Reserve (PBR) between September and December 2011. To conduct the owl census, a playback technique was applied at hearing points distributed to cover different vegetation types in the study area. A total of 56 individual owls of six species were recorded: Tropical Screech-Owl (Megascops choliba), Black-capped Screech-Owl (Megascops atricapilla), Tawny-browed Owl (Pulsatrix koeniswaldiana), Ferruginous Pygmy-Owl (Glaucidium brasilianum), Mottled Owl (Strix virgata) and Stygian Owl (Asio stygius). The results suggest that the variables of vegetation structure have impact on the occurrence of owls. The canopy height, the presence of hollow trees, fallen trees and glades are the most important structural components influencing owl distribution in the sampled area.

  17. 3 CFR - Proposed Revised Habitat for the Spotted Owl: Minimizing Regulatory Burdens

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 3 The President 1 2013-01-01 2013-01-01 false Proposed Revised Habitat for the Spotted Owl..., 2012 Proposed Revised Habitat for the Spotted Owl: Minimizing Regulatory Burdens Memorandum for the...) proposed critical habitat for the northern spotted owl. The proposal is an initial step in...

  18. 77 FR 12985 - Proposed Revised Habitat for the Spotted Owl: Minimizing Regulatory Burdens

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ...#0;#0; ] Memorandum of February 28, 2012 Proposed Revised Habitat for the Spotted Owl: Minimizing... Department of the Interior (Department) proposed critical habitat for the northern spotted owl. The proposal... should be designated as critical habitat for the spotted owl, based on a full evaluation of all...

  19. 75 FR 63800 - Information Collection; Commercial Use of the Woodsy Owl Symbol

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... Forest Service Information Collection; Commercial Use of the Woodsy Owl Symbol AGENCY: Forest Service... currently approved information collection, Commercial Use of the Woodsy Owl Symbol. DATES: Comments must be...: Commercial Use of the Woodsy Owl Symbol. OMB Number: 0596-0087. Expiration Date of Approval: 04/30/2011....

  20. 77 FR 50526 - Proposed Safe Harbor Agreement for the Northern Spotted Owl, Skamania, Klickitat, and Yakima...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-08-21

    ... Fish and Wildlife Service Proposed Safe Harbor Agreement for the Northern Spotted Owl, Skamania... take of the threatened northern spotted owl (Strix occidentalis caurina) at a level that enables the... would also authorize incidental take of the spotted owl as a result of management activities during...

  1. 76 FR 37141 - Notice of Availability for Comment: Draft Recovery Plan, First Revision; Mexican Spotted Owl

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-06-24

    ...; Mexican Spotted Owl AGENCY: Fish and Wildlife Service, Interior. ACTION: Notice of availability; request... recovery plan, first revision, for the Mexican Spotted Owl (Strix occidentalis lucida) under the Endangered... will also accept any new information on the status of the Mexican spotted owl throughout its range...

  2. Clinical findings, lesions, and viral antigen distribution in great gray owls (Strix nebulosa) and barred owls (Strix varia) with spontaneous West Nile virus infection.

    PubMed

    Lopes, Hugo; Redig, Pat; Glaser, Amy; Armien, Anibal; Wünschmann, Arno

    2007-03-01

    West Nile Virus (WNV) infection manifests itself clinically a nd pathologically differently in various species of birds. The clinicopathologic findings and WNV antigen tissue distribution of six great gray owls (Strix nebulosa) and two barred owls (Strix varia) with WNV infection are described in this report. Great gray owls usually live in northern Canada, whereas the phylogenetically related barred owls are native to the midwestern and eastern United States and southern Canada. Naturally acquired WNV infection caused death essentially without previous signs of disease in the six great gray owls during a mortality event. Lesions of WNV infection we re dominated by hepatic and splenic necrosis, with evidence o f disseminatedintravascular coagulation in the great gray owls. WNV antigen was widely distributed in th e organs of the great gray owls and appeared totarget endothelial cells, macrophages, and hepatocytes. The barred owls represented two sporadic cases. They had neurologic disease with mental dullness that led to euthanasia. These birds had mild to moderate lymphoplasmacytic encephalitis with glial nodules and lymphoplasmacytic pectenitis. WNV antigen was sparse in barred owls and only present in a few brain neurons and renaltubular epithelial cells. The cause of the different manifestations of WNV disease in these fairly closely related owl species is uncertain.

  3. Otoacoustic interrelationships of the barn owl

    NASA Astrophysics Data System (ADS)

    Bergevin, Christopher; Manley, Geoffrey A.; Köppl, Christine

    2015-12-01

    Significant debate still exists about the biophysical mechanisms at work in otoacoustic emission (OAE) generation and how such may differ between mammals and non-mammals given gross morphological differences (e.g., existence of basilar membrane traveling waves, degree of tectorial membrane coupling). To further elucidate general principles at work, we examined the barn owl for interrelationships between spontaneous emissions (SOAEs) and those evoked using a single tone (SFOAEs). First, most ears exhibited SOAEs as a stable periodic `rippling' whose peak-to-peak spacing was relatively constant (˜0.4 kHz). Some ears showed substantially larger narrowband peaks, although their statistical distributions were highly noisy. Second, significant interactions between a low-level tone and SOAE activity were observed via an interference pattern as the tone frequency was swept. Using a suppression paradigm to extract SFOAEs as the residual, the magnitude exhibited a stable pattern of peaks and valleys unique to each ear. Third, SFOAE phase exhibited significant accumulation as frequency was swept, with a phase-gradient delay of approximately 2 ms that was constant across frequency. The amount of SFOAE phase accumulation between adjacent SOAE peaks tended to cluster about an integral number of cycles, as previously observed for humans. Taken together, our data suggest that the principles underlying how active hair cells work together (e.g., entrainment, phase coherence) are shared between widely different inner ear morphologies, leading to the generation of OAEs with similar properties.

  4. The type specimens of Hekstra's owl

    USGS Publications Warehouse

    Browning, M.R.

    1989-01-01

    Twenty-four new subspecies of New World owls of the genus Otus were named in a paper by Hekstra (1982b) issued 17 December 1982. These same new names also appeared in Hekstra's (1982a) unpublished thesis. The holotypes of the new taxa are in 10 different collections, most of which are in the United States. Incorrect information was published with regard to museum designation, museum number, and collecting locality of many of the holotypes. I here list the holotypes with their correct specimen label data. The species names are here presented in the sequence proposed by Marshall & King (1988). The subspecies are generally arranged from north to south. The type localities given are standardized, and the spellings are corrected where required. Abbreviations for museum designations are given under acknowledgments. The numbers following the names refer to the pages where the descriptions were given (Hekstra 1982b). Several of the scientific names proposed were spelled incorrectly and these have been emended in accord with Article 31c and Appendix D of the International Code (International Commission on Zoological Nomenclature 1985). Taxonomic comments are appended for a small number of Hekstra's proposed taxa. The remaining forms he named require further study.

  5. Do owls use torpor? Winter thermoregulation in free-ranging pearl-spotted owlets and African scops-owls.

    PubMed

    Smit, Ben; McKechnie, Andrew E

    2010-01-01

    Numerous avian taxa use torpor, which involves pronounced reductions in body temperature (T(b)) to below normothermic levels. However, the occurrence of this phenomenon in owls (Strigidae) remains largely unknown. We investigated winter patterns of thermoregulation in the crepuscular 80-g pearl-spotted owlet Glaucidium perlatum and the strictly nocturnal 61-g African scops-owl Otus senegalensis by obtaining telemetric measurements of skin temperature (T(skin)) from free-ranging individuals in the Kalahari Desert of southern Africa. Pearl-spotted owlets remained homeothermic throughout the study period, whereas African scops-owls routinely used shallow torpor, with T(skin) reduced by 3.3 degrees -8.6 degrees C (pooled mean, 5.3+/- 1.1 degrees C) below normothermic levels for 3-4 h after sunrise. The mean lowest T(skin) recorded in three African scops-owl individuals was 29.0 degrees C +/- 0.1 degrees C. The thermoregulatory differences between these two species may be related to their diets and activity patterns. African scops-owls are almost exclusively insectivorous and experience a marked reduction in food availability on cold winter nights. In contrast, pearl-spotted owlets have more flexible activity patterns and include larger or diurnal vertebrate prey in their diet.

  6. Complex state-dependent games between owls and gerbils.

    PubMed

    Berger-Tal, Oded; Mukherjee, Shomen; Kotler, Burt P; Brown, Joel S

    2010-03-01

    Predator-prey interactions are often behaviourally sophisticated games in which the predator and prey are players. Past studies teach us that hungrier prey take higher risks when foraging and that hungrier predators increase their foraging activity and are willing to take higher risks of injury. Yet no study has looked at the simultaneous responses of predator and prey to their own and each other's hunger levels in a controlled environment. We looked for evidence of a state-dependent game between predators and their prey by simultaneously manipulating the hunger state of barn owls, and Allenby's gerbils as prey. The owls significantly increased their activity when hungry. However, they did not appear to respond to changes in the hunger state of the gerbils. The gerbils reacted strongly to the owls' state, as well as to their own state when the risk was perceived as high. Our study shows that predator-prey interactions give rise to a complex state-dependent game.

  7. First observed instance of polygyny in Flammulated Owls

    USGS Publications Warehouse

    Linkhart, B.D.; Evers, E.M.; Megler, J.D.; Palm, E.C.; Salipante, C.M.; Yanco, S.W.

    2008-01-01

    We document the first observed instance of polygyny in Flammulated Owls (Otus flammeolus) and the first among insectivorous raptors. Chronologies of the male's two nests, which were 510 m apart, were separated by nearly 2 weeks. Each brood initially consisted of three owlets, similar to the mean brood size in monogamous pairs. The male delivered considerably fewer prey to the secondary nest, compared with prey-delivery rates at nests of monogamous males during the nestling period. Evidence suggested that all owlets fledged from the primary brood, but only one fledged from the secondary brood. We were uncertain of the cause of polygyny, but a possible explanation is the Hayman Fire shifted the operational sex ratio of the owls in favor of females. The extent of polygyny in Flammulated Owls may be limited by costs to the reproductive success of secondary females.

  8. Gongylonema sp. infection in the scops owl (Otus scops).

    PubMed

    Esperón, Fernando; Martín, María Paz; Lopes, Francisca; Orejas, Patricia; Carrero, Laura; Muñoz, María Jesús; Alonso, Raúl

    2013-12-01

    Since 1997, it has been observed that fledging scops owls often develop necrotic plaques in their oral cavities, which in severe cases can even affect bone tissue. This condition has been defined as a necrotic oropharyngeal disease based on gross lesions. In 2011 alone, thirty-five cases were identified at the Brinzal Owl Rescue Centre (Madrid, Spain), of which four were chosen to perform a complete diagnostic study. Histopathology was carried out in three cases and cytology in one case. Using morphological traits cytology identified two larvae as third-stage larvae of a Spiruridae nematode. Histology detected parasite sections in the mucosal epithelium of the mouth of one owl. In addition, four samples of mucosal lesions were subjected to a PCR amplification of the nematode ribosomal RNA gene using a pair of universal primers, three of which were positive. Of available sequences, the sequence obtained showed the closest affinity to that of Gongylonema pulchrum (97.8-98.0%). Clinical treatment was based on supportive therapy, the daily removal of caseous material from the oral cavity and the administration of fenbendazol (50mg/kg PO for 5 days). Approximately 60% of the affected scops owls that arrived at the rescue centre in 2011 were cured and released back into the wild. Clinical, pathological and molecular findings are consistent with Gongylonema sp. infection. Since no evidence of the presence of adult parasites was found, we suggest that these scops owls should be considered as accidental hosts. This is the first description of severe Gongylonema infection in fledgling scops owls, a disease can lead to starvation and death if proper treatment is not provided.

  9. Socialization of adult owl monkeys (Aotus sp.) in Captivity.

    PubMed

    Williams, Lawrence E; Coke, C S; Weed, J L

    2017-01-01

    Social housing has often been recommended as one-way to address the psychological well-being of captive non-human primates. Published reports have examined methods to socialize compatible animals by forming pairs or groups. Successful socialization rates vary depending on the species, gender, and environment. This study presents a retrospective look at pairing attempts in two species of owl monkeys, Aotus nancymaae and A. azarae, which live in monogamous pairs in the wild. The results of 477 pairing attempt conducted with captive, laboratory housed owl monkeys and 61 hr of behavioral observations are reported here. The greatest success pairing these owl monkeys occurred with opposite sex pairs, with an 82% success rate. Opposite sex pairs were more successful when females were older than males. Female-female pairs were more successful than male-male (MM) pairs (62% vs 40%). Successful pairs stayed together between 3 and 7 years before the animals were separated due to social incompatibility. Vigilance, eating, and sleeping during introductions significantly predicted success, as did the performance of the same behavior in both animals. The results of this analysis show that it is possible to give captive owl monkeys a social alternative even if species appropriate social partners (i.e., opposite sex partners) are not available. The focus of this report is a description of one potential way to enhance the welfare of a specific new world primate, the owl monkey, under laboratory conditions. More important is how the species typical social structure of owl monkeys in nature affects the captive management of this genus. Am. J. Primatol. 79:e22521, 2017. © 2015 Wiley Periodicals, Inc.

  10. Morphological Variations of Leading-Edge Serrations in Owls (Strigiformes)

    PubMed Central

    Weger, Matthias; Wagner, Hermann

    2016-01-01

    Background Owls have developed serrations, comb-like structures, along the leading edge of their wings. Serrations were investigated from a morphological and a mechanical point of view, but were not yet quantitatively compared for different species. Such a comparative investigation of serrations from species of different sizes and activity patterns may provide new information about the function of the serrations. Results Serrations on complete wings and on tenth primary remiges of seven owl species were investigated. Small, middle-sized, and large owl species were investigated as well as species being more active during the day and owls being more active during the night. Serrations occurred at the outer parts of the wings, predominantly at tenth primary remiges, but also on further wing feathers in most species. Serration tips were oriented away from the feather rachis so that they faced into the air stream during flight. The serrations of nocturnal owl species were higher developed as demonstrated by a larger inclination angle (the angle between the base of the barb and the rachis), a larger tip displacement angle (the angle between the tip of the serration and the base of the serration) and a longer length. Putting the measured data into a clustering algorithm yielded dendrograms that suggested a strong influence of activity pattern, but only a weak influence of size on the development of the serrations. Conclusions Serrations are supposed to be involved in noise reduction during flight and also depend on the aerodynamic properties that in turn depend on body size. Since especially nocturnal owls have to rely on hearing during prey capture, the more pronounced serrations of nocturnal species lend further support to the notion that serrations have an important function in noise reduction. The differences in shape of the serrations investigated indicate that a silent flight requires well-developed serrations. PMID:26934104

  11. Activated partial thromboplastin time of owl monkey (Aotus trivirgatus) plasma.

    PubMed

    Mrema, J E; Johnson, G S; Kelley, S T; Green, T J

    1984-06-01

    Owl monkey plasma samples produced short, reproducible activated partial thromboplastin times, similar to those obtained with samples from many other mammalian species. This was an apparent contradiction to an earlier report of long irreproducible activated partial thromboplastin times from owl monkey samples. The discrepant data could not be explained by differences in anticoagulants (citrate or oxalate), assay reagents (partial thromboplastin with either diatomaceous earth or ellagic acid), or activation incubation times (2, 5, or 10 minutes); nor could they be explained by differences in the monkeys' sex, age or previous experimental exposure to Plasmodium falciparum malaria.

  12. Eye shape and retinal topography in owls (Aves: Strigiformes).

    PubMed

    Lisney, Thomas J; Iwaniuk, Andrew N; Bandet, Mischa V; Wylie, Douglas R

    2012-01-01

    The eyes of vertebrates show adaptations to the visual environments in which they evolve. For example, eye shape is associated with activity pattern, while retinal topography is related to the symmetry or 'openness' of the habitat of a species. Although these relationships are well documented in many vertebrates including birds, the extent to which they hold true for species within the same avian order is not well understood. Owls (Strigiformes) represent an ideal group for the study of interspecific variation in the avian visual system because they are one of very few avian orders to contain species that vary in both activity pattern and habitat preference. Here, we examined interspecific variation in eye shape and retinal topography in nine species of owl. Eye shape (the ratio of corneal diameter to eye axial length) differed among species, with nocturnal species having relatively larger corneal diameters than diurnal species. All the owl species have an area of high retinal ganglion cell (RGC) density in the temporal retina and a visual streak of increased cell density extending across the central retina from temporal to nasal. However, the organization and degree of elongation of the visual streak varied considerably among species and this variation was quantified using H:V ratios. Species that live in open habitats and/or that are more diurnally active have well-defined, elongated visual streaks and high H:V ratios (3.88-2.33). In contrast, most nocturnal and/or forest-dwelling owls have a poorly defined visual streak, a more radially symmetrical arrangement of RGCs and lower H:V ratios (1.77-1.27). The results of a hierarchical cluster analysis indicate that the apparent interspecific variation is associated with activity pattern and habitat as opposed to the phylogenetic relationships among species. In seven species, the presence of a fovea was confirmed and it is suggested that all strigid owls may possess a fovea, whereas the tytonid barn owl (Tyto alba

  13. Thermal adaptiveness of plumage color in screech owls

    USGS Publications Warehouse

    Mosher, J.A.; Henny, C.J.

    1976-01-01

    We measured oxygen consumption rates of 8 Screech? Owls (4 red and 4 gray phase) at 4 environmental temperatures, -10?, -5?, 5?, and 15?C. These data demonstrated a significant difference in oxygen uptake between color phases at -10? and -5?C. This supports our hypothesis that red phase Screech Owls are restricted in their northern distribution by color-related metabolic differences from the gray phase birds. The problems of low red phase occurrence in the Gulf Coast states and their absence from the Western states remain to be studied.

  14. Auditory Processing, Plasticity, and Learning in the Barn Owl

    PubMed Central

    Peña, José L.; DeBello, William M.

    2011-01-01

    The human brain has accumulated many useful building blocks over its evolutionary history, and the best knowledge of these has often derived from experiments performed in animal species that display finely honed abilities. In this article we review a model system at the forefront of investigation into the neural bases of information processing, plasticity, and learning: the barn owl auditory localization pathway. In addition to the broadly applicable principles gleaned from three decades of work in this system, there are good reasons to believe that continued exploration of the owl brain will be invaluable for further advances in understanding of how neuronal networks give rise to behavior. PMID:21131711

  15. Comparison of Plasmodium falciparum infections in Panamanian and Colombian owl monkeys.

    PubMed

    Rossan, R N; Harper, J S; Davidson, D E; Escajadillo, A; Christensen, H A

    1985-11-01

    Parameters of blood-induced infections of the Vietnam Oak Knoll, Vietnam Smith, and Uganda Palo Alto strains of Plasmodium falciparum studied in 395 Panamanian owl monkeys in this laboratory between 1976-1984 were compared with those reported from another laboratory for 665 Colombian owl monkeys, studied between 1968-1975, and, at the time, designated Aotus trivirgatus griseimembra. The virulence of these strains was less in Panamanian than in Colombian owl monkeys, as indicated by lower mortality rates of the Panamanian monkeys during the first 30 days of patency. Maximum parasitemias of the Vietnam Smith and Uganda Palo Alto strain, in Panamanian owl monkeys dying during the first 15 days of patent infection, were significantly higher than in Colombian owl monkeys. Panamanian owl monkeys that survived the primary attack had significantly higher maximum parasitemias than the surviving Colombian owl monkeys. Peak parasitemias were attained significantly earlier after patency in Panamanian than in Colombian owl monkeys, irrespective of the strain of P. falciparum. More Panamanian than Colombian owl monkeys evidenced self-limited infection after the primary attack of either the Vietnam Smith or Uganda Palo Alto strain. The duration of the primary attacks and recrudescences were significantly shorter in Panamanian than in Colombian owl monkeys. Mean peak parasitemias during recrudescence were usually higher in Panamanian owl monkeys than in Colombian monkeys. Differences of infection parameters were probably attributable, in part, to geographical origin of the two monkey hosts and parasite strains.

  16. Effects of experimental removal of barred owls on population demography of northern spotted owls in Washington and Oregon—2015 progress report

    USGS Publications Warehouse

    Wiens, J. David; Dugger, Katie M.; Lewicki, Krista E.; Simon, David C.

    2016-03-14

    Evidence indicates that competition with newly established barred owls (Strix varia) is causing rapid declines in populations of northern spotted owls (Strix occidentalis caurina), and that the longterm persistence of spotted owls may be in question without additional management intervention. A pilot study in California showed that lethal removal of barred owls in combination with habitat conservation may be able to slow or even reverse population declines of spotted owls at local scales, but it remains unknown whether similar results can be obtained in larger areas with different forest conditions and where barred owls are more abundant. In 2015, we implemented a before-after-controlimpact (BACI) experimental design on two study areas in Oregon and Washington with at least 20 years of pre-treatment demographic data on spotted owls to determine if removal of barred owls can improve population trends of spatially associated spotted owls. Here we provide an overview of our research accomplishments and preliminary results in Oregon and Washington in 2015.

  17. Effects of experimental removal of barred owls on population demography of northern spotted owls in Washington and Oregon—2016 progress report

    USGS Publications Warehouse

    Wiens, J. David; Dugger, Katie M.; Lewicki, Krista E.; Simon, David C.

    2017-04-13

    Evidence indicates that competition with invasive barred owls (Strix varia) is causing rapid declines in populations of northern spotted owls (S. occidentalis caurina), and that the long-term persistence of spotted owls may be in question without additional management intervention. A pilot study in California showed that removal of barred owls in combination with habitat conservation may be able to slow or even reverse population declines of spotted owls at local scales, but it remains unknown whether similar results can be obtained in areas with different forest conditions and a greater density of barred owls. In 2015, we implemented a before-after-control-impact (BACI) experimental design on three study areas in Oregon and Washington with at least 20 years of pre-treatment demographic data on spotted owls to determine if removal of barred owls can improve localized population trends of spotted owls. Here, we report on research accomplishments and preliminary results from the first 21 months (March 2015–December 2016) of the planned 5-year experiment.

  18. Serologic evidence of exposure of raptors to influenza A virus.

    PubMed

    Redig, Patrick T; Goyal, Sagar M

    2012-06-01

    Serum or plasma samples from raptors that prey or scavenge upon aquatic birds were tested by a commercially available blocking enzyme-linked immunosorbent assay for the evidence of antibodies to influenza A virus. Samples were taken from birds (n = 616) admitted to two rehabilitation centers in the United States. In addition, samples from 472 migrating peregrine falcons (Falco peregrinus) trapped on autumnal and vernal migrations for banding purposes were also tested. Only bald eagles were notably seropositive (22/406). One each of peregrine falcon, great horned owl (Bubo virginianus), and Cooper's hawk (Accipiter cooperi) from a total of 472, 81, and 100, respectively, were also positive. None of the turkey vultures (n = 21) or black vultures (n = 8) was positive. No clinical signs referable to avian influenza were seen in any bird at the time of capture. These data indicate that, among raptors, bald eagles do have exposure to influenza A viruses.

  19. Case histories of bald eagles and other raptors killed by organophosphorus insecticides topically applied to livestock.

    PubMed

    Henny, C J; Kolbe, E J; Hill, E F; Blus, L J

    1987-04-01

    Since 1982 when secondary poisoning of a red-tailed hawk (Buteo jamaicensis) was documented following the recommended use of famphur applied topically to cattle, the Patuxent Wildlife Research Center has tested dead birds of prey for poisoning by famphur and other pour-on organophosphorus (OP) insecticides. Brain cholinesterase (ChE) activity was first determined, then if ChE was depressed greater than or equal to 50%, stomach and/or crop contents were evaluated for anti-ChE compounds. This report presents the circumstances surrounding the OP-caused deaths of eight bald eagles (Haliaeetus leucocephalus), two red-tailed hawks, and one great horned owl (Bubo virginianus) between March 1984 and March 1985. OP poisoning of raptors by pour-on insecticides in the United States is widespread, but its magnitude is unknown.

  20. Case histories of bald eagles and other raptors killed by organophosphorus insecticides topically applied to livestock

    USGS Publications Warehouse

    Henny, C.J.; Kolbe, E.J.; Hill, E.F.; Blus, L.J.

    1987-01-01

    Since 1982 when secondary poisoning of a red-tailed hawk (Buteo jamaicensis) was documented following the recommended use of famphur applied topically to cattle, the Patuxent Wildlife Research Center has tested dead birds of prey for poisoning by famphur and other pour-on organophosphorus (OP) insecticides. Brain cholinesterase (ChE) activity was first determined, then if ChE was depressed greater than or equal to 50%, stomach and/or crop contents were evaluated for anti-ChE compounds. This report presents the circumstances surrounding the OP-caused deaths of eight bald eagles (Haliaeetus leucocephalus), two red-tailed hawks, and one great horned owl (Bubo virginianus) between March 1984 and March 1985. OP poisoning of raptors by pour-on insecticides in the United States is widespread, but its magnitude is unknown.

  1. Quantifying space use of breeders and floaters of a long-lived species using individual movement data

    NASA Astrophysics Data System (ADS)

    Penteriani, Vincenzo; del Mar Delgado, Maria; Campioni, Letizia

    2015-06-01

    To date, animal movement studies have mostly analysed the movement behaviours of individuals at specific times of their lives, but we lack detailed information on how individual movements may be affected by the various and different changes that individuals experience throughout their life (e.g. life history phases, experience, age). Here, we attempt to identify differences in home range and movement behaviour between two different statuses, disperser vs. breeder, of a long-lived species (the eagle owl Bubo bubo). Information on home range and movement behaviour between different stages of an individual life are crucial for species conservation and management, as well as for basic knowledge on space use and rhythm of activity. Does the transition from an exploratory stage to moving within more familiar surroundings call for changes in the movement behaviour? We observed notable differences during the two stages of the owls' lives, with individuals having different home range behaviours and rhythms of activity depending on their social status. Significant differences in home range behaviour between the sexes began only with the acquisition of a breeding site. Breeders showed larger home ranges than dispersing individuals, although nightly variation of home ranges size was higher for dispersers than for breeders. Finally, dispersers were active throughout the night, whereas breeders displayed a less active movement phase at both the beginning and end of the night. Our results demonstrate it is important to consider individual variations in space use and movement behaviour due to the different life history phases that they attain during their lifetime. The knowledge of the different needs of a species across life stages may represent an important tool for species conservation because each phase of an individual life may need different requirements.

  2. Owls see in stereo much like humans do.

    PubMed

    van der Willigen, Robert F

    2011-06-10

    While 3D experiences through binocular disparity sensitivity have acquired special status in the understanding of human stereo vision, much remains to be learned about how binocularity is put to use in animals. The owl provides an exceptional model to study stereo vision as it displays one of the highest degrees of binocular specialization throughout the animal kingdom. In a series of six behavioral experiments, equivalent to hallmark human psychophysical studies, I compiled an extensive body of stereo performance data from two trained owls. Computer-generated, binocular random-dot patterns were used to ensure pure stereo performance measurements. In all cases, I found that owls perform much like humans do, viz.: (1) disparity alone can evoke figure-ground segmentation; (2) selective use of "relative" rather than "absolute" disparity; (3) hyperacute sensitivity; (4) disparity processing allows for the avoidance of monocular feature detection prior to object recognition; (5) large binocular disparities are not tolerated; (6) disparity guides the perceptual organization of 2D shape. The robustness and very nature of these binocular disparity-based perceptual phenomena bear out that owls, like humans, exploit the third dimension to facilitate early figure-ground segmentation of tangible objects.

  3. From optics to attention: visual perception in barn owls.

    PubMed

    Harmening, Wolf M; Wagner, Hermann

    2011-11-01

    Barn owls are nocturnal predators which have evolved specific sensory and morphological adaptations to a life in dim light. Here, some of the most fundamental properties of spatial vision in barn owls are reviewed. The eye with its tubular shape is rigidly integrated in the skull so that eye movements are very much restricted. The eyes are oriented frontally, allowing for a large binocular overlap. Accommodation, but not pupil dilation, is coupled between the two eyes. The retina is rod dominated and lacks a visible fovea. Retinal ganglion cells form a marked region of highest density that extends to a horizontally oriented visual streak. Behavioural visual acuity and contrast sensitivity are poor, although the optical quality of the ocular media is excellent. A low f-number allows high image quality at low light levels. Vernier acuity was found to be a hyperacute percept. Owls have global stereopsis with hyperacute stereo acuity thresholds. Neurons of the visual Wulst are sensitive to binocular disparities. Orientation based saliency was demonstrated in a visual-search experiment, and higher cognitive abilities were shown when the owl's were able to use illusory contours for object discrimination.

  4. tOWL: a temporal Web Ontology Language.

    PubMed

    Milea, Viorel; Frasincar, Flavius; Kaymak, Uzay

    2012-02-01

    Through its interoperability and reasoning capabilities, the Semantic Web opens a realm of possibilities for developing intelligent systems on the Web. The Web Ontology Language (OWL) is the most expressive standard language for modeling ontologies, the cornerstone of the Semantic Web. However, up until now, no standard way of expressing time and time-dependent information in OWL has been provided. In this paper, we present a temporal extension of the very expressive fragment SHIN(D) of the OWL Description Logic language, resulting in the temporal OWL language. Through a layered approach, we introduce three extensions: 1) concrete domains, which allow the representation of restrictions using concrete domain binary predicates; 2) temporal representation , which introduces time points, relations between time points, intervals, and Allen's 13 interval relations into the language; and 3) timeslices/fluents, which implement a perdurantist view on individuals and allow for the representation of complex temporal aspects, such as process state transitions. We illustrate the expressiveness of the newly introduced language by using an example from the financial domain.

  5. The "Owl Trail"--A Sensory Awareness Rope Trail

    ERIC Educational Resources Information Center

    Kauffman, Robert B.

    1978-01-01

    Constructed and experienced by students engaged in an outdoor education class at East Stroudsburg State College in Pennsylvania, the "Owl Trail" is a self guided rope trail (600 yards in length) employing such devices as sensory corrals, bridges, and "go to" ropes (ropes attached to the main rope which provide side trip…

  6. Diet of western Burrowing Owls wintering in southern Texas

    USGS Publications Warehouse

    Littles, C.J.; Williford, D.; Skoruppa, M.K.; Woodin, M.C.; Hickman, G.C.

    2007-01-01

    Winter diets of the western Burrowing Owl (Athene cunicularia hypugaea) are little known. We determined the diet of western Burrowing Owls wintering in southern Texas by analyzing the contents of 182 pellets collected over four winters (1999-2000, 2001-2002, 2002-2003, and 2003-2004) in three habitat types (agricultural, mainland grassland, and barrier island). Remains of a total of 7476 prey items were recovered, 98% of which were arthropods. Gryllidae (crickets) formed the largest component (50%) of the prey, followed by lepidopteran larvae (13%), beetles (8%), spiders (7%), and earwigs (6%). Although vertebrates, primarily small mammals and birds, represented only 2% of prey items by number, they represented most (71%) of the biomass. Northern pygmy mice (Baiomys taylori) and fulvous harvest mice (Reithrodontomys fulveccens) were the two most frequently consumed vertebrate species. In all habitats, arthropods, especially orthopterans, were the primary prey item by number, whereas vertebrates, primarily small mammals, were the most important by biomass. Greater consumption of arthropods by Burrowing Owls in agricultural areas may be a factor contributing to owl use of these highly altered environments. ?? 2007 The Raptor Research Foundation, Inc.

  7. Online Writing Labs (OWLs): A Taxonomy of Options and Issues.

    ERIC Educational Resources Information Center

    Harris, Muriel; Pemberton, Michael

    1995-01-01

    Offers an overview and schema for understanding frequently used network technologies available for Online Writing Labs (OWLs)--electronic mail, gopher, World Wide Web, newsgroups, synchronous chat systems, and automated file retrieval systems. Considers ways writing centers' choices among these technologies are impacted by user access, network…

  8. Night Owl: Maryland's After-Hours Reference Service.

    ERIC Educational Resources Information Center

    Duke, Deborah C.

    1994-01-01

    Discusses "Night Owl," a Maryland public library's after hours telephone reference service. Issues include project start-up, user profiles, types of questions, volume, after hours reference accessibility, security, costs, service limits, publicity, staffing, and employee turnover. Similar services in other states are cited. (Contains six…

  9. Comparative study of visual pathways in owls (Aves: Strigiformes).

    PubMed

    Gutiérrez-Ibáñez, Cristián; Iwaniuk, Andrew N; Lisney, Thomas J; Wylie, Douglas R

    2013-01-01

    Although they are usually regarded as nocturnal, owls exhibit a wide range of activity patterns, from strictly nocturnal, to crepuscular or cathemeral, to diurnal. Several studies have shown that these differences in the activity pattern are reflected in differences in eye morphology and retinal organization. Despite the evidence that differences in activity pattern among owl species are reflected in the peripheral visual system, there has been no attempt to correlate these differences with changes in the visual regions in the brain. In this study, we compare the relative size of nuclei in the main visual pathways in nine species of owl that exhibit a wide range of activity patterns. We found marked differences in the relative size of all visual structures among the species studied, both in the tectofugal and the thalamofugal pathway, as well in other retinorecipient nuclei, including the nucleus lentiformis mesencephali, the nucleus of the basal optic root and the nucleus geniculatus lateralis, pars ventralis. We show that the barn owl (Tyto alba), a species widely used in the study of the integration of visual and auditory processing, has reduced visual pathways compared to strigid owls. Our results also suggest there could be a trade-off between the relative size of visual pathways and auditory pathways, similar to that reported in mammals. Finally, our results show that although there is no relationship between activity pattern and the relative size of either the tectofugal or the thalamofugal pathway, there is a positive correlation between the relative size of both visual pathways and the relative number of cells in the retinal ganglion layer.

  10. Factors affecting detection of burrowing owl nests during standardized surveys

    USGS Publications Warehouse

    Conway, C.J.; Garcia, V.; Smith, M.D.; Hughes, K.

    2008-01-01

    Identifying causes of declines and evaluating effects of management practices on persistence of local populations of burrowing owls (Athene cunicularia) requires accurate estimates of abundance and population trends. Moreover, regulatory agencies in the United States and Canada typically require surveys to detect nest burrows prior to approving developments or other activities in areas that are potentially suitable for nesting burrowing owls. In general, guidelines on timing of surveys have been lacking and surveys have been conducted at different times of day and in different stages of the nesting cycle. We used logistic regression to evaluate 7 factors that could potentially affect probability of a surveyor detecting a burrowing owl nest. We conducted 1,444 detection trials at 323 burrowing owl nests within 3 study areas in Washington and Wyoming, USA, between February and August 2000-2002. Detection probability was highest during the nestling period and increased with ambient temperature. The other 5 factors that we examined (i.e., study area, time of day, timing within the breeding season, wind speed, % cloud cover) interacted with another factor to influence detection probability. Use of call-broadcast surveys increased detection probability, even during daylight hours when we detected >95% of owls visually. Optimal timing of surveys will vary due to differences in breeding phenology and differences in nesting behavior across populations. Nevertheless, we recommend ???3 surveys per year: one that coincides with the laying and incubation period, another that coincides with the early nestling period, and a third that coincides with the late nestling period. In northern latitudes, surveys can be conducted throughout the day.

  11. How barn owls (Tyto alba) visually follow moving voles (Microtus socialis) before attacking them.

    PubMed

    Fux, Michal; Eilam, David

    2009-09-07

    The present study focused on the movements that owls perform before they swoop down on their prey. The working hypothesis was that owl head movements reflect the capacity to efficiently follow visually and auditory a moving prey. To test this hypothesis, five tame barn owls (Tyto alba) were each exposed 10 times to a live vole in a laboratory setting that enabled us to simultaneously record the behavior of both owl and vole. Bi-dimensional analysis of the horizontal and vertical projections of movements revealed that owl head movements increased in amplitude parallel to the vole's direction of movement (sideways or away from/toward the owl). However, the owls also performed relatively large repetitive horizontal head movements when the voles were progressing in any direction, suggesting that these movements were critical for the owl to accurately locate the prey, independent of prey behavior. From the pattern of head movements we conclude that owls orient toward the prospective clash point, and then return to the target itself (the vole) - a pattern that fits an interception rather than a tracking mode of following a moving target. The large horizontal component of head movement in following live prey may indicate that barn owls either have a horizontally narrow fovea or that these movements serve in forming a motion parallax along with preserving image acuity on a horizontally wide fovea.

  12. Population dynamics of spotted owls in the Sierra Nevada, California

    USGS Publications Warehouse

    Blakesley, J.A.; Seamans, M.E.; Conner, M.M.; Franklin, A.B.; White, Gary C.; Gutierrez, R.J.; Hines, J.E.; Nichols, J.D.; Munton, T.E.; Shaw, D.W.H.; Keane, J.J.; Steger, G.N.; McDonald, T.L.

    2010-01-01

    The California spotted owl (Strix occidentalis occidentalis) is the only spotted owl subspecies not listed as threatened or endangered under the United States Endangered Species Act despite petitions to list it as threatened. We conducted a meta-analysis of population data for 4 populations in the southern Cascades and Sierra Nevada, California, USA, from 1990 to 2005 to assist a listing evaluation by the United States Fish and Wildlife Service. Our study areas (from N to S) were on the Lassen National Forest (LAS), Eldorado National Forest (ELD), Sierra National Forest (SIE), and Sequoia and Kings Canyon National Parks (SKC). These study areas represented a broad spectrum of habitat and management conditions in these mountain ranges. We estimated apparent survival probability, reproductive output, and rate of population change for spotted owls on individual study areas and for all study areas combined (meta-analysis) using model selection or model-averaging based on maximum-likelihood estimation. We followed a formal protocol to conduct this analysis that was similar to other spotted owl meta-analyses. Consistency of field and analytical methods among our studies reduced confounding methodological effects when evaluating results. We used 991 marked spotted owls in the analysis of apparent survival. Apparent survival probability was higher for adult than for subadult owls. There was little difference in apparent survival between male and female owls. Model-averaged mean estimates of apparent survival probability of adult owls varied from 0.811 ?? 0.021 for females at LAS to 0.890 ?? 0.016 for males at SKC. Apparent survival increased over time for owls of all age classes at LAS and SIE, for adults at ELD, and for second-year subadults and adults at SKC. The meta-analysis of apparent survival, which included only adult owls, confirmed an increasing trend in survival over time. Survival rates were higher for owls on SKC than on the other study areas. We analyzed data

  13. The Dusk Chorus from an Owl Perspective: Eagle Owls Vocalize When Their White Throat Badge Contrasts Most

    PubMed Central

    Penteriani, Vincenzo; Delgado, Maria del Mar

    2009-01-01

    Background An impressive number of studies have investigated bird vocal displays, and many of them have tried to explain the widespread phenomenon of the so-called dawn and dusk chorus, the sunrise and sunset peaks in bird song output. As many as twelve non-exclusive hypotheses have been proposed to explain why twilight peaks in vocal display might be advantageous; but, even after more than two decades of study, the basis underlying the dusk and dawn chorus is still unclear. Moreover, to date, the majority of studies on this topic have focused on songbirds. Methodology/Principal Findings We investigate here a novel hypothesis on why nocturnal birds with patches of white feathers call at twilight. We propose that white plumage patches and the timing of visual signaling have co-evolved to maximize the effectiveness of social communication such as the dusk chorus. This hypothesis centers on the recent discovery that eagle owls can adopt specific forms of visual signaling and is supported by the observation that adult eagle owls possess a white throat badge that is only visible during vocal displays. By monitoring the calling of eagle owls at dusk, a peak time for bird call output, we found that white throat badges contrasted most with the surrounding background during the owls' twilight chorusing. Conclusions/Significance Crepuscular and nocturnal species appear to have evolved white patches that, shown in association with vocal displays, allow them to communicate in dark surroundings. The evolution of a white badge that operates jointly with call displays at dawn and dusk may be relevant to the eagle owls' social dynamics. Our explanation for the dusk chorus may possibly represent an overlooked but common pattern of signaling among crepuscular and nocturnal birds that combine patches of white feathers with twilight displays. Furthermore, our findings could be relevant to songbirds that breed in dark forest habitats and have contrasting white badges, as well as birds

  14. [Brant goose colonies near snowy owls: internest distances in relation to lemming and arctic fox abundance].

    PubMed

    Kharitonov, S P; Volkov, A E; Willems, F; van Kleef, H; Klaassen, R H G; Nowak, D J; Nowak, A I; Bublichenko, A G

    2008-01-01

    Brant goose colonies around snowy owl nests have been studied near Meduza Bay (73 degrees 21' N, 80 degrees 32' E) and in the lower reaches of the Uboinaya River (73 degrees 37' N, 82 degrees 10' E), the northwestern Taimyr Peninsula, from 1999 to 2006. All brant nests within 680 m from an owl nest have been regarded as an individual colony. The results show that the area of the colony is always larger than the guarded area around the owl nest. In years of high abundance of lemmings, brant geese nest generally closer to the owl nest than in years of high abundance. When arctic foxes are abundant, however, brant geese nest significantly closer to owls than when the foxes are scarce, irrespective of lemming abundance. The mechanism of brant colony formation around owl nests is based on a number of stimuli.

  15. A Process for the Representation of openEHR ADL Archetypes in OWL Ontologies.

    PubMed

    Porn, Alex Mateus; Peres, Leticia Mara; Didonet Del Fabro, Marcos

    2015-01-01

    ADL is a formal language to express archetypes, independent of standards or domain. However, its specification is not precise enough in relation to the specialization and semantic of archetypes, presenting difficulties in implementation and a few available tools. Archetypes may be implemented using other languages such as XML or OWL, increasing integration with Semantic Web tools. Exchanging and transforming data can be better implemented with semantics oriented models, for example using OWL which is a language to define and instantiate Web ontologies defined by W3C. OWL permits defining significant, detailed, precise and consistent distinctions among classes, properties and relations by the user, ensuring the consistency of knowledge than using ADL techniques. This paper presents a process of an openEHR ADL archetypes representation in OWL ontologies. This process consists of ADL archetypes conversion in OWL ontologies and validation of OWL resultant ontologies using the mutation test.

  16. Burrowing owl nesting productivity: A comparison between artificial and natural burrows on and off golf courses

    USGS Publications Warehouse

    Smith, M.D.; Conway, C.J.; Ellis, L.A.

    2005-01-01

    Burrowing owl (Athene cunicularia) populations are declining in many portions of their range, and lack of suitable nesting burrows is thought to be one reason for observed declines. Burrowing owls are attracted to golf courses because the birds generally nest and forage in short-grass, open areas, yet golf courses seldom have suitable nesting burrows. We examined the efficacy of installing artificial nesting burrows on golf courses as a way to help restore local burrowing owl populations. From 2001-2004 we monitored over 175 natural burrows off golf courses, 14 natural burrows on golf courses, 86 artificial burrows off golf courses, and 130 artificial burrows on golf courses. Owls located and used 8 of the 130 artificial burrows installed on golf courses (4 were used as nests). Owls selected burrows that were closer to existing natural burrows, farther from maintained areas (areas receiving turf maintenance by golf course staff), and farther from sprinkler heads. All 4 of the artificial burrows used as nests successfully fledged young, and annual site fidelity for owls nesting on golf courses was higher than for owls nesting off golf courses. However, annual fecundity of owls nesting on golf courses was lower than that of owls nesting off golf courses. If golf courses have sufficiently large nonmaintained areas and there are nesting owls nearby, course managers potentially can help in restoring local burrowing owl populations by installing artificial nesting burrows on the periphery of the course. However, the low fecundity on golf courses reported here should be more thoroughly examined before artificial burrows are used to attract owls to golf courses.

  17. Multiscale habitat selection by burrowing owls in black-tailed prairie dog colonies

    USGS Publications Warehouse

    Lantz, S.J.; Conway, C.J.; Anderson, S.H.

    2007-01-01

    Some populations of western burrowing owls (Athene cunicularia hypugaea) have declined in recent decades. To design and implement effective recovery efforts, we need a better understanding of how distribution and demographic traits are influenced by habitat quality. To this end, we measured spatial patterns of burrowing owl breeding habitat selection within black-tailed prairie dog (Cynomys ludovicianus) colonies in northeastern Wyoming, USA. We compared burrow-, site-, colony-, and landscape-scale habitat parameters between burrowing owl nest burrows (n = 105) and unoccupied burrows (n = 85). We sampled 4 types of prairie dog colonies: 1) owl-occupied, active with prairie dogs (n = 16); 2) owl-occupied, inactive (n = 13); 3) owl-unoccupied, active (n = 14); and 4) owl-unoccupied, inactive (n = 14). We used an information-theoretic approach to examine a set of candidate models of burrowing owl nest-site selection. The model with the most support included variables at all 4 spatial scales, and results were consistent among the 4 types of prairie dog colonies. Nest burrows had longer tunnels, more available burrows within 30 m, and less shrub cover within 30 m, more prairie dog activity within 100 m, and were closer to water than unoccupied burrows. The model correctly classified 76% of cases, all model coefficients were stable, and the model had high predictive ability. Based on our results, we recommend actions to ensure persistence of the remaining prairie dog colonies as an important management strategy for burrowing owl conservation in the Great Plains of North America.

  18. Home range characteristics of Mexican Spotted Owls in the Rincon Mountains, Arizona

    USGS Publications Warehouse

    Willey, David W.; Van Riper, Charpes III

    2014-01-01

    We studied a small isolated population of Mexican Spotted Owls (Strix occidentalis lucida) from 1996–1997 in the Rincon Mountains of Saguaro National Park, southeastern Arizona, USA. All mixed-conifer and pine-oak forest patches in the park were surveyed for Spotted Owls, and we located, captured, and radio-tagged 10 adult birds representing five mated pairs. Using radio-telemetry, we examined owl home range characteristics, roost habitat, and monitored reproduction within these five territories. Breeding season (Mar–Sep) home range size for 10 adult owls (95% adaptive kernel isopleths) averaged 267 ha (±207 SD), and varied widely among owls (range 34–652 ha). Mean home range size for owl pairs was 478 ha (±417 ha SD), and ranged from 70–1,160 ha. Owls that produced young used smaller home ranges than owls that had no young. Six habitat variables differed significantly between roost and random sites, including: percent canopy cover, number of trees, number of vegetation layers, average height of trees, average diameter of trees, and tree basal area. Radio-marked owls remained in their territories following small prescribed management fires within those territories, exhibiting no proximate effects to the presence of prescribed fire.

  19. Avian trichomonosis in spotted owls (Strix occidentalis): Indication of opportunistic spillover from prey.

    PubMed

    Rogers, Krysta H; Girard, Yvette A; Woods, Leslie; Johnson, Christine K

    2016-12-01

    Avian trichomonosis, caused by the flagellated protozoan parasite Trichomonas gallinae, has variable pathogenicity among bird species ranging from asymptomatic infections to severe disease periodically manifesting in epidemic mortality. Traditionally, columbids are identified as highly susceptible to infection with occasional spillover into raptors that prey on infected birds. We identified avian trichomonosis in two dead California spotted owls (Strix occidentalis occidentalis) and three dead northern spotted owls (S. o. caurina) in California during 2011-2015; infection was confirmed in four owls by PCR. Pathologic lesions associated with trichomonosis in the owls included caseonecrotic lesions of the upper palate accompanied by oropharyngitis, cellulitis, myositis, and/or sinusitis. Spotted owls are known to mainly feed on small mammals; therefore, the source of infection as well as the significance of the disease in spotted owls is unclear. These owl trichomonosis cases coincided temporally and spatially with three trichomonosis epidemics in band-tailed pigeons (Patagioenas fasciata monilis). The same parasite, T. gallinae subtype A2, was isolated from the spotted owls and band-tailed pigeons, suggesting the owls became infected when opportunistically feeding on pigeons during mortality events. Avian trichomonosis is an important factor in the decline of the Pacific Coast band-tailed pigeon population with near-annual mortality events during the last 10 years and could have conservation implications for raptor species at risk, particularly those that are facing multiple threats.

  20. Airborne ocean water lidar (OWL) real time processor (RTP)

    NASA Astrophysics Data System (ADS)

    Hryszko, M.

    1995-03-01

    The Hyperflo Real Time Processor (RTP) was developed by Pacific-Sierra Research Corporation as a part of the Naval Air Warfare Center's Ocean Water Lidar (OWL) system. The RTP was used for real time support of open ocean field tests at Barbers Point, Hawaii, in March 1993 (EMERALD I field test), and Jacksonville, Florida, in July 1994 (EMERALD I field test). This report describes the system configuration, and accomplishments associated with the preparation and execution of these exercises. This document is intended to supplement the overall test reports and provide insight into the development and use of the PTP. A secondary objective is to provide basic information on the capabilities, versatility and expandability of the Hyperflo RTP for possible future projects. It is assumed herein that the reader has knowledge of the OWL system, field test operations, general lidar processing methods, and basic computer architecture.

  1. Nanoscale Bio-Molecular Control Using EC-OWLS

    SciTech Connect

    Bearinger, J P; Voros, J; Hubbell, J A; Textor, M

    2002-11-20

    A recently developed technique termed ''Electrochemical Optical Waveguide Lightmode Spectroscopy'' (EC-OWLS) [1] combines evanescent-field optical sensing with electrochemical control of surface adsorption processes. Initial EC-OWLS investigations efficiently monitored molecular surface adsorption and layer thickness changes of an adsorbed polymer layer examined in situ as a function of potential applied to a waveguide1. A layer of indium tin oxide (ITO) served as both a high refractive index waveguide for optical sensing, and a conductive electrode; an electrochemical flow-through fluid cell incorporated working, reference and counter electrodes. Poly(L-lysine)-grafted-poly(ethylene glycol) (PLL-g-PEG) served as a model, polycation adsorbate. Results indicate that adsorption and desorption of PLL-g-PEG from aqueous buffer are a function of applied potential, and that binding events subsequent to PLL-g-PEG functionalization are dependent on reorganization in the molecular adlayer.

  2. Endangered Species. Spotted Owl Petition Evaluation Beset by Problems

    DTIC Science & Technology

    1989-02-01

    5Population viability analysis is a technique for determining the likelihood of species extinction under various conditions. Page 8 GAO/RCED-89-79 Spotted...alternative would lead to the species ’ extinction in the foresee- able future. * The draft also evaluated the five conditions the act requires to be...accepted a petition from an environmental organi- zation to list the spotted owl as an endangered species under the Endan- gered Species Act. Pursuant to

  3. Observing the Ultrahigh Energy Universe with OWL Eyes

    NASA Technical Reports Server (NTRS)

    Stecker, F. W.; Krizmanic, J. F.; Barbier, L. M.; Loh, E.; Mitchell, J. W.; Sokolsky, P.; Streitmatter, R. E.

    2004-01-01

    The goal of the Orbiting Wide-field Light-collectors (0WL) mission is to study the origin and physics of the highest energy particles known in nature, the ultra- high energy cosmic rays (UHECRs). The OWL mission consists of telescopes with UV sensitive cameras on two satellites operating in tandem to view in stereo the development of the giant particle showers induced in the Earth s atmosphere by UHECRs. This paper discusses the characteristics of the 0WL mission.

  4. Miniature Optical Wide-Angle-Lens Startracker (Mini-OWLS)

    NASA Technical Reports Server (NTRS)

    Miller, Rick; Coulter, Joe E.; Levine, Seymour

    1993-01-01

    This paper provides a brief overview of the design considerations and the current status of the Miniature Optical Wide-Angle Lens Startracker Program. Mini-OWLS offers a revolutionary alternative to the conventional startracker. It is a small, lightweight, low cost, high performance startracker that can be used in a variety of applications including calibration and alignment of Inertial Measurement Units (IMU's) Mini-OWLS makes use of a strap down design incorporating Holographic Optical Elements (HOES) in place of conventional optics. HOES can be multiplexed so that the same aperture can be used for multiple separate optical paths looking in several directions simultaneously without startracker rotation. Additionally, separate Schmidt corrector plates are not required to compensate for spherical aberration. The optical assembly, or what would normally be considered as the telescope, is less than 20 cc in volume, weighs less than 55 grams, and contains the equivalent of three individual telescopes. Each one has a 4 deg Field of View (FOV) with a field of regard of 48 square degrees. Mini-OWLS has a bandwidth of approximately 300 nm in or near the visible wavelength. The projected resolution of the startracker is 5 to 10 arcseconds, depending on the centroiding algorithm used. The Mini-OWLS program was initiated last year and represents a miniaturized version of a similar design for aeronautical applications. The contract is managed by Wright Laboratory, Air Force Systems Command, Wright-Patterson AFB, Ohio, with funding from the Strategic Defense Initiative Organization through Eglin AFB. The initial phase of the program is to build and test a development unit. The second phase is to integrate the startracker with the Charles Stark Draper Laboratory Micromechanical Inertial Guidance System (MIGS) and the Signal Processing Packaging Design (SPPD) being developed by Texas Instruments. The preliminary design review was conducted in November 1991. Three-axes prototype

  5. Diets and foraging behavior of northern Spotted Owls in Oregon

    USGS Publications Warehouse

    Forsman, E.D.; Anthony, R.G.; Meslow, E.C.; Zabel, C.J.

    2004-01-01

    We describe local, regional, and annual variation in diets of northern Spotted Owls (Strix occidentalis caurina) in Oregon based on 24 497 prey collected at 1118 owl territories in 1970-2003. The sample included 91.5% mammals, 4.3% birds, 4.1% insects, and 0.1% other prey. The diet included ???131 species, including 49 mammals, 41 birds, 3 reptiles, 1 frog, 1 crayfish, 1 scorpion, 2 snails, and 33 species of insects. On average, 91.9 ?? 0.3% (SE) of prey in the diet were nocturnal animals, 3.3 ?? 0.2% were diurnal, and 4.8 ?? 0.2% were active both day and night. Of the prey captured, 50.5 ?? 0.8% were arboreal, 18.7 ?? 0.7% were scansorial, 4.8 ?? 0.2% were aerial, and 26.0 = 0.7% were terrestrial. Mean mass of prey was 116.6 ?? 6.5 g. Diets varied among owl territories, geographic regions, and years; but were generally dominated by four to six species of nocturnal mammals, including northern flying squirrels (Glaucomys sabrinus), woodrats (Neotoma fuscipes and N. cinerea), red tree voles (Arborimus longicaudus), western red-backed voles (Clethrionomys californicus), deer mice (Peromyscus maniculatus), or gophers (Thomomys spp.). Estimates of dietary evenness were low, indicating diets dominated by a few species of mammals. Forest management practices that produce healthy populations of arboreal and scansorial mammals such as flying squirrels, woodrats, and red tree voles should benefit northern Spotted Owls in Oregon and Washington. ?? 2004 The Raptor Research Foundation, Inc.

  6. Renal pathology in owl monkeys in Plasmodium falciparum vaccine trials.

    PubMed

    Iseki, M; Broderson, J R; Pirl, K G; Igarashi, I; Collins, W E; Aikawa, M

    1990-08-01

    Renal specimens of 16 owl monkeys (Aotus vociferans) were studied by light microscopy and immunohistochemistry during a vaccine trial with recombinant proteins of the ring-infected erythrocyte surface antigen (RESA) of Plasmodium falciparum. Deposition of IgG, C3, and P. falciparum antigens in the mesangium was demonstrated by the peroxidase anti-peroxidase (PAP) method. A relationship between the severity of parasitemia at the time of death and the presence of nephropathy was not apparent.

  7. Spatial contrast sensitivity and grating acuity of barn owls.

    PubMed

    Harmening, Wolf M; Nikolay, Petra; Orlowski, Julius; Wagner, Hermann

    2009-07-22

    The eyes of barn owls (Tyto alba pratincola) display very little aberrations, and have thus excellent optical quality. In a series of behavioral experiments, we tested whether this presumably beneficial feature is also reflected at a perceptual level in this species. As fundamental indicators for visual performance, the spatial contrast sensitivity function (CSF) and grating acuity were measured in two barn owls with psychophysical techniques. Stimulus luminance was 2.7 cd/m(2). The CSF found here renders the typical band-limited, inverted U-shaped function, with a low maximum contrast sensitivity of 8-19 at a spatial frequency of 1 cyc/deg. Grating acuity was estimated from the CSF high frequency cut-off and yielded 3.0-3.7 cyc/deg. In a second experiment, in which contrast was held constant and spatial frequency was varied, grating acuity was measured directly (2.6-4.0 cyc/deg). These results put barn owls at the very low end of the visual acuity spectrum of birds, and demonstrate that visual resolution and sensitivity cannot be predicted by optical considerations alone.

  8. The Structure and Noise Reduction Capacity of Owl Down

    NASA Astrophysics Data System (ADS)

    Jaworski, Justin; Clark, Ian; Alexander, Nathan; Devenport, William; Daly, Conor; Peake, Nigel; Glegg, Stewart

    2014-11-01

    Many species of owl rely on specialized plumage to reduce their self-noise levels and enable hunting in acoustic stealth. In contrast to the leading-edge comb and compliant trailing-edge fringe attributes of owls, the aeroacoustic impact of the fluffy down material on the upper wing surface remains largely speculative as a means to eliminate aerodynamic noise across a broad range of frequencies. Photographic analysis of the owl down reveals a unique forest-like structure, whereby the down fibers rise straight up from the wing surface and then bend into the flow direction to form a porous canopy, with an open area fraction of approximately 70%. Experimental measurements demonstrate that the canopy feature reduces dramatically the turbulent pressure levels on the wing surface by up to 30dB, which affects the roughness noise characteristic of the down in a manner consistent with the theory of flows over and through vegetation. Mathematical models developed for the turbulence noise generation by the down fibers and for the mixing-layer instability above the porous canopy furnish a theoretical basis to understand the influence of the down geometric structure on its self-noise signature and noise suppression characteristics.

  9. Intraspecific variation in reproductive traits of burrowing owls

    USGS Publications Warehouse

    Conway, Meaghan; Nadeau, Christopher P.; Conway, Courtney J.

    2012-01-01

    Reviews of hatching asynchrony in birds recommended more studies on intraspecific variation in the extent of hatching asynchrony. We examined intraspecific variation in clutch size, laying chronology, onset of incubation, incubation period, and hatching asynchrony in burrowing owls (Athene cunicularia) in the Imperial Valley of California. Mean clutch size was 7.4 eggs and owls averaged 0.5 eggs laid per day. Females varied considerably in laying interval and onset of incubation (range = 1st to 9th egg in the clutch). The mean incubation period was 21.9 days. Hatching interval also varied greatly among females (x = 0.8, range 0.1-2.0 days between successively hatched eggs). Past burrowing owl studies have largely overlooked the substantial intraspecific variation in these traits or have reported estimates that differ from ours. Future studies designed to identify the environmental factors that explain the large intraspecific variation in these traits will likely provide insights into the constraints on local abundance.

  10. Features of owl wings that promote silent flight.

    PubMed

    Wagner, Hermann; Weger, Matthias; Klaas, Michael; Schröder, Wolfgang

    2017-02-06

    Owls are an order of birds of prey that are known for the development of a silent flight. We review here the morphological adaptations of owls leading to silent flight and discuss also aerodynamic properties of owl wings. We start with early observations (until 2005), and then turn to recent advances. The large wings of these birds, resulting in low wing loading and a low aspect ratio, contribute to noise reduction by allowing slow flight. The serrations on the leading edge of the wing and the velvet-like surface have an effect on noise reduction and also lead to an improvement of aerodynamic performance. The fringes at the inner feather vanes reduce noise by gliding into the grooves at the lower wing surface that are formed by barb shafts. The fringed trailing edge of the wing has been shown to reduce trailing edge noise. These adaptations to silent flight have been an inspiration for biologists and engineers for the development of devices with reduced noise production. Today several biomimetic applications such as a serrated pantograph or a fringed ventilator are available. Finally, we discuss unresolved questions and possible future directions.

  11. Distribution of burrowing owls in east-central South Dakota

    USGS Publications Warehouse

    Shaffer, Jill A; Thiele, Jason P.

    2013-01-01

    Western burrowing owl (Athene cunicularia hypugaea) populations have declined across much of western North America, particularly at the northern and eastern edges of the species’ breeding range (Martell et al. 2001, Murphy et al. 2001, Shyry et al. 2001, Skeel et al. 2001, Klute et al. 2003). In South Dakota, the burrowing owl is a summer resident that historically was relatively common throughout the state, but its range has decreased in recent decades, especially in the eastern half of the state (Whitney et al. 1978, South Dakota Ornithologists’ Union [SDOU] 1991, Peterson 1995). Tallman et al. (2002) described the species as uncommon to locally common in western South Dakota, uncommon in the north-central part of the state, and casual (i.e., not within the species’ normal range, but with 3–10 records in the past 10 years) elsewhere in the eastern half. The burrowing owl is a Species of Greatest Conservation Need (South Dakota Department of Game, Fish and Parks [SDGFP] 2006) and a Level I Priority Species in South Dakota (Bakker 2005).

  12. Estimates of density, detection probability, and factors influencing detection of burrowing owls in the Mojave Desert

    USGS Publications Warehouse

    Crowe, D.E.; Longshore, K.M.

    2010-01-01

    We estimated relative abundance and density of Western Burrowing Owls (Athene cunicularia hypugaea) at two sites in the Mojave Desert (200304). We made modifications to previously established Burrowing Owl survey techniques for use in desert shrublands and evaluated several factors that might influence the detection of owls. We tested the effectiveness of the call-broadcast technique for surveying this species, the efficiency of this technique at early and late breeding stages, and the effectiveness of various numbers of vocalization intervals during broadcasting sessions. Only 1 (3) of 31 initial (new) owl responses was detected during passive-listening sessions. We found that surveying early in the nesting season was more likely to produce new owl detections compared to surveying later in the nesting season. New owls detected during each of the three vocalization intervals (each consisting of 30 sec of vocalizations followed by 30 sec of silence) of our broadcasting session were similar (37, 40, and 23; n 30). We used a combination of detection trials (sighting probability) and double-observer method to estimate the components of detection probability, i.e., availability and perception. Availability for all sites and years, as determined by detection trials, ranged from 46.158.2. Relative abundance, measured as frequency of occurrence and defined as the proportion of surveys with at least one owl, ranged from 19.232.0 for both sites and years. Density at our eastern Mojave Desert site was estimated at 0.09 ?? 0.01 (SE) owl territories/km2 and 0.16 ?? 0.02 (SE) owl territories/km2 during 2003 and 2004, respectively. In our southern Mojave Desert site, density estimates were 0.09 ?? 0.02 (SE) owl territories/km2 and 0.08 ?? 0.02 (SE) owl territories/km 2 during 2004 and 2005, respectively. ?? 2010 The Raptor Research Foundation, Inc.

  13. Using detection dogs to conduct simultaneous surveys of northern spotted (Strix occidentalis caurina) and barred owls (Strix varia).

    PubMed

    Wasser, Samuel K; Hayward, Lisa S; Hartman, Jennifer; Booth, Rebecca K; Broms, Kristin; Berg, Jodi; Seely, Elizabeth; Lewis, Lyle; Smith, Heath

    2012-01-01

    State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia)-a significant threat to northern spotted owls-can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris) located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service's Draft 2010 Survey Protocol. Seventeen 2 km × 2 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the Northern Spotted Owl.

  14. Natal and breeding dispersal of northern spotted owls

    USGS Publications Warehouse

    Forsman, E.D.; Anthony, R.G.; Reid, J.A.; Loschl, P.J.; Sovern, S.G.; Taylor, M.; Biswell, B.L.; Ellingson, A.; Meslow, E.C.; Miller, G.S.; Swindle, K.A.; Thrailkill, J.A.; Wagner, F.F.; Seaman, D.E.

    2002-01-01

    We studied the dispersal behavior of 1,475 northern spotted owls (Strix occidentalis caurina) during banding and radio-telemetry studies in Oregon and Washington in 1985-1996. The sample included 324 radio-marked juveniles and 1,151 banded individuals (711 juveniles, 440 non-juveniles) that were recaptured or resighted after dispersing from the initial banding location. Juveniles typically left the nest during the last week in May and the first two weeks in June (x?? ?? SE = 8 June ?? 0.53 days, n = 320, range = 15 May-1 July), and spent an average of 103.7 days in the natal territory after leaving the nest (SE = 0.986 days, n = 137, range = 76-147 days). The estimated mean date that juveniles began to disperse was 19 September in Oregon (95% CI = 17-21 September) and 30 September in Washington (95% CI = 25 September-4 October). Mean dispersal dates did not differ between males and females or among years. Siblings dispersed independently. Dispersal was typically initiated with a series of rapid movements away from the natal site during the first few days or weeks of dispersal. Thereafter, most juveniles settled into temporary home ranges in late October or November and remained there for several months. In February-April there was a second pulse of dispersal activity, with many owls moving considerable distances before settling again in their second summer. Subsequent dispersal patterns were highly variable, with some individuals settling permanently in their second summer and others occupying a series of temporary home ranges before eventually settling on territories when they were 2-5 years old. Final dispersal distances ranged from 0.6-111.2 km for banded juveniles and 1.8-103.5 km for radio-marked juveniles. The distribution of dispersal distances was strongly skewed towards shorter distances, with only 8.7% of individuals dispersing more than 50 km. Median natal dispersal distances were 14.6 km for banded males, 13.5 km for radio-marked males, 24.5 km for

  15. A Korean Space Situational Awareness Program : OWL Network

    NASA Astrophysics Data System (ADS)

    Park, J.; Choi, Y.; Jo, J.; Moon, H.; Im, H.; Park, J.

    2012-09-01

    We are going to present a brief introduction to the OWL (Optical Wide-field patroL) network, one of Korean space situational awareness facilities. Primary objectives of the OWL network are 1) to obtain orbital information of Korean domestic LEOs using optical method, 2) to monitor GEO-belt over territory of Korea, and 3) to alleviate collisional risks posed to Korean satellites from space debris. For these purposes, we are planning to build a global network of telescopes which consists of five small wide-field telescopes and one 2m class telescope. The network of small telescopes will be dedicated mainly to the observation of domestic LEOs, but many slots will be open to other scientific programs such as GRB follow-up observations. Main targets of 2m telescope not only include artificial objects such as GEO debris and LEO debris with low inclination and high eccentricity, but also natural objects such as near Earth asteroids. We expect to monitor space objects down to 10cm in size in GEO using the 2m telescope system. Main research topics include size distribution and evolution of space debris. We also expect to utilize this facility for physical characterization and population study of near Earth asteroids. The aperture size of the small telescope system is 0.5m with Rechey-Cretian configuration and its field of view is 1.75 deg x 1.75 deg. It is equipped with 4K CCD with 9um pixel size, and its plate scale is 1.3 arcsec/pixel. A chopper wheel is employed to maximize astrometric solutions in a single CCD frame, and a de-rotator is used to compensate field rotation of the alt-az type mount. We have designed a compact end unit in which three rotating parts (chopper wheel, filter wheel, de-rotator) and a CCD camera are integrated, and dedicated telescope/site control boards for the OWL network. The design of 2m class telescope is still under discussion yet is expected to be fixed in the first half of 2013 at the latest. The OWL network will be operated in a fully

  16. OWL (On-Lie Webstories for Learning): A Unique Web-based Literacy Resource for Primary/Elementary Children.

    ERIC Educational Resources Information Center

    Juliebo, Moira; Durnford, Carol

    2000-01-01

    Describes Online Webstories for Learning (OWL), a Web-based resource for elementary school literacy education that was initially developed for use in the United Kingdom. Discusses the importance of including narrative, how OWL is being adapted for use in other countries, and off-line class activities suggested as part of OWL. (Contains 8…

  17. 76 FR 38575 - Endangered and Threatened Wildlife and Plants; Revised Recovery Plan for the Northern Spotted Owl...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-01

    ... Recovery Plan for the Northern Spotted Owl (Strix occidentalis caurina) AGENCY: Fish and Wildlife Service... Wildlife Service, announce the availability of the Revised Recovery Plan for the Northern Spotted Owl... Spotted Owl available for public review and comment from September 15 through November 15, 2010...

  18. Emaciation and larval filarioid nematode infection in boreal owls (Aegolius funereus).

    PubMed

    Larrat, Sylvain; Dallaire, André D; Lair, Stéphane

    2012-01-01

    Microfilariae are considered non-pathogenic in wild birds. The objective of the current communication is to report host reactions to microfilarial infection of unusual intensity in emaciated boreal owls (Aegolius funereus). An unusually large number of boreal owls (n = 21) were submitted to the Canadian Cooperative Wildlife Health Center-Quebec Region for post-mortem examination during the winter of 2009. Nineteen out of 21 birds were considered emaciated based on atrophy of adipose tissue and pectoral muscles and suboptimal weight. A microscopic examination of a subset of nine owls revealed the presence of microfilariae in six owls. Three of the birds with a heavy parasite burden had masses of larval nematodes obstructing large vessels of the lungs. The emaciated owls are believed to have died from starvation due to a cyclic decrease in prey abundance in the boreal forest. This cycle also drives winter movements of boreal owls to urbanized areas of southern Quebec, presumably accounting for the large number of birds submitted in 2009. In the most severely infected owls, the extreme microfilarial burden might have caused an alteration in circulatory dynamics, gaseous exchanges and also probably some metabolic cost. Consequently, microfilariae could have significantly contributed to the death of some of these owls.

  19. "Not in the Middle Ages"?: Alan Garner's "The Owl Service" and the Literature of Adolescence.

    ERIC Educational Resources Information Center

    Hardwick, Paul

    2000-01-01

    Discusses connecting with the Middle Ages in adolescent fiction. Discusses how, in "The Owl Service," Garner addresses a relationship between adolescence in the late twentieth century and an aspect of the past--specifically the Middle Ages. Considers how "The Owl Service" is a story energized by myth, concerning the…

  20. Summer Professional Development in Chemistry for Inservice Teachers Using OWL Quick Prep

    ERIC Educational Resources Information Center

    Powell, Cynthia B.; Pamplin, Kim L.; Blake, Robert E.; Mason, Diana S.

    2010-01-01

    Secondary teachers participating in summer professional development chemistry workshops in Texas used an online chemistry tutoring program, OWL Quick Prep (Day et al. in OWL: Online Web-based Learning, Brooks-Cole Cengage Learning, Florence, KY, 1997) as a part of the inservice training. Self-reported demographic data were used to identify factors…

  1. Unusual leg malformations in screech owls from a South Carolina Superfund site.

    PubMed

    Albers, P H; Hoffman, D J; Brisbin, I L

    2001-05-25

    In 1995, the discovery of leg malformations in several screech owl (Otis asio) nestlings and in their female parent at a Department of Energy (DOE) Superfund site in South Carolina prompted an investigation into the nature of the observed abnormalities. Surviving nestlings and the female parent were transferred to a captive screech owl breeding colony at the USGS Patuxent Wildlife Research Center, Laurel, MD. The malformed female parent and her offspring were each mated with normal owls from the colony for 3 yr. Matings of the malfored female produced five malformed and six normal owls; all owls produced by matings of normal offspring were normal. Malformed offspring were euthanized when it became apparent that their physical distress precluded survival under normal conditions of colony care. Euthanized owls were necropsied and examined for skeletal development. Detailed descriptions of eight malformed owls are presented. Results of the matings indicated that the leg mafformations were caused by a genetic trait in the female parent that was heterozygous dominant. The characteristic was lethal except in occasional mild manifestations and resembled an extreme form of a dominant abnormality previously described for domestic fowl called duplicate polydactyly. Other reports of skeletal abnormalities in wild birds and potential environmental causes of genetic mutations at the DOE Superfund site are presented. Other studies performed at the DOE Superfund site do not implicate elevated (above background) ionizing radiation from 137Cs, the dominant radionuclide where the owls were captured, as the cause of the mutation. The cause of this genetic abnormality remains unknown.

  2. OPTIMAL WELL LOCATOR (OWL): A SCREENING TOOL FOR EVALUATING LOCATIONS OF MONITORING WELLS

    EPA Science Inventory

    The Optimal Well Locator ( OWL) program was designed and developed by USEPA to be a screening tool to evaluate and optimize the placement of wells in long term monitoring networks at small sites. The first objective of the OWL program is to allow the user to visualize the change ...

  3. The influence of hunger on meal to pellet intervals in barred owls

    USGS Publications Warehouse

    Duke, G.E.; Fuller, M.R.; Huberty, B.J.

    1980-01-01

    1. 1. Barred owls fed at a sub-maintenance (SM) level had significantly (P < 0.01) longer meal to pellet intervals (MPI)/g eaten/kg body weight (BW) than those fed at an above maintenance (AM) level; MPI/g per kg for owls fed at a maintenance (M) level was intermediate but significantly (P < 0.01) different from both SM and AM. 2. 2. During SM feeding, MPI/g per kg gradually increased. 3. 3. The proportion of a meal occurring in a pellet was less in ?hungry? owls whether losing weight (SM) or gaining (AM) as compared to owls maintaining their normal body weight (M). 4. 4. SM fed owls appear to be able to increase digestion time as well as thoroughness of digestion.

  4. Using Detection Dogs to Conduct Simultaneous Surveys of Northern Spotted (Strix occidentalis caurina) and Barred Owls (Strix varia)

    PubMed Central

    Wasser, Samuel K.; Hayward, Lisa S.; Hartman, Jennifer; Booth, Rebecca K.; Broms, Kristin; Berg, Jodi; Seely, Elizabeth; Lewis, Lyle; Smith, Heath

    2012-01-01

    State and federal actions to conserve northern spotted owl (Strix occidentalis caurina) habitat are largely initiated by establishing habitat occupancy. Northern spotted owl occupancy is typically assessed by eliciting their response to simulated conspecific vocalizations. However, proximity of barred owls (Strix varia)–a significant threat to northern spotted owls–can suppress northern spotted owl responsiveness to vocalization surveys and hence their probability of detection. We developed a survey method to simultaneously detect both species that does not require vocalization. Detection dogs (Canis familiaris) located owl pellets accumulated under roost sites, within search areas selected using habitat association maps. We compared success of detection dog surveys to vocalization surveys slightly modified from the U.S. Fish and Wildlife Service’s Draft 2010 Survey Protocol. Seventeen 2 km ×2 km polygons were each surveyed multiple times in an area where northern spotted owls were known to nest prior to 1997 and barred owl density was thought to be low. Mitochondrial DNA was used to confirm species from pellets detected by dogs. Spotted owl and barred owl detection probabilities were significantly higher for dog than vocalization surveys. For spotted owls, this difference increased with number of site visits. Cumulative detection probabilities of northern spotted owls were 29% after session 1, 62% after session 2, and 87% after session 3 for dog surveys, compared to 25% after session 1, increasing to 59% by session 6 for vocalization surveys. Mean detection probability for barred owls was 20.1% for dog surveys and 7.3% for vocal surveys. Results suggest that detection dog surveys can complement vocalization surveys by providing a reliable method for establishing occupancy of both northern spotted and barred owl without requiring owl vocalization. This helps meet objectives of Recovery Actions 24 and 25 of the Revised Recovery Plan for the Northern Spotted

  5. Winter ecology of the western burrowing owl (Athene cunicularia hypugaea) in southern Texas 1999-2004

    USGS Publications Warehouse

    Woodin, Marc C.; Skoruppa, Mary K.; Hickman, Graham C.

    2007-01-01

    This study examines the winter ecology of the western burrowing owl (Athene cunicularia hypugaea) in five Texas counties surrounding Corpus Christi, in southern Texas. There is a substantial gap in information on the owl's life cycle during migration and non-breeding winter months; almost all previous research on western burrowing owls has been conducted during the breeding season. The western burrowing owl currently is federally threatened in Mexico, federally endangered in Canada, and in the United States is considered a National Bird of Conservation Concern by the U.S. Fish and Wildlife Service. Topics investigated included status, effectiveness of public outreach, roost sites and use of culverts and artificial burrows, roost site fidelity, diet, contaminant burdens, body mass, and ectoparasites. Early ornithological reports and a museum egg set revealed that burrowing owls once bred in southern Texas and were common in winter; however, since the 1950's they have been reported in relatively low numbers and only during winter. In this study, public outreach increased western burrowing owl detections by 68 percent. Owls selected winter roost sites with small-diameter openings, including culverts less than or equal to 16 centimeters and artificial burrows of 15 centimeters, probably because the small diameters deterred mammalian predators. Owls showed strong roost site fidelity; 15 banded birds stayed at the same roost sites within a winter, and 8 returned to the same site the following winter. The winter diet was over 90 percent insects, with crickets the primary prey. Analyses of invertebrate prey and regurgitated pellets showed that residues of all but 3 of 28 carbamate and organophosphate pesticides were detected at least once, but all were below known lethal concentrations. Mean body mass of western burrowing owls was 168 grams and was highest in midwinter. Feather lice were detected in low numbers on a few owls, but no fleas or other ectoparasites were found.

  6. Anticoagulant rodenticide exposure and toxicosis in four species of birds of prey presented to a wildlife clinic in Massachusetts, 2006-2010.

    PubMed

    Murray, Maureen

    2011-03-01

    Mortalities among birds of prey from anticoagulant rodenticide (AR) toxicosis have been documented in several countries. Reports on extent of exposure within regions of the United States are limited. This study investigated AR exposure and toxicosis in four species of birds of prey (red-tailed hawks [Buteo jamaicensis], barred owls [Strix varia], eastern screech owls [Megascops asio] and great horned owls [Bubo virginianus]) presented to a wildlife clinic in Massachusetts. The aims of this study are to document the proportion of these four species that died or were euthanized due to their presenting injuries that had detectable amounts of ARs in liver tissue; to identify and quantify ARs present; to describe clinical, postmortem, and histopathologic signs of toxicosis; to evaluate potential sublethal effects of AR exposure; and to associate liver AR level with toxicosis. Birds included in the study were sampled without regard to signs of AR toxicosis. Postmortem examinations were conducted, and liver samples were analyzed for AR residues. Of 161 birds tested, 86% had AR residues in liver tissue. The second-generation AR (SGAR) brodifacoum was identified in 99% of positive birds. Mortality from AR toxicosis was diagnosed in 6% of birds. No indications of sublethal effects of exposure were found, and no association between liver brodifacoum level and signs of toxicosis was apparent. Given the high proportion of birds in this study exposed to ARs, specifically brodifacoum, continued monitoring is warranted as new U.S. Environmental Protection Agency regulations on the sale and use of SGARs are enacted.

  7. Antibody Prevalence and Isolation of Viable Toxoplasma gondii from Raptors in the Southeastern USA.

    PubMed

    Love, David; Kwok, Oliver C; Verma, Shiv Kumar; Dubey, Jitender P; Bellah, Jamie

    2016-07-01

    Raptors are good indicators of the prevalence of Toxoplasma gondii in the environment because they prey on small mammals and birds. These prey species are a major source of infection in domestic cats ( Felis catus ), which shed the environmentally resistant oocysts. We assessed T. gondii infection in 281 opportunistically available raptors at a rehabilitation facility between 2012 and 2014. Antibodies to T. gondii were assayed by a modified agglutination test (cutoff 1:25) and found in serum of 22/71 Red-tailed Hawks ( Buteo jamaicensis ), 25/54 Barred Owls ( Strix varia ), 9/41 Red-shouldered Hawks ( Buteo lineatus ), 13/28 Great Horned Owls ( Bubo virginianus ), 6/20 Broad-winged Hawks ( Buteo platypterus ), 2/16 Eastern Screech Owls (Megascops asio), 12/13 Bald Eagles ( Haliaeetus leucocephalus ), 6/12 Cooper's Hawks ( Accipiter cooperii ), 1/8 Black Vultures ( Coragyps atratus ), and 1/1 Golden Eagle ( Aquila chrysaetos ). Antibodies were not detected in 5 Barn Owls ( Tyto alba ), 3 American Kestrels ( Falco sparverius ), 1 Mississippi Kite ( Ictinia mississippiensis ), and 1 Osprey ( Pandion haliaetus ). Viable T. gondii was isolated from the tissues of 1 antibody-positive Barred Owl and identified as a strain having type II alleles at all 10 loci tested, except one (ToxoDB polymerase chain reaction-restriction fragment length polymorphism genotype 3). Type II strain is the most common strain in the US. Results of this study indicate a high prevalence of T. gondii in some raptor species and the first reported genotyping from a Barred Owl.

  8. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence

    PubMed Central

    Colihueque, Nelson; Gantz, Alberto; Rau, Jaime Ricardo; Parraguez, Margarita

    2015-01-01

    Abstract In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy. PMID:26668551

  9. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence.

    PubMed

    Colihueque, Nelson; Gantz, Alberto; Rau, Jaime Ricardo; Parraguez, Margarita

    2015-01-01

    In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy.

  10. Life-history tradeoffs and reproductive cycles in Spotted Owls

    USGS Publications Warehouse

    Stoelting, Ricka E.; Gutierrez, R.J.; Kendall, William; Peery, M. Zachariah

    2015-01-01

    The study of tradeoffs among life-history traits has long been key to understanding the evolution of life-history strategies. However, more recently, evolutionary ecologists have realized that reproductive costs have the potential to influence population dynamics. Here, we tested for costs of reproduction in the California Spotted Owl (Strix occidentalis occidentalis), and assessed whether costs of reproduction in year t − 1 on reproduction in year t could be responsible for regionally synchronized biennial cycles in reproductive output. Logistic regression analysis and multistate mark–recapture models with state uncertainty revealed that breeding reduced the likelihood of reproducing in the subsequent year by 16% to 38%, but had no influence on subsequent survival. We also found that costs of reproduction in year t − 1 were correlated with climatic conditions in year t, with evidence of higher costs during the dry phase of the El Niño–Southern Oscillation. Using a simulation-based population model, we showed that strong reproductive costs had the potential to create biennial cycles in population-level reproductive output; however, estimated costs of reproduction appeared to be too small to explain patterns observed in Spotted Owls. In the absence of strong reproductive costs, we hypothesize that observed natural cycles in the reproductive output of Spotted Owls are related to as-yet-unmeasured, regionally concordant fluctuations in environmental conditions or prey resources. Despite theoretical evidence for demographic effects, our analyses illustrate that linking tradeoffs to actual changes in population processes will be challenging because of the potential confounding effects of individual and environmental variation.

  11. Focal plane detectors possible detector technologies for OWL/AIRWATCH

    SciTech Connect

    Flyckt, Esso

    1998-06-15

    New satellite-born projects OWL and AIRWATCH will need single-photon focal-plane detectors of a million pixels in a design which is optimized to the focusing optics and electronics at acceptable cost. We discuss different phototube possibilities and their pros and cons with crude cost estimates. We conclude that a multichannel-photomultiplier solution is safe. A better compromise may be to adapt a 6 or 9 inch X-ray image intensifier tube or develop a 12 inch image intensifier for detecting individual photons, and adapt the optics to have many mirror modules. The possibility of developing super-large-area phototubes is also discussed.

  12. What Do Owls, Salamanders, Flycatchers and Cuckoos Have In Common?

    SciTech Connect

    Musgrave, Maria A.

    2016-09-27

    This is an article from the Los Alamos Living magazine. Los Alamos National Laboratory sits on a beautiful and unique landscape that provides important protected habitat to many species, including a few that are federally-listed as threatened or endangered. These species are the Jemez Mountains Salamander, the Mexican Spotted Owl, the Southwestern Willow Flycatcher, the Yellow-billed Cuckoo, and the New Mexico Meadow Jumping Mouse. Part of the job of the Laboratory's wildlife biologists is to survey for these species each year and determine what actions need to be taken if they are found.

  13. Individual and spatio-temporal variations in the home range behaviour of a long-lived, territorial species.

    PubMed

    Campioni, Letizia; Delgado, María del Mar; Lourenço, Rui; Bastianelli, Giulia; Fernández, Nestor; Penteriani, Vincenzo

    2013-06-01

    Despite the fact that investigations of home range behaviour have exponentially evolved on theoretical, analytical and technological grounds, the factors that shape animal home range behaviour still represent an unsolved question and a challenging field of research. However, home range studies have recently begun to be approached under a new integrated conceptual framework, considering home range behaviour as the result of the simultaneous influences of temporal, spatial and individual-level processes, with potential consequences at the population level. Following an integrated approach, we studied the influence of both external and internal factors on variations in the home range behaviour of 34 radiotagged eagle owl (Bubo bubo) breeders. Home range behaviour was characterised through complementary analysis of space use, movement patterns and rhythms of activity at multiple spatio-temporal scales. The effects of the different phases of the biological cycle became considerably evident at the level of movement patterns, with males travelling longer distances than females during incubation and nestling periods. Both external (i.e. habitat structure and composition) and internal (i.e. sex and health state) factors explained a substantial amount of the variation in home range behaviour. At the broader temporal scale, home range and core area size were negatively correlated with landscape heterogeneity. Males showed (1) smaller home range and core area sizes, (2) more complex home range internal structure and (3) higher rates of movement. The better the physiological condition of the individuals, the simpler the internal home range structure. Finally, inter- and intra-individual effects contributed to shaping space use and movement patterns during the biological cycle. Because of the plurality of behavioural and ecological processes simultaneously involved in home range behaviour, we claim that an integrative approach is required for adequate investigation of its

  14. A new owl species of the genus Otus (aves: strigidae) from Lombok, Indonesia.

    PubMed

    Sangster, George; King, Ben F; Verbelen, Philippe; Trainor, Colin R

    2013-01-01

    The avifauna of Indonesia is one of the richest in the world but the taxonomic status of many species remains poorly documented. The sole species of scops owl known from Lombok has long been assigned to the widespread Moluccan Scops Owl Otus magicus on the basis of superficial similarities in morphology. Field work in 2003 has shown that the territorial song of the scops owls inhabiting the foothills of Gunung Rinjani differs dramatically from that of O. magicus and is more similar to those of Rufescent Scops Owl O. rufescens and Singapore Scops Owl O. cnephaeus. Detailed comparisons of sound recordings and museum specimens with those of other scops owls in Wallacea and the Indo-Malayan region have confirmed the distinctiveness of the Lombok population. We describe Otus jolandae as a new species, the Rinjani Scops Owl. It is locally common at elevations from 25-1350 m. and occurs within Gunung Rinjani National Park. The new species is known from seven specimens collected by Alfred Everett in 1896. Otus jolandae represents the first endemic bird species from Lombok.

  15. Aerodynamics of a freely flying owl from PIV measurements in the wake

    NASA Astrophysics Data System (ADS)

    Ben-Gida, Hadar; Gurka, Roi; Weihs, Daniel

    2015-11-01

    The mechanisms of the silent flight of owls have been the subject of scientific interest for many decades and a source of inspiration in the context of reducing flight noise. Over millions of years of evolution, owls have produced many specialized configurations to reduce the aerodynamic noise, which is found to be essential for successful hunting of potential prey. Here, we study how the three-dimensional flow field formed over the wing affect the vortical structures develop in the wake of a freely flying owl. We study the unique flight patterns of the Boobook owl; a mid-sized owl, which has the feature of stealth flight during both gliding and flapping flight. The owl was flown in a hypobaric avian wind tunnel at its comfort speed for various flight modes. The wake velocity field was sampled using long duration high speed PIV whilst the wing's kinematics were imaged using high speed video simultaneously with the PIV. The time series velocity maps acquired during few consecutive wingbeat cycles enabled to describe the various flow features as formed at the owl's wake by reconstructing the wake patterns and associate them with the various phases of the wingbeat cycle. The stealthy flight mode, which is a result of noise reduction mechanisms, formed over the wings (presumably by the leading-edge serrations) results in a unique signature in the wake flow field, which is characterized using the present data.

  16. Effects of radiotransmitter necklaces on behaviors of adult male western burrowing owls

    USGS Publications Warehouse

    Chipman, E.D.; McIntyre, N.E.; Ray, J.D.; Wallace, M.C.; Boal, C.W.

    2007-01-01

    We studied the behavioral effects of necklace-style radiotransmitters on breeding male western burrowing owls (Athene cunicularia hypugaea) in 2 areas of northwestern Texas, USA, in 2004 and 2005. We tested the hypothesis that transmittered owls would spend time interacting with their necklaces and as a result spend less time in vigilance and resting activities than would nontransmittered owls. Nontransmittered owls (n = 6) spent significantly more time being vigilant (P = 0.007) than did transmittered owls (n = 3) in 2004, who spent significant amounts of time interacting with their necklaces. In 2005, behaviors of transmittered owls (n = 8) were significantly different (P < 0.001) from control individuals (n = 4), but behaviors did not vary consistently by treatment period (prenecklace vs. necklace vs. postnecklace periods). Behavioral activity budgets varied considerably among individuals. Although the owls spent a significant amount of time interacting with their necklaces, they appeared to habituate to the presence of the transmitters within a relatively short period (<1 week), and necklaces did not affect survivorship or fitness in the short-term.

  17. Differential risk perception of rural and urban Burrowing Owls exposed to humans and dogs.

    PubMed

    Cavalli, Matilde; Baladrón, Alejandro V; Isacch, Juan Pablo; Biondi, Laura M; Bó, María Susana

    2016-03-01

    Urban areas expose wildlife to an array of novel predators, amongst which, humans and dogs are highly frequent. Thus, wild animals living in urban areas are forced to invest more time and energy in defence behaviours, which depend on how the risk is perceived and assessed. We experimentally tested whether Burrowing owls coming from rural and urban habitats showed differences in behavioural responses when facing humans and domestic dogs. We measured flight initiation distances (FIDs), nest returning, and aggressiveness level when owls faced a human and a human with a dog walking towards them. Our results showed that urban owls recognise a human with a dog as a greater threat than a human alone, thus indicating that fear of domestic animals should be considered as affecting owls' settlement in cities and towns. On the other hand, rural owls perceived human and dogs as similar threats, but showed higher FIDs, less aggressiveness, and lower tendency to return to the nest than urban owls in both treatments. These findings emphasize the importance of modified habitats in modelling the response of urban and rural owls to predators and represent another step in the explanation of how wild animals assess and respond to threats associated with living in urbanized environments.

  18. Collection of mammal manure and other Debris by nesting Burrowing Owls

    USGS Publications Warehouse

    Smith, M.D.; Conway, C.J.

    2011-01-01

    Burrowing Owls (Athene cunicularia) routinely collect and scatter dry manure of mammals around their nesting burrows. Recent studies have suggested this behavior attracts insect prey to the nesting burrow. However, some Burrowing Owls do not use manure, but instead, collect and scatter other materials (e.g., grass, moss, paper, plastic) around their nesting burrow in a similar fashion. Use of these materials seemingly contradicts the prey-attraction hypothesis. Using observational and experimental methods, we tested whether Burrowing Owls preferred manure to other materials commonly found at nesting burrows in eastern Washington. We found a wide variety of materials at nests, but grass and manure were the most common materials. The amount of manure present at nests was negatively correlated with the amount of other materials, and with the distance to the nearest source of manure. Burrowing Owls showed no preference between horse manure and grass divots at experimental supply stations that we placed near nesting burrows. They did prefer these two materials to carpet pieces and aluminum foil (both materials that are often found at Burrowing Owl nests). Our results did not support the premise that Burrowing Owls specifically seek out manure when lining their nesting burrows. The unusual behavior of collecting and scattering mammal manure and other debris at Burrowing Owl nests may serve functions other than (or in addition to) prey attraction and alternative hypotheses need further testing before the function of this behavior is certain. ?? 2011 The Raptor Research Foundation, Inc.

  19. A New Owl Species of the Genus Otus (Aves: Strigidae) from Lombok, Indonesia

    PubMed Central

    Sangster, George; King, Ben F.; Verbelen, Philippe; Trainor, Colin R.

    2013-01-01

    The avifauna of Indonesia is one of the richest in the world but the taxonomic status of many species remains poorly documented. The sole species of scops owl known from Lombok has long been assigned to the widespread Moluccan Scops Owl Otus magicus on the basis of superficial similarities in morphology. Field work in 2003 has shown that the territorial song of the scops owls inhabiting the foothills of Gunung Rinjani differs dramatically from that of O. magicus and is more similar to those of Rufescent Scops Owl O. rufescens and Singapore Scops Owl O. cnephaeus. Detailed comparisons of sound recordings and museum specimens with those of other scops owls in Wallacea and the Indo-Malayan region have confirmed the distinctiveness of the Lombok population. We describe Otus jolandae as a new species, the Rinjani Scops Owl. It is locally common at elevations from 25–1350 m. and occurs within Gunung Rinjani National Park. The new species is known from seven specimens collected by Alfred Everett in 1896. Otus jolandae represents the first endemic bird species from Lombok. PMID:23418422

  20. In-flight corrections in free-flying barn owls (Tyto alba) during sound localization tasks.

    PubMed

    Hausmann, Laura; Plachta, Dennis T T; Singheiser, Martin; Brill, Sandra; Wagner, Hermann

    2008-09-01

    Barn owls localize a stationary auditory target with high accuracy. They might also be able to hit a target that is intermittently moving while the owl is approaching. If so, there should be a critical delay before strike initiation, up to which the owl can adapt its flight path to a new stimulus position. In this study, this critical stimulus delay was determined in a three-dimensional free-flight paradigm. Barn owls localized a pulsed broadband noise while sitting on a perch in total darkness. This initial signal stopped with the owl's take-off and an in-flight stimulus (target sound), lasting 200 ms, was introduced at variable time delays (300-1200 ms) during the approximate flight time of 1300 ms. The owls responded to the in-flight signal with a corrective head and body turn. The percentage of trials in which correction turns occurred (40-80%) depended upon the individual bird, but was independent of the stimulus delay within a range of 800 ms after take-off. Correction turns strongly decreased at delays >or=800 ms. The landing precision of the owls, defined as their distance to the in-flight speaker, did not decrease with increasing stimulus delay, but decreased if the owl failed to perform a correction turn towards that speaker. Landing precision was higher for a short (50 cm) than for a large (100 cm) distance between the initial and the new target. Thus, the ability of barn owls to adapt their flight path to a new sound target depends on the in-flight stimulus delay, as well as on the distance between initial and novel targets.

  1. Prey composition modulates exposure risk to anticoagulant rodenticides in a sentinel predator, the barn owl.

    PubMed

    Geduhn, Anke; Esther, Alexandra; Schenke, Detlef; Gabriel, Doreen; Jacob, Jens

    2016-02-15

    Worldwide, small rodents are main prey items for many mammalian and avian predators. Some rodent species have pest potential and are managed with anticoagulant rodenticides (ARs). ARs are consumed by target and non-target small mammals and can lead to secondary exposure of predators. The development of appropriate risk mitigation strategies is important and requires detailed knowledge of AR residue pathways. From July 2011 to October 2013 we collected 2397 regurgitated barn owl (Tyto alba) pellets to analyze diet composition of owls on livestock farms in western Germany. 256 of them were fresh pellets that were collected during brodifacoum baiting. Fresh pellets and 742 liver samples of small mammals that were trapped during baiting in the same area were analyzed for residues of ARs. We calculated exposure risk of barn owls to ARs by comparing seasonal diet composition of owls with AR residue patterns in prey species. Risk was highest in autumn, when barn owls increasingly preyed on Apodemus that regularly showed AR residues, sometimes at high concentrations. The major prey species (Microtus spp.) that was consumed most frequently in summer had less potential to contribute to secondary poisoning of owls. There was no effect of AR application on prey composition. We rarely detected ARs in pellets (2 of 256 samples) but 13% of 38 prey individuals in barn owl nests were AR positive and substantiated the expected pathway. AR residues were present in 55% of 11 barn owl carcasses. Fluctuation in non-target small mammal abundance and differences in AR residue exposure patterns in prey species drives exposure risk for barn owls and probably other predators of small mammals. Exposure risk could be minimized through spatial and temporal adaption of AR applications (avoiding long baiting and non-target hot spots at farms) and through selective bait access for target animals.

  2. Exploiting Semantic Web Technologies to Develop OWL-Based Clinical Practice Guideline Execution Engines.

    PubMed

    Jafarpour, Borna; Abidi, Samina Raza; Abidi, Syed Sibte Raza

    2016-01-01

    Computerizing paper-based CPG and then executing them can provide evidence-informed decision support to physicians at the point of care. Semantic web technologies especially web ontology language (OWL) ontologies have been profusely used to represent computerized CPG. Using semantic web reasoning capabilities to execute OWL-based computerized CPG unties them from a specific custom-built CPG execution engine and increases their shareability as any OWL reasoner and triple store can be utilized for CPG execution. However, existing semantic web reasoning-based CPG execution engines suffer from lack of ability to execute CPG with high levels of expressivity, high cognitive load of computerization of paper-based CPG and updating their computerized versions. In order to address these limitations, we have developed three CPG execution engines based on OWL 1 DL, OWL 2 DL and OWL 2 DL + semantic web rule language (SWRL). OWL 1 DL serves as the base execution engine capable of executing a wide range of CPG constructs, however for executing highly complex CPG the OWL 2 DL and OWL 2 DL + SWRL offer additional executional capabilities. We evaluated the technical performance and medical correctness of our execution engines using a range of CPG. Technical evaluations show the efficiency of our CPG execution engines in terms of CPU time and validity of the generated recommendation in comparison to existing CPG execution engines. Medical evaluations by domain experts show the validity of the CPG-mediated therapy plans in terms of relevance, safety, and ordering for a wide range of patient scenarios.

  3. Landscape Features Shape Genetic Structure in Threatened Northern Spotted Owls

    USGS Publications Warehouse

    Funk, W. Chris; Forsman, Eric D.; Mullins, Thomas D.; Haig, Susan M.

    2008-01-01

    Several recent studies have shown that landscape features can strongly affect spatial patterns of gene flow and genetic variation. Understanding landscape effects on genetic variation is important in conservation for defining management units and understanding movement patterns. The landscape may have little effect on gene flow, however, in highly mobile species such as birds. We tested for genetic breaks associated with landscape features in the northern spotted owl (Strix occidentalis caurina), a threatened subspecies associated with old forests in the U.S. Pacific Northwest and extreme southwestern Canada. We found little evidence for distinct genetic breaks in northern spotted owls using a large microsatellite dataset (352 individuals from across the subspecies' range genotyped at 10 loci). Nonetheless, dry low-elevation valleys and the Cascade and Olympic Mountains restrict gene flow, while the Oregon Coast Range facilitates it. The wide Columbia River is not a barrier to gene flow. In addition, inter-individual genetic distance and latitude were negatively related, likely reflecting northward colonization following Pleistocene glacial recession. Our study shows that landscape features may play an important role in shaping patterns of genetic variation in highly vagile taxa such as birds.

  4. Reproduction in eastern screech-owls fed selenium

    USGS Publications Warehouse

    Wiemeyer, Stanley N.; Hoffman, D.J.

    1996-01-01

    Raptors are occasionally exposed to excessive selenium from contaminated prey, but the effects of this exposure on reproduction are unknown. Therefore, we fed captive eastern screech-owls (Otus asio) diets containing 0, 4.4, or 13.2 ppm (wet wt) added selenium in the form of seleno-DL-methionine. Adult mass at sacrifice and reproductive success of birds receiving 13.2 ppm selenium were depressed (P < 0.05) relative to controls. Parents given 4.4 ppm selenium produced no malformed nestlings, but femur lengths of young were shorter (P = 0.015) than those of controls. Liver biochemistries indicative of oxidative stress were affected (P < 0.05) in 5-day-old nestlings from parents fed 4.4 ppm selenium and included a 19% increase in glutathione peroxidase activity, a 43% increase in the ratio of oxidized glutathione (GSSG) to reduced glutathione (GSH), and a 17% increase in lipid peroxidation. Based on reproductive effects relative to dietary exposure, sensitivity of eastern screech-owls to selenium was similar to that of black-crowned night-herons (Nycticorax nycticorax) but less than that of mallards (Anas platyrhynchos).

  5. West Nile virus outbreak in North American owls, Ontario, 2002.

    PubMed

    Gancz, Ady Y; Barker, Ian K; Lindsay, Robbin; Dibernardo, Antonia; McKeever, Katherine; Hunter, Bruce

    2004-12-01

    From July to September 2002, an outbreak of West Nile virus (WNV) caused a high number of deaths in captive owls at the Owl Foundation, Vineland, Ontario, Canada. Peak death rates occurred in mid-August, and the epidemiologic curve resembled that of corvids in the surrounding Niagara region. The outbreak occurred in the midst of a louse fly (Icosta americana, family Hippoboscidae) infestation. Of the flies tested, 16 (88.9 %) of 18 contained WNV RNA. Species with northern native breeding range and birds >1 year of age were at significantly higher risk for WNV-related deaths. Species with northern native breeding range and of medium-to-large body size were at significantly higher risk for exposure to WNV. Taxonomic relations (at the subfamily level) did not significantly affect exposure to WNV or WNV-related deaths. Northern native breeding range and medium-to-large body size were associated with earlier death within the outbreak period. Of the survivors, 69 (75.8 %) of 91 were seropositive for WNV.

  6. Live blind snakes (Leptotyphlops dulcis) in eastern screech owl (Otus asio) nests: a novel commensalism.

    PubMed

    Gehlbach, F R; Baldridge, R S

    1987-03-01

    Eastern screech owls bring live blind snakes to their nestlings, whereas all other prey are delivered dead. Some of the snakes are eaten but most live in nest debris, where they eat soft-bodied insect larvae from the decomposer community in fecal matter, pellets, and uneaten prey. Consumption of larvae may reduce larval parasitism on owl nestlings or larval competition with nestlings for food stored in the nest, because nestlings with live-in blind snakes grow faster and experience lower mortality than same-season broods lacking snakes. We propose a commensalistic association in which the screech owl benefits reproductively and the live-in blind snake is not affected.

  7. Surveys of Puerto Rican screech-owl populations in large-tract and fragmented forest habitats

    USGS Publications Warehouse

    Pardieck, K.L.; Meyers, J.M.; Pagan, M.

    1996-01-01

    We conducted road surveys of Puerto Rican Screech-Owls (Otus nudipes) by playing conspecific vocalizations in secondary wet forest and fragmented secondary moist forest in rural areas of eastern Puerto Rico. Six paired surveys were conducted bi-weekly beginning in April. We recorded number of owl responses, cloud cover, wind speed, moon phase, and number of passing cars during 5-min stops at 60 locations. Owls responded in similar numbers (P > 0.05) in both habitat types. Also, we detected no association with cloud cover, wind speed, moon phase, or passing cars.

  8. Night vision in barn owls: visual acuity and contrast sensitivity under dark adaptation.

    PubMed

    Orlowski, Julius; Harmening, Wolf; Wagner, Hermann

    2012-12-06

    Barn owls are effective nocturnal predators. We tested their visual performance at low light levels and determined visual acuity and contrast sensitivity of three barn owls by their behavior at stimulus luminances ranging from photopic to fully scotopic levels (23.5 to 1.5 × 10⁻⁶). Contrast sensitivity and visual acuity decreased only slightly from photopic to scotopic conditions. Peak grating acuity was at mesopic (4 × 10⁻² cd/m²) conditions. Barn owls retained a quarter of their maximal acuity when luminance decreased by 5.5 log units. We argue that the visual system of barn owls is designed to yield as much visual acuity under low light conditions as possible, thereby sacrificing resolution at photopic conditions.

  9. Overt attention toward oriented objects in free-viewing barn owls.

    PubMed

    Harmening, Wolf Maximilian; Orlowski, Julius; Ben-Shahar, Ohad; Wagner, Hermann

    2011-05-17

    Visual saliency based on orientation contrast is a perceptual product attributed to the functional organization of the mammalian brain. We examined this visual phenomenon in barn owls by mounting a wireless video microcamera on the owls' heads and confronting them with visual scenes that contained one differently oriented target among similarly oriented distracters. Without being confined by any particular task, the owls looked significantly longer, more often, and earlier at the target, thus exhibiting visual search strategies so far demonstrated in similar conditions only in primates. Given the considerable differences in phylogeny and the structure of visual pathways between owls and humans, these findings suggest that orientation saliency has computational optimality in a wide variety of ecological contexts, and thus constitutes a universal building block for efficient visual information processing in general.

  10. A new species of masked-owl (Aves: Strigiformes: Tytonidae) from Seram, Indonesia.

    PubMed

    Jønsson, Knud Andreas; Poulsen, Michael Køie; Haryoko, Tri; Reeve, Andrew Hart; Fabre, Pierre-Henri

    2013-01-01

    We describe a new species of masked-owl from the lower montane forest of Seram, one of the largest islands in the Moluccas of eastern Indonesia, for which we propose the name Tyto almae (Seram Masked-Owl), sp. nov. Molecular (mitochondrial cyt-b) differences show that Tyto sororcula of Buru and Tanimbar is closely related to T novaehollandiae of Australia and New Guinea (-1% uncorrected pairwise distance), and that Tyto almae of Seram differs by -3% (uncorrected pairwise distance) from both of them. These differences are further corroborated by morphology and colouration. Although a photograph from Seram published in 1987 had already established the presence of a Tyto owl on the island, ours represents the first specimen of this species. The bird was mist-netted in wet, mossy lower montane forest at an elevation of 1,350 m. No further observations of the owl were made during four weeks of fieldwork in Seram.

  11. Rodents new to the diet of the western burrowing owl(athene CUNICULARIA HYPUGAEA )

    USGS Publications Warehouse

    Wiluford, D.L.; Woodin, M.C.; Skoruppa, M.K.; Hickman, G.C.

    2009-01-01

    The northern pygmy mouse (Baiomys taylori), fulvous harvest mouse (Reithrodontomys fulvescens), and Merriam's pocket mouse (Pemgnathus merriami) are new to the diet of the western burrowing owl (Athene cuniculana hypugaed). All three species were identified from remains in regurgitated pellets collected from roost sites of burrowing owls in southern Texas over a period of 4 winters. Together, northern pygmy mice and fulvous harvest mice represented 58% of mammals identified in 182 pellets regurgitated by western burrowing owls. Merriam's pocket mouse accounted for only 4% of identified mammalian prey. Frequency of occurrence in pellets was 16% for northern pygmv mice, 11% for fulvous harvest mice, and 3% for Merriam's pocket mice. The primary reason for absence of these species in previous studies of foods of western burrowing owls is that most were conducted in latitudes north of these southern-distributed species of mammals.

  12. CALVARIAL OSTEOSARCOMA WITH CEREBRAL COMPRESSION IN A FREE-RANGING POWERFUL OWL (NINOX STRENUA).

    PubMed

    Sladakovic, Izidora; Sangster, Cheryl R; Allan, Graeme S; Portas, Timothy J; Howlett, Cameron R; Blas-Machado, Uriel

    2017-03-01

    A free-ranging powerful owl (Ninox strenua) presented in a dull state with extensive bruising of the skin overlying the skull, due to suspected trauma. Supportive care was provided, which resulted in the return to a normal state, although intermittent subtle neurologic abnormalities remained. One month from original presentation, intermittent episodes of head turning and a possible seizure were noted, but behavior and appetite were otherwise normal. The owl was referred to Taronga Wildlife Hospital for evaluation. On presentation, the owl exhibited severe neurologic abnormalities, prompting euthanasia. At necropsy the dorsum of the skull exhibited marked osseous proliferation, extending ventrally and compressing the cerebrum. The skull was radiographed and submitted for histopathology. A diagnosis of osteoblastic osteosarcoma was made. This is the first report of a calvarial osteosarcoma in a powerful owl.

  13. EPA Science Matters Newsletter: EPA Recovery Champions Help Effort to Save Threatened Owl (Published January 2014)

    EPA Pesticide Factsheets

    Learn abut HexSim, a program developed by the EPA, that incorporates vast amounts of available data about dwindling wildlife species, such as spotted owls, to create scenarios involving virtual populations

  14. Estimating inbreeding rates in Northern Spotted Owls: insights from pedigrees and spatio-demographic models

    EPA Science Inventory

    The federally-threatened Northern Spotted Owl (Strix occidentalis caurina) has a substantial influence on management of federal lands. Despite decades of investigation, important details about its status and habits remain unknown. In particular, determining the frequency of inbre...

  15. Documenting Western Burrowing Owl Reproduction and Activity Patterns Using Motion-Activated Cameras

    SciTech Connect

    Hall, Derek B.; Greger, Paul D.

    2014-08-01

    We used motion-activated cameras to monitor the reproduction and patterns of activity of the Burrowing Owl (Athene cunicularia) above ground at 45 burrows in south-central Nevada during the breeding seasons of 1999, 2000, 2001, and 2005. The 37 broods, encompassing 180 young, raised over the four years represented an average of 4.9 young per successful breeding pair. Young and adult owls were detected at the burrow entrance at all times of the day and night, but adults were detected more frequently during afternoon/early evening than were young. Motion-activated cameras require less effort to implement than other techniques. Limitations include photographing only a small percentage of owl activity at the burrow; not detecting the actual number of eggs, young, or number fledged; and not being able to track individual owls over time. Further work is also necessary to compare the accuracy of productivity estimates generated from motion-activated cameras with other techniques.

  16. Home range characteristics of great gray owls in Yosemite National Park, California

    USGS Publications Warehouse

    Van Riper, Charles; van Wagtendonk, Jan W.

    2006-01-01

    We studied home range and habitat use of radio-tagged Great Gray Owls (Strix nebulosa) in Yosemite, California. From 1986–90 we made 5338 relocations on nine adult and three juvenile owls. Home-range size was not correlated with number of locations and was significantly different between breeding and nonbreeding periods. Breeding female summer home range averaged 61.47 ha and during the winter 2457.27 ha, while males average 19.89 and 2112.87 ha, respectively. Juveniles and nonbreeding birds had home-range sizes intermediate between seasonal values of breeding owls. Home ranges for California Great Gray Owls were larger than has been recorded for all studies in North America, but smaller than in Europe. All owls were found to have intensive high-use activity centers (x− = 17.56 ha) in summer, with use patterns influenced primarily by meadows. Over 60% of all relocations occurred within 100 m of a meadow. Great Gray Owls habitat usage during summer was concentrated in fir (Abies spp.) and lodgepole (Pinus contorta) habitat types, while during the winter, birds moved to lower elevations into Sierra mixed conifer habitats. This post-breeding movement was the cause of the large nonbreeding home ranges. During winter, paired birds did not remain together, even though all birds moved to lower elevation habitats below deep snow-pack levels. We suggest that Great Gray Owls in California have responded to the relatively hot and southern habitat with unique adaptations that have allowed several local populations to persist within the upper montane Sierra Nevada forest zone. The protection of meadow foraging habitat, as well as nesting locations, will be important for the continued preservation of this southernmost North American population of Great Gray Owls in Yosemite National Park.

  17. Relative size of auditory pathways in symmetrically and asymmetrically eared owls.

    PubMed

    Gutiérrez-Ibáñez, Cristián; Iwaniuk, Andrew N; Wylie, Douglas R

    2011-01-01

    Owls are highly efficient predators with a specialized auditory system designed to aid in the localization of prey. One of the most unique anatomical features of the owl auditory system is the evolution of vertically asymmetrical ears in some species, which improves their ability to localize the elevational component of a sound stimulus. In the asymmetrically eared barn owl, interaural time differences (ITD) are used to localize sounds in azimuth, whereas interaural level differences (ILD) are used to localize sounds in elevation. These two features are processed independently in two separate neural pathways that converge in the external nucleus of the inferior colliculus to form an auditory map of space. Here, we present a comparison of the relative volume of 11 auditory nuclei in both the ITD and the ILD pathways of 8 species of symmetrically and asymmetrically eared owls in order to investigate evolutionary changes in the auditory pathways in relation to ear asymmetry. Overall, our results indicate that asymmetrically eared owls have much larger auditory nuclei than owls with symmetrical ears. In asymmetrically eared owls we found that both the ITD and ILD pathways are equally enlarged, and other auditory nuclei, not directly involved in binaural comparisons, are also enlarged. We suggest that the hypertrophy of auditory nuclei in asymmetrically eared owls likely reflects both an improved ability to precisely locate sounds in space and an expansion of the hearing range. Additionally, our results suggest that the hypertrophy of nuclei that compute space may have preceded that of the expansion of the hearing range and evolutionary changes in the size of the auditory system occurred independently of phylogeny.

  18. Effects of fire on spotted owl site occupancy in a late-successional forest

    USGS Publications Warehouse

    Roberts, Susan L.; van Wagtendonk, Jan W.; Miles, A. Keith; Kelt, Douglas A.

    2011-01-01

    The spotted owl (Strix occidentalis) is a late-successional forest dependent species that is sensitive to forest management practices throughout its range. An increase in the frequency and spatial extent of standreplacing fires in western North America has prompted concern for the persistence of spotted owls and other sensitive late-successional forest associated species. However, there is sparse information on the effects of fire on spotted owls to guide conservation policies. In 2004-2005, we surveyed for California spotted owls during the breeding season at 32 random sites (16 burned, 16 unburned) throughout late-successional montane forest in Yosemite National Park, California. Our burned areas burned at all severities, but predominately involved low to moderate fire severity. Based on an information theoretic approach, spotted owl detection and occupancy rates were similar between burned and unburned sites. Nest and roost site occupancy was best explained by a model that combined total tree basal area (positive effect) with cover by coarse woody debris (negative effect). The density estimates of California spotted owl pairs were similar in burned and unburned forests, and the overall mean density estimate for Yosemite was higher than previously reported for montane forests. Our results indicate that low to moderate severity fires, historically common within montane forests of the Sierra Nevada, California, maintain habitat characteristics essential for spotted owl site occupancy. These results suggest that managed fires that emulate the historic fire regime of these forests may maintain spotted owl habitat and protect this species from the effects of future catastrophic fires.

  19. Importance of agricultural landscapes to nesting burrowing owls in the Northern Great Plains, USA

    USGS Publications Warehouse

    Restani, M.; Davies, J.M.; Newton, W.E.

    2008-01-01

    Anthropogenic habitat loss and fragmentation are the principle factors causing declines of grassland birds. Declines in burrowing owl (Athene cunicularia) populations have been extensive and have been linked to habitat loss, primarily the decline of black-tailed prairie dog (Cynomys ludovicianus) colonies. Development of habitat use models is a research priority and will aid conservation of owls inhabiting human-altered landscapes. From 2001 to 2004 we located 160 burrowing owl nests on prairie dog colonies on the Little Missouri National Grassland in North Dakota. We used multiple linear regression and Akaike's Information Criterion to estimate the relationship between cover type characteristics surrounding prairie dog colonies and (1) number of owl pairs per colony and (2) reproductive success. Models were developed for two spatial scales, within 600 m and 2,000 m radii of nests for cropland, crested wheatgrass (Agropyron cristatum), grassland, and prairie dog colonies. We also included number of patches as a metric of landscape fragmentation. Annually, fewer than 30% of prairie dog colonies were occupied by owls. None of the models at the 600 m scale explained variation in number of owl pairs or reproductive success. However, models at the 2,000 m scale did explain number of owl pairs and reproductive success. Models included cropland, crested wheatgrass, and prairie dog colonies. Grasslands were not included in any of the models and had low importance values, although percentage grassland surrounding colonies was high. Management that protects prairie dog colonies bordering cropland and crested wheatgrass should be implemented to maintain nesting habitat of burrowing owls. ?? 2008 Springer Science+Business Media B.V.

  20. Conservation of the northern spotted owl under the Northwest Forest Plan.

    PubMed

    Noon, Barry R; Blakesley, Jennifer A

    2006-04-01

    Development of the Northwest Forest Plan (NWFP) was motivated by concerns about the over-harvest of late-seral forests and the effects of intensive forest management on the long-term viability of the Northern Spotted Owl (Strix occidentalis caurina). Following several years of intense political and legal debates, the final NWFP was approved in 1994. Even though the plan evolved with a broad ecosystem perspective, it remained anchored in the Spotted Owl reserve design proposed in 1990. Based on a criterion of stable or increasing populations, a decade later it remains unclear whether the enactment of the NWFP has improved the conservation status of Spotted Owls. The results of intensive monitoring of several Spotted Owl populations for over a decade suggest a continuing range-wide decline even though rates of timber harvest have declined dramatically on federal lands. The cause of the decline is difficult to determine because the research needed to establish cause and effect relations has not been done. One plausible hypothesis is that the owl's life history greatly constrains its rate of population growth even when habitat is no longer limiting. Since enactment of the NWFP, new threats have arisen, including the movement of Barred Owls (S. varia) into the range of the Spotted Owl, political pressure to increase levels of timber harvest, and recent changes to forest laws that eliminate the requirement to assess the viability of wildlife populations on U.S. Department of Agriculture Forest Service lands. At this time is appears that Spotted Owl conservation rests critically on continued implementation of the protections afforded by the NWFP and the U.S. Endangered Species Act.

  1. Unusual leg malformations in screech owls from a South Carolina Superfund site

    USGS Publications Warehouse

    Albers, P.H.; Hoffman, D.J.; Brisbin, I.L.

    2001-01-01

    In 1995, the discovery of leg malformations in several screech owl (Otis asio) nestlings and in their female parent at a Department of Energy (DOE) Superfund site in South Carolina prompted an investigation into the nature of the observed abnormalities. Surviving nestlings and the female parent were transferred to a captive screech owl breeding colony at the USGS Patuxent Wildlife Research Center, Laurel, MD. The malformed female parent and her offspring were each mated with normal owls from the colony for 3 yr. Matings of the malformed female produced five malformed and six normal owls; all owls produced by matings of normal offspring were normal. Malformed offspring were euthanized when it became apparent that their physical distress precluded survival under normal conditions of colony care. Euthanized owls were necropsied and examined for skeletal development. Detailed descriptions of eight malformed owls are presented. Results of the matings indicated that the leg malformations were caused by a genetic trait in the female parent that was heterozygous dominant. The characteristic was lethal except in occasional mild manifestations and resembled an extreme form of a dominant abnormality previously described for domestic fowl called duplicate polydactyly. Other reports of skeletal abnormalities in wild birds and potential environmental causes of genetic mutations at the DOE Super-fund site are presented. Other studies performed at the DOE Superfund site do not implicate elevated (above background) ionizing radiation from '37Cs, the dominant radio-nuclide where the owls were captured, as the cause of the mutation. The cause of this genetic abnormality remains unknown.

  2. Factors influencing nesting success of burrowing owls in southeastern Idaho

    SciTech Connect

    Gleason, R.S.; Johnson, D.R.

    1985-01-31

    A burrowing owl (Athene cunicularia) population nesting on the Idaho National Engineering Laboratory (INEL) in southeastern Idaho utilized burrows excavated by badgers (Taxidea taxus) or natural cavities in lava flows as nesting sites. The size of the population was small (N = 13-14 pairs) in relation to the number of available nesting sites, suggesting that factors other than burrow availability limited this population. Rodents and Jerusalem crickets (Stenopelmatus fuscus) represented the primary prey utilized during the nesting season. This population demonstrated both a numerical (brood size) and functional (dietary) response to a decrease in the density of three species of rodents on the INEL during a drought in 1977. 11 references, 1 figure, 2 table.

  3. Traffic noise reduces foraging efficiency in wild owls

    NASA Astrophysics Data System (ADS)

    Senzaki, Masayuki; Yamaura, Yuichi; Francis, Clinton D.; Nakamura, Futoshi

    2016-08-01

    Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for localizing prey when hunting. We conducted field experiments to examine the effect of traffic noise on owls’ ability to detect prey. Results suggest that foraging efficiency declines with increasing traffic noise levels due to acoustic masking and/or distraction and aversion to traffic noise. Moreover, we estimate that effects of traffic noise on owls’ ability to detect prey reach >120 m from a road, which is larger than the distance estimated from captive studies with bats. Our study provides the first evidence that noise reduces foraging efficiency in wild animals, and highlights the possible pervasive impacts of noise.

  4. Dyscoria associated with herpesvirus infection in owl monkeys (Aotus nancymae)

    SciTech Connect

    Gozalo, Alfonso S.; Montoya, Enrique J.; Weller, Richard E.

    2008-08-16

    Abstract Dyscoria was observed in a female owl monkey and her two offspring. A third offspring was found dead with necrohemorrhagic encephalitis. Two males paired with the female died, one of which showed oral ulcers at necropsy. Histologic examination of the oral ulcers revealed syncytia and eosinophilic intranuclear inclusion bodies in epithelial cells. Ocular examination revealed posterior synechia associated with the dyscoria in all three animals. Serum samples from the female and her offspring were positive for Herpesvirus simplex antibodies by enzyme-linked immunosorbent assay. The clinical history, gross and microscopic lesions, and serology results suggests a herpesviral etiology, possibly, H. simplex or H. saimiri-1. This report underscores the risks associated with introducing animals into breeding or research colonies that were previously kept as pets or those from unknown origin that could carry asymptomatic pathogenic Herpesvirus infections. In addition, herpesviral infection should be considered among the differential diagnoses if dyscoria is observed in nonhuman primates.

  5. Data Reduction Algorithm for Optical Wide Field Patrol (OWL)

    NASA Astrophysics Data System (ADS)

    Park, S.; Park, Y.; Yim, H.; Jo, J.; Moon, H.; Bae, Y.; Lim, Y.; Choi, J.; Choi, Y.; Park, J.; Son, J.

    2014-09-01

    OWL (Optical Wide-field Patrol) has a detector system which has the chopper which consists of 4 blades in front of the CCD camera to acquire efficiently the position and time information of moving objects such as artificial satellites. Using this system, it is possible to get more position data by splitting the streaks of the moving object into many pieces with fast rotating blades during tracking. At the same time, the time data of the rotating chopper can be acquired by the time tagger connected to the photo diode. In order to derive the orbits of the targets, we need a sequential data reduction procedure including the calculation of WCS (World Coordinate System) solution to transform the positions into equatorial coordinate systems, and the combination of the time data from the time tagger and the position data. We present such a data reduction procedure and the preliminary results after applying this procedure to the observation images.

  6. Comment on 'Are survival rates for northern spotted owls biased?'

    USGS Publications Warehouse

    Franklin, A.B.; Nichols, J.D.; Anthony, R.G.; Burnham, K.P.; White, Gary C.; Forsman, E.D.; Anderson, D.R.

    2006-01-01

    Loehle et al. recently estimated survival rates from radio-telemetered northern spotted owls (Strix occidentalis caurina (Merriam, 1898)) and suggested that survival rates estimated for this species from capture-recapture studies were negatively biased, which subsequently resulted in the negatively biased estimates of rates of population change (lambda) reported by Anthony et al. (Wildl. Monogr. No. 163, pp. 1-47 (2006)). We argue that their survival estimates were inappropriate for comparison with capture-recapture estimates because (i) the manner in which they censored radio-telemetered individuals had the potential to positively bias their survival estimates, (ii) their estimates of survival were not valid for evaluating bias, and (iii) the size and distribution of their radiotelemetry study areas were sufficiently different from capture-recapture study areas to preclude comparisons. In addition, their inferences of negative bias in rates of population change estimated by Anthony et al. were incorrect and reflected a misunderstanding about those estimators.

  7. Traffic noise reduces foraging efficiency in wild owls

    PubMed Central

    Senzaki, Masayuki; Yamaura, Yuichi; Francis, Clinton D.; Nakamura, Futoshi

    2016-01-01

    Anthropogenic noise has been increasing globally. Laboratory experiments suggest that noise disrupts foraging behavior across a range of species, but to reveal the full impacts of noise, we must examine the impacts of noise on foraging behavior among species in the wild. Owls are widespread nocturnal top predators and use prey rustling sounds for localizing prey when hunting. We conducted field experiments to examine the effect of traffic noise on owls’ ability to detect prey. Results suggest that foraging efficiency declines with increasing traffic noise levels due to acoustic masking and/or distraction and aversion to traffic noise. Moreover, we estimate that effects of traffic noise on owls’ ability to detect prey reach >120 m from a road, which is larger than the distance estimated from captive studies with bats. Our study provides the first evidence that noise reduces foraging efficiency in wild animals, and highlights the possible pervasive impacts of noise. PMID:27537709

  8. Dyscoria Associated with Herpesvirus Infection in Owl Monkeys (Aotus nancymae)

    PubMed Central

    Gozalo, Alfonso S; Montoya, Enrique J; Weller, Richard E

    2008-01-01

    Dyscoria was noted in a female owl monkey and 2 of her offspring. The third offspring was found dead with necrohemorrhagic encephalitis. Two male monkeys paired with the female died, 1 of which showed oral ulcers at necropsy. Histologic examination of the oral ulcers revealed syncytia and eosinophilic intranuclear inclusion bodies in epithelial cells. Ocular examination revealed posterior synechia associated with the dyscoria in all 3 animals. Serum samples from the female and her offspring were positive for Herpesvirus simplex antibodies by ELISA. The clinical history, gross and microscopic lesions, and serology results suggests a herpesviral etiology, possibly H. simplex or H. saimiri 1. This report underscores the risks associated with introducing into breeding or research colonies animals that previously were kept as pets or those from unknown origin that could carry asymptomatic pathogenic Herpesvirus infections. In addition, herpesviral infection should be considered among the differential diagnoses if dyscoria is noted in nonhuman primates. PMID:18702455

  9. Dyscoria associated with herpesvirus infection in owl monkeys (Aotus nancymae).

    PubMed

    Gozalo, Alfonso S; Montoya, Enrique J; Weller, Richard E

    2008-07-01

    "Dyscoria was noted in a female owl monkey and 2 of her offspring. The third offspring was found dead with necrohemorrhagic encephalitis. Two male monkeys paired with the female died, 1 of which showed oral ulcers at necropsy. Histologic examination of the oral ulcers revealed syncytia and eosinophilic intranuclear inclusion bodies in epithelial cells. Ocular examination revealed posterior synechia associated with the dyscoria in all 3 animals. Serum samples from the female and her offspring were positive for Herpesvirus simplex antibodies by ELISA. The clinical history, gross and microscopic lesions, and serology results suggests a herpesviral etiology, possibly H. simplex or H. saimiri 1. This report underscores the risks associated with introducing into breeding or research colonies animals that previously were kept as pets or those from unknown origin that could carry asymptomatic pathogenic Herpesvirus infections. In addition, herpesviral infection should be considered among the differential diagnoses if dyscoria is noted in nonhuman primates."

  10. Nocturnal activity by diurnal lizards (Sceloporus jarrovi, S. virgatus) eaten by small owls (Glaucidium gnoma, Otus trichopsis)

    USGS Publications Warehouse

    Duncan, W.W.; Gehlbach, F.R.; Middendorf, G. A.

    2003-01-01

    Whiskered screech-owls (Otus trichopsis) and northern pygmy-owls (Glaucidium gnoma) delivered freshly caught Yarrow's spiny lizards (Sceloporus jarrovi) and striped plateau lizards (S. virgatus) to nestlings from dusk to dark in southeastern Arizona. This observation stimulated studies of the prey deliveries by the owls and lizard activity patterns, because the lizards are not known to be nocturnal. Lizards were more frequent prey of both owls than endothermic vertebrates but infrequent compared to arthropods, a pattern in the pygmy-owl that differs from its northern populations. Yarrow's spiny lizard, the most abundant and frequently captured lizard, was most active in the morning but also active in the evening. Striped plateau lizard, the second most abundant and depredated species, had morning and evening peaks of activity. Few lizards, including S. clarki and Urosaurus ornatus, but not Cnemidophorus exsanguis and C. sonorae, were active at or after dark, when relatively few were captured by the owls.

  11. The screech owl: Its life history and population ecology in northern Ohio

    USGS Publications Warehouse

    Vancamp, Laurel F.; Henny, Charles J.

    1975-01-01

    The screech owl (Otus asio) is native to North America and breeds throughout the United States and in portions of Canada and Mexico. It is a small owl, 20 cm (8 in) in length from the tip of the bill to the tip of the tail, with a wing span of 56 cm (22 in); it has yellow eyes and prominent ear tufts (see Frontispiece). Although the species is common throughout much of North America, it has not been studied intensively, particularly over a long period. The published literature is concerned mostly with food habits, color phase, taxonomy, and miscellaneous observations. Breeding biology and population dynamics have received little attention. This report presents the basic life history and population information about screech owls in northern Ohio over a 30-yr period. The owls studied were nesting in boxes (Fig. 1) established for wood ducks (Aix sponsa) along rivers, creeks, and marshes in a four-county area (Ottawa, Sandusky, Wood, and Lucas Counties) near Lake Erie (Fig. 2). No special trapping techniques were required as the screech owls readily used these nesting boxes and could be easily captured while in them. More than 3,000 owls were captured and banded; 500 were recaptured after the initial banding, some 10 or 15 times. This process provided a large quanity of basic information for this report.

  12. Alarm calls modulate the spatial structure of a breeding owl community.

    PubMed

    Parejo, Deseada; Avilés, Jesús M; Rodríguez, Juan

    2012-06-07

    Animals should continuously assess the threat of predation. Alarm calls inform on predation risk and are often used as cues to shape behavioural responses in birds and mammals. Hitherto, however, the ecological consequences of alarm calls in terms of organization of animal communities have been neglected. Here, we show experimentally that calls of a resident nocturnal raptor, the little owl Athene noctua, triggered a response in terms of breeding habitat selection and investment in current reproduction in conspecifics and heterospecifics. Little owls preferred to settle in territories where calls of conspecifics, irrespective of their type (i.e. alarm versus contact calls), were broadcasted, indicating that either conspecific attraction exists or calls are interpreted as foreign calls, eliciting settlement as a mode of defence against competitors. Also, we found that little owls seemed to invest more in current reproduction in safe territories as revealed by conspecific calls. Innovatively, we reported that a second owl species, the migratory scops owl Otus scops, preferred to breed in safe territories as indicated by little owls' calls. These results evidence that the emission of alarm calls may have, apart from well-known behavioural effects, ecological consequences in natural communities by inducing species-specific biases in breeding habitat selection. This study demonstrates a previously unsuspected informative role of avian alarm calls which may modulate the spatial structure of species within communities.

  13. Auditory brainstem responses in the Eastern Screech Owl: An estimate of auditory thresholds

    USGS Publications Warehouse

    Brittan-Powell, E.F.; Lohr, B.; Hahn, D.C.; Dooling, R.J.

    2005-01-01

    The auditory brainstem response (ABR), a measure of neural synchrony, was used to estimate auditory sensitivity in the eastern screech owl (Megascops asio). The typical screech owl ABR waveform showed two to three prominent peaks occurring within 5 ms of stimulus onset. As sound pressure levels increased, the ABR peak amplitude increased and latency decreased. With an increasing stimulus presentation rate, ABR peak amplitude decreased and latency increased. Generally, changes in the ABR waveform to stimulus intensity and repetition rate are consistent with the pattern found in several avian families. The ABR audiogram shows that screech owls hear best between 1.5 and 6.4 kHz with the most acute sensitivity between 4?5.7 kHz. The shape of the average screech owl ABR audiogram is similar to the shape of the behaviorally measured audiogram of the barn owl, except at the highest frequencies. Our data also show differences in overall auditory sensitivity between the color morphs of screech owls.

  14. Second generation anticoagulant rodenticides in tawny owls (Strix aluco) from Great Britain.

    PubMed

    Walker, Lee A; Turk, Anthony; Long, Sara M; Wienburg, Claire L; Best, Jennifer; Shore, Richard F

    2008-03-15

    Secondary exposure of vertebrate predators to second generation anticoagulant rodenticides (SGARs) is widespread in Britain. Tawny owl (Strix aluco) populations in the UK are thought to have declined since the 1970s, when SGARs were first introduced, and these compounds may have contributed to any decline in owl numbers. Our aims were to conduct the first systematic survey of SGAR exposure in tawny owls and ascertain whether there had been a change in the proportion of exposed birds that was concurrent with the decline in the population. Liver difenacoum, bromadiolone, flocoumafen and brodifacoum concentrations in British tawny owls from two periods (1990-1993 and 2003-2005) were quantified. In total, some 20% of birds contained detectable residues of one or more SGAR. The extent of exposure (% of birds exposed, magnitude of residues) to different SGARs did not change consistently between time periods. Of the raptors analysed to date in Britain, tawny owls had the lowest proportion of individuals that contained detectable liver residues and so appear to be the least vulnerable to exposure and/or assimilation of SGARs. We found no clear evidence to implicate SGARs as a major factor affecting tawny owl numbers in Britain between 1990 and 2005.

  15. The barn owl wing: an inspiration for silent flight in the aviation industry?

    NASA Astrophysics Data System (ADS)

    Bachmann, Thomas; Mühlenbruch, Georg; Wagner, Hermann

    2011-04-01

    Barn owls are specialists in prey detection using acoustic information. The flight apparatus of this bird of prey is most efficiently adapted to the hunting behavior by reducing flight noise. An understanding of the underlying mechanisms owls make use of could help minimize the noise disturbances in airport or wind power plant neighborhood. Here, we characterize wings of barn owls in terms of an airfoil as a role model for studying silent flight. This characterization includes surface and edge specialization (serrations, fringes) evolved by the owl. Furthermore, we point towards possible adaptations of either noise suppression or air flow control that might be an inspiration for the construction of modern aircraft. Three-dimensional imaging techniques such as surface digitizing, computed tomography and confocal laser scanning microscopy were used to investigate the wings and feathers in high spatial resolution. We show that wings of barn owls are huge in relation to their body mass resulting in a very low wing loading which in turn enables a slow flight and an increased maneuverability. Profiles of the wing are highly cambered and anteriorly thickened, especially at the proximal wing, leading to high lift production during flight. However, wind tunnel experiments showed that the air flow tends to separate at such wing configurations, especially at low-speed flight. Barn owls compensated this problem by evolving surface and edge modifications that stabilize the air flow. A quantitative three-dimensionally characterization of some of these structures is presented.

  16. Barn Owl Productivity Response to Variability of Vole Populations

    PubMed Central

    Pavluvčík, Petr; Poprach, Karel; Machar, Ivo; Losík, Jan; Gouveia, Ana; Tkadlec, Emil

    2015-01-01

    We studied the response of the barn owl annual productivity to the common vole population numbers and variability to test the effects of environmental stochasticity on their life histories. Current theory predicts that temporal environmental variability can affect long-term nonlinear responses (e.g., production of young) both positively and negatively, depending on the shape of the relationship between the response and environmental variables. At the level of the Czech Republic, we examined the shape of the relationship between the annual sum of fledglings (annual productivity) and vole numbers in both non-detrended and detrended data. At the districts’ level, we explored whether the degree of synchrony (measured by the correlation coefficient) and the strength of the productivity response increase (measured by the regression coefficient) in areas with higher vole population variability measured by the s-index. We found that the owls’ annual productivity increased linearly with vole numbers in the Czech Republic. Furthermore, based on district data, we also found that synchrony between dynamics in owls’ reproductive output and vole numbers increased with vole population variability. However, the strength of the response was not affected by the vole population variability. Additionally, we have shown that detrending remarkably increases the Taylor’s exponent b relating variance to mean in vole time series, thereby reversing the relationship between the coefficient of variation and the mean. This shift was not responsible for the increased synchrony with vole population variability. Instead, we suggest that higher synchrony could result from high food specialization of owls on the common vole in areas with highly fluctuating vole populations. PMID:26709518

  17. OWL-based reasoning methods for validating archetypes.

    PubMed

    Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás

    2013-04-01

    Some modern Electronic Healthcare Record (EHR) architectures and standards are based on the dual model-based architecture, which defines two conceptual levels: reference model and archetype model. Such architectures represent EHR domain knowledge by means of archetypes, which are considered by many researchers to play a fundamental role for the achievement of semantic interoperability in healthcare. Consequently, formal methods for validating archetypes are necessary. In recent years, there has been an increasing interest in exploring how semantic web technologies in general, and ontologies in particular, can facilitate the representation and management of archetypes, including binding to terminologies, but no solution based on such technologies has been provided to date to validate archetypes. Our approach represents archetypes by means of OWL ontologies. This permits to combine the two levels of the dual model-based architecture in one modeling framework which can also integrate terminologies available in OWL format. The validation method consists of reasoning on those ontologies to find modeling errors in archetypes: incorrect restrictions over the reference model, non-conformant archetype specializations and inconsistent terminological bindings. The archetypes available in the repositories supported by the openEHR Foundation and the NHS Connecting for Health Program, which are the two largest publicly available ones, have been analyzed with our validation method. For such purpose, we have implemented a software tool called Archeck. Our results show that around 1/5 of archetype specializations contain modeling errors, the most common mistakes being related to coded terms and terminological bindings. The analysis of each repository reveals that different patterns of errors are found in both repositories. This result reinforces the need for making serious efforts in improving archetype design processes.

  18. Reproductive consequences of farmland heterogeneity in little owls (Athene noctua).

    PubMed

    Michel, Vanja T; Naef-Daenzer, Beat; Keil, Herbert; Grüebler, Martin U

    2017-04-01

    The amount of high-quality habitat patches, their distribution, and the resource accessibility therein play a key role in regulating habitat effects on reproductive success. Heterogeneous habitats offer non-substitutable resources (e.g. nest sites and food) and substitutable resources (e.g. different types of food) in close proximity, thereby facilitating landscape complementation and supplementation. However, it remains poorly understood how spatial resource separation in homogeneous agricultural landscapes affects reproductive success. To fill this gap, we investigated the relationships between farmland heterogeneity and little owl (Athene noctua) reproductive success, including potential indirect effects of the heterogeneity-dependent home-range size on reproduction. Little owl home-ranges were related to field heterogeneity in summer and to structural heterogeneity in winter. Clutch size was correlated with the amount of food-rich habitat close to the nest irrespective of female home-range size, suggesting importance of landscape complementation. Nestling survival was positively correlated with male home-range size, suggesting importance of landscape supplementation. At the same time, fledgling condition was negatively correlated with male home-range size. We conclude that decreasing farmland heterogeneity constrains population productivity by two processes: increasing separation of food resources from nest or roost sites results in low landscape complementation, and reduction of alternative food resources limits landscape supplementation. Our results suggest that structural heterogeneity affects landscape complementation, whereas the heterogeneity and management of farmland fields affect landscape supplementation. Thus, to what extent a reduction of the heterogeneity within agricultural landscapes results in species-specific habitat degradation depends on the ecological processes (i.e. landscape complementation or supplementation) which are affected.

  19. Behavioural and physiological responses of wood mice (Apodemus sylvaticus) to experimental manipulations of predation and starvation risk.

    PubMed

    Monarca, Rita I; Mathias, Maria da Luz; Speakman, John R

    2015-10-01

    Body weight and the levels of stored body fat have fitness consequences. Greater levels of fat may provide protection against catastrophic failures in the food supply, but they may also increase the risk of predation. Animals may therefore regulate their fatness according to their perceived risks of predation and starvation: the starvation-predation trade-off model. We tested the predictions of this model in wood mice (Apodemus sylvaticus) by experimentally manipulating predation risk and starvation risk. We predicted that under increased predation risk individuals would lose weight and under increased starvation risk they would gain it. We simulated increased predation risk by playing the calls made by predatory birds (owls: Tyto alba and Bubo bubo) to the mice. Control groups included exposure to calls of a non-predatory bird (blackbird: Turdus merula) or silence. Mice exposed to owl calls at night lost weight relative to the silence group, mediated via reduced food intake, but exposure to owl calls in the day had no significant effect. Exposure to blackbird calls at night also resulted in weight loss, but blackbird calls in the day had no effect. Mice seemed to have a generalised response to bird calls at night irrespective of their actual source. This could be because in the wild any bird calling at night will be a predation risk, and any bird calling in the day would not be, because at that time the mice would normally be resting, and hence not exposed to avian predators. Consequently, mice have not evolved to distinguish different types of call but only to respond to the time of day that they occur. Mice exposed to stochastic 24h starvation events altered their behaviour (reduced activity) during the refeeding days that followed the deprivation periods to regain the lost mass. However, they only marginally elevated their food intake and consequently had reduced body weight/fat storage compared to that of the control unstarved group. This response may have

  20. Seropositivity and Risk Factors Associated with Toxoplasma gondii Infection in Wild Birds from Spain

    PubMed Central

    Cabezón, Oscar; García-Bocanegra, Ignacio; Molina-López, Rafael; Marco, Ignasi; Blanco, Juan M.; Höfle, Ursula; Margalida, Antoni; Bach-Raich, Esther; Darwich, Laila; Echeverría, Israel; Obón, Elena; Hernández, Mauro; Lavín, Santiago; Dubey, Jitender P.; Almería, Sonia

    2011-01-01

    Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n = 610), Strigiformes (n = 260), Ciconiiformes (n = 156), Gruiformes (n = 21), and other orders (n = 32), from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1∶25) were found in 282 (26.1%, IC95%:23.5–28.7) of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus), short-toed snake-eagle (Circaetus gallicus), Bonelli's eagle (Aquila fasciata), golden eagle (Aquila chrysaetos), bearded vulture (Gypaetus barbatus), osprey (Pandion haliaetus), Montagu's harrier (Circus pygargus), Western marsh-harrier (Circus aeruginosus), peregrine falcon (Falco peregrinus), long-eared owl (Asio otus), common scops owl (Otus scops), Eurasian spoonbill (Platalea leucorodia), white stork (Ciconia ciconia), grey heron (Ardea cinerea), common moorhen (Gallinula chloropus); in the International Union for Conservation of Nature (IUCN) “vulnerable” Spanish imperial eagle (Aquila adalberti), lesser kestrel (Falco naumanni) and great bustard (Otis tarda); and in the IUCN “near threatened” red kite (Milvus milvus). The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo) (68.1%, 98 of 144). The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is

  1. Are rainforest owl monkeys cathemeral? Diurnal activity of black-headed owl monkeys, Aotus nigriceps, at Manu Biosphere Reserve, Peru.

    PubMed

    Khimji, Shenaz N; Donati, Giuseppe

    2014-01-01

    Members of the genus Aotus are traditionally considered strictly nocturnal, however, in recent years cathemeral habits have been described in a single species of owl monkey, Aotus azarai, which occur in the highly seasonal habitat of the Argentinean Chaco. This finding raises the question as to whether other species of Aotus exhibit cathemeral activity in less seasonal habitats. In this study, we observed the diurnal activity of one group of A. nigriceps living in the Manu Biosphere Reserve, Peru over 65 days. The data collected indicate that A. nigriceps has only sporadic diurnal bouts of activity. In addition, nocturnal luminosity of the previous night, rainfall, and temperature did not correlate with the minor diurnal activity exhibited. This suggests that for A. nigriceps the potential costs of shifting to diurnality may outweigh its prospective advantages in this rainforest environment.

  2. To dare or not to dare? Risk management by owls in a predator-prey foraging game.

    PubMed

    Embar, Keren; Raveh, Ashael; Burns, Darren; Kotler, Burt P

    2014-07-01

    In a foraging game, predators must catch elusive prey while avoiding injury. Predators manage their hunting success with behavioral tools such as habitat selection, time allocation, and perhaps daring-the willingness to risk injury to increase hunting success. A predator's level of daring should be state dependent: the hungrier it is, the more it should be willing to risk injury to better capture prey. We ask, in a foraging game, will a hungry predator be more willing to risk injury while hunting? We performed an experiment in an outdoor vivarium in which barn owls (Tyto alba) were allowed to hunt Allenby's gerbils (Gerbillus andersoni allenbyi) from a choice of safe and risky patches. Owls were either well fed or hungry, representing the high and low state, respectively. We quantified the owls' patch use behavior. We predicted that hungry owls would be more daring and allocate more time to the risky patches. Owls preferred to hunt in the safe patches. This indicates that owls manage risk of injury by avoiding the risky patches. Hungry owls doubled their attacks on gerbils, but directed the added effort mostly toward the safe patch and the safer, open areas in the risky patch. Thus, owls dared by performing a risky action-the attack maneuver-more times, but only in the safest places-the open areas. We conclude that daring can be used to manage risk of injury and owls implement it strategically, in ways we did not foresee, to minimize risk of injury while maximizing hunting success.

  3. Visual-auditory integration for visual search: a behavioral study in barn owls.

    PubMed

    Hazan, Yael; Kra, Yonatan; Yarin, Inna; Wagner, Hermann; Gutfreund, Yoram

    2015-01-01

    Barn owls are nocturnal predators that rely on both vision and hearing for survival. The optic tectum of barn owls, a midbrain structure involved in selective attention, has been used as a model for studying visual-auditory integration at the neuronal level. However, behavioral data on visual-auditory integration in barn owls are lacking. The goal of this study was to examine if the integration of visual and auditory signals contributes to the process of guiding attention toward salient stimuli. We attached miniature wireless video cameras on barn owls' heads (OwlCam) to track their target of gaze. We first provide evidence that the area centralis (a retinal area with a maximal density of photoreceptors) is used as a functional fovea in barn owls. Thus, by mapping the projection of the area centralis on the OwlCam's video frame, it is possible to extract the target of gaze. For the experiment, owls were positioned on a high perch and four food items were scattered in a large arena on the floor. In addition, a hidden loudspeaker was positioned in the arena. The positions of the food items and speaker were changed every session. Video sequences from the OwlCam were saved for offline analysis while the owls spontaneously scanned the room and the food items with abrupt gaze shifts (head saccades). From time to time during the experiment, a brief sound was emitted from the speaker. The fixation points immediately following the sounds were extracted and the distances between the gaze position and the nearest items and loudspeaker were measured. The head saccades were rarely toward the location of the sound source but to salient visual features in the room, such as the door knob or the food items. However, among the food items, the one closest to the loudspeaker had the highest probability of attracting a gaze shift. This result supports the notion that auditory signals are integrated with visual information for the selection of the next visual search target.

  4. mtDNA diversity in Azara's owl monkeys (Aotus azarai azarai) of the Argentinean Chaco.

    PubMed

    Babb, Paul L; Fernandez-Duque, Eduardo; Baiduc, Caitlin A; Gagneux, Pascal; Evans, Sian; Schurr, Theodore G

    2011-10-01

    Owl monkeys (Aotus spp.) inhabit much of South America yet represent an enigmatic evolutionary branch among primates. While morphological, cytogenetic, and immunological evidence suggest that owl monkey populations have undergone isolation and diversification since their emergence in the New World, problems with adjacent species ranges, and sample provenance have complicated efforts to characterize genetic variation within the genus. As a result, the phylogeographic history of owl monkey species and subspecies remains unclear, and the extent of genetic diversity at the population level is unknown. To explore these issues, we analyzed mitochondrial DNA (mt DNA) variation in a population of wild Azara's owl monkeys (Aotus azarai azarai) living in the Gran Chaco region of Argentina. We sequenced the complete mitochondrial genome from one individual (16,585 base pairs (bp)) and analyzed 1,099 bp of the hypervariable control region (CR) and 696 bp of the cytochrome oxidase II (COII) gene in 117 others. In addition, we sequenced the mitochondrial genome (16,472 bp) of one Nancy Ma's owl monkey (A. nancymaae). Based on the whole mtDNA and COII data, we observed an ancient phylogeographic discontinuity among Aotus species living north, south, and west of the Amazon River that began more than eight million years ago. Our population analyses identified three major CR lineages and detected a high level of haplotypic diversity within A. a. azarai. These data point to a recent expansion of Azara's owl monkeys into the Argentinean Chaco. Overall, we provide a detailed view of owl monkey mtDNA variation at genus, species, and population levels.

  5. Larks and owls and health, wealth, and wisdom

    PubMed Central

    Gale, Catharine; Martyn, Christopher

    1998-01-01

    Objective To test the validity of Benjamin Franklin’s maxim “early to bed and early to rise makes a man healthy, wealthy, and wise.” Design Cross sectional analysis of sleeping patterns in a nationally representative group of elderly people, and longitudinal investigation of mortality. Setting Eight areas in Britain (five in England, two in Scotland, and one in Wales). Subjects 1229 men and women aged 65 and over who in 1973-4 had taken part in a survey funded by the Department of Health and Social Security and for whom data on sleeping patterns, health, socioeconomic circumstances, and cognitive function had been recorded. Main outcome measures Self reported income, access to a car, standard of accommodation, performance on a test of cognitive function, state of health and mortality during 23 years of follow up. Results 356 people (29%) were defined as larks (to bed before 11 pm and up before 8 am) and 318 (26%) were defined as owls (to bed at or after 11 pm and up at or after 8 am). There was no indication that larks were richer than those with other sleeping patterns. On the contrary, owls had the largest mean income and were more likely to have access to a car. There was also no evidence that larks were superior to those with other sleeping patterns with regard to their cognitive performance or their state of health. Both larks and owls had a slightly reduced risk of death compared with the rest of the study sample, but this was accounted for by the fact that they spent less time in bed at night. In the study sample as a whole, longer periods of time in bed were associated with increased mortality. After adjustment for age, sex, the presence of illness, and other risk factors, people who spent 12 or more hours in bed had a relative risk of death of 1.7 (1.2 to 2.5) compared with those who were in bed for 9 hours. The lowest risk occurred in people who spent 8 hours in bed (adjusted relative risk 0.8; 0.7 to 1.0). Conclusion These findings do not

  6. Natural and experimental West Nile virus infection in five raptor species.

    PubMed

    Nemeth, Nicole; Gould, Daniel; Bowen, Richard; Komar, Nicholas

    2006-01-01

    We studied the effects of natural and/or experimental infections of West Nile virus (WNV) in five raptor species from July 2002 to March 2004, including American kestrels (Falco sparverius), golden eagles (Aquila chrysaetos), red-tailed hawks (Buteo jamaicensis), barn owls (Tyto alba), and great horned owls (Bubo virginianus). Birds were infected per mosquito bite, per os, or percutaneously by needle. Many experimentally infected birds developed mosquito-infectious levels of viremia (>10(5) WNV plaque forming units per ml serum) within 5 days postinoculation (DPI), and/ or shed virus per os or per cloaca. Infection of organs 15-27 days postinoculation was infrequently detected by virus isolation from spleen, kidney, skin, heart, brain, and eye in convalescent birds. Histopathologic findings varied among species and by method of infection. The most common histopathologic lesions were subacute myocarditis and encephalitis. Several birds had a more acute, severe disease condition represented by arteritis and associated with tissue degeneration and necrosis. This study demonstrates that raptor species vary in their response to WNV infection and that several modes of exposure (e.g., oral) may result in infection. Wildlife managers should recognize that, although many WNV infections are sublethal to raptors, subacute lesions could potentially reduce viability of populations. We recommend that raptor handlers consider raptors as a potential source of WNV contamination due to oral and cloacal shedding.

  7. Predator removal enhances waterbird restoration in Chesapeake Bay (Maryland)

    USGS Publications Warehouse

    Erwin, R. Michael; McGowan, Peter C.; Reese, Jan

    2011-01-01

    This report represents an update to an earlier report(Erwin et al. 2007a) on wildlife restoration on the largest dredge material island project in the United States underway in Talbot County, Maryland (Figure 1) in the mid–Chesapeake Bay region, referred to as the Paul Sarbanes Ecosystem Restoration Project at Poplar Island (www.nab.usace.army.mil/projects/Maryland/PoplarIsland/documents.html). An important component of this largescale restoration effort focused on water birds, as many of these species have undergone significant declines in the Chesapeake region over the past 30 years (Erwin et al. 2007b). The priority waterbird species include common terns (Sterna hirundo), least terns (S. antillarum), snowy egrets (Egretta thula), and ospreys (Pandion haliaetus). Although significant numbers of common terns (more than 800 pairs in 2003), least terns (62 pairs in 2003), snowy egrets (50 or more pairs by 2005), and ospreys (7 to 10 pairs) have nested on Poplar Island since early 2000, tern productivity especially had been strongly limited by a combination of red fox (Vulpes vulpes) and great horned owl (Bubo virginianus) predation. Fox trapping began in 2004, and four were removed that year; no more evidence of fox presence was found in 2005 or subsequently. The owls proved to be more problematic.

  8. Mercury concentrations in breast feathers of three upper trophic level marine predators from the western Aleutian Islands, Alaska

    USGS Publications Warehouse

    Kaler, Robb S.A.; Kenney, Leah A.; Bond, Alexander L.; Eagles-Smith, Collin A.

    2014-01-01

    Mercury (Hg) is a toxic element distributed globally through atmospheric transport. Agattu Island, located in the western Aleutian Islands, Alaska, has no history of point-sources of Hg contamination. We provide baseline levels of total mercury (THg) concentrations in breast feathers of three birds that breed on the island. Geometric mean THg concentrations in feathers of fork-tailed storm-petrels (Oceanodroma furcata; 6703 ± 1635, ng/g fresh weight [fw]) were higher than all other species, including snowy owl (Bubo scandiacus; 2105 ± 1631, ng/g fw), a raptor with a diet composed largely of storm-petrels at Agattu Island. There were no significant differences in mean THg concentrations of breast feathers among adult Kittlitz’s murrelet (Brachyramphus brevirostris; 1658 ± 1276, ng/g fw) and chicks (1475 ± 671, ng/g fw) and snowy owls. The observed THg concentrations in fork-tailed storm-petrel feathers emphasizes the need for further study of Hg pollution in the western Aleutian Islands.

  9. OWL representation of the geologic timescale implementing stratigraphic best practice

    NASA Astrophysics Data System (ADS)

    Cox, S. J.

    2011-12-01

    The geologic timescale is a cornerstone of the earth sciences. Versions are available from many sources, with the following being of particular interest: (i) The official International Stratigraphic Chart (ISC) is maintained by the International Commission for Stratigraphy (ICS), following principles developed over the last 40 years. ICS provides the data underlying the chart as part of a specialized software package, and the chart itself as a PDF using the standard colours; (ii) ITC Enschede has developed a representation of the timescale as a thesaurus in SKOS, used in a Web Map Service delivery system; (iii) JPL's SWEET ontology includes a geologic timescale. This takes full advantage of the capabilities of OWL. However, each of these has limitations - The ISC falls down because of incompatibility with web technologies; - While SKOS supports multilingual labelling, SKOS does not adequately support timescale semantics, in particular since it does not include ordering relationships; - The SWEET version (as of version 2) is not fully aligned to the model used by ICS, in particular not recognizing the role of the Global Boundary Stratotype Sections and Point (GSSP). Furthermore, it is distributed as static documents, rather than through a dynamic API using SPARQL. The representation presented in this paper overcomes all of these limitations as follows: - the timescale model is formulated as an OWL ontology - the ontology is directly derived from the UML representation of the ICS best practice proposed by Cox & Richard [2005], and subsequently included as the Geologic Timescale package in GeoSciML (http://www.geosciml.org); this includes links to GSSPs as per the ICS process - key properties in the ontology are also asserted to be subProperties of SKOS properties (topConcept and broader/narrower relations) in order to support SKOS-based queries; SKOS labelling is used to support multi-lingual naming and synonyms - the International Stratigraphic Chart is implemented

  10. Roosting habitat use and selection by northern spotted owls during natal dispersal

    USGS Publications Warehouse

    Sovern, Stan G.; Forsman, Eric D.; Dugger, Catherine M.; Taylor, Margaret

    2015-01-01

    We studied habitat selection by northern spotted owls (Strix occidentalis caurina) during natal dispersal in Washington State, USA, at both the roost site and landscape scales. We used logistic regression to obtain parameters for an exponential resource selection function based on vegetation attributes in roost and random plots in 76 forest stands that were used for roosting. We used a similar analysis to evaluate selection of landscape habitat attributes based on 301 radio-telemetry relocations and random points within our study area. We found no evidence of within-stand selection for any of the variables examined, but 78% of roosts were in stands with at least some large (>50 cm dbh) trees. At the landscape scale, owls selected for stands with high canopy cover (>70%). Dispersing owls selected vegetation types that were more similar to habitat selected by adult owls than habitat that would result from following guidelines previously proposed to maintain dispersal habitat. Our analysis indicates that juvenile owls select stands for roosting that have greater canopy cover than is recommended in current agency guidelines.

  11. The influence of Pleistocene glacial refugia on tawny owl genetic diversity and phylogeography in western Europe.

    PubMed

    Brito, Patrícia H

    2005-09-01

    The glacial refugia hypothesis indicates that during the height of the Pleistocene glaciations the temperate species that are today widespread in western Europe must have survived in small and climatically favourable areas located in the southern peninsulas of Iberia, Italy and Balkans. One such species is the tawny owl, a relatively sedentary, nonmigratory bird presently distributed throughout Europe. It is a tree-nesting species closely associated with deciduous and mixed coniferous woodlands. In this study I used control region mtDNA sequences from 187 individuals distributed among 14 populations to determine whether current genetic patterns in tawny owl populations were consistent with postglacial expansion from peninsular refugia. European, North African and Asian tawny owls were found to represent three distinct lineages, where North Africa is the sister clade to all European owls. Within Europe, I found three well-supported clades that correspond to each of the three allopatric refugia. Expansion patterns indicate that owls from the Balkan refugium repopulated most of northern Europe, while expansion out of Iberia and Italy had only regional effects leading to admixture in France. Estimates of population divergence times between refugia populations are roughly similar, but one order of magnitude smaller between Greece and northern Europe. Based on a wide range of mutation rates and generation times, divergence between refugia appears to date to the Pleistocene.

  12. Home range characteristics of Mexican Spotted Owls in the canyonlands of Utah

    USGS Publications Warehouse

    Willey, D.W.; van Riper, Charles

    2007-01-01

    We studied home-range characteristics of adult Mexican Spotted Owls (Strix occidentalis lucida) in southern Utah. Twenty-eight adult owls were radio-tracked using a ground-based telemetry system during 1991-95. Five males and eight females molted tail feathers and dropped transmitters within 4 wk. We estimated cumulative home ranges for 15 Spotted Owls (12 males, 3 females). The mean estimate of cumulative home-range size was not statistically different between the minimum convex polygon and adaptive kernel (AK) 95% isopleth. Both estimators yielded relatively high SD, and male and female range sizes varied widely. For 12 owls tracked during both the breeding and nonbreeding seasons, the mean size of the AK 95% nonbreeding home range was 49% larger than the breeding home-range size. The median AK 75% bome-range isopleth (272 ha) we observed was similar in size to Protected Activity Centers (PACs) recommended by a recovery team. Our results lend support to the PAC concept and we support continued use of PACs to conserve Spotted Owl habitat in Utah. ?? 2007 The Raptor Research Foundation, Inc.

  13. Genetics Show Current Decline and Pleistocene Expansion in Northern Spotted Owls

    USGS Publications Warehouse

    Funk, W. Chris; Forsman, Eric D.; Mullins, Thomas D.; Haig, Susan M.

    2008-01-01

    The northern spotted owl (Strix occidentalis caurina) is one of the most controversial threatened subspecies ever listed under the U.S. Endangered Species Act. Because of concern for persistence of the subspecies, logging on Federal lands in the U.S. Pacific Northwest was dramatically reduced under the Northwest Forest Plan in 1994. Despite protection of its remaining forest habitat, recent field studies show continued demographic declines of northern spotted owls. One potential threat to northern spotted owls that has not yet been shown is loss of genetic variation from population bottlenecks that can increase inbreeding depression and decrease adaptive potential. Here, we show recent genetic bottlenecks in northern spotted owls using a large genetic dataset (352 individuals from across the subspecies' range and 11 microsatellite loci). The signature of bottlenecks was strongest in Washington State, in agreement with field data. Interestingly, we also found a genetic signature of Pleistocene expansion in the same study areas where recent bottlenecks were shown. Our results provide independent evidence that northern spotted owls have recently declined, and suggest that loss of genetic variation is an emerging threat to the subspecies' persistence. Reduced effective population size (Ne), shown here in addition to field evidence for demographic decline, highlights the increasing vulnerability of this bird to extinction.

  14. Developmental changes in serum androgen levels of Eastern Screech-Owls (Megascops asio)

    USGS Publications Warehouse

    Kozlowski, Corinne P.; Hahn, D. Caldwell

    2010-01-01

    We studied androgen production during development in nestling Eastern Screech-Owls (Megascops asio) and hypothesized that gender and hatch order might influence serum levels of testosterone and androstenedione. Testosterone levels were highest immediately after hatching and declined significantly in the 4 weeks leading to fledging. The average level of testosterone for 1-7 day-old owls was 3.99 - 0.68 ng/ml. At 22-28 days of age, the average testosterone level for nestling owls was 0.83 - 0.18 ng/ml. Testosterone levels did not differ between males or females. The average testosterone level for male nestlings was 2.23 - 0.29 ng/ml and 2.39 - 0.56 ng/ml for female nestlings. The average level of androstenedione for nestling owls was 1.92 - 0.11 ng/ml and levels remained constant throughout development. Levels were significantly higher in males than females. The average androstenedione level was 1.77 - 0.16 ng/ml for male nestlings and 1.05 - 0.24 ng/ml for female nestlings. Hatching order did not affect levels of either androgen. Our results provide a foundation for future studies of androgen production by nestling owls.

  15. OPTIMAL WELL LOCATOR (OWL): A SCREENING TOOL FOR EVALUATING LOCATIONS OF MONITORING WELLS: USER'S GUIDE VERSION 1.2

    EPA Science Inventory

    The Optimal Well Locator ( OWL) program was designed and developed by USEPA to be a screening tool to evaluate and optimize the placement of wells in long term monitoring networks at small sites. The first objective of the OWL program is to allow the user to visualize the change ...

  16. Global inhibition and stimulus competition in the owl optic tectum

    PubMed Central

    Mysore, Shreesh P.; Asadollahi, Ali; Knudsen, Eric I.

    2010-01-01

    Stimulus selection for gaze and spatial attention involves competition among stimuli across sensory modalities and across all of space. We demonstrate that such cross-modal, global competition takes place in the intermediate and deep layers of the optic tectum, a structure known to be involved in gaze control and attention. A variety of either visual or auditory stimuli located anywhere outside of a neuron's receptive field (RF) were shown to suppress or completely eliminate responses to a visual stimulus located inside the RF in nitrous oxide sedated owls. The essential mechanism underlying this stimulus competition is global, divisive inhibition. Unlike the effect of the classical inhibitory surround, which decreases with distance from the RF center and shapes neuronal responses to individual stimuli, global inhibition acts across the entirety of space and modulates responses primarily in the context of multiple stimuli. Whereas the source of this global inhibition is as yet unknown, our data indicate that different networks mediate the classical surround and global inhibition. We hypothesize that this global, cross-modal inhibition, which acts automatically in a bottom-up fashion even in sedated animals, is critical to the creation of a map of stimulus salience in the optic tectum. PMID:20130182

  17. Direction Selectivity Mediated by Adaptation in the Owl's Inferior Colliculus

    PubMed Central

    Peña, José Luis

    2013-01-01

    Motion direction is a crucial cue for predicting future states in natural scenes. In the auditory system, the mechanisms that confer direction selectivity to neurons are not well understood. Neither is it known whether sound motion is encoded independently of stationary sound location. Here we investigated these questions in neurons of the owl's external nucleus of the inferior colliculus, where auditory space is represented in a map. Using a high-density speaker array, we show that the preferred direction and the degree of direction selectivity can be predicted by response adaptation to sounds moving over asymmetric spatial receptive fields. At the population level, we found that preference for sounds moving toward frontal space increased with eccentricity in spatial tuning. This distribution was consistent with larger receptive-field asymmetry in neurons tuned to more peripheral auditory space. A model of suppression based on spatiotemporal summation predicted the observations. Thus, response adaptation and receptive-field shape can explain direction selectivity to acoustic motion and an orderly distribution of preferred direction. PMID:24305813

  18. Optimal Prediction of Moving Sound Source Direction in the Owl

    PubMed Central

    Cox, Weston; Fischer, Brian J.

    2015-01-01

    Capturing nature’s statistical structure in behavioral responses is at the core of the ability to function adaptively in the environment. Bayesian statistical inference describes how sensory and prior information can be combined optimally to guide behavior. An outstanding open question of how neural coding supports Bayesian inference includes how sensory cues are optimally integrated over time. Here we address what neural response properties allow a neural system to perform Bayesian prediction, i.e., predicting where a source will be in the near future given sensory information and prior assumptions. The work here shows that the population vector decoder will perform Bayesian prediction when the receptive fields of the neurons encode the target dynamics with shifting receptive fields. We test the model using the system that underlies sound localization in barn owls. Neurons in the owl’s midbrain show shifting receptive fields for moving sources that are consistent with the predictions of the model. We predict that neural populations can be specialized to represent the statistics of dynamic stimuli to allow for a vector read-out of Bayes-optimal predictions. PMID:26226048

  19. Multiple paternity in polyandrous barn owls (Tyto alba).

    PubMed

    Henry, Isabelle; Antoniazza, Sylvain; Dubey, Sylvain; Simon, Céline; Waldvogel, Céline; Burri, Reto; Roulin, Alexandre

    2013-01-01

    In polyandrous species females produce successive clutches with several males. Female barn owls (Tyto alba) often desert their offspring and mate to produce a 2(nd) annual brood with a second male. We tested whether copulating during chick rearing at the 1(st) annual brood increases the male's likelihood to obtain paternity at the 2(nd) annual breeding attempt of his female mate in case she deserts their brood to produce a second brood with a different male. Using molecular paternity analyses we found that 2 out of 26 (8%) second annual broods of deserting females contained in total 6 extra-pair young out of 15 nestlings. These young were all sired by the male with whom the female had produced the 1(st) annual brood. In contrast, none of the 49 1(st) annual breeding attempts (219 offspring) and of the 20 2(nd) annual breeding attempts (93 offspring) of non-deserting females contained extra-pair young. We suggest that female desertion can select male counter-strategies to increase paternity and hence individual fitness. Alternatively, females may copulate with the 1(st) male to derive genetic benefits, since he is usually of higher quality than the 2(nd) male which is commonly a yearling individual.

  20. Central projections of auditory nerve fibers in the barn owl.

    PubMed

    Carr, C E; Boudreau, R E

    1991-12-08

    The central projections of the auditory nerve were examined in the barn owl. Each auditory nerve fiber enters the brain and divides to terminate in both the cochlear nucleus angularis and the cochlear nucleus magnocellularis. This division parallels a functional division into intensity and time coding in the auditory system. The lateral branch of the auditory nerve innervates the nucleus angularis and gives rise to a major and a minor terminal field. The terminals range in size and shape from small boutons to large irregular boutons with thorn-like appendages. The medial branch of the auditory nerve conveys phase information to the cells of the nucleus magnocellularis via large axosomatic endings or end bulbs of Held. Each medial branch divides to form 3-6 end bulbs along the rostrocaudal orientation of a single tonotopic band, and each magnocellular neuron receives 1-4 end bulbs. The end bulb envelops the postsynaptic cell body and forms large numbers of synapses. The auditory nerve profiles contain round clear vesicles and form punctate asymmetric synapses on both somatic spines and the cell body.

  1. Sleep and vigilance linked to melanism in wild barn owls.

    PubMed

    Scriba, M F; Rattenborg, N C; Dreiss, A N; Vyssotski, A L; Roulin, A

    2014-10-01

    Understanding the function of variation in sleep requires studies in the natural ecological conditions in which sleep evolved. Sleep has an impact on individual performance and hence may integrate the costs and benefits of investing in processes that are sensitive to sleep, such as immunity or coping with stress. Because dark and pale melanic animals differentially regulate energy homeostasis, immunity and stress hormone levels, the amount and/or organization of sleep may covary with melanin-based colour. We show here that wild, cross-fostered nestling barn owls (Tyto alba) born from mothers displaying more black spots had shorter non-REM (rapid eye movement) sleep bouts, a shorter latency until the occurrence of REM sleep after a bout of wakefulness and more wakefulness bouts. In male nestlings, the same sleep traits also correlated with their own level of spotting. Because heavily spotted male nestlings and the offspring of heavily spotted biological mothers switched sleep-wakefulness states more frequently, we propose the hypothesis that they could be also behaviourally more vigilant. Accordingly, nestlings from mothers displaying many black spots looked more often towards the nest entrance where their parents bring food and towards their sibling against whom they compete. Owlets from heavily spotted mothers might invest more in vigilance, thereby possibly increasing associated costs due to sleep fragmentation. We conclude that different strategies of the regulation of brain activity have evolved and are correlated with melanin-based coloration.

  2. Helminth communities of owls (strigiformes) indicate strong biological and ecological differences from birds of prey (accipitriformes and falconiformes) in southern Italy.

    PubMed

    Santoro, Mario; Mattiucci, Simonetta; Nascetti, Giuseppe; Kinsella, John M; Di Prisco, Francesca; Troisi, Sabatino; D'Alessio, Nicola; Veneziano, Vincenzo; Aznar, Francisco J

    2012-01-01

    We compared the helminth communities of 5 owl species from Calabria (Italy) and evaluated the effect of phylogenetic and ecological factors on community structure. Two host taxonomic scales were considered, i.e., owl species, and owls vs. birds of prey. The latter scale was dealt with by comparing the data here obtained with that of birds of prey from the same locality and with those published previously on owls and birds of prey from Galicia (Spain). A total of 19 helminth taxa were found in owls from Calabria. Statistical comparison showed only marginal differences between scops owls (Otus scops) and little owls (Athene noctua) and tawny owls (Strix aluco). It would indicate that all owl species are exposed to a common pool of 'owl generalist' helminth taxa, with quantitative differences being determined by differences in diet within a range of prey relatively narrow. In contrast, birds of prey from the same region exhibited strong differences because they feed on different and wider spectra of prey. In Calabria, owls can be separated as a whole from birds of prey with regard to the structure of their helminth communities while in Galicia helminths of owls represent a subset of those of birds of prey. This difference is related to the occurrence in Calabria, but not Galicia, of a pool of 'owl specialist' species. The wide geographical occurrence of these taxa suggest that local conditions may determine fundamental differences in the composition of local communities. Finally, in both Calabria and Galicia, helminth communities from owls were species-poor compared to those from sympatric birds of prey. However, birds of prey appear to share a greater pool of specific helmith taxa derived from cospeciation processes, and a greater potential exchange of parasites between them than with owls because of phylogenetic closeness.

  3. Helminth Communities of Owls (Strigiformes) Indicate Strong Biological and Ecological Differences from Birds of Prey (Accipitriformes and Falconiformes) in Southern Italy

    PubMed Central

    Santoro, Mario; Mattiucci, Simonetta; Nascetti, Giuseppe; Kinsella, John M.; Di Prisco, Francesca; Troisi, Sabatino; D’Alessio, Nicola; Veneziano, Vincenzo; Aznar, Francisco J.

    2012-01-01

    We compared the helminth communities of 5 owl species from Calabria (Italy) and evaluated the effect of phylogenetic and ecological factors on community structure. Two host taxonomic scales were considered, i.e., owl species, and owls vs. birds of prey. The latter scale was dealt with by comparing the data here obtained with that of birds of prey from the same locality and with those published previously on owls and birds of prey from Galicia (Spain). A total of 19 helminth taxa were found in owls from Calabria. Statistical comparison showed only marginal differences between scops owls (Otus scops) and little owls (Athene noctua) and tawny owls (Strix aluco). It would indicate that all owl species are exposed to a common pool of ‘owl generalist’ helminth taxa, with quantitative differences being determined by differences in diet within a range of prey relatively narrow. In contrast, birds of prey from the same region exhibited strong differences because they feed on different and wider spectra of prey. In Calabria, owls can be separated as a whole from birds of prey with regard to the structure of their helminth communities while in Galicia helminths of owls represent a subset of those of birds of prey. This difference is related to the occurrence in Calabria, but not Galicia, of a pool of ‘owl specialist’ species. The wide geographical occurrence of these taxa suggest that local conditions may determine fundamental differences in the composition of local communities. Finally, in both Calabria and Galicia, helminth communities from owls were species-poor compared to those from sympatric birds of prey. However, birds of prey appear to share a greater pool of specific helmith taxa derived from cospeciation processes, and a greater potential exchange of parasites between them than with owls because of phylogenetic closeness. PMID:23300921

  4. [Brent goose colonies near snowy owls: internest distances in relation to breeding Arctic fox densities].

    PubMed

    Kharitonov, S P; Ebbinge, B S; De Fou, J

    2013-01-01

    This study was conducted in 2005 near Medusa Bay (73 degrees 21' N, 80 degrees 32' E) and the delta of the Pyasina River (74 degrees 10' N, 86 degrees 45' E), northwest of the Taimyr Peninsula. It was shown that in the years when the numbers of the Arctic foxes are high, even though the lemming numbers are high as well, Brent geese nest considerably closer to owls' nests than in the years with low Arctic fox numbers. At values of the Arctic fox densities greater than one breeding pair per 20 km2, the factor of lemming numbers ceases to affect the distance between owl and geese nests. This distance becomes dependent on the Arctic fox density (numbers). When the Arctic fox density is greater than the pronounced threshold, the owl-Brent internest distance is inversely and linearly related to the Arctic fox density.

  5. Low frequency eardrum directionality in the barn owl induced by sound transmission through the interaural canal.

    PubMed

    Kettler, Lutz; Christensen-Dalsgaard, Jakob; Larsen, Ole Næsbye; Wagner, Hermann

    2016-10-01

    The middle ears of birds are typically connected by interaural cavities that form a cranial canal. Eardrums coupled in this manner may function as pressure difference receivers rather than pressure receivers. Hereby, the eardrum vibrations become inherently directional. The barn owl also has a large interaural canal, but its role in barn owl hearing and specifically in sound localization has been controversial so far. We discuss here existing data and the role of the interaural canal in this species and add a new dataset obtained by laser Doppler vibrometry in a free-field setting. Significant sound transmission across the interaural canal occurred at low frequencies. The sound transmission induces considerable eardrum directionality in a narrow band from 1.5 to 3.5 kHz. This is below the frequency range used by the barn owl for locating prey, but may conceivably be used for locating conspecific callers.

  6. An OWL meta-ontology for representing the Clinical Element Model.

    PubMed

    Tao, Cui; Parker, Craig G; Oniki, Thomas A; Pathak, Jyotishman; Huff, Stanley M; Chute, Christopher G

    2011-01-01

    The Clinical Element Model (CEM) is a strategy designed to represent logical models for clinical data elements to ensure unambiguous data representation, interpretation, and exchange within and across heterogeneous sources and applications. The current representations of CEMs have limitations on expressing semantics and formal definitions of the structure and the semantics. Here we introduce our initial efforts on representing the CEM in OWL, so that the enrichment with OWL semantics and further semantic processing can be achieved in CEM. The focus of this paper is the CEM meta-ontology where the basic structures, the properties and their relationships, and the constraints are defined. These OWL representation specifications have been reviewed by CEM experts to ensure they capture the intended meaning of the model faithfully.

  7. Survival and home-range size of Northern Spotted Owls in southwestern Oregon

    USGS Publications Warehouse

    Schilling, Jason W.; Dugger, Katie M.; Anthony, Robert G.

    2013-01-01

    In the Klamath province of southwestern Oregon, Northern Spotted Owls (Strix occidentalis caurina) occur in complex, productive forests that historically supported frequent fires of variable severity. However, little is known about the relationships between Spotted Owl survival and home-range size and the characteristics of fire-prone, mixed-conifer forests of the Klamath province. Thus, the objectives of this study were to estimate monthly survival rates and home-range size in relation to habitat characteristics for Northern Spotted Owls in southwestern Oregon. Home-range size and survival of 15 Northern Spotted Owls was monitored using radiotelemetry in the Ashland Ranger District of the Rogue River–Siskiyou National Forest from September 2006 to October 2008. Habitat classes within Spotted Owl home ranges were characterized using a remote-sensed vegetation map of the study area. Estimates of monthly survival ranged from 0.89 to 1.0 and were positively correlated with the number of late-seral habitat patches and the amount of edge, and negatively correlated with the mean nearest neighbor distance between late-seral habitats. Annual home-range size varied from to 189 to 894 ha ( x =  576; SE  =  75), with little difference between breeding and nonbreeding home ranges. Breeding-season home-range size increased with the amount of hard edge, and the amount of old and mature forest combined. Core area, annual and nonbreeding season home-range sizes all increased with increased amounts of hard edge, suggesting that increased fragmentation is associated with larger core and home-range sizes. Although no effect of the amount of late-seral stage forest on either survival or home-range size was detected, these results are the first to concurrently demonstrate increased forest fragmentation with decreased survival and increased home-range size of Northern Spotted Owls.

  8. Haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) and potential insect vectors of their transmission.

    PubMed

    Synek, Petr; Popelková, Alena; Koubínová, Darina; Šťastný, Karel; Langrová, Iva; Votýpka, Jan; Munclinger, Pavel

    2016-01-01

    Sedentary bird species are suitable model hosts for identifying potential vectors of avian blood parasites. We studied haemosporidian infections in the Tengmalm's Owl (Aegolius funereus) in the Ore Mountains of the Czech Republic using molecular detection methods. Sex of owl nestlings was scored using molecular sexing based on fragment analysis of PCR-amplified CHD1 introns. Observed infection prevalences in nestlings and adult owls were 51 and 86 %, respectively. Five parasite lineages were detected. Most of the infections comprised the Leucocytozoon AEFUN02 and STOCC06 lineages that probably refer to distinct Leucocytozoon species. Other lineages were detected only sporadically. Mixed infections were found in 49 % of samples. The main factor affecting the probability of infection was host age. No effect of individual sex on infection probability was evidenced. The youngest infected nestling was 12 days old. High parasite prevalence in the Tengmalm's Owl nestlings suggests that insect vectors must enter nest boxes to transmit parasites before fledging. Hence, we placed sticky insect traps into modified nest boxes, collected potential insect vectors, and examined them for the presence of haemosporidian parasites using molecular detection. We trapped 201 insects which were determined as biting midges from the Culicoides genus and two black fly species, Simulium (Nevermannia) vernum and Simulium (Eusimulium) angustipes. Six haemosporidian lineages were detected in the potential insect vectors, among which the Leucocytozoon lineage BT2 was common to the Tengmalm's Owl and the trapped insects. However, we have not detected the most frequently encountered Tengmalm's Owl Leucocytozoon lineages AEFUN02 and STOCC06 in insects.

  9. Roost habitat of Mexican Spotted Owls (Strix occidentalis lucida) in the canyonlands of Utah

    USGS Publications Warehouse

    Willey, David W.; Van Riper, Charles

    2015-01-01

    In large portions of their geographic range, Mexican Spotted Owls (Strix occidentalis lucida) roost in forest-dominated environments, but in some areas the owls use relatively arid rocky canyonlands. We measured habitat characteristics at 133 male roosts (n = 20 males) during 1992-95, and 56 female roosts (n = 13 females) during 1994-95. Across all years and study areas, 44% of Mexican Spotted Owl roosts occurred in mixed-conifer forest patches, 30% in desert scrub habitat, 16% in pinyon-juniper woodlands, and 10% of roosts occurred in riparian vegetation. Two basic substrates were used as perches by owls, including rock ledges or various trees, where roost height averaged 9 m (0.54 SD), and average height of cliffs above perched owls was 50 m (58 SD). For both males and females, trees types used most frequently included various firs (51%), followed by pinyon pine (18%), Utah juniper (15%), and big-tooth maple or box elder combined (15%). Roost sites were located in canyons composed of cliff-forming geologic formations, primarily oriented north-west to south-east. The width of canyons measured at roosts averaged 68 m (105 SD), but ranged from 1-500 m. Canopy cover at roosts used by owls ranged from 44% to 71%, mean tree height of all trees present was 9.5 m and mean diameter of trees was 25.4 cm. Non-roost habitat was warmer, not as steep, and possessed fewer caves and ledges than roost habitat. Trees present in roost plots were taller, and thus showed greater average diameter than trees present in non-roost habitat.

  10. Differential Diagnosis of Dysgraphia, Dyslexia, and OWL LD: Behavioral and Neuroimaging Evidence.

    PubMed

    Berninger, Virginia W; Richards, Todd; Abbott, Robert D

    2015-10-01

    In Study 1, children in grades 4 to 9 (N= 88, 29 females and 59 males) with persisting reading and/or writing disabilities, despite considerable prior specialized instruction in and out of school, were given an evidence-based comprehensive assessment battery at the university while parents completed questionnaires regarding past and current history of language learning and other difficulties. Profiles (patterns) of normed measures for different levels of oral and written language used to categorize participants into diagnostic groups for dysgraphia (impaired subword handwriting) (n=26), dyslexia (impaired word spelling and reading) (n=38), or oral and written language learning disability OWL LD (impaired oral and written syntax comprehension and expression) (n=13) or control oral and written language learners (OWLs) without SLDs (n=11) were consistent withreported history. Impairments in working memory components supporting language learning were also examined. In Study 2, right handed children from Study 1 who did not wear braces (controls, n=9, dysgraphia, n= 14; dyslexia, n=17, OWL LD, n=5) completed an fMRI functional connectivity brain imaging study in which they performed a word-specific spelling judgment task, which is related to both word reading and spelling, and may be impaired in dysgraphia, dyslexia, and OWL LD for different reasons. fMRI functional connectivity from 4 seed points in brain locations involved in written word processing to other brain regions also differentiated dysgraphia, dyslexia, and OWL LD; both specific regions to which connected and overall number of functional connections differed. Thus, results provide converging neurological and behavioral evidence, for dysgraphia, dyslexia, and OWL LD being different, diagnosable specific learning disabilities (SLDs) for persisting written language problems during middle childhood and early adolescence. Translation of the research findings into practice at policy and administrative levels and

  11. Influence of bill and foot morphology on the ectoparasites of barn owls.

    PubMed

    Bush, Sarah E; Villa, Scott M; Boves, Than J; Brewer, Dallas; Belthoff, James R

    2012-04-01

    Preening is the principle behavioral defense used by birds to combat ectoparasites. Most birds have a small overhang at the tip of their bills that is used to shear through the tough cuticle of ectoparasitic arthropods, making preening much more efficient. Birds may also scratch with their feet to defend against ectoparasites. This is particularly important for removing ectoparasites on the head, which birds cannot preen. Scratching may be enhanced by the comb-like serrations that are found on the claws of birds in many avian families. We examined the prevalence and intensity of ectoparasites of barn owls (Tyto alba pratincola) in southern Idaho in relation to bill hook length and morphological characteristics of the pectinate claw. The barn owls in our study were infested with 3 species of lice (Phthiraptera: Ischnocera): Colpocephalum turbinatum , Kurodaia subpachygaster, and Strigiphilus aitkeni . Bill hook length was associated with the prevalence of these lice. Owls with longer hooks were more likely to be infested with lice. Conventional wisdom suggests that the bill morphology of raptors has been shaped by selection for efficient foraging; our data suggest that hook morphology may also play a role in ectoparasite defense. The number of teeth on the pectinate claw was also associated with the prevalence of lice. Owls that had claws with more teeth were less likely to be infested with lice, which suggests that larger pectinate claws may offer relatively more protection against ectoparasitic lice. Experiments that manipulate the bill hook and pectinate claw are needed to confirm whether these host characters are involved in ectoparasite defense. Finally, we recovered mammalian ectoparasites from 4 barn owls. We recovered species of mammalian lice (Phthiraptera:Anoplura) and fleas (Siphonaptera) that are commonly found on microtine rodents. The owls probably acquired these parasites from recently eaten prey. This represents 1 of the few documented cases of

  12. Trace metals in primary feathers of the Barn Owl (Tyto alba guttatus) in The Netherlands.

    PubMed

    Denneman, W D; Douben, P E

    1993-01-01

    The number of Barn Owls in The Netherlands has been reduced substantially over the last few decades. Death as a result of poisoning seems unlikely, but the pathology of all bird species found dead in The Netherlands between 1975 and 1988 (n = 15 422) shows that 21% of all the birds were contaminated. However, the most important factor responsible for the decline in Barn Owl numbers in The Netherlands has not yet been established. As a part of a new national protection plan for the Barn Owl, the role of heavy metals has been investigated. Concentrations of heavy metals in the primary feathers of the Barn Owl varied according to their position in the wing; especially As, Sb, Fe and Zn whose concentrations depended on the place of the primary feather in the wing and the part of the vane which is used for the monitoring. The HS7 feather vane appears to provide a good estimate, even though the metal concentrations of this feather are always slightly lower than the concentrations in mixed samples of all ten primaries. It is recommended that they are used as a standard. Many factors affect metal concentrations. Increasing levels with age are found, presumably because metals are stored during growth at the end of the feathers as a method of reducing possible harmful effects. No significant correlations were found between the metal concentrations in the organs and those in the feather. Kidney and liver concentrations are always lower than the generally accepted levels for pathological damage of these organs. Even though metal concentrations in Barn Owl feathers are high compared with those reported for other birds in the Netherlands, it is concluded that Barn Owls are not adversely affected by current levels of heavy metal contamination in The Netherlands.

  13. Parasitic helminths in the digestive tract of six species of owls (Strigiformes) in Spain.

    PubMed

    Ferrer, David; Molina, Rafael; Castellà, Joaquim; Kinsella, John M

    2004-03-01

    A survey was carried out in Catalonia, Spain to determine the prevalence of parasitic helminths infesting the digestive tract of nocturnal raptors (Strigiformes). One hundred birds belonging to six owl species were examined. The number of birds examined ranged between three and 30. The overall level of infestation was 65% and the most frequent helminths present were nematodes, followed by trematodes, cestodes and acanthocephalans. Strigiformes showing the highest levels of infestation were little owls (Athene noctua), 86.7% of which were infested. Helminths with the highest prevalence were Synhimantus spp., intestinal capillarids, Brachylaima spp., cestodes and Centrorhynchus aluconis.

  14. Magnitude Standardization Procedure for OWL-Net Optical Observations of LEO Satellites

    NASA Astrophysics Data System (ADS)

    Roh, Dong-Goo; Choi, Jin; Jo, Jung Hyun; Yim, Hong-Suh; Park, Sun-Youp; Park, Maru; Choi, Young-Jun; Bae, Young-Ho; Park, Young-Sik; Jang, Hyun-Jung; Cho, Sungki; Kim, Ji-Hye; Park, Jang-Hyun

    2015-12-01

    As a governmentally approved domestic entity for Space Situational Awareness, Korea Astronomy and Space Science Institute (KASI) is developing and operating an optical telescopes system, Optical Wide-field PatroL (OWL) Network. During the test phase of this system, it is necessary to determine the range of brightness of the observable satellites. We have defined standard magnitude for Low Earth Orbit (LEO) satellites to calibrate their luminosity in terms of standard parameters such as distance, phase angle, and angular rate. In this work, we report the optical brightness range of five LEO Satellites using OWL-Net.

  15. Passive West Nile virus antibody transfer from maternal Eastern Screech-Owls (Megascops asio) to progeny

    USGS Publications Warehouse

    Hahn, D.C.; Nemeth, N.M.; Edwards, E.; Bright, P.R.; Komar, N.

    2006-01-01

    Transovarial antibody transfer in owls has not been demonstrated for West Nile virus (WNV). We sampled chicks from captive adult WNV-antibody-positive Eastern Screech-Owls (Megascops asio) to evaluate the prevalence of transovarial maternal antibody transfer, as well as titers and duration of maternal antibodies. Twenty-four owlets aged 1 to 27 days old circulated detectable antibodies with neutralizing antibody titers ranging from 20 to 1600 (median 1:40). Demonstrating that WNV antibodies are passively transferred transovarially is important for accurate interpretation of serologic data from young birds.

  16. Fatal combined infection with Haemoproteus noctuae and Leucocytozoon ziemanni in juvenile snowy owls (Nyctea scandiaca)

    PubMed

    Evans, M; Otter, A

    1998-07-18

    Two juvenile snowy owls (Nyctea scandiaca) died after short episodes of lethargy and anorexia. Postmortem examination of the first was inconclusive but clinical and laboratory examinations on the second owlet revealed a high level of erythrocyte parasitaemia by Haemoproteus noctuae. After a period of intensive nursing and chemotherapy during which it improved clinically and the red cell parasitism decreased, the bird's condition relapsed and it died. Postmortem examination revealed H noctuae infection in addition to heavy red blood cell parasitism by Leucocytozoon ziemanni. Although neither H noctuae nor L ziemanni are generally considered to be pathogenic, their combined presence in the young owl apparently resulted in its death.

  17. An Owl in the Woods. ArtsEdge Curricula, Lessons and Activities.

    ERIC Educational Resources Information Center

    James, Rose

    Introducing children to well written and beautifully illustrated books will help build basic skills while providing for the aesthetic need for beauty and pleasure. This lesson is designed as an integrated literature and visual arts lesson, revolving around the story book, "Owl Moon," written by Jane Yolen and illustrated by John…

  18. Testing the Shapes Vector Derived UniSec Ontology in OWL using Protege and Pellet

    DTIC Science & Technology

    2011-12-01

    UNCLASSIFIED Testing the Shapes Vector derived UniSec Ontology in OWL using Protégé and Pellet Tamas Abraham and Dean Philp...ARE LIMITED RELEASE USE (L) NEXT TO DOCUMENT CLASSIFICATION) Document (U) Title (U) Abstract (U) 4. AUTHOR(S) Tamas Abraham and Dean

  19. First-year movements by juvenile Mexican spotted owls in the Canyonlands of Utah

    USGS Publications Warehouse

    Willey, D.W.; van Riper, Charles

    2000-01-01

    We studied first-year movements of Mexican Spotted Owls (Strix occidentalis lucida) during natal dispersal in canyonlands of southern Utah. Thirty-one juvenile Mexican Spotted Owls were captured and radiotracked during 1992-95 to examine behavior and conduct experiments related to the onset of natal dispersal. Juvenile Spotted Owls dispersed from their nest areas during September to October each year, with 85% leaving in September. The onset of movements was sudden and juveniles dispersed in varied directions. The median distance from nest area to last observed location was 25.7 km (range = 1.7-92.3 km). Three of 26 juveniles tracked (11%) were alive after one year, although none were observed with mates. We conducted a feeding experiment, using Mongolian gerbils (Meriones unguicuculatus), to test the influence of increased food supply on dispersal onset. The mean dispersal date of five owls that received supplemental food (Julian day no. 255 ?? 2.6 SD) was significantly different than a control group (day no. 273 ?? 12.3).

  20. The tissue microarray OWL schema: An open-source tool for sharing tissue microarray data

    PubMed Central

    Kang, Hyunseok P.; Borromeo, Charles D.; Berman, Jules J.; Becich, Michael J.

    2010-01-01

    Background: Tissue microarrays (TMAs) are enormously useful tools for translational research, but incompatibilities in database systems between various researchers and institutions prevent the efficient sharing of data that could help realize their full potential. Resource Description Framework (RDF) provides a flexible method to represent knowledge in triples, which take the form Subject-Predicate-Object. All data resources are described using Uniform Resource Identifiers (URIs), which are global in scope. We present an OWL (Web Ontology Language) schema that expands upon the TMA data exchange specification to address this issue and assist in data sharing and integration. Methods: A minimal OWL schema was designed containing only concepts specific to TMA experiments. More general data elements were incorporated from predefined ontologies such as the NCI thesaurus. URIs were assigned using the Linked Data format. Results: We present examples of files utilizing the schema and conversion of XML data (similar to the TMA DES) to OWL. Conclusion: By utilizing predefined ontologies and global unique identifiers, this OWL schema provides a solution to the limitations of XML, which represents concepts defined in a localized setting. This will help increase the utilization of tissue resources, facilitating collaborative translational research efforts. PMID:20805954

  1. Systematics and distribution of the giant fossil barn owls of the West Indies (Aves: Strigiformes: Tytonidae).

    PubMed

    Suárez, William; Olson, Storrs L

    2015-09-23

    After reviewing the systematics and distribution of the extinct West Indian taxa of Tytonidae (Tyto) larger than the living barn owl Tyto alba (Scopoli), we reached the following conclusions: (1) the species T. ostologa Wetmore (1922) is the only giant barn owl known so far from Hispaniola; (2) T. pollens Wetmore (1937) was a somewhat larger and even more robust representative of T. ostologa known from the Great Bahama Bank and Cuba; (3) the very rare species T. riveroi Arredondo (1972b) is here synonymized with T. pollens; (4) the smallest taxon of these giant barn owls is T. noeli Arredondo (1972a), which is widespread and abundant in Quaternary deposits of Cuba and is here reported for the first time from two cave deposits in Jamaica; (5) the only large barn owl named so far from the Lesser Antilles is T. neddi Steadman & Hilgartner (1999), which is here synonymized with T. noeli; (6) a new taxon from Cuba, T. cravesae new species, which in size approached the linear dimensions of T. ostologa, is named and described herein.

  2. Visual pop-out in barn owls: Human-like behavior in the avian brain.

    PubMed

    Orlowski, Julius; Beissel, Christian; Rohn, Friederike; Adato, Yair; Wagner, Hermann; Ben-Shahar, Ohad

    2015-01-01

    Visual pop-out is a phenomenon by which the latency to detect a target in a scene is independent of the number of other elements, the distractors. Pop-out is an effective visual-search guidance that occurs typically when the target is distinct in one feature from the distractors, thus facilitating fast detection of predators or prey. However, apart from studies on primates, pop-out has been examined in few species and demonstrated thus far in rats, archer fish, and pigeons only. To fill this gap, here we study pop-out in barn owls. These birds are a unique model system for such exploration because their lack of eye movements dictates visual behavior dominated by head movements. Head saccades and interspersed fixation periods can therefore be tracked and analyzed with a head-mounted wireless microcamera--the OwlCam. Using this methodology we confronted two owls with scenes containing search arrays of one target among varying numbers (15-63) of similar looking distractors. We tested targets distinct either by orientation (Experiment 1) or luminance contrast (Experiment 2). Search time and the number of saccades until the target was fixated remained largely independent of the number of distractors in both experiments. This suggests that barn owls can exhibit pop-out during visual search, thus expanding the group of species and brain structures that can cope with this fundamental visual behavior. The utility of our automatic analysis method is further discussed for other species and scientific questions.

  3. Using Bakhtin's Competing Voices To Interpret "An Occurrence at Owl Creek Bridge."

    ERIC Educational Resources Information Center

    Bednar, Lucy

    According to Mikhail Bakhtin, a 20th century Russian linguist and literacy critic, texts represent battlegrounds for competing voices, including the author's, the narrator's, and the characters'. This concept of "heteroglossia" can be applied to a short story such as Ambrose Bierce's "An Occurrence at Owl Creek Bridge," about…

  4. 77 FR 14036 - Draft Environmental Impact Statement for Experimental Removal of Barred Owls to Benefit...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ... alternatives vary by the number and location of study areas, the type of experimental design, duration of study... areas within the range of the northern spotted owl. Action areas may include from one to several study areas in western Washington, western Oregon, and northwestern California. The action alternatives...

  5. Neural Coding of Relational Invariance in Speech: Human Language Analogs to the Barn Owl.

    ERIC Educational Resources Information Center

    Sussman, Harvey M.

    1989-01-01

    The neuronal model shown to code sound-source azimuth in the barn owl by H. Wagner et al. in 1987 is used as the basis for a speculative brain-based human model, which can establish contrastive phonetic categories to solve the problem of perception "non-invariance." (SLD)

  6. Contemporary American Indian Life in "The Owl's Song" and "Smoke Signals."

    ERIC Educational Resources Information Center

    Charles, Jim

    2001-01-01

    Discusses "Smoke Signals" (a 1998 award-winning film) and "The Owl's Song" (a 1974 novel), both of which feature young adult American Indian protagonists. Suggests instructional strategies for teaching these works in tandem. Argues that teaching these works informs students about relevant literary, historical, social, and cultural topics in ways…

  7. Simulated Performance of the Orbiting Wide-angle Light Collectors (OWL) Experiment

    NASA Technical Reports Server (NTRS)

    Krizmanic, J. F.; Whitaker, Ann F. (Technical Monitor)

    2001-01-01

    The Orbiting Wide-angle Light collectors (OWL) experiment is in NASA's mid-term strategic plan and will stereoscopically image, from equatorial orbit, the air fluorescence signal generated by airshowers induced by the ultrahigh energy (E greater than few x 10(exp 19) eV) component of the cosmic radiation. The use of a space-based platform enables an extremely large event acceptance aperture and thus will allow a high statistics measurement of these rare events. Detailed Monte Carlo simulations are required to quantify the physics potential of the mission as well as optimize the instrumental parameters. This paper reports on the results of the GSFC Monte Carlo simulation for two different, OWL instrument baseline designs. These results indicate that, assuming a continuation of the cosmic ray spectrum (theta approximately E(exp -2.75), OWL could have an event rate of 4000 events/year with E greater than or equal to 10(exp 20) eV. Preliminary results, based upon these Monte Carlo simulations, indicate that events can be accurately reconstructed in the detector focal plane arrays for the OWL instrument baseline designs under consideration.

  8. US EPA OPTIMAL WELL LOCATOR (OWL): A SCREENING TOOL FOR EVALUATING LOCATIONS OF MONITORING WELLS

    EPA Science Inventory

    The Optimal Well Locator (OWL): uses linear regression to fit a plane to the elevation of the water table in monitoring wells in each round of sampling. The slope of the plane fit to the water table is used to predict the direction and gradient of ground water flow. Along with ...

  9. The "Night Owl" Learning Style of Art Students: Creativity and Daily Rhythm

    ERIC Educational Resources Information Center

    Wang, Sy-Chyi; Chern, Jin-Yuan

    2008-01-01

    This article explores the deep-rooted "night owl" image of art practitioners and calls for attention on a consideration of the time for learning in art. It has been recognised that the human body has its own internal timings and knowing the "time" pattern is important for better productivity in conducting creativity-related activities. This study…

  10. Newspaper Coverage of Biological Subissues in the Spotted Owl Debate, 1989-1993.

    ERIC Educational Resources Information Center

    Furlow, F. Bryant

    1994-01-01

    Computer archives for 27 U.S. daily newspapers were accessed to evaluate the levels of coverage for 5 biological subissues and 5 ecological concepts in articles on the spotted owl debate. The author identified a correlation between biologist/reporter contact and increased biological subissue and ecological concepts coverage. (LZ)

  11. The Online Writing Lab (OWL) and the Forum: A Tool for Writers in Distance Education Environments.

    ERIC Educational Resources Information Center

    Terryberry, Karl

    2002-01-01

    Demonstrates how to integrate static web pages with the dynamic forum for an effective learning experience on the online writing lab (OWL). Explains why asynchronous feedback provides effective, individualized writing instruction to students with various learning styles and how collaborative learning is fostered through threaded discussion groups.…

  12. Harnessing the Power of Language: First Graders' Literature Engagement with "Owl Moon."

    ERIC Educational Resources Information Center

    Egawa, Kathy

    1990-01-01

    Offers guidelines for using literature in the primary classroom. Shares the experiences of first graders with the book "Owl Moon." Notes that it is important to retain the essence of the story--to demonstrate for young readers how readers connect with books. (MG)

  13. The Reliability of the OWLS Written Expression Scale with ESL Kindergarten Students

    ERIC Educational Resources Information Center

    Harrison, Gina L.; Ogle, Keira C.; Keilty, Megan

    2011-01-01

    A reliability analysis was conducted on the Written Expression Scale from the Oral and Written Language Scales, (OWLS, Carrow-Woolfolk, 1996), with 68 ESL and 56 non-ESL kindergarten students. Interrater and internal consistency estimates for the Written Expression Scale were examined separately for each language group. Despite lower oral English…

  14. Who are the bosses? Group influence on the behavior of voles following owl attack.

    PubMed

    Kleiman, Michal; Bodek, Sivan; Eilam, David

    2014-10-01

    Individual members of a group must conform to the group norms, as they may otherwise become isolated from the group or the group may split. On the other hand, social groups usually comprise various social ranks and display a differential division of labor and consequently different behaviors. The present study was aimed at examining how the above factors are manifested in social voles that had experienced owl attack. Here, we reconfirm the findings of past studies: that grouped voles converge to display similar behavior after owl attack. In addition, we found that high-mass voles were more active in the open sectors of the experimental set-ups both before and after the owl attack, whereas low-mass voles dichotomized to those that increased and those that decreased their activity in the open following owl attack. Taking body mass as a proxy for social rank, it is suggested that as a consequence of their larger size and of their experience and physical strength, high-mass voles both presented an exemplary model for the low-mass voles and, accordingly, assumed leadership and stabilized their group's behavior. We also suggest a hypothetical model for the propagation of behavior in hierarchical groups.

  15. Some Guides to Discovery About Elm Trees, Owls, Cockroaches, Earthworms, Cement and Concrete.

    ERIC Educational Resources Information Center

    Busch, Phyllis S.

    The introduction emphasizes the need for environmental and conservation education, and advocates an inquiry approach. Outdoor resources available to every school are listed. Detailed suggestions are made for investigating cement and concrete, cockroaches, earthworms, elm trees, and owls. In each case general background information and a list of…

  16. Social huddling and physiological thermoregulation are related to melanism in the nocturnal barn owl.

    PubMed

    Dreiss, Amélie N; Séchaud, Robin; Béziers, Paul; Villain, Nicolas; Genoud, Michel; Almasi, Bettina; Jenni, Lukas; Roulin, Alexandre

    2016-02-01

    Endothermic animals vary in their physiological ability to maintain a constant body temperature. Since melanin-based coloration is related to thermoregulation and energy homeostasis, we predict that dark and pale melanic individuals adopt different behaviours to regulate their body temperature. Young animals are particularly sensitive to a decrease in ambient temperature because their physiological system is not yet mature and growth may be traded-off against thermoregulation. To reduce energy loss, offspring huddle during periods of cold weather. We investigated in nestling barn owls (Tyto alba) whether body temperature, oxygen consumption and huddling were associated with melanin-based coloration. Isolated owlets displaying more black feather spots had a lower body temperature and consumed more oxygen than those with fewer black spots. This suggests that highly melanic individuals display a different thermoregulation strategy. This interpretation is also supported by the finding that, at relatively low ambient temperature, owlets displaying more black spots huddled more rapidly and more often than those displaying fewer spots. Assuming that spot number is associated with the ability to thermoregulate not only in Swiss barn owls but also in other Tytonidae, our results could explain geographic variation in the degree of melanism. Indeed, in the northern hemisphere, barn owls and allies are less spotted polewards than close to the equator, and in the northern American continent, barn owls are also less spotted in colder regions. If melanic spots themselves helped thermoregulation, we would have expected the opposite results. We therefore suggest that some melanogenic genes pleiotropically regulate thermoregulatory processes.

  17. Mapping sources, sinks, and connectivity using a simulation model of Northern Spotted Owls

    EPA Science Inventory

    This is a study of source-sink dynamics at a landscape scale. In conducting the study, we make use of a mature simulation model for the northern spotted owl (Strix occidentalis caurina) that was developed as part of the US Fish and Wildlife Service’s most recent recovery plannin...

  18. A retrospective study of etiological factors of abortion in the owl monkey, Aotus trivirgatus.

    PubMed

    Rouse, R; Bronson, R T; Sehgal, P K

    1981-01-01

    Abortions in owl monkeys occurred in the late second and early third trimesters. Retrospective study of clinical records showed that handling, maternal anemia, karyotype, and season were unassociated with abortion. Most aborted infants had no gross lesions at necropsy. Some had renal tubular necorsis, probably a postmortem change.

  19. Overestimation of fire risk in the northern spotted owl recovery plan.

    PubMed

    Hanson, Chad T; Odion, Dennis C; DellaSala, Dominick A; Baker, William L

    2009-10-01

    The U.S. Fish and Wildlife Service's recent recovery plan for one of the most carefully watched threatened species worldwide, the Northern Spotted Owl (Strix occidentalis caurina), recommended a major departure in conservation strategies in the northwestern United States. Due to concern about fire, the plan would switch from a reserve to a no-reserve strategy in up to 52% of the owl's range. Fuel treatments (e.g., thinning) at regular intervals also would occur on up to 65-70% of dry forests in this area. Estimations of fire risk, however, were based on less than a decade of data and an anecdotal assessment of a single, large fire. We found that decadal data are inherently too short, given infrequent large fires, to accurately predict fire risk and trends. Rates of high-severity fire, based on remote-sensing data, are far lower than reported in the plan and in comparison with the rate of old-forest recruitment. In addition, over a 22-year period, there has been no increase in the proportion of high-severity fire. Our findings refute the key conclusions of the plan that are the basis for major changes in conservation strategies for the Spotted Owl. The best available science is needed to address these strategies in an adaptive-management framework. From the standpoint of fire risk, there appears to be ample time for research on fire and proposed treatment effects on Spotted Owls before designing extensive management actions or eliminating reserves.

  20. Optical waveguide lightmode spectroscopy (OWLS) as a sensor for thin film and quantum dot corrosion.

    PubMed

    Yu, Hao; Eggleston, Carrick M; Chen, Jiajun; Wang, Wenyong; Dai, Qilin; Tang, Jinke

    2012-12-13

    Optical waveguide lightmode spectroscopy (OWLS) is usually applied as a biosensor system to the sorption-desorption of proteins to waveguide surfaces. Here, we show that OWLS can be used to monitor the quality of oxide thin film materials and of coatings of pulsed laser deposition synthesized CdSe quantum dots (QDs) intended for solar energy applications. In addition to changes in data treatment and experimental procedure, oxide- or QD-coated waveguide sensors must be synthesized. We synthesized zinc stannate (Zn(2)SnO(4)) coated (Si,Ti)O(2) waveguide sensors, and used OWLS to monitor the relative mass of the film over time. Films lost mass over time, though at different rates due to variation in fluid flow and its physical effect on removal of film material. The Pulsed Laser Deposition (PLD) technique was used to deposit CdSe QD coatings on waveguides. Sensors exposed to pH 2 solution lost mass over time in an expected, roughly exponential manner. Sensors at pH 10, in contrast, were stable over time. Results were confirmed with atomic force microscopy imaging. Limiting factors in the use of OWLS in this manner include limitations on the annealing temperature that maybe used to synthesize the oxide film, and limitations on the thickness of the film to be studied. Nevertheless, the technique overcomes a number of difficulties in monitoring the quality of thin films in-situ in liquid environments.

  1. Moonstruck primates: owl monkeys (Aotus) need moonlight for nocturnal activity in their natural environment.

    PubMed

    Fernández-Duque, Eduardo; de la Iglesia, Horacio; Erkert, Hans G

    2010-09-03

    Primates show activity patterns ranging from nocturnality to diurnality, with a few species showing activity both during day and night. Among anthropoids (monkeys, apes and humans), nocturnality is only present in the Central and South American owl monkey genus Aotus. Unlike other tropical Aotus species, the Azara's owl monkeys (A. azarai) of the subtropics have switched their activity pattern from strict nocturnality to one that also includes regular diurnal activity. Harsher climate, food availability, and the lack of predators or diurnal competitors, have all been proposed as factors favoring evolutionary switches in primate activity patterns. However, the observational nature of most field studies has limited an understanding of the mechanisms responsible for this switch in activity patterns. The goal of our study was to evaluate the hypothesis that masking, namely the stimulatory and/or inhibitory/disinhibitory effects of environmental factors on synchronized circadian locomotor activity, is a key determinant of the unusual activity pattern of Azara's owl monkeys. We use continuous long-term (6-18 months) 5-min-binned activity records obtained with actimeter collars fitted to wild owl monkeys (n =  10 individuals) to show that this different pattern results from strong masking of activity by the inhibiting and enhancing effects of ambient luminance and temperature. Conclusive evidence for the direct masking effect of light is provided by data showing that locomotor activity was almost completely inhibited when moonlight was shadowed during three lunar eclipses. Temperature also negatively masked locomotor activity, and this masking was manifested even under optimal light conditions. Our results highlight the importance of the masking of circadian rhythmicity as a determinant of nocturnality in wild owl monkeys and suggest that the stimulatory effects of dim light in nocturnal primates may have been selected as an adaptive response to moonlight. Furthermore

  2. Morphometric characterisation of wing feathers of the barn owl Tyto alba pratincola and the pigeon Columba livia

    PubMed Central

    Bachmann, Thomas; Klän, Stephan; Baumgartner, Werner; Klaas, Michael; Schröder, Wolfgang; Wagner, Hermann

    2007-01-01

    Background Owls are known for their silent flight. Even though there is some information available on the mechanisms that lead to a reduction of noise emission, neither the morphological basis, nor the biological mechanisms of the owl's silent flight are known. Therefore, we have initiated a systematic analysis of wing morphology in both a specialist, the barn owl, and a generalist, the pigeon. This report presents a comparison between the feathers of the barn owl and the pigeon and emphasise the specific characteristics of the owl's feathers on macroscopic and microscopic level. An understanding of the features and mechanisms underlying this silent flight might eventually be employed for aerodynamic purposes and lead to a new wing design in modern aircrafts. Results A variety of different feathers (six remiges and six coverts), taken from several specimen in either species, were investigated. Quantitative analysis of digital images and scanning electron microscopy were used for a morphometric characterisation. Although both species have comparable body weights, barn owl feathers were in general larger than pigeon feathers. For both species, the depth and the area of the outer vanes of the remiges were typically smaller than those of the inner vanes. This difference was more pronounced in the barn owl than in the pigeon. Owl feathers also had lesser radiates, longer pennula, and were more translucent than pigeon feathers. The two species achieved smooth edges and regular surfaces of the vanes by different construction principles: while the angles of attachment to the rachis and the length of the barbs was nearly constant for the barn owl, these parameters varied in the pigeon. We also present a quantitative description of several characteristic features of barn owl feathers, e.g., the serrations at the leading edge of the wing, the fringes at the edges of each feather, and the velvet-like dorsal surface. Conclusion The quantitative description of the feathers and

  3. Composition of the body mass overshoot in European barn owl nestlings (Tyto alba): insurance against scarcity of energy or water?

    PubMed

    Durant, Joël M; Landys, Meta M; Handrich, Yves

    2008-07-01

    European barn owl chicks (Tyto alba) show a body mass overshoot prior to fledging that has been predicted to serve as an energy reservoir during periods of stochastic food availability. However, the composition of the mass overshoot has heretofore not been directly examined in nestlings of this or any other species displaying a body mass overshoot during growth (e.g., raptors and seabirds). To experimentally determine whether the overshoot in body mass in juvenile European barn owls (Tyto alba) may act as an energy reservoir, we compared the body composition of owl chicks raised on an ad libitum diet to those fed a restricted diet designed to eliminate the overshoot. Chicks raised on the two diets were also compared for differences in maturation of diverse functions (e.g., locomotion) and tissues (e.g., skeletal development). Contrary to expectations, our results on body composition in juvenile barn owls indicate that the mass overshoot prior to fledging is primarily comprised of an increased water compartment. Thus, we suggest that the mass overshoot in owls (and possibly in other species) does not serve as an energy reservoir but, rather, may function as an insurance against dehydration when hot in-nest conditions force chicks to rely on evaporative cooling: temperatures in barn owl nests can reach up to 43 degrees C. We found no significant differences in maturation indexes between diet treatments at the time of fledging.

  4. What do predators really want? The role of gerbil energetic state in determining prey choice by Barn Owls.

    PubMed

    Embar, Keren; Mukherjee, Shomen; Kotler, Burt P

    2014-02-01

    In predator-prey foraging games, predators should respond to variations in prey state. The value of energy for the prey changes depending on season. Prey in a low energetic state and/or in a reproductive state should invest more in foraging and tolerate higher predation risk. This should make the prey more catchable, and thereby, more preferable to predators. We ask, can predators respond to prey state? How does season and state affect the foraging game from the predator's perspective? By letting owls choose between gerbils whose states we experimentally manipulated, we could demonstrate predator sensitivity to prey state and predator selectivity that otherwise may be obscured by the foraging game. During spring, owls invested more time and attacks in the patch with well-fed gerbils. During summer, owls attacked both patches equally, yet allocated more time to the patch with hungry gerbils. Energetic state per se does not seem to be the basis of owl choice. The owls strongly responded to these subtle differences. In summer, gerbils managed their behavior primarily for survival, and the owls equalized capture opportunities by attacking both patches equally.

  5. Herpesviral inclusion body disease in owls and falcons is caused by the pigeon herpesvirus (columbid herpesvirus 1).

    PubMed

    Gailbreath, Katherine L; Oaks, J Lindsay

    2008-04-01

    A herpesviral disease of Rock Pigeons (Columba livia), called "inclusion body disease" or "inclusion body hepatitis," was first described in the 1940s. The disease involves hepatic and splenic necrosis with associated intranuclear inclusion bodies and occurs primarily in young squabs. A similar herpesviral disease occurs in falcons and owls. Serologic and restriction endonuclease digestion studies indicate that herpesviruses from pigeons, falcons, and owls are very closely related and that most reported cases of disease in falcons and owls involve prior documented or possible ingestion of pigeons. These findings led to the hypothesis that an endemic herpesvirus of pigeons may be causing disease in falcons and owls. In order to test this hypothesis, we sequenced a fragment of the herpesviral DNA polymerase gene from naturally infected owls, falcons, and pigeons with inclusion body disease collected between 1991 and 2006. Sequences from all three sources were almost identical, and we therefore propose that the usual agent of inclusion body hepatitis in owls and falcons is columbid herpesvirus 1.

  6. Great gray owls (Strix nebulosa) in Yosemite National Park: on the importance of food, forest structure, and human disturbance

    USGS Publications Warehouse

    van Riper, Charles; Fontaine, Joseph J.; van Wagtendonk, Jan W.

    2013-01-01

    We studied great gray owls (Strix nebulosa Forster) in Yosemite National Park, California, measuring variables that could potentially influence patterns of occurrence and conservation of this stateendangered species. We found that owl presence was closely tied to habitat (red fir (Abies magnified A. Murray) and the abundance of meadows), prey, and snags across the landscape. We also found that indicators of human recreational activities negatively influenced owl distribution and habitat use. Great gray owls appear to prefer mid-elevation red fir forest with meadows that are drier and more productive in terms of small mammal populations. That these areas also have the highest human activity presents a paradox, both for individual owls and for the future conservation and management of this California endangered species. The extent to which human recreation in natural areas affects animal behavior, species distribution, and productivity is a growing issue in natural area management. We present information that will allow land managers to better understand how existing natural resources, coupled with human recreation, influence the distribution and habitat use of the great gray owl.

  7. Bird predation by tawny owls ( Strix aluco L.) and its effect on the reproductive performance of tits

    NASA Astrophysics Data System (ADS)

    Sasvári, Lajos; Hegyi, Zoltán

    1998-11-01

    The density of great tit Parus major L. and blue tit Parus caeruleus L. was artificially increased by placing nest-box colonies for these species in the vicinity of the nests of breeding tawny owls during 1993-1997. Bird prey composition in the owl nests, the proportion of parents disappearing from the breeding tit populations and the reproductive performance of the widowed parents were analysed. The frequency of predation on tits by tawny owls was greater in areas where tit density had been artificially increased. Owls preyed more on tits during the feeding period of owlets than during the incubation period and more in years when snow covered the ground during the incubation period than when it did not. Mortality due to predation was male biased and more females lost their mates in populations breeding near tawny owl nests. Reproductive performance of the widowed parents was lower and their body weights were lighter at the end of the nestling period than those found in birds rearing youngs with their mates. Predation by owls increased the between-year turnover in the breeding tit population: widowed parents did not return to the nesting site for the next breeding season.

  8. Ground-water and stream-water interaction in the Owl Creek basin, Wyoming

    USGS Publications Warehouse

    Ogle, K.M.

    1996-01-01

    Understanding of the interaction of ground-water and surface-water resources is vital to water management when water availability is limited.Inflow of ground water is the primary source ofwater during stream base flow. The water chemistry of streams may substantially be affected by that inflow of ground water. This report is part of a study to examine ground-water and surface-water interaction in the Owl Creek Basin, Wyoming, completed by the U.S. Geological Survey incooperation with the Northern Arapaho Tribe and the Shoshone Tribe. During a low flow period between November\\x1113 - 17, 1991, streamflowmeasurements and water-quality samples were collected at 16 selected sites along major streams and tributaries in the Owl Creek Basin,Wyoming. The data were used to identify stream reaches receiving ground-water inflow and to examine causes of changes in stream chemistry.Streamflow measurements, radon-222 activity load, and dissolved solids load were used to identified stream reaches receiving ground-water inflow.Streamflow measurements identified three stream reaches receiving ground-water inflow. Analysis of radon-222 activity load identified five stream reaches receiving ground-water inflow. Dissolvedsolids load identified six stream reaches receiving ground-water inflow. When these three methods were combined, stream reaches in two areas, theEmbar Area and the Thermopolis Anticline Area, were identified as receiving ground-water inflow.The Embar Area and the Thermopolis Anticline Area were then evaluated to determine the source of increased chemical load in stream water. Three potential sources were analyzed: tributary inflow, surficial geology, and anticlines. Two sources,tributary inflow and surficial geology, were related to changes in isotopic ratios and chemical load in the Embar Area. In two reaches in the Embar Area, isotopic ratios of 18O/16O, D/H, and 34S/32S indicated that tributary inflow affected stream-water chemistry. Increased chemical load of

  9. Plague's partners in crime.

    PubMed

    Davis, Kimberly M; Isberg, Ralph R

    2014-09-18

    The hallmark of bubonic plague is the presence of grotesquely swollen lymph nodes, called buboes. This frenzied inflammatory response to Yersinia pestis is poorly understood. In this issue of Immunity, St. John et al. (2014) explore the mechanism by which Y. pestis spreads and thus leads to this striking lymphadenopathy.

  10. The Best of All Possible Worlds: Applying the Model Driven Architecture Approach to a JC3IEDM OWL Ontology Modeled in UML

    DTIC Science & Technology

    2014-06-01

    model written with the ODM profile. Figure 2 . Workflow for Generating OWL Specifications out of Legacy ER Specifications 4 3. GENERATING A  UML ...developed an implementation of the ODM profile that can be used with the Sparx Systems Enterprise Architect (SPARX EA) UML modeling tool.[8] The...profile is not fully conformant with the ODM standard. When we started, the available version of ODM was 1.0, which supported OWL 1 but not OWL 2 . The

  11. West Nile virus in raptors from Virginia during 2003: clinical, diagnostic, and epidemiologic findings.

    PubMed

    Joyner, Priscilla H; Kelly, Sean; Shreve, Allison A; Snead, Sarah E; Sleeman, Jonathan M; Pettit, Denise A

    2006-04-01

    Sixty-one birds of prey admitted to The Wildlife Center of Virginia (WCV; Waynesboro, Virginia, USA) from June to November 2003 were tested for West Nile virus (WNV) infection. Choanal and/or cloacal swabs were obtained and submitted to Virginia's Division of Consolidated Laboratory Services (Richmond, Virginia, USA) for analysis with real-time reverse transcriptase polymerase chain reaction (RT-PCR). Forty birds of prey were positive for WNV by RT-PCR. Five avian families and nine species of raptors were represented, with great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) most frequently affected. Presenting clinical signs were consistent with previous reports of WNV infection in raptors; however, these differed between species. Of WNV positive birds, nonspecific signs of illness were the most common clinical findings, particularly in red-tailed hawks; signs included dehydration (n = 20), emaciation (n = 18), and depression (n = 15). Neurologic abnormalities were frequently identified, especially in great horned owls, and included head tremors (n = 17), ataxia (n = 13), head incoordination (n = 7), torticollis (n = 3), nystagmus (n = 3), and head tilt (n = 3). Great horned owls exhibited anemia and leukocytosis with heterophilia, eosinophilia, and monocytosis consistent with chronic inflammation. Red-tailed hawks were anemic with a heterophilic leukocytosis and regenerative left shift. The majority of WNV cases occurred during August and September; there was a marked increase in the number of raptors admitted to WCV during these months followed by a marked decrease during October, November, and December. This pattern differed from mean monthly admissions during the previous 10 years and suggests a negative impact on local raptor populations. The effects of WNV on avian populations are largely unknown; however, because of their ecological importance, further investigation of the effects of WNV on raptor populations is warranted.

  12. Second generation anticoagulant rodenticides in predatory birds: Probabilistic characterisation of toxic liver concentrations and implications for predatory bird populations in Canada.

    PubMed

    Thomas, Philippe J; Mineau, Pierre; Shore, Richard F; Champoux, Louise; Martin, Pamela A; Wilson, Laurie K; Fitzgerald, Guy; Elliott, John E

    2011-07-01

    Second-generation anticoagulant rodenticides (SGARs) are widely used to control rodent pests but exposure and poisonings occur in non-target species, such as birds of prey. Liver residues are often analysed to detect exposure in birds found dead but their use to assess toxicity of SGARs is problematic. We analysed published data on hepatic rodenticide residues and associated symptoms of anticoagulant poisoning from 270 birds of prey using logistic regression to estimate the probability of toxicosis associated with different liver SGAR residues. We also evaluated exposure to SGARs on a national level in Canada by analysing 196 livers from great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis) found dead at locations across the country. Analysis of a broader sample of raptor species from Quebec also helped define the taxonomic breadth of contamination. Calculated probability curves suggest significant species differences in sensitivity to SGARs and significant likelihood of toxicosis below previously suggested concentrations of concern (<0.1mg/kg). Analysis of birds from Quebec showed that a broad range of raptor species are exposed to SGARs, indicating that generalised terrestrial food chains could be contaminated in the vicinity of the sampled areas. Of the two species for which we had samples from across Canada, great horned owls are exposed to SGARs to a greater extent than red-tailed hawks and the liver residue levels were also higher. Using our probability estimates of effect, we estimate that a minimum of 11% of the sampled great horned owl population is at risk of being directly killed by SGARs. This is the first time the potential mortality impact of SGARs on a raptor population has been estimated.

  13. Chromosome mapping of the owl monkey CSF1R and IL5 genes.

    PubMed

    Ma, N S; Lin, K C

    1992-08-01

    We mapped the owl monkey colony-stimulating factor 1 receptor (CSF1R) locus to the proximal region of chromosome 3q of karyotype VI(K-VI) and karyotype V(K-V) and the interleukin 5 (IL5) locus to the mid-region of chromosome 3q(K-VI) and 19q(K-IV) using a combination of Southern hybridization of somatic cells and in situ chromosomal hybridization methodologies. The findings support the proposed evolution of owl monkey chromosome 3(K-VI) from a fusion of two smaller structures, the homologs of chromosomes 6 and 19 (K-IV). The data also indicate genomic conservation of the HSA 5q23-q35 segment in the higher primates.

  14. Scanning electron microscopic study of the tongue in the Oriental scops owl (Otus scops).

    PubMed

    Emura, Shoichi; Okumura, Toshihiko; Chen, Huayue

    2009-05-01

    The dorsal lingual surface of an adult owl (Otus scops) was examined by scanning electron microscopy. The tongue of the adult owl was about 1 cm long. Three parts were distinguished in the dorsal surface of the tongue: the apex, the body and the root of the tongue. The conical region between the lingual apex and lingual root was very wide area. The conical papillae of the lingual body were inclined toward the posterior of the tongue. At low magnification of scanning electron microscopy, the desquamated cells were observed in the entire dorsal surface of the lingual apex. The connective tissue cores of the epithelium of the lingual apex showed the rod-shaped protrusions. The border between the lingual apex and body was clear and the small conical papillae were observed in the lingual body. The small and large conical papillae were observed on the lingual body. The many openings of the lingual glands existed in the lingual body and lingual root.

  15. Spatial hearing in echoic environments: the role of the envelope in owls.

    PubMed

    Nelson, Brian S; Takahashi, Terry T

    2010-08-26

    In the precedence effect, sounds emanating directly from the source are localized preferentially over their reflections. Although most studies have focused on the delay between the onset of a sound and its echo, humans still experience the precedence effect when this onset delay is removed. We tested in barn owls the hypothesis that an ongoing delay, equivalent to the onset delay, is discernible from the envelope features of amplitude-modulated stimuli and may be sufficient to evoke this effect. With sound pairs having only envelope cues, owls localized direct sounds preferentially, and neurons in their auditory space-maps discharged more vigorously to them, but only if the sounds were amplitude modulated. Under conditions that yielded the precedence effect, acoustical features known to evoke neuronal discharges were more abundant in the envelopes of the direct sounds than of the echoes, suggesting that specialized neural mechanisms for echo suppression were unnecessary.

  16. Inner vane fringes of barn owl feathers reconsidered: morphometric data and functional aspects.

    PubMed

    Bachmann, Thomas; Wagner, Hermann; Tropea, Cameron

    2012-07-01

    It is a challenge to understand how barn owls (Tyto alba) reduce noise during flight to be able to hunt small mammals by audition. Several specializations of the wing and the wing feathers have been implicated in noise reduction. What has been overlooked so far are the fringes at the inner vanes of remiges. We demonstrated, by using precise imaging techniques combined with morphometric measurements and air-flow studies, that these fringes merge into neighboring feather vanes by gliding into the grooves at the lower wing surface that are formed by parallel-oriented barb shafts. The connection of adjacent feathers results in a smooth lower wing surface and thus reduces sharp and noisy edges. This finding sheds new light on the mechanisms underlying noise reduction of flying owls.

  17. A Pilot Study on Modeling of Diagnostic Criteria Using OWL and SWRL.

    PubMed

    Hong, Na; Jiang, Guoqian; Pathak, Jyotishiman; Chute, Christopher G

    2015-01-01

    The objective of this study is to describe our efforts in a pilot study on modeling diagnostic criteria using a Semantic Web-based approach. We reused the basic framework of the ICD-11 content model and refined it into an operational model in the Web Ontology Language (OWL). The refinement is based on a bottom-up analysis method, in which we analyzed data elements (including value sets) in a collection (n=20) of randomly selected diagnostic criteria. We also performed a case study to formalize rule logic in the diagnostic criteria of metabolic syndrome using the Semantic Web Rule Language (SWRL). The results demonstrated that it is feasible to use OWL and SWRL to formalize the diagnostic criteria knowledge, and to execute the rules through reasoning.

  18. A chronic disease dietary consultation system using OWL-based ontologies and semantic rules.

    PubMed

    Chi, Yu-Liang; Chen, Tsang-Yao; Tsai, Wan-Ting

    2015-02-01

    Chronic diseases patients often require constant dietary control that involves complicated interaction among factors such as the illness stage, the patient's physical condition, the patient's activity level, the amount of food intake, and key nutrient restrictions. This study aims to integrate multiple knowledge sources for problem solving modeling and knowledge-based system (KBS) development. A chronic kidney disease dietary consultation system is constructed by using Web Ontology Language (OWL) and Semantic Web Rule Language (SWRL) to demonstrate how a KBS approach can achieve sound problem solving modeling and effective knowledge inference. For system evaluation, information from 84 case patients is used to evaluate the performance of the system in recommending appropriate food serving amounts from different food groups for balanced key nutrient ingestion. The results show that, excluding interference factors, the OWL-based KBS can achieve accurate problem solving reasoning while maintaining knowledge base shareability and extensibility.

  19. Old-growth and mature forests near spotted owl nests in western Oregon

    NASA Technical Reports Server (NTRS)

    Ripple, William J.; Johnson, David H.; Hershey, K. T.; Meslow, E. Charles

    1995-01-01

    We investigated how the amount of old-growth and mature forest influences the selection of nest sites by northern spotted owls (Strix occidentalis caurina) in the Central Cascade Mountains of Oregon. We used 7 different plot sizes to compare the proportion of mature and old-growth forest between 30 nest sites and 30 random sites. The proportion of old-growth and mature forest was significantly greater at nests sites than at random sites for all plot sizes (P less than or equal to 0.01). Thus, management of the spotted owl might require setting the percentage of old-growth and mature forest retained from harvesting at least 1 standard deviation above the mean for the 30 nest sites we examined.

  20. Bionic Design of Wind Turbine Blade Based on Long-Eared Owl's Airfoil.

    PubMed

    Tian, Weijun; Yang, Zhen; Zhang, Qi; Wang, Jiyue; Li, Ming; Ma, Yi; Cong, Qian

    2017-01-01

    The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl's wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl's wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift.

  1. Bionic Design of Wind Turbine Blade Based on Long-Eared Owl's Airfoil

    PubMed Central

    Li, Ming

    2017-01-01

    The main purpose of this paper is to demonstrate a bionic design for the airfoil of wind turbines inspired by the morphology of Long-eared Owl's wings. Glauert Model was adopted to design the standard blade and the bionic blade, respectively. Numerical analysis method was utilized to study the aerodynamic characteristics of the airfoils as well as the blades. Results show that the bionic airfoil inspired by the airfoil at the 50% aspect ratio of the Long-eared Owl's wing gives rise to a superior lift coefficient and stalling performance and thus can be beneficial to improving the performance of the wind turbine blade. Also, the efficiency of the bionic blade in wind turbine blades tests increases by 12% or above (up to 44%) compared to that of the standard blade. The reason lies in the bigger pressure difference between the upper and lower surface which can provide stronger lift. PMID:28243053

  2. Embryonic and posthatching development of the barn owl (Tyto alba): reference data for age determination.

    PubMed

    Köppl, Christine; Futterer, Eva; Nieder, Bärbel; Sistermann, Ralf; Wagner, Hermann

    2005-08-01

    The normal development of the barn owl was documented with the intent of providing a guideline for determining the maturational stage of embryos and posthatching individuals. Embryonic development up to stage 39 could be well described using the well-known developmental atlas for the chicken (Hamburger and Hamilton [1951] J. Morphol. 88:49-92). For later stages, limb size was established as a suitable indicator. In addition, measuring the egg's vascularized area through candling was found to be a useful, noninvasive method for staging very early embryos, up to stage 25. An average relationship between incubation period and embryonic stage was derived, which showed that development in the barn owl initially lags that in the chicken. For posthatching individuals, skeletal measures (tarsal and ulnar length, skull width and length) were the most reliable parameters for judging maturation, up to 1 month. For older individuals, feather development (e.g., length of primary wing feathers) provided the only cue.

  3. Enteric coccidia (Apicomplexa) in the small intestine of the northern spotted owl (Strix occidentalis caurina).

    PubMed

    Hoberg, E P; Cawthorn, R J; Hedstrom, O R

    1993-07-01

    Sporulated oocysts (mean dimensions = 13.0 x 10.8 microns) and sporocysts (11.3 x 5.5 microns) of a coccidian resembling Frenkelia sp. or Sarcocystis sp. were present in the lamina propria of the small intestine of a naturally-infected northern spotted owl (Strix occidentalis caurina) collected near Medford, Oregon (USA). Dimensions of these oocytes and sporocysts appear to be considerably smaller than those from other sarcocystid species with avian definitive hosts. Additionally, numerous developmental stages and unsporulated oocysts (mean dimensions 22.8 x 17.8 microns) of a possible species of Isospora also were observed in the intestinal epithelium. This constitutes the first report of enteric coccidia from spotted owls. Neither parasite appeared to cause the death of the bird.

  4. Heavy metal contamination in little owl (Athene noctua) and common buzzard (Buteo buteo) from northern Italy.

    PubMed

    Battaglia, Alessandra; Ghidini, Sergio; Campanini, Giorgio; Spaggiari, Roberto

    2005-01-01

    In this study, two raptor species, the common buzzard (Buteo buteo) and the little owl (Athene noctua), were investigated for lead and cadmium concentrations, using liver, kidneys, pectoral muscle, sternum bone, and feathers. All the collected birds died at the Centro Recupero Rapaci of Lega Italiana Protezione Uccelli in Sala Baganza (Parma, Italy). They arrived alive at the Centro between November 1998 and November 1999 but died or were put to death as a consequence of injuries or other ailments. The results of the investigation do not show an excessive exposure to cadmium, whereas some interesting data have emerged in the case of lead. The concentration of the latter in the liver and in the bone of two little owls seem to suggest the possibility of chronic exposure. The high values found in one common buzzard, on the other hand, suggest an acute exposure and, probably, a case of lead shot ingestion.

  5. Trends in North American small mammals found in common barn-owl (Tyto alba) dietary studies

    USGS Publications Warehouse

    Clark, D.R.; Bunck, C.M.

    1991-01-01

    Data on mammals were compiled from published studies of common barn-owl (Tyto alba) pellets. Mammalian composition of pellet samples was analyzed within geographic regions in regard to year, mean annual precipitation, latitude, and number of individual mammals in the sample. Percentages of individuals in pellets that were shrews increased whereas the percentages of rodents decreased with greater mean annual precipitation, especially in northern and western areas of North America. From the 1920s through 1980s, in northern and eastern areas the percentage of species that was shrews decreased, and in northern and central areas the percentage of individuals that was murid rats and mice increased. Human alterations of habitats during these seven decades are postulated to have caused changes in available small mammals, leading to changes in the barn-owl diet.

  6. Growth and immunity conferred by a Plasmodium falciparum temperature sensitive mutant in Panamanian owl monkeys.

    PubMed

    Inselburg, J; Rossan, R N; Escajadillo, A

    1989-05-01

    We have compared the growth of the wild type Plasmodium falciparum strain Honduras 1 and a previously isolated temperature sensitive mutant of it, AP1-16, in Panamanian owl monkeys. We examined serially infected splenectomized and normal animals that were initially infected with cultured parasites that had been grown in a mixture of owl monkey and human erythrocytes. Initial infections in splenectomized monkeys were marked by multiple recrudescences. The mutant grew less well than the wild type in the splenectomized monkeys, as determined by lower peak and total parasitemias. In the splenectomized monkeys tested by rechallenge with the wild type parasite, the mutant stimulated a comparable degree of protection. That protection was manifested in 2 ways. There was a marked reduction in the level of the primary parasitemia in the rechallenged monkeys and an absence of recrudescent parasitemias after the primary parasitemia. The potential value of generating and studying temperature sensitive P. falciparum strains that show attenuated growth is considered.

  7. Local weather, regional climate, and annual survival of the northern spotted owl

    USGS Publications Warehouse

    Glenn, E.M.; Anthony, R.G.; Forsman, E.D.; Olson, G.S.

    2011-01-01

    We used an information-theoretical approach and Cormack-Jolly-Seber models for open populations in program MARK to examine relationships between survival rates of Northern Spotted Owls and a variety of local weather variables and long-term climate variables. In four of the six populations examined, survival was positively associated with wetter than normal conditions during the growing season or high summer temperatures. At the three study areas located at the highest elevations, survival was positively associated with winter temperature but also had a negative or quadratic relation with the number of storms and winter precipitation. A metaanalysis of all six areas combined indicated that annual survival was most strongly associated with phase shifts in the Southern Oscillation and Pacific Decadal Oscillation, which reflect large-scale temperature and precipitation patterns in this region. Climate accounted for a variable amount (1-41%) of the total process variation in annual survival but for more year-to-year variation (3-66%) than did spatial variation among owl territories (0-7%). Negative associations between survival and cold, wet winters and nesting seasons were similar to those found in other studies of the Spotted Owl. The relationships between survival and growing-season precipitation and regional climate patterns, however, had not been reported for this species previously. Climate-change models for the first half of the 21st century predict warmer, wetter winters and hotter, drier summers for the Pacific Northwest. Our results indicate that these conditions could decrease Spotted Owl survival in some areas. Copyright ?? The Cooper Ornithological Society 2011.

  8. Complete Genome Sequence of a Vaccinal Newcastle Disease Virus Strain Isolated from an Owl (Rhinoptynx clamator)

    PubMed Central

    Van Borm, Steven; Rizotto, Laís S.; Ullmann, Leila S.; Scagion, Guilherme P.; Malossi, Camila D.; Simão, Raphael M.; Araújo, João P.; Cordeiro, Izabelle M.; Keid, Lara B.; Oliveira, Trícia Maria F. Sousa; Soares, Rodrigo M.; Martini, Matheus C.; Orsi, Maria A.; Arns, Clarice W.

    2016-01-01

    A Newcastle disease virus (NDV) was isolated in chicken embryonated eggs after detection by real-time reverse transcription-PCR (RRT-PCR) from a captive owl swab. The complete genome sequence of APMV-1/Rhinoptynx clamator/Brazil/22516/2009 (APMV-1, avian paramyxovirus type 1) was obtained using Illumina sequencing. Phylogenetic analysis of the complete genome classified the isolate within NDV class II genotype II. PMID:27856578

  9. Owl monkeys (Aotus spp.) perform self- and social anointing in captivity.

    PubMed

    Jefferson, Jay P; Tapanes, Elizabeth; Evans, Sian

    2014-01-01

    Several species of primates, including owl monkeys (Aotus spp.), anoint by rubbing their fur with odiferous substances. Previous research has shown that capuchin monkeys (Cebus and Sapajus) anoint socially by rubbing their bodies together in groups of two or more while anointing. Owl monkeys housed at the DuMond Conservancy have been observed to anoint over the last 10 years, and we report detailed new information on the anointing behavior of this population, including descriptions of social anointing which occurs frequently. We first investigated the occurrence of self-anointing in 35 Aotus spp. presented with millipedes. Detailed descriptions regarding body regions anointed were obtained for all anointers (n = 28). The median duration for a self-anointing bout was 3.6 min (range from approx. 2 s to 14.15 min). While the latency and length of anointing bouts showed considerable interindividual differences, no statistically significant differences were found between sexes, wild- or captive-born owl monkeys or across age groups. However, we found the lower back and tail were anointed at a rate significantly greater than other body parts, but there were no differences in these patterns across sex or wild- or captive-born owl monkeys. More recently, social anointing was investigated in 26 Aotus spp. presented with millipedes, of which half were observed to anoint socially. The average duration for all social anointing bouts was 72.88 s, with a median duration of 30 s (range 5-322 s). A detailed ethogram was also generated that included behaviors that were performed while anointing, including facial expressions and vocalizations. The intraindividual variability for 8 monkeys used in both investigations is discussed. These findings extend our knowledge of anointing and confirm the existence of social anointing in another genus with a unique biology (nocturnal and socially monogamous) distinct from capuchins.

  10. Use of mammal manure by nesting burrowing owls: a test of four functional hypotheses

    USGS Publications Warehouse

    Smith, M.D.; Conway, C.J.

    2007-01-01

    Animals have evolved an impressive array of behavioural traits to avoid depredation. Olfactory camouflage of conspicuous odours is a strategy to avoid depredation that has been implicated only in a few species of birds. Burrowing owls, Athene cunicularia, routinely collect dried manure from mammals and scatter it in their nest chamber, in the tunnel leading to their nest and at the entrance to their nesting burrow. This unusual behaviour was thought to reduce nest depredation by concealing the scent of adults and juveniles, but a recent study suggests that manure functions to attract arthropod prey. However, burrowing owls routinely scatter other materials in the same way that they scatter manure, and this fact seems to be at odds with both of these hypotheses. Thus, we examined the function of this behaviour by testing four alternative hypotheses. We found no support for the widely cited olfactory-camouflage hypothesis (manure did not lower the probability of depredation), or for the mate-attraction hypothesis (males collected manure after, not before, pair formation). Predictions of the burrow-occupied hypothesis (manure indicates occupancy to conspecifics and thereby reduces agonistic interactions) were supported, but results were not statistically significant. Our results also supported several predictions of the prey-attraction hypothesis. Pitfall traps at sampling sites with manure collected more arthropod biomass (of taxa common in the diet of burrowing owls) than pitfall traps at sampling sites without manure. Scattering behaviour of burrowing owls appears to function to attract arthropod prey, but may also signal occupancy of a burrow to conspecifics. ?? 2006 The Association for the Study of Animal Behaviour.

  11. Pattern of maternal circulating CRH in laboratory-housed squirrel and owl monkeys.

    PubMed

    Power, M L; Williams, L E; Gibson, S V; Schulkin, J; Helfers, J; Zorrilla, E P

    2010-11-01

    The anthropoid primate placenta appears to be unique in producing corticotropin-releasing hormone (CRH). Placental CRH is involved in an endocrine circuit key to the production of estrogens during pregnancy. CRH induces cortisol production by the maternal and fetal adrenal glands, leading to further placental CRH production. CRH also stimulates the fetal adrenal glands to produce dehydroepiandrostendione sulfate (DHEAS), which the placenta converts into estrogens. There are at least two patterns of maternal circulating CRH across gestation among anthropoids. Monkeys examined to date (Papio and Callithrix) have an early-to-mid gestational peak of circulating CRH, followed by a steady decline to a plateau level, with a possible rise near parturition. In contrast, humans and great apes have an exponential rise in circulating CRH peaking at parturition. To further document and compare patterns of maternal circulating CRH in anthropoid primates, we collected monthly blood samples from 14 squirrel monkeys (Saimiri boliviensis) and ten owl monkeys (Aotus nancymaae) during pregnancy. CRH immunoreactivity was measured from extracted plasma by using solid-phase radioimmunoassay. Both squirrel and owl monkeys displayed a mid-gestational peak in circulating CRH: days 45-65 of the 152-day gestation for squirrel monkeys (mean±SEM CRH=2,694±276 pg/ml) and days 60-80 of the 133-day gestation for owl monkeys (9,871±974 pg/ml). In squirrel monkeys, circulating CRH declined to 36% of mean peak value by 2 weeks before parturition and then appeared to increase; the best model for circulating CRH over gestation in squirrel monkeys was a cubic function, similar to previous results for baboons and marmosets. In owl monkeys, circulating CRH appeared to reach plateau with no subsequent significant decline approaching parturition, although a cubic function was the best fit. This study provides additional evidence for a mid-gestational peak of maternal circulating CRH in ancestral

  12. Potential Influences of Climate and Nest Structure on Spotted Owl Reproductive Success: A Biophysical Approach

    PubMed Central

    Rockweit, Jeremy T.; Franklin, Alan B.; Bakken, George S.; Gutiérrez, R. J.

    2012-01-01

    Many bird species do not make their own nests; therefore, selection of existing sites that provide adequate microclimates is critical. This is particularly true for owls in north temperate climates that often nest early in the year when inclement weather is common. Spotted owls use three main types of nest structures, each of which are structurally distinct and may provide varying levels of protection to the eggs or young. We tested the hypothesis that spotted owl nest configuration influences nest microclimate using both experimental and observational data. We used a wind tunnel to estimate the convective heat transfer coefficient (hc) of eggs in 25 potential nest configurations that mimicked 2 nest types (top-cavity and platform nests), at 3 different wind speeds. We then used the estimates of hc in a biophysical heat transfer model to estimate how long it would take unattended eggs to cool from incubation temperature (∼36°C) to physiological zero temperature (PZT; ∼26°C) under natural environmental conditions. Our results indicated that the structural configuration of nests influences the cooling time of the eggs inside those nests, and hence, influences the nest microclimate. Estimates of time to PZT ranged from 10.6 minutes to 33.3 minutes. Nest configurations that were most similar to platform nests always had the fastest egg cooling times, suggesting that platform nests were the least protective of those nests we tested. Our field data coupled with our experimental results suggested that nest choice is important for the reproductive success of owls during years of inclement weather or in regions characterized by inclement weather during the nesting season. PMID:22859993

  13. Validation of the openEHR archetype library by using OWL reasoning.

    PubMed

    Menárguez-Tortosa, Marcos; Fernández-Breis, Jesualdo Tomás

    2011-01-01

    Electronic Health Record architectures based on the dual model architecture use archetypes for representing clinical knowledge. Therefore, ensuring their correctness and consistency is a fundamental research goal. In this work, we explore how an approach based on OWL technologies can be used for such purpose. This method has been applied to the openEHR archetype repository, which is the largest available one nowadays. The results of this validation are also reported in this study.

  14. Toxicokinetics and coagulopathy threshold of the rodenticide diphacinone in eastern screech-owls (Megascops asio).

    PubMed

    Rattner, Barnett A; Horak, Katherine E; Lazarus, Rebecca S; Goldade, David A; Johnston, John J

    2014-01-01

    In the United States, new regulations on second-generation anticoagulant rodenticides will likely be offset by expanded use of first-generation anticoagulant rodenticides. In the present study, eastern screech-owls (Megascops asio) were fed 10 µg diphacinone/g wet weight food for 7 d, and recovery was monitored over a 21-d postexposure period. By day 3 of exposure, diphacinone (DPN) was detected in liver (1.63 µg/g wet wt) and kidney (5.83 µg/g) and coagulopathy was apparent. By day 7, prothrombin time (PT) and Russell's viper venom time (RVVT) were prolonged, and some individuals were anemic. Upon termination of exposure, coagulopathy and anemia were resolved within 4 d, and residues decreased to <0.3 µg/g by day 7. Liver and kidney DPN elimination occurred in 2 phases (initial rapid loss, followed by slower loss rate), with overall half-lives of 11.7 d and 2.1 d, respectively. Prolonged PT and RVVT occurred in 10% of the exposed owls with liver DPN concentrations of 0.122 µg/g and 0.282 µg/g and in 90% of the owls with liver concentrations of 0.638 µg/g and 0.361 µg/g. These liver residue levels associated with coagulopathy fall in the range of values reported in raptor mortality incidents involving DPN. These tissue-based toxicity reference values for coagulopathy in adult screech-owls have application for interpreting nontarget mortality and assessing the hazard of DPN in rodent-control operations. Diphacinone exposure evokes toxicity in raptors within a matter of days; but once exposure is terminated, recovery of hemostasis occurs rapidly.

  15. Mortality causes of owl monkeys (Aotus nancymae and Aotus vociferans) in captivity.

    PubMed

    Gozalo, A; Montoya, E

    1990-01-01

    To determine the main causes of death in "owl monkeys" (Aotus nancymae and A. vociferans) in captivity, 115 necropsies were performed. According to the macroscopic findings and clinical data, results are as follow: acute lobular pneumonia (25.2%), chronic nephropathy (10.4%), acute catarrhal enteritis (8.7%), acute hemorrhagic enteritis (7%), acute toxic hepatitis (5.2%), trauma (5.2%), and others.

  16. Potential influences of climate and nest structure on spotted owl reproductive success: a biophysical approach.

    PubMed

    Rockweit, Jeremy T; Franklin, Alan B; Bakken, George S; Gutiérrez, R J

    2012-01-01

    Many bird species do not make their own nests; therefore, selection of existing sites that provide adequate microclimates is critical. This is particularly true for owls in north temperate climates that often nest early in the year when inclement weather is common. Spotted owls use three main types of nest structures, each of which are structurally distinct and may provide varying levels of protection to the eggs or young. We tested the hypothesis that spotted owl nest configuration influences nest microclimate using both experimental and observational data. We used a wind tunnel to estimate the convective heat transfer coefficient (h(c)) of eggs in 25 potential nest configurations that mimicked 2 nest types (top-cavity and platform nests), at 3 different wind speeds. We then used the estimates of h(c) in a biophysical heat transfer model to estimate how long it would take unattended eggs to cool from incubation temperature (~36 °C) to physiological zero temperature (PZT; ~26 °C) under natural environmental conditions. Our results indicated that the structural configuration of nests influences the cooling time of the eggs inside those nests, and hence, influences the nest microclimate. Estimates of time to PZT ranged from 10.6 minutes to 33.3 minutes. Nest configurations that were most similar to platform nests always had the fastest egg cooling times, suggesting that platform nests were the least protective of those nests we tested. Our field data coupled with our experimental results suggested that nest choice is important for the reproductive success of owls during years of inclement weather or in regions characterized by inclement weather during the nesting season.

  17. Toxicokinetics and coagulopathy threshold of the rodenticide diphacinone in eastern screech-owls (Megascops asio)

    USGS Publications Warehouse

    Rattner, Barnett A.; Horak, K.E.; Lazarus, Rebecca; Goldade, D.A.; Johnston, J.J.

    2014-01-01

    In the United States, new regulations on second-generation anticoagulant rodenticides will likely be offset by expanded use of first-generation anticoagulant rodenticides. In the present study, eastern screech-owls (Megascops asio) were fed 10 µg diphacinone/g wet weight food for 7 d, and recovery was monitored over a 21-d postexposure period. By day 3 of exposure, diphacinone (DPN) was detected in liver (1.63 µg/g wet wt) and kidney (5.83 µg/g) and coagulopathy was apparent. By day 7, prothrombin time (PT) and Russell's viper venom time (RVVT) were prolonged, and some individuals were anemic. Upon termination of exposure, coagulopathy and anemia were resolved within 4 d, and residues decreased to <0.3 µg/g by day 7. Liver and kidney DPN elimination occurred in 2 phases (initial rapid loss, followed by slower loss rate), with overall half-lives of 11.7 d and 2.1 d, respectively. Prolonged PT and RVVT occurred in 10% of the exposed owls with liver DPN concentrations of 0.122 µg/g and 0.282 µg/g and in 90% of the owls with liver concentrations of 0.638 µg/g and 0.361 µg/g. These liver residue levels associated with coagulopathy fall in the range of values reported in raptor mortality incidents involving DPN. These tissue-based toxicity reference values for coagulopathy in adult screech-owls have application for interpreting nontarget mortality and assessing the hazard of DPN in rodent-control operations. Diphacinone exposure evokes toxicity in raptors within a matter of days; but once exposure is terminated, recovery of hemostasis occurs rapidly

  18. Spatial and temporal variation in diets of Spotted Owls in Washington

    USGS Publications Warehouse

    Forsman, E.D.; Otto, I.A.; Sovern, S.G.; Taylor, M.; Hays, D.W.; Allen, H.; Roberts, S.L.; Seaman, D.E.

    2001-01-01

    We studied diets of Northern Spotted Owls (Strix occidentalis caurina) in three different regions of Washington State during 1983-96. Northern flying squirrels (Glaucomys sabrinus) were the most important prey in most areas, comprising 29-54% of prey numbers and 45-59% of prey biomass. Other important prey included snowshoe hares (Lepus americanus), bushy-tailed woodrats (Neoloma cinerea), boreal red-backed voles (Clethrionomys gapperi), and mice (Peromyscus maniculatus, P. oreas). Non-mammalian prey generally comprised less than 15% of prey numbers and biomass. Mean prey mass was 111.4 ?? 1.5 g on the Olympic Peninsula, 74.8 ?? 2.9 g in the Western Cascades, and 91.3 ?? 1.7 g in the Eastern Cascades. Diets varied among territories, years, and seasons. Annual variation in diet was characterized by small changes in relative occurrence of different prey types rather than a complete restructuring of the diet. Predation on snowshoe hares was primarily restricted to small juveniles captured during spring and summer. Mean prey mass did not differ between nesting and nonnesting owls in 19 of 21 territories examined. However, the direction of the difference was positive in 15 of the 21 cases (larger mean for nesting owls), suggesting a trend toward larger prey in samples collected from nesting owls. We suggest that differences in diet among years, seasons, and territories are probably due primarily to differences in prey abundance. However, there are other factors that could cause such differences, including individual variation in prey selection, variation in the timing of pellet collections, and variation in prey accessibility in different cover types. ?? 2001 The Raptor Research Foundation, Inc.

  19. Vestibular functions and sleep in space experiments. [using rhesus and owl monkeys

    NASA Technical Reports Server (NTRS)

    Perachio, A. A.

    1977-01-01

    Physical indices of sleep were continuously monitored in an owl monkey living in a chamber continuously rotating at a constant angular velocity. The electrophysiological data obtained from chronically implanted electrodes was analyzed to determine the chronic effects of vestibular stimulation on sleep and wakefulness cycles. The interaction of linear and angular acceleration on the vestibulo-ocular reflex was investigated in three rhesus monkeys at various angular accelerations.

  20. Spatial cue reliability drives frequency tuning in the barn Owl's midbrain

    PubMed Central

    Cazettes, Fanny; Fischer, Brian J; Pena, Jose L

    2014-01-01

    The robust representation of the environment from unreliable sensory cues is vital for the efficient function of the brain. However, how the neural processing captures the most reliable cues is unknown. The interaural time difference (ITD) is the primary cue to localize sound in horizontal space. ITD is encoded in the firing rate of neurons that detect interaural phase difference (IPD). Due to the filtering effect of the head, IPD for a given location varies depending on the environmental context. We found that, in barn owls, at each location there is a frequency range where the head filtering yields the most reliable IPDs across contexts. Remarkably, the frequency tuning of space-specific neurons in the owl's midbrain varies with their preferred sound location, matching the range that carries the most reliable IPD. Thus, frequency tuning in the owl's space-specific neurons reflects a higher-order feature of the code that captures cue reliability. DOI: http://dx.doi.org/10.7554/eLife.04854.001 PMID:25531067

  1. Organochlorine Pesticides in the Ferruginous Pygmy Owl (Glaucidium brasilianum) in Chiapas, Mexico.

    PubMed

    Arrona-Rivera, Alicia E; Enríquez, Paula L; García-Feria, Luis M; Orellana, Sergio Alvarado; von Osten, Jaime Rendón

    2016-09-01

    Concentrations of organochlorine pesticides were quantified in samples of feathers (n = 17) and blood (n = 15) of the ferruginous pygmy owl (Glaucidium brasilianum). The individuals were captured near the Protected Natural Area Cerro Sonsonate, Chiapas, Mexico, between February and June 2014. In both tissues, pesticides belonging to seven organochlorine chemical families were detected. However, the organochlorine pesticide concentrations differed between feathers and blood. The highest concentrations of hexachlorocyclohexanes were found in feathers (0.63 ± 0.89 μg/g), whereas the highest concentrations of ΣDrines were found in blood (0.31 ± 0.47 μg/mL). By using the summed concentrations for each of the seven families of pesticides found in feathers, we did not find any significant correlation between the pesticides and pectoral muscle or body weight (p > 0.15). The ΣDDT group was the only pesticide family that showed a positive correlation with owl body weight (r = 0.60, p = 0.05); the concentrations of these pesticides were also high in feather and blood tissues (r = 0.87, p = 0.02). Our results confirm that ferruginous pygmy owls in the study area are exposed to these pesticides.

  2. Target-approaching behavior of barn owls (Tyto alba): influence of sound frequency.

    PubMed

    Singheiser, Martin; Plachta, Dennis T T; Brill, Sandra; Bremen, Peter; van der Willigen, Robert F; Wagner, Hermann

    2010-03-01

    We studied the influence of frequency on sound localization in free-flying barn owls by quantifying aspects of their target-approaching behavior to a distant sound source during ongoing auditory stimulation. In the baseline condition with a stimulus covering most of the owls hearing range (1-10 kHz), all owls landed within a radius of 20 cm from the loudspeaker in more than 80% of the cases and localization along the azimuth was more accurate than localization in elevation. When the stimulus contained only high frequencies (>5 kHz) no changes in striking behavior were observed. But when only frequencies from 1 to 5 kHz were presented, localization accuracy and precision decreased. In a second step we tested whether a further border exists at 2.5 kHz as suggested by optimality models. When we compared striking behavior for a stimulus having energy from 2.5 to 5 kHz with a stimulus having energy between 1 and 2.5 kHz, no consistent differences in striking behavior were observed. It was further found that pre-takeoff latency was longer for the latter stimulus than for baseline and that center frequency was a better predictor for landing precision than stimulus bandwidth. These data fit well with what is known from head-turning studies and from neurophysiology.

  3. Ipsilateral cortical connections of dorsal and ventral premotor areas in New World owl monkeys.

    PubMed

    Stepniewska, Iwona; Preuss, Todd M; Kaas, Jon H

    2006-04-20

    In order to compare connections of premotor cortical areas of New World monkeys with those of Old World macaque monkeys and prosimian galagos, we placed injections of fluorescent tracers and wheat germ agglutinin-horseradish peroxidase (WGA-HRP) in dorsal (PMD) and ventral (PMV) premotor areas of owl monkeys. Motor areas and injection sites were defined by patterns of movements electrically evoked from the cortex with microelectrodes. Labeled neurons and axon terminals were located in brain sections cut either in the coronal plane or parallel to the surface of flattened cortex, and they related to architectonically and electrophysiologically defined cortical areas. Both the PMV and PMD had connections with the primary motor cortex (M1), the supplementary motor area (SMA), cingulate motor areas, somatosensory areas S2 and PV, and the posterior parietal cortex. Only the PMV had connections with somatosensory areas 3a, 1, 2, PR, and PV. The PMD received inputs from more caudal portions of the cortex of the lateral sulcus and more medial portions of the posterior parietal cortex than the PMV. The PMD and PMV were only weakly interconnected. New World owl monkeys, Old World macaque monkeys, and galagos share a number of PMV and PMD connections, suggesting preservation of a common sensorimotor network from early primates. Comparisons of PMD and PMV connectivity with the cortex of the lateral sulcus and posterior parietal cortex of owl monkeys, galagos, and macaques help identify areas that could be homologous.

  4. Nest site characteristics and nesting success of the Western Burrowing Owl in the eastern Mojave Desert

    USGS Publications Warehouse

    Longshore, Kathleen M.; Crowe, Dorothy E.

    2013-01-01

    We evaluated nest site selection at two spatial scales (microsite, territory) and reproductive success of Western Burrowing Owls (Athene cunicularia hypugaea) at three spatial scales (microsite, territory, landscape) in the eastern Mojave Desert. We used binary logistic regression within an information-theoretic approach to assess factors influencing nest site choice and nesting success. Microsite-scale variables favored by owls included burrows excavated by desert tortoise (Gopherus agassizii), burrows with a large mound of excavated soil at the entrance, and a greater number of satellite burrows within 5 m of the nest burrow. At the territory scale, owls preferred patches with greater cover of creosote bush (Larrea tridentata) within 50 m of the nest burrow. An interaction between the presence or absence of a calcic soil horizon layer over the top of the burrow (microsite) and the number of burrows within 50 m (territory) influenced nest site choice. Nesting success was influenced by a greater number of burrows within 5 m of the nest burrow. Total cool season precipitation was a predictor of nesting success at the landscape scale. Conservation strategies can rely on management of habitat for favored and productive nesting sites for this declining species.

  5. Distribution of the characteristics of barbs and barbules on barn owl wing feathers.

    PubMed

    Weger, Matthias; Wagner, Hermann

    2017-05-01

    Owls are known for the development of a silent flight. One conspicuous specialization of owl wings that has been implied in noise reduction and that has been demonstrated to change the aerodynamic behavior of the wing is a soft dorsal wing surface. The soft surface is a result of changes in the shape of feather barbs and barbules in owls compared with other bird species. We hypothesized that as the aerodynamic characteristics of a wing change along its chordwise and spanwise direction, so may the shape of the barbs and barbules. Therefore, we examined in detail the shapes of the barbs and barbules in chordwise and spanwise directions. The results showed changes in the shapes of barbs and barbules at the anterior and distal parts of the wing, but not at more posterior parts. The increased density of hook radiates at the distalmost wing position could serve to stiffen that vane part that is subject to the highest forces. The change of pennulum length in the anterior part of the wing and the uniformity further back could mean that a soft surface may be especially important in regions where flow separation may occur.

  6. Minimum Number of Observation Points for LEO Satellite Orbit Estimation by OWL Network

    NASA Astrophysics Data System (ADS)

    Park, Maru; Jo, Jung Hyun; Cho, Sungki; Choi, Jin; Kim, Chun-Hwey; Park, Jang-Hyun; Yim, Hong-Suh; Choi, Young-Jun; Moon, Hong-Kyu; Bae, Young-Ho; Park, Sun-Youp; Kim, Ji-Hye; Roh, Dong-Goo; Jang, Hyun-Jung; Park, Young-Sik; Jeong, Min-Ji

    2015-12-01

    By using the Optical Wide-field Patrol (OWL) network developed by the Korea Astronomy and Space Science Institute (KASI) we generated the right ascension and declination angle data from optical observation of Low Earth Orbit (LEO) satellites. We performed an analysis to verify the optimum number of observations needed per arc for successful estimation of orbit. The currently functioning OWL observatories are located in Daejeon (South Korea), Songino (Mongolia), and Oukaïmeden (Morocco). The Daejeon Observatory is functioning as a test bed. In this study, the observed targets were Gravity Probe B, COSMOS 1455, COSMOS 1726, COSMOS 2428, SEASAT 1, ATV-5, and CryoSat-2 (all in LEO). These satellites were observed from the test bed and the Songino Observatory of the OWL network during 21 nights in 2014 and 2015. After we estimated the orbit from systematically selected sets of observation points (20, 50, 100, and 150) for each pass, we compared the difference between the orbit estimates for each case, and the Two Line Element set (TLE) from the Joint Space Operation Center (JSpOC). Then, we determined the average of the difference and selected the optimal observation points by comparing the average values.

  7. Evolutionary conservation of Kv3.1 in the barn owl Tyto alba.

    PubMed

    Kullmann, Lars; Schlüter, Tina; Wagner, Hermann; Nothwang, Hans Gerd

    2013-01-01

    For prey capture in the dark, the barn owl Tyto alba has evolved into an auditory specialist with an exquisite capability of sound localization. Adaptations include asymmetrical ears, enlarged auditory processing centers, the utilization of minute interaural time differences, and phase locking along the entire hearing range up to 10 kHz. Adaptations on the molecular level have not yet been investigated. Here, we tested the hypothesis that divergence in the amino acid sequence of the voltage-gated K(+) channel Kv3.1 contributes to the accuracy and high firing rates of auditory neurons in the barn owl. We therefore cloned both splice variants of Kcnc1, the gene encoding Kv3.1. Both splice variants, Kcnc1a and Kcnc1b, encode amino acids identical to those of the chicken, an auditory generalist. Expression analyses confirmed neural-restricted expression of the channel. In summary, our data reveal strong evolutionary conservation of Kcnc1 in the barn owl and point to other genes involved in auditory specializations of this animal. The data also demonstrate the feasibility to address neuroethological questions in organisms with no reference genome by molecular approaches. This will open new avenues for neuroethologists working in these organisms.

  8. Factors Affecting Growth of Tengmalm's Owl (Aegolius funereus) Nestlings: Prey Abundance, Sex and Hatching Order.

    PubMed

    Zárybnická, Markéta; Riegert, Jan; Brejšková, Lucie; Šindelář, Jiří; Kouba, Marek; Hanel, Jan; Popelková, Alena; Menclová, Petra; Tomášek, Václav; Šťastný, Karel

    2015-01-01

    In altricial birds, energy supply during growth is a major predictor of the physical condition and survival prospects of fledglings. A number of experimental studies have shown that nestling body mass and wing length can vary with particular extrinsic factors, but between-year observational data on this topic are scarce. Based on a seven-year observational study in a central European Tengmalm's owl population we examine the effect of year, brood size, hatching order, and sex on nestling body mass and wing length, as well as the effect of prey abundance on parameters of growth curve. We found that nestling body mass varied among years, and parameters of growth curve, i.e. growth rate and inflection point in particular, increased with increasing abundance of the owl's main prey (Apodemus mice, Microtus voles), and pooled prey abundance (Apodemus mice, Microtus voles, and Sorex shrews). Furthermore, nestling body mass varied with hatching order and between sexes being larger for females and for the first-hatched brood mates. Brood size had no effect on nestling body mass. Simultaneously, we found no effect of year, brood size, hatching order, or sex on the wing length of nestlings. Our findings suggest that in this temperate owl population, nestling body mass is more sensitive to prey abundance than is wing length. The latter is probably more limited by the physiology of the species.

  9. Characteristics of roost sites used by burrowing owls (Athene cunicularia) wintering in Southern Texas

    USGS Publications Warehouse

    Williford, D.L.; Woodin, M.C.; Skoruppa, M.K.; Hickman, G.C.

    2007-01-01

    The western burrowing owl (Athene cunicularia hypugaea) is threatened in Mexico, endangered in Canada, and declining in most of the western United States. Most previous research has focused on burrowing owl breeding biology, and little is known about its winter ecology. We determined characteristics of roost sites used by western burrowing owls in southern Texas during winter. Data on 46 winter roost sites were collected from 15 November 2001 to 15 February 2002. Of these roost sites, 87% were located on agricultural land, 80% were along roads, and 74% were concrete, steel, or cast-iron culverts. Mean diameter (??SE) of roost site openings was 22 ?? 1.5 cm. Most roost sites (70%) were located on inaccessible private lands. Bare ground comprised 61% of ground cover within a 10-m radius of roost sites. We recommend that landowners and public-land managers should be encouraged to use smaller-diameter culverts when building roads or replacing old or damaged culverts and to graze livestock or mow around these culverts during winter.

  10. Population trends in northern spotted owls: Associations with climate in the Pacific Northwest

    USGS Publications Warehouse

    Glenn, E.M.; Anthony, R.G.; Forsman, E.D.

    2010-01-01

    We used reverse time capture-mark-recapture models to describe associations between rate of population change (??) and climate for northern spotted owls (Strix occidentalis caurina) at six long-term study areas in Washington and Oregon, USA. Populations in three of six areas showed strong evidence of declining populations, while populations in two additional areas were likely declining as well. At four areas, ?? was positively associated with wetter-than-normal conditions during the growing season, which likely affects prey availability. Lambda was also negatively associated with cold, wet winters and nesting seasons, and the number of hot summer days. The amount of annual variation in ?? accounted for by climate varied across study areas (3-85%). Rate of population change was more sensitive to adult survival than to recruitment; however, there was considerable variation among years and across study areas for all demographic rates. While annual survival was more closely related to regional climate conditions, recruitment was often associated with local weather. In addition to climate, declines in recruitment at four of six areas were associated with increased presence of barred owls. Climate change models predict warmer, wetter winters and hotter, drier summers for the Pacific Northwest in the first half of the 21st century. Our results indicate that these conditions have the potential to negatively affect annual survival, recruitment, and consequently population growth rates for northern spotted owls. ?? 2010 Elsevier Ltd.

  11. Organochlorine residues, eggshell thickness, and nest success in barn owls from the Chesapeake Bay

    USGS Publications Warehouse

    Klaas, E.E.; Wiemeyer, Stanley N.; Ohlendorf, H.M.; Swineford, D.M.

    1978-01-01

    Eggs of barn owls (Tyto alba) were collected from 18 nests in offshore duck blinds on the Maryland side of the lower Potomac River estuary in 1972 and 1973 and analyzed for organochlorine residues. DDE was found in 100% of the clutches, PCBs in 89%, and dieldrin in 78%. Eggshell thickness was inversely correlated with concentrations of DDE, DDD, and dieldrin residues. Six of the 18 clutches had mean DDE residues above 5 ppm, and eggshell thickness in these six clutches was significantly less (P < 0.001) than in the other 12 clutches. The owls produced 1.7 young per active nest in 1973. This rate is slightly below the reproductive rate needed to maintain a stable population. An estimated 15% of the population carried concentrations of organochlorine residues that may have been detrimental to their reproduction. Passerine birds, taken extensively as food by a small proportion of the population, are believed to have been the source of elevated concentrations of organochlorines in these barn owls.

  12. Effects of vole fluctuations on the population dynamics of the barn owl Tyto alba.

    PubMed

    Klok, Chris; de Roos, Andre M

    2007-01-01

    Many predator species feed on prey that fluctuates in abundance from year to year. Birds of prey can face large fluctuations in food abundance i.e. small mammals, especially voles. These annual changes in prey abundance strongly affect the reproductive success and mortality of the individual predators and thus can be expected to influence their population dynamics and persistence. The barn owl, for example, shows large fluctuations in breeding success that correlate with the dynamics in voles, their main prey species. Analysis of the impact of fluctuations in vole abundance (their amplitude, peaks and lows, cycle length and regularity) with a simple predator prey model parameterized with literature data indicates population persistence is especially affected by years with low vole abundance. In these years the population can decline to low owl numbers such that the ensuing peak vole years cannot be exploited. This result is independent of the length and regularity of vole fluctuations. The relevance of this result for conservation of the barn owl and other birds of prey that show a numerical response to fluctuating prey species is discussed.

  13. Distribution of the Chuckwalla, Western Burrowing Owl, and Six Bat Species on the Nevada Test Site

    SciTech Connect

    Cathy A. Willis

    1997-05-01

    Field Surveys were conducted in 1996 to determine the current distribution of several animal species of concern on the Nevada Test Site (NTS). They included the chuckwall (Sauromalus obesus), western burrowing owl (Speotyto cunicularia), and six species of bats. Nineteen chuckwallas and 118 scat locations were found during the chuckwalla field study. Eighteen western burrowing owls were found at 12 sighting locations during the 1996 field study. Of the eleven bat species of concern which might occur on the NTS, five, and possibly six, were captured during this survey. The U.S. Department of Energy, Nevada Operations Office, takes certain management actions to protect and conserve the chuckwalla, western burrowing owl, and bats on the NTS. These actions are described and include: (1) conducting surveys at sites of proposed land-disturbing activities (2) altering projects whenever possible to avoid or minimize impacts to these species (3) maintaining a geospatial database of known habitat for species of concern (4) sharing sighting and trap location data gathered on the NTS with other local land and resource managers, and (5) conducting periodic field surveys to monitor these species distribution and relative abundance on the NTS.

  14. Properties of low-frequency head-related transfer functions in the barn owl (Tyto alba).

    PubMed

    Hausmann, Laura; von Campenhausen, Mark; Wagner, Hermann

    2010-09-01

    The barn owl (Tyto alba) possesses several specializations regarding auditory processing. The most conspicuous features are the directionally sensitive facial ruff and the asymmetrically arranged ears. The frequency-specific influence of these features on sound has consequences for sound localization that might differ between low and high frequencies. Whereas the high-frequency range (>3 kHz) is well investigated, less is known about the characteristics of head-related transfer functions for frequencies below 3 kHz. In the present study, we compared 1/3 octaveband-filtered transfer functions of barn owls with center frequencies ranging from 0.5 to 9 kHz. The range of interaural time differences was 600 micros at frequencies above 4 kHz, decreased to 505 micros at 3 kHz and increased again to about 615 micros at lower frequencies. The ranges for very low (0.5-1 kHz) and high frequencies (5-9 kHz) were not statistically different. Interaural level differences and monaural gains increased monotonically with increasing frequency. No systematic influence of the body temperature on the measured localization cues was observed. These data have implications for the mechanism underlying sound localization and we suggest that the barn owl's ears work as pressure receivers both in the high- and low-frequency ranges.

  15. Acanthocephalans of the genus Centrorhynchus (Palaeacanthocephala: Centrorhynchidae) of birds of prey (Falconiformes) and owls (Strigiformes) in Slovakia.

    PubMed

    Komorová, P; Špakulová, M; Hurníková, Z; Uhrín, M

    2015-06-01

    Three species of thorny-headed worms of the genus Centrorhynchus were found to parasitize birds of prey and owls in the territory of the Slovakia during the years 2012-2014. Out of 286 examined bird individuals belonging to 23 species, only Buteo buteo, Buteo rufinus, Falco tinnunculus (Falconiformes), Asio otus, Strix aluco, Strix uralensis and Tyto alba (Strigiformes) were infected by acanthocephalans. All the bird species except for S. aluco represent new host records for Slovakia. The most prevalent acanthocephalan Centrorhynchus aluconis was detected in all 15 examined birds of non-migratory Ural owl S. uralensis (P = 100%); however, it was found occasionally also in two individuals of the tawny owl S. aluco (P = 20%), one long-eared owl A. otus (P = 7.7%), one barn owl T. alba (P = 33.3%) and the common buzzard B. buteo (P = 0.8%). Two other thorny-headed worms occurred exclusively in Falconiformes in raw or mixed infections: Centrorhynchus buteonis was found in 11 individuals of B. buteo (P = 9.2%), and two birds (B. buteo and B. rufinus) were parasitized simultaneously by C. buteonis and the species Centrorhynchus globocaudatus. Moreover, the latest, relatively rare acanthocephalan was found alone in two common kestrels F. tinnunculus (P = 2.7%). Regarding intensity of infection, it ranged from a single female of C. buteonis, C. globocaudatus or C. aluconis per host (four cases) to a maximum of 82 C. aluconis per an Ural owl. The difference in acanthocephalan species spectrum between birds of prey and owls in Slovakia was apparent.

  16. Raptor mortality due to West Nile virus in the United States, 2002.

    PubMed

    Saito, Emi K; Sileo, Louis; Green, D Earl; Meteyer, Carol U; McLaughlin, Grace S; Converse, Kathryn A; Docherty, Douglas E

    2007-04-01

    West Nile virus (WNV) has affected many thousands of birds since it was first detected in North America in 1999, but the overall impact on wild bird populations is unknown. In mid-August 2002, wildlife rehabilitators and local wildlife officials from multiple states began reporting increasing numbers of sick and dying raptors, mostly red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus). Commonly reported clinical signs were nonspecific and included emaciation, lethargy, weakness, inability to perch, fly or stand, and nonresponse to danger. Raptor carcasses from 12 states were received, and diagnostic evaluation of 56 raptors implicated WNV infection in 40 (71%) of these cases. Histologically, nonsuppurative encephalitis and myocarditis were the salient lesions (79% and 61%, respectively). Other causes of death included lead poisoning, trauma, aspergillosis, and Salmonella spp. and Clostridium spp. infections. The reason(s) for the reported increase in raptor mortality due to WNV in 2002 compared with the previous WNV seasons is unclear, and a better understanding of the epizootiology and pathogenesis of the virus in raptor populations is needed.

  17. Does predator management enhance survival of reintroduced black-footed ferrets?

    USGS Publications Warehouse

    Breck, Stewart W.; Biggins, Dean E.; Livieri, Travis M.; Matchett, Marc R.; Kopcso, Valerie

    2006-01-01

    Predation on black-footed ferrets (Mustela nigripes) is a potential problem at reintroduction sites, causing up to 95 percent of the documented mortality of ferrets. Strategies to reduce mortality due to predation can focus on preconditioning ferrets prior to reintroduction and/or managing predators of ferrets. Biologists have tried three general strategies to control predators at reintroduction sites: (1) selective removal of individual predators, (2) nonselective removal of coyotes (Canis latrans), and (3) electric fences to exclude coyotes from release sites. We conducted a post hoc review of data from releases during 1994–2003 at 11 sites in South Dakota and Montana to address whether or not predator management has benefited reintroduced black-footed ferrets. Limited evidence indicates that (1) individual great horned owls (Bubo virginianus) can cause significant ferret mortality and that identifying and removing these individuals can be beneficial, (2) lethal control of coyotes may have inverse effects on ferret survival, and (3) electric fencing does not enhance short- or long-term survival of reintroduced ferrets. The data are confounded by a variety of factors, making conclusions tenuous. Well designed studies are needed to properly address the effectiveness of predator management for enhancing ferret survival.

  18. Avian vacuolar myelinopathy outbreaks at a southeastern reservoir.

    PubMed

    Fischer, John R; Lewis-Weis, Lynn A; Tate, Cynthia M; Gaydos, Joseph K; Gerhold, Richard W; Poppenga, Robert H

    2006-07-01

    Avian vacuolar myelinopathy (AVM) is a neurologic disease of unknown etiology that affects bald eagles (Haliaeetus leucocephalus), American coots (Fulica americana), and several species of waterfowl. An unidentified neurotoxin is suspected as the cause of AVM, which has been documented at several reservoirs in the southeastern United States. We conducted diagnostic and epidemiologic studies annually during October-March from 1998-2004 at Clarks Hill/Strom Thurmond Lake on the Georgia/South Carolina border to better understand the disease. Avian vacuolar myelinopathy was confirmed or suspected as the cause of morbidity and mortality of 28 bald eagles, 16 Canada geese (Branta canadensis), six American coots, two great-horned owls (Bubo virginianus), and one killdeer (Charadrius vociferus). Active surveillance during the outbreaks yielded annual average prevalence of vacuolar lesions in 17-94% of coots, but not in 10 beavers (Castor canadensis), four raccoons (Procyon lotor), and one gray fox (Urocyon cinereoargenteus) collected for the study. Brain lesions were not apparent in 30 Canada geese collected and examined in June 2002. The outbreaks at this location from 1998-2004 represent the most significant AVM-related bald eagle mortality since the Arkansas epornitics of 1994-95 and 1996-97, as well as the first confirmation of the disease in members of Strigiformes and Charadriiformes.

  19. Poplar Island Environmental Restoration Project: Challenges in waterbird restoration on an island in Chesapeake Bay

    USGS Publications Warehouse

    Erwin, R.M.; Miller, J.; Reese, J.G.

    2007-01-01

    At 460 hectares, the Paul Sarbanes Environmental Restoration Project at Poplar Island, Talbot County, Maryland, represents the largest 'beneficial use' dredged material project of the U. S. Army Corps of Engineers (a cooperative project with Maryland Port Administration). Begun in 1998, the 15-year restoration project will ultimately consist of roughly 220 ha of uplands and 220 ha of tidal wetland habitats, with limited areas of dike roads, perimeter riprap, and unvegetated mudflats. Wetland restoration began in one small section (or 'cell') in 2002, but not all cells will be filled with dredged material until at least 2013. As a major objective of the restoration, six species of waterbirds were identified as 'priority species' for Chesapeake Bay: American black duck (Anas rubripes), snowy egret (Egretta thula), cattle egret (Bubulcus ibis), osprey (Pandion haliaetus), common tern (Sterna hirundo), and least tern (S. antillarum). Monitoring of nesting activities of these species from 2002 to 2005 indicated that all species except black ducks colonized the site rapidly. More than 800 pairs of common terns nested in 2003 to 2004. Because of predation by red fox (Vulpes vulpes) and great horned owl (Bubo virginianus), reproductive success was very low for the terns. Trapping was effective in removing the foxes, and other controls have been applied to opportunistic nesting species including herring gulls (Larus argentatus) and Canada geese (Branta canadensis). An effective public education program on the island has helped address concerns about animal control.

  20. Seasonally Varying Predation Behavior and Climate Shifts Are Predicted to Affect Predator-Prey Cycles.

    PubMed

    Tyson, Rebecca; Lutscher, Frithjof

    2016-11-01

    The functional response of some predator species changes from a pattern characteristic for a generalist to that for a specialist according to seasonally varying prey availability. Current theory does not address the dynamic consequences of this phenomenon. Since season length correlates strongly with altitude and latitude and is predicted to change under future climate scenarios, including this phenomenon in theoretical models seems essential for correct prediction of future ecosystem dynamics. We develop and analyze a two-season model for the great horned owl (Bubo virginialis) and snowshoe hare (Lepus americanus). These species form a predator-prey system in which the generalist to specialist shift in predation pattern has been documented empirically. We study the qualitative behavior of this predator-prey model community as summer season length changes. We find that relatively small changes in summer season length can have a profound impact on the system. In particular, when the predator has sufficient alternative resources available during the summer season, it can drive the prey to extinction, there can be coexisting stable states, and there can be stable large-amplitude limit cycles coexisting with a stable steady state. Our results illustrate that the impacts of global change on local ecosystems can be driven by internal system dynamics and can potentially have catastrophic consequences.

  1. Red-shouldered hawk broadcast surveys: Factors affecting detection of responses and population trends

    USGS Publications Warehouse

    McLeod, M.A.; Andersen, D.E.

    1998-01-01

    Forest-nesting raptors are often difficult to detect and monitor because they can be secretive, and their nests can be difficult to locate. Some species, however, respond to broadcasts of taped calls, and these responses may be useful both in monitoring population trends and in locating nests. We conducted broadcast surveys on roads and at active red-shouldered hawk (Buteo lineatus) nests in northcentral Minnesota to determine effects of type of call (conspecific or great horned owl [Bubo virginianus]), time of day, and phase of the breeding cycle on red-shouldered hawk response behavior and to evaluate usefulness of broadcasts as a population monitoring tool using area occupied-probability-of-detection techniques. During the breeding seasons of 1994 and 1995, we surveyed 4 10-station road transects 59 times and conducted 76 surveys at 24 active nests. Results of these surveys indicated conspecific calls broadcast prior to hatch and early in the day were the most effective method of detecting red-shouldered hawks. Probability of detection via conspecific calls averaged 0.25, and area occupied was 100%. Computer simulations using these field data indicated broadcast surveys have the potential to be used as a population monitoring tool.

  2. Raptor mortality due to West Nile virus in the United States, 2002

    USGS Publications Warehouse

    Saito, E.K.; Sileo, L.; Green, D.E.; Meteyer, C.U.; McLaughlin, G.S.; Converse, K.A.; Docherty, D.E.

    2007-01-01

    West Nile virus (WNV) has affected many thousands of birds since it was first detected in North America in 1999, but the overall impact on wild bird populations is unknown. In mid-August 2002, wildlife rehabilitators and local wildlife officials from multiple states began reporting increasing numbers of sick and dying raptors, mostly red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus. Commonly reported clinical signs were nonspecific and included emaciation, lethargy, weakness, inability to perch, fly or stand, and nonresponse to danger. Raptor carcasses from 12 states were received, and diagnostic evaluation of 56 raptors implicated WNV infection in 40 (71%) of these cases. Histologically, nonsuppurative encephalitis and myocarditis were the salient lesions (79% and 61%, respectively). Other causes of death included lead poisoning, trauma, aspergillosis, and Salmonella spp. and Clostridium spp. infections. The reason(s) for the reported increase in raptor mortality due to WNV in 2002 compared with the previous WNV seasons is unclear, and a better understanding of the epizootiology and pathogenesis of the virus in raptor populations is needed. ?? Wildlife Disease Association 2007.

  3. Multistate Models Reveal Long-Term Trends of Northern Spotted Owls in the Absence of a Novel Competitor.

    PubMed

    Kroll, Andrew J; Jones, Jay E; Stringer, Angela B; Meekins, Douglas J

    2016-01-01

    Quantifying spatial and temporal variability in population trends is a critical aspect of successful management of imperiled species. We evaluated territory occupancy dynamics of northern spotted owls (Strix occidentalis caurina), California, USA, 1990-2014. The study area possessed two unique aspects. First, timber management has occurred for over 100 years, resulting in dramatically different forest successional and structural conditions compared to other areas. Second, the barred owl (Strix varia), an exotic congener known to exert significant negative effects on spotted owls, has not colonized the study area. We used a Bayesian dynamic multistate model to evaluate if territory occupancy of reproductive spotted owls has declined as in other study areas. The state-space approach for dynamic multistate modeling imputes the number of territories for each nesting state and allows for the estimation of longer-term trends in occupied or reproductive territories from longitudinal studies. The multistate approach accounts for different detection probabilities by nesting state (to account for either inherent differences in detection or for the use of different survey methods for different occupancy states) and reduces bias in state assignment. Estimated linear trends in the number of reproductive territories suggested an average loss of approximately one half territory per year (-0.55, 90% CRI: -0.76, -0.33), in one management block and a loss of 0.15 per year (-0.15, 90% CRI: -0.24, -0.07), in another management block during the 25 year observation period. Estimated trends in the third management block were also negative, but substantial uncertainty existed in the estimate (-0.09, 90% CRI: -0.35, 0.17). Our results indicate that the number of territories occupied by northern spotted owl pairs remained relatively constant over a 25 year period (-0.07, 90% CRI: -0.20, 0.05; -0.01, 90% CRI: -0.19, 0.16; -0.16, 90% CRI: -0.40, 0.06). However, we cannot exclude small

  4. Assessment of toxicity and potential risk of the anticoagulant rodenticide diphacinone using Eastern screech-owls (Megascops asio).

    PubMed

    Rattner, Barnett A; Horak, Katherine E; Lazarus, Rebecca S; Eisenreich, Karen M; Meteyer, Carol U; Volker, Steven F; Campton, Christopher M; Eisemann, John D; Johnston, John J

    2012-04-01

    In the United States, new regulatory restrictions have been placed on the use of some second-generation anticoagulant rodenticides. This action may be offset by expanded use of first-generation compounds (e.g., diphacinone; DPN). Single-day acute oral exposure of adult Eastern screech-owls (Megascops asio) to DPN evoked overt signs of intoxication, coagulopathy, histopathological lesions (e.g., hemorrhage, hepatocellular vacuolation), and/or lethality at doses as low as 130 mg/kg body weight, although there was no dose-response relation. However, this single-day exposure protocol does not mimic the multiple-day field exposures required to cause mortality in rodent pest species and non-target birds and mammals. In 7-day feeding trials, similar toxic effects were observed in owls fed diets containing 2.15, 9.55 or 22.6 ppm DPN, but at a small fraction (<5%) of the acute oral dose. In the dietary trial, the average lowest-observed-adverse-effect-level for prolonged clotting time was 1.68 mg DPN/kg owl/week (0.24 mg/kg owl/day; 0.049 mg/owl/day) and the lowest lethal dose was 5.75 mg DPN/kg owl/week (0.82 mg/kg owl/day). In this feeding trial, DPN concentration in liver ranged from 0.473 to 2.21 μg/g wet weight, and was directly related to the daily and cumulative dose consumed by each owl. A probabilistic risk assessment indicated that daily exposure to as little as 3-5 g of liver from DPN-poisoned rodents for 7 days could result in prolonged clotting time in the endangered Hawaiian short-eared owl (Asio flammeus sandwichensis) and Hawaiian hawk (Buteo solitarius), and daily exposure to greater quantities (9-13 g of liver) could result in low-level mortality. These findings can assist natural resource managers in weighing the costs and benefits of anticoagulant rodenticide use in pest control and eradication programs.

  5. Multistate Models Reveal Long-Term Trends of Northern Spotted Owls in the Absence of a Novel Competitor

    PubMed Central

    Kroll, Andrew J.; Jones, Jay E.; Stringer, Angela B.; Meekins, Douglas J.

    2016-01-01

    Quantifying spatial and temporal variability in population trends is a critical aspect of successful management of imperiled species. We evaluated territory occupancy dynamics of northern spotted owls (Strix occidentalis caurina), California, USA, 1990–2014. The study area possessed two unique aspects. First, timber management has occurred for over 100 years, resulting in dramatically different forest successional and structural conditions compared to other areas. Second, the barred owl (Strix varia), an exotic congener known to exert significant negative effects on spotted owls, has not colonized the study area. We used a Bayesian dynamic multistate model to evaluate if territory occupancy of reproductive spotted owls has declined as in other study areas. The state-space approach for dynamic multistate modeling imputes the number of territories for each nesting state and allows for the estimation of longer-term trends in occupied or reproductive territories from longitudinal studies. The multistate approach accounts for different detection probabilities by nesting state (to account for either inherent differences in detection or for the use of different survey methods for different occupancy states) and reduces bias in state assignment. Estimated linear trends in the number of reproductive territories suggested an average loss of approximately one half territory per year (-0.55, 90% CRI: -0.76, -0.33), in one management block and a loss of 0.15 per year (-0.15, 90% CRI: -0.24, -0.07), in another management block during the 25 year observation period. Estimated trends in the third management block were also negative, but substantial uncertainty existed in the estimate (-0.09, 90% CRI: -0.35, 0.17). Our results indicate that the number of territories occupied by northern spotted owl pairs remained relatively constant over a 25 year period (-0.07, 90% CRI: -0.20, 0.05; -0.01, 90% CRI: -0.19, 0.16; -0.16, 90% CRI: -0.40, 0.06). However, we cannot exclude small

  6. Assessment of toxicity and potential risk of the anticoagulant rodenticide diphacinone using Eastern screech-owls (Megascops asio)

    USGS Publications Warehouse

    Rattner, Barnett A.; Horak, Katherine E.; Lazarus, Rebecca S.; Eisenreich, Karen M.; Meteyer, Carol U.; Volker, Steven F.; Campton, Christopher M.; Eisemann, John D.; Johnston, John J.

    2012-01-01

    In the United States, new regulatory restrictions have been placed on the use of some second-generation anticoagulant rodenticides. This action may be offset by expanded use of first-generation compounds (e.g., diphacinone; DPN). Single-day acute oral exposure of adult Eastern screech-owls (Megascops asio) to DPN evoked overt signs of intoxication, coagulopathy, histopathological lesions (e.g., hemorrhage, hepatocellular vacuolation), and/ or lethality at doses as low as 130 mg/kg body weight, although there was no dose-response relation. However, this single-day exposure protocol does not mimic the multiple-day field exposures required to cause mortality in rodent pest species and non-target birds and mammals. In 7-day feeding trials, similar toxic effects were observed in owls fed diets containing 2.15, 9.55 or 22.6 ppm DPN, but at a small fraction (<5%) of the acute oral dose. In the dietary trial, the average lowest-observed-adverse-effect-level for prolonged clotting time was 1.68 mg DPN/kg owl/week (0.24 mg/kg owl/day; 0.049 mg/owl/day) and the lowest lethal dose was 5.75 mg DPN/kg owl/week (0.82 mg/kg owl/day). In this feeding trial, DPN concentration in liver ranged from 0.473 to 2.21 μg/g wet weight, and was directly related to the daily and cumulative dose consumed by each owl. A probabilistic risk assessment indicated that daily exposure to as little as 3-5 g of liver from DPN-poisoned rodents for 7 days could result in prolonged clotting time in the endangered Hawaiian shorteared owl (Asio flammeus sandwichensis) and Hawaiian hawk (Buteo solitarius), and daily exposure to greater quantities (9-13 g of liver) could result in low-level mortality. These findings can assist natural resource managers in weighing the costs and benefits of anticoagulant rodenticide use in pest control and eradication programs.

  7. A critical period for the recovery of sound localization accuracy following monaural occlusion in the barn owl.

    PubMed

    Knudsen, E I; Knudsen, P F; Esterly, S D

    1984-04-01

    We studied the ability of barn owls to recover accurate sound localization after being raised with one ear occluded. Most of the owls had ear plugs inserted before they reached adult size, and therefore they never experienced normal adult localization cues until their ear plugs were removed. Upon removal of their ear plugs, these owls exhibited large systematic sound localization errors. The rate at which they recovered accurate localization decreased with the age of the bird at the time of plug removal, and recovery essentially ceased when owls reached 38 to 42 weeks of age. We interpret this age as the end of a critical period for the consolidation of associations between auditory cues and locations in space. Owls that had experienced adult localization cues for a short period of time before ear plugging recovered normal accuracy rapidly, even if they remained plugged well past the end of the critical period. This suggests that a brief exposure to normal adult cues early in the critical period is sufficient to enable the recovery of localization accuracy much later in life.

  8. Representing Human Expertise by the OWL Web Ontology Language to Support Knowledge Engineering in Decision Support Systems.

    PubMed

    Ramzan, Asia; Wang, Hai; Buckingham, Christopher

    2014-01-01

    Clinical decision support systems (CDSSs) often base their knowledge and advice on human expertise. Knowledge representation needs to be in a format that can be easily understood by human users as well as supporting ongoing knowledge engineering, including evolution and consistency of knowledge. This paper reports on the development of an ontology specification for managing knowledge engineering in a CDSS for assessing and managing risks associated with mental-health problems. The Galatean Risk and Safety Tool, GRiST, represents mental-health expertise in the form of a psychological model of classification. The hierarchical structure was directly represented in the machine using an XML document. Functionality of the model and knowledge management were controlled using attributes in the XML nodes, with an accompanying paper manual for specifying how end-user tools should behave when interfacing with the XML. This paper explains the advantages of using the web-ontology language, OWL, as the specification, details some of the issues and problems encountered in translating the psychological model to OWL, and shows how OWL benefits knowledge engineering. The conclusions are that OWL can have an important role in managing complex knowledge domains for systems based on human expertise without impeding the end-users' understanding of the knowledge base. The generic classification model underpinning GRiST makes it applicable to many decision domains and the accompanying OWL specification facilitates its implementation.

  9. The impact of uropygial gland secretions on mechanically induced wearing of barn owl and pigeon body feathers

    NASA Astrophysics Data System (ADS)

    Ott, Benjamin; Müsse, Annika; Wagner, Hermann

    2016-04-01

    Bird feathers are remarkable structures light but yet durable providing insulation and the ability of flight. Owls are highly specialized birds of prey, widely known for their ability to y silently which is enabled by (micro-) structural specializations of the feathers. The barn owl replaces feathers less frequently in comparison to other same sized birds like pigeons, indicating a much better resistance against material fatigue of these delicate microstructures. We used axisymmetric drop shape analysis (ADSA) of water drop contact angles as a non-destructive method of characterizing wearing processes in feathers. We hypothesized that feathers become more wettable when worn. We also investigated the impact of ethanol treatment in order to remove fatty residues of the uropygial gland secretions, barn owls and pigeons use for preening, on ageing processes. Ethanol treatment resulted in a slight, but significant increase of water repellency in barn owl but not in pigeon flight feathers. Our preliminary data also suggest that the uropygial gland secretions decelerate the wearing process of the feather keratin. We observed this effect in both species, however, it was more distinct for barn owl uropygial gland secretions. The results of this study, obtained by contact angle measurements used as a non-destructive evaluation method of material fatigue, yield insights into the material fatigue of feathers and the decelerating effect of uropygial gland secretions on wear on the other hand.

  10. The winter diet of short-eared owls in subtropical Texas: Do southern diets provide evidence of opportunity?

    USGS Publications Warehouse

    Williford, Damon; Woodin, Marc C.; Skoruppa, Mary Kay

    2011-01-01

    Winter diet of the Short-eared Owl (Asio flammeus) in Texas is little known. We investigated the diet of Short-eared Owls wintering in McMullen County, in subtropical Texas, by analyzing the contents of 129 pellets collected over two winters (28 November 2007 to 22 February 2008 and 11 December 2008 to 11 February 2009) and conducted a latitudinal-based comparison of published diet studies of Short-eared Owls. In southern Texas, we recovered the remains of 162 prey items, 98% of which were vertebrates. Hispid cotton rats (Sigmodon hispidus) were the most important prey species in terms of percent of total number (67%) and percent of total biomass (87%). Most (86%) Short-eared Owl diet studies (based on ≥100 pellets) have been conducted north of 35°N, with only six studies, including the present study, conducted at or south of 35°N latitude. Voles (primarily Microtus spp.) were the dominant prey in North American studies (71%), but microtines were not the dominant prey in any of the six studies conducted south of 35°N latitude. We suggest that Short-eared Owls do not specialize on microtines, as is often implied, but rather depend on rodents with cyclic populations, such as the hispid cotton rat in southern areas.

  11. Possible mechanisms for sensitivity to organophosphorus and carbamate insecticides in eastern screech-owls and American kestrels

    USGS Publications Warehouse

    Vyas, N.B.; Thiele, L.A.; Garland, S.C.

    1998-01-01

    Effects of a single dietary exposure to fenthion and carbofuran on the survival, feeding behavior and brain ChE activity of eastern screech-owls, Otus asio and American kestrels, Falco sparverius, were evaluated. Birds were exposed to fenthion (23.6189.0 ppm) or carbofuran (31.7253.6 ppm) via meatballs. Carbofuran-exposed owls ate either = 80% of the meatball whereas all kestrels ate <= 10% of the meatball before exhibiting acute signs of toxicity. Fenthion-exposed owls and kestrels displayed a wide spectrum of meatball consumption (<10100%). Significant brain ChE inhibition was observed in dead and surviving kestrels exposed to fenthion and carbofuran and dead owls exposed to fenthion (P < 0.0001). Brain ChE activity of owls exposed to carbofuran that survived was not different from that of controls (P = 0.25). Data suggest: (1) slow feeding on a carbamate-contaminated item may provide limited protection from the toxicity of the chemical at certain rates of exposure; (2) the degree of ChE inhibition at neuromuscular junctions may be critical in determining the sensitivity of a species to a carbamate insecticide; (3) sensitivity may be a function of the ChE affinity for the carbamate inhibitor; and (4) the importance of neuromuscular junction ChE depression in determining the sensitivity of an animal may be species-specific.

  12. [Book review] The Eastern Screech Owl: Life History, Ecology and Behavior in the Suburbs and Countryside, by Frederick Gehlback

    USGS Publications Warehouse

    Hahn, D.C.

    1995-01-01

    Review of: Eastern Screech Owl: Life History, Ecology, and Behavior in the Suburbs and Countryside. Frederick R. Gehlbach. Issue 16; Issue 2008 of W. L. Moody Jr. Natural History Series. Texas A&M University Press; 1st edition (November 1994). ISBN: 0890966095. For ornithologists and ecologists alike, Fred Gehlbach's book promises to hold both interest and information value as a comprehensive study of the eastern screech owl (Otus asio hasbroucki). Gehlbach was intrigued with screech owls as a boy and encouraged as an undergraduate by William Hamilton, who underscored that in-depth studies of familiar backyard species can be as fascinating as those in exotic sites. Correspondence with another owl-aficionado, the late H. N. Southern, inspired the author's long-term study of screech owls in a woodland landscape in central Texas and led him to provide nest boxes to enhance his access and sample size. This book is based on observations over a 25-year period-beginning in 1967, with intensive study during an 11-year period (1976-1987) in Texas south of Waco, where Gehlbach teaches at Baylor University. The study represents observations on 659 screech owls, covering several generations of birds and entire lives of many individuals. Gehlbach compares screech owl nesting behavior in a rural versus suburban setting and includes chapters on food supplies and predation tactics; egg-laying, incubation, and parental behavior; vocalizations; and population structure and flux. He discusses why screech owls are widespread across the eastern half of North America and why they succeed among people in suburban environments, where they adapt as easily to mailboxes and porch columns as to natural tree cavities. The book mixes two approaches: on the one hand the dense style of a technical book in which the professional biologist can find information on many aspects of screech owl behavior, life history, and population, including tables, figures, summary statistics, results of statistical

  13. Particle-image velocimetry investigation of the fluid-structure interaction mechanisms of a natural owl wing.

    PubMed

    Winzen, A; Roidl, B; Schröder, W

    2015-09-15

    The increasing interest in the development of small flying air vehicles has given rise to a strong need to thoroughly understand low-speed aerodynamics. The barn owl is a well-known example of a biological system that possesses a high level of adaptation to its habitat and as such can inspire future small-scale air vehicle design. The combination of the owl-specific wing geometry and plumage adaptations with the flexibility of the wing structure yields a highly complex flow field, still enabling the owl to perform stable and at the same time silent low-speed gliding flight. To investigate the effects leading to such a characteristic flight, time-resolved stereoscopic particle-image velocimetry (TR-SPIV) measurements are performed on a prepared natural owl wing in a range of angles of attack 0° ≤ α ≤ 6° and Reynolds numbers 40,000 ≤ Re(c) ≤ 120,000 based on the chord length at a position located at 30% of the halfspan from the owl's body. The flow field does not show any flow separation on the suction side, whereas flow separation is found on the pressure side for all investigated cases. The flow field on the pressure side is characterized by large-scale vortices which interact with the flexible wing structure. The good agreement of the shedding frequency of the pressure side vortices with the frequency of the trailing-edge deflection indicates that the structural deformation is induced by the flow field on the pressure side. Additionally, the reduction of the time-averaged mean wing curvature at high Reynolds numbers indicates a passive lift-control mechanism that provides constant lift in the entire flight envelope of the owl.

  14. Optimization of the Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle and Neutrino Astronomy

    NASA Technical Reports Server (NTRS)

    Krizmanic, John F.; Mitchell, John W.; Streitmatter, Robert E.

    2013-01-01

    OWL [1] uses the Earth's atmosphere as a vast calorimeter to fully enable the emerging field of charged-particle astronomy with high-statistics measurements of ultra-high-energy cosmic rays (UHECR) and a search for sources of UHE neutrinos and photons. Confirmation of the Greisen-Zatsepin-Kuzmin (GZK) suppression above approx. 4 x 10(exp 19) eV suggests that most UHECR originate in astrophysical objects. Higher energy particles must come from sources within about 100 Mpc and are deflected by approx. 1 degree by predicted intergalactic/galactic magnetic fields. The Pierre Auger Array, Telescope Array and the future JEM-EUSO ISS mission will open charged-particle astronomy, but much greater exposure will be required to fully identify and measure the spectra of individual sources. OWL uses two large telescopes with 3 m optical apertures and 45 degree FOV in near-equatorial orbits. Simulations of a five-year OWL mission indicate approx. 10(exp 6) sq km/ sr/ yr of exposure with full aperture at approx. 6 x 10(exp 19) eV. Observations at different altitudes and spacecraft separations optimize sensitivity to UHECRs and neutrinos. OWL's stereo event reconstruction is nearly independent of track inclination and very tolerant of atmospheric conditions. An optional monocular mode gives increased reliability and can increase the instantaneous aperture. OWL can fully reconstruct horizontal and upward-moving showers and so has high sensitivity to UHE neutrinos. New capabilities in inflatable structures optics and silicon photomultipliers can greatly increase photon sensitivity, reducing the energy threshold for n detection or increasing viewed area using a higher orbit. Design trades between the original and optimized OWL missions and the enhanced science capabilities are described.

  15. Chemical and isotopic studies of granitic Archean rocks, Owl Creek Mountains, Wyoming: Geochronology of an Archean granite, Owl Creek Mountains, Wyoming

    SciTech Connect

    Hedge, C.E.; Simmons, K.R.; Stuckless, J.S.

    1986-01-01

    Rubidium-strontium analyses of whole-rock samples of an Archean granite from the Owl Creek Mountains, Wyo., indicate an intrusive age of 2640 {plus minus} 125 Ma. Muscovite-bearing samples give results suggesting that these samples were altered about 2300 Ma. This event may have caused extensive strontium loss from the rocks as potassium feldspar was altered to muscovite. Alteration was highly localized in nature as evidence by unaffected rubidium-strontium mineral ages in the Owl Creek Mountains area. Furthermore, the event probably involved a small volume of fluid relative to the volume of rock because whole-rock {delta}{sup 18}O values of altered rocks are not distinct from those of unaltered rocks. In contrast to the rubidium-strontium whole-rock system, zircons from the granite have been so severely affected by the alteration event, and possibly by a late-Precambrian uplift event, that the zircon system yields little usable age information. The average initial {sup 87}Sr/{sup 86}Sr (0.7033 {plus minus} 0.0042) calculated from the isochron intercept varies significantly. Calculated initial {sup 87}Sr/{sup 86}Sr ratios for nine apparently unaltered samples yield a range of 0.7025 to 0.7047. These calculated initial ratios correlate positively with whole-rock {delta}{sup 18}O values; and, therefore, the granite was probably derived from an isotopically heterogeneous source. The highest initial {sup 87}Sr/{sup 86}Sr ratio is lower than the lowest reported for the metamorphic rocks intruded by the granite as it would have existed at 2640 Ma. Thus, the metamorphic sequence, at its current level of exposure, can represent no more than a part of the protolith for the granite.

  16. Chemical and isotopic studies of granitic Archean rocks, Owl Creek Mountains, Wyoming: Uranium-thorium-lead systematics of an Archean granite from the Owl Creek Mountains, Wyoming

    SciTech Connect

    Stuckless, J.S.; Nkomo, I.T.; Butt, K.A.

    1986-01-01

    Isotopic analyses of apparently unaltered whole-rock samples of a granite from the Owl Creek Mountains, Wyo., yield a lead-lead isochron age of 2730 {plus minus} 35 Ma, which is somewhat older than the age obtained by the rubidium-strontium whole-rock method. Thorium-lead data for the same samples deviate markedly from an isochronal relation; however, calculated initial {sup 208}Pb/{sup 204}Pb ratios correlate with whole-rock {delta}{sup 18}O values and lead to the conclusion that the {sup 232}Th-{sup 208}Pb data are not colinear because of an originally heterogeneous granitic magma. Relationships in the {sup 207}Pb/{sup 235}U-{sup 206}Pb/{sup 238}U system show that uranium was mobilized during early Laramide time or shortly before, such that most surface and shallow drill-core samples lost 60-80 percent of their uranium, and some fractured, deeper drill-core samples gained from 50 to 10,000 percent uranium. Fission-track maps show that much uranium is located along edges and cleavages of biotite and magnetic where it is readily accessible to oxidizing ground water. Furthermore, qualitative comparisons of uranium distribution in samples with excess radiogenic lead and in samples with approximately equilibrium amounts of uranium and lead suggest that the latter contain more uranium in these readily accessible sites. Unlike other granites that have uranium distributions and isotopic systematics similar to those observed in this study, the granite of the Owl Creek Mountains is not associated with economic uranium deposits.

  17. The Orbiting Wide-Angle Light Collectors (OWL) Mission for Charged-Particle Astronomy

    NASA Technical Reports Server (NTRS)

    Mitchell, John; Krizmanic, J. F.; Stecker, F. W.; Streitmatter, R. E.

    2009-01-01

    The space-based OWL mission is designed to perform high-statistics measurements of ultra-high-energy cosmic rays (UHECR) using the Earth's atmosphere as a vast particle calorimeter, furthering the field of charged-particle astronomy. OWL has been developed in formal NASA instrument and mission studies and is comprised of two large telescopes separated by approx.600 km in 1000 km, near-equatorial orbits to stereoscopically image the near-UV air fluorescence emitted by UHECR-induced particle cascades. The High Resolution Fly's Eye (HiRes) Collaboration, and subsequently the Pierre Auger Observatory, recently reported confirmation of the expected Greisen-Zatsepin-Kuzmin (GZK) suppression of the UHECR flux above a few times 10(exp 19) eV. This observation is consistent with the majority of UHECR originating in astrophysical objects and reduces the need to invoke exotic physical processes. Particles observed above the GZK threshold energy must have come from sources within about 100 Mpc from the Earth. The small particle deflection angles expected at UHECR energies, with standard assumptions of extragalactic magnetic fields, are on the order of 1 degree. Thus by observing particles above the GZK threshold with sufficient exposure, there is the potential of identifying and characterizing individual UHECR sources. Auger has reported significant anisotropy in the arrival directions of UHECR at energies above about 6 10(exp 19) eV observed in the South, and a correlation to AGN in the 12th VCV catalog, suggesting that the sources of UHECR are traced by the distribution of luminous matter in the Universe. However, with similar statistics and the same event selection criteria, HiRes observations in the North are consistent with isotropy. Extended observations by Auger-South, by Telescope Array in the North, and possibly by the proposed Auger-North, will further these investigations. However, much greater exposures will be required to fully identify individual sources and

  18. Bi-sensory, striped representations: comparative insights from owl and platypus.

    PubMed

    Pettigrew, John D

    2004-01-01

    Bi-sensory striped arrays are described in owl and platypus that share some similarities with the other variant of bi-sensory striped array found in primate and carnivore striate cortex: ocular dominance columns. Like ocular dominance columns, the owl and platypus striped systems each involve two different topographic arrays that are cut into parallel stripes, and interdigitated, so that higher-order neurons can integrate across both arrays. Unlike ocular dominance stripes, which have a separate array for each eye, the striped array in the middle third of the owl tectum has a separate array for each cerebral hemisphere. Binocular neurons send outputs from both hemispheres to the striped array where they are segregated into parallel stripes according to hemisphere of origin. In platypus primary somatosensory cortex (S1), the two arrays of interdigitated stripes are derived from separate sensory systems in the bill, 40,000 electroreceptors and 60,000 mechanoreceptors. The stripes in platypus S1 cortex produce bimodal electrosensory-mechanosensory neurons with specificity for the time-of-arrival difference between the two systems. This "thunder-and-lightning" system would allow the platypus to estimate the distance of the prey using time disparities generated at the bill between the earlier electrical wave and the later mechanical wave caused by the motion of benthic prey. The functional significance of parallel, striped arrays is not clear, even for the highly-studied ocular dominance system, but a general strategy is proposed here that is based on the detection of temporal disparities between the two arrays that can be used to estimate distance.

  19. A Quantitative Evaluation of the Conservation Umbrella of Spotted Owl Management Areas in the Sierra Nevada

    PubMed Central

    Burnett, Ryan D.; Roberts, L. Jay

    2015-01-01

    Whether by design or default, single species management often serves as an umbrella for species with similar habitat requirements. In recent decades the focus of National Forest management in the Sierra Nevada of California has shifted towards increasing closed canopy mature forest conditions through the protection of areas occupied by the California Spotted Owl (Strix occidentalis occidentalis). To evaluate the implications of these habitat changes and the potential umbrella resulting from a system of owl reserves on the broader avian community, we estimated occupancy of birds inside and outside of Spotted Owl Home Range Core Areas in northeastern California. We used point count data in a multi-species hierarchical Bayesian model incorporating the detection history of 81 species over a two-year time period (2005-2006). A small set of vegetation cover and topography covariates were included in the model to account for broad differences in habitat conditions, as well as a term identifying whether or not a site was within a Core Area. Seventeen species had a negative Core Area effect, seven had a positive effect, and the rest were not significant. Estimated species richness was significantly different with 23.1 species per 100 m radius circle outside Core Areas and 21.7 inside Core Areas. The majority of the species negatively associated with Core Areas are tied to early successional and other disturbance-dependent habitats. Conservation and climate vulnerability rankings were mixed. On average we found higher scores (greater risk) for the species positively associated with Core Areas, but a larger number of species with the highest scores were negatively associated with Core Areas. We discuss the implications for managing the Sierra Nevada ecosystem and illustrate the role of monitoring broader suites of species in guiding management of large complex ecosystems. PMID:25905920

  20. Fabrication and characterization of ultrathin dextran layers: Time dependent nanostructure in aqueous environments revealed by OWLS.

    PubMed

    Saftics, Andras; Kurunczi, Sándor; Szekrényes, Zsolt; Kamarás, Katalin; Khánh, Nguyen Quoc; Sulyok, Attila; Bősze, Szilvia; Horvath, Robert

    2016-10-01

    Surface coatings of the polysaccharide dextran and its derivatives are key ingredients especially in label-free biosensors for the suppression of non-specific binding and for receptor immobilization. Nevertheless, the nanostructure of these ultrathin coatings and its tailoring by the variation of the preparation conditions have not been profoundly characterized and understood. In this work carboxymethylated dextran (CMD) was prepared and used for fabricating ultrathin surface coatings. A grafting method based on covalent coupling to aminosilane- and epoxysilane-functionalized surfaces was applied to obtain thin CMD layers. The carboxyl moiety of the CMD was coupled to the aminated surface by EDC-NHS reagents, while CMD coupling through epoxysilane molecules was performed without any additional reagents. The surface analysis following the grafting procedures consisted of X-ray photoelectron spectroscopy (XPS), attenuated total reflection infrared spectroscopy (ATR-IR), spectroscopic ellipsometry, atomic force microscopy (AFM) and optical waveguide lightmode spectroscopy (OWLS). The XPS and AFM measurements showed that the grafting resulted in a very thin dextran layer of a few nanometers. The OWLS method allowed devising the structure of the interfacial dextran layers by the evaluation of the optogeometrical parameters. The alteration in the nanostructure of the CMD layer with the chemical composition of the silane coverage and the pH of the grafting solution was revealed by in situ OWLS, specifically, lain down chains were found to be prevalent on the surface under neutral and basic conditions on epoxysilylated surfaces. The developed methodologies allowed to design and fabricate nanometer scale CMD layers with well-controlled surface structure, which are very difficult to characterize in aqueous environments using present instrumentations and highly hydrated surface layers.

  1. Medical management of acute ocular hypertension in a western screech owl (Megascops kennicottii).

    PubMed

    Jayson, Stephanie; Sanchez-Migallon Guzman, David; Petritz, Olivia; Freeman, Kate; Maggs, David J

    2014-03-01

    A wild young adult western screech owl (Megascops kennicottii) of unknown sex was presented for evaluation of an abnormal left eye (OS). Ophthalmic examination OS revealed raised intraocular pressure (37 mm Hg; reference interval 7-16 mm Hg), mydriasis, conjunctival and episcleral hyperemia, shallow anterior chamber due to anterior displacement of the lens and iris, rubeosis iridis, and engorgement of the pecten. The intraocular pressure in the right eye (OD) was 11 mm Hg. Multifocal pale, variably translucent, curvilinear to vermiform opacities were observed in the medial and ventral peripheral regions of the retina OD, consistent with focal retinitis. Mannitol (0.46 g/kg IV) was administered over 10 minutes. Forty minutes later, the intraocular pressure was 27 mm Hg OS and 13 mm Hg OD. Dorzolamide (one drop OS q12h), diclofenac (one drop OU q8-12h), and meloxicam (0.5 mg/kg PO q24h) were administered for 3 days. The intraocular pressure OS was within normal limits 1 day (11 mm Hg), 7 days (13 mm Hg), and 4 weeks (14 mm Hg) after this treatment. Complications arising during hospitalization and rehabilitation included superficial corneal ulceration of both eyes presumed secondary to trauma on being caught and superficial damage to a talon. The owl was released after a period of rehabilitation. Characteristic presenting signs as well as response to therapy suggest aqueous misdirection was the cause of ocular hypertension in this owl. To our knowledge, this is the first report of suspected aqueous misdirection and its medical management in a raptor.

  2. A quantitative evaluation of the conservation umbrella of spotted owl management areas in the Sierra Nevada.

    PubMed

    Burnett, Ryan D; Roberts, L Jay

    2015-01-01

    Whether by design or default, single species management often serves as an umbrella for species with similar habitat requirements. In recent decades the focus of National Forest management in the Sierra Nevada of California has shifted towards increasing closed canopy mature forest conditions through the protection of areas occupied by the California Spotted Owl (Strix occidentalis occidentalis). To evaluate the implications of these habitat changes and the potential umbrella resulting from a system of owl reserves on the broader avian community, we estimated occupancy of birds inside and outside of Spotted Owl Home Range Core Areas in northeastern California. We used point count data in a multi-species hierarchical Bayesian model incorporating the detection history of 81 species over a two-year time period (2005-2006). A small set of vegetation cover and topography covariates were included in the model to account for broad differences in habitat conditions, as well as a term identifying whether or not a site was within a Core Area. Seventeen species had a negative Core Area effect, seven had a positive effect, and the rest were not significant. Estimated species richness was significantly different with 23.1 species per 100 m radius circle outside Core Areas and 21.7 inside Core Areas. The majority of the species negatively associated with Core Areas are tied to early successional and other disturbance-dependent habitats. Conservation and climate vulnerability rankings were mixed. On average we found higher scores (greater risk) for the species positively associated with Core Areas, but a larger number of species with the highest scores were negatively associated with Core Areas. We discuss the implications for managing the Sierra Nevada ecosystem and illustrate the role of monitoring broader suites of species in guiding management of large complex ecosystems.

  3. Long-term population dynamics of a managed burrowing owl colony

    USGS Publications Warehouse

    Barclay, John H.; Korfanta, Nicole M.; Kauffman, Matthew J.

    2011-01-01

    We analyzed the population dynamics of a burrowing owl (Athene cunicularia) colony at Mineta San Jose International Airport in San Jose, California, USA from 1990-2007. This colony was managed by using artificial burrows to reduce the occurrence of nesting owls along runways and within major airport improvement projects during the study period. We estimated annual reproduction in natural and artificial burrows and age-specific survival rates with mark-recapture techniques, and we estimated the relative contribution of these vital rates to population dynamics using a life table response experiment. The breeding colony showed 2 distinct periods of change: high population growth from 7 nesting pairs in 1991 to 40 pairs in 2002 and population decline to 17 pairs in 2007. Reproduction was highly variable: annual nesting success (pairs that raised =1 young) averaged 79% and ranged from 36% to 100%, whereas fecundity averaged 3.36 juveniles/pair and ranged from 1.43 juveniles/pair to 4.54 juveniles/pair. We estimated annual adult survival at 0.710 during the period of colony increase from 1996 to 2001 and 0.465 during decline from 2002 to 2007, but there was no change in annual survival of juveniles between the 2 time periods. Long-term population growth rate (lambda) estimated from average vital rates was lambdaa=1.072 with lambdai=1.288 during colony increase and lambdad=0.921 (DELTA lambda=0.368) during decline. A life table response experiment showed that change in adult survival rate during increasing and declining phases explained more than twice the variation in growth rate than other vital rates. Our findings suggest that management and conservation of declining burrowing owl populations should address factors that influence adult survival.

  4. The Binaural Interaction Component in Barn Owl (Tyto alba) Presents few Differences to Mammalian Data.

    PubMed

    Palanca-Castan, Nicolas; Laumen, Geneviève; Reed, Darrin; Köppl, Christine

    2016-12-01

    The auditory brainstem response (ABR) is an evoked potential that reflects the responses to sound by brainstem neural centers. The binaural interaction component (BIC) is obtained by subtracting the sum of the monaural ABR responses from the binaural response. Its latency and amplitude change in response to variations in binaural cues. The BIC is thus thought to reflect the activity of binaural nuclei and is used to non-invasively test binaural processing. However, any conclusions are limited by a lack of knowledge of the relevant processes at the level of individual neurons. The aim of this study was to characterize the ABR and BIC in the barn owl, an animal where the ITD-processing neural circuits are known in great detail. We recorded ABR responses to chirps and to 1 and 4 kHz tones from anesthetized barn owls. General characteristics of the barn owl ABR were similar to those observed in other bird species. The most prominent peak of the BIC was associated with nucleus laminaris and is thus likely to reflect the known processes of ITD computation in this nucleus. However, the properties of the BIC were very similar to previously published mammalian data and did not reveal any specific diagnostic features. For example, the polarity of the BIC was negative, which indicates a smaller response to binaural stimulation than predicted by the sum of monaural responses. This is contrary to previous predictions for an excitatory-excitatory system such as nucleus laminaris. Similarly, the change in BIC latency with varying ITD was not distinguishable from mammalian data. Contrary to previous predictions, this behavior appears unrelated to the known underlying neural delay-line circuitry. In conclusion, the generation of the BIC is currently inadequately understood and common assumptions about the BIC need to be reconsidered when interpreting such measurements.

  5. Comparing food limitation among three stages of nesting: supplementation experiments with the burrowing owl

    PubMed Central

    Wellicome, Troy I; Danielle Todd, L; Poulin, Ray G; Holroyd, Geoffrey L; Fisher, Ryan J

    2013-01-01

    Abstract Food availability is an important limiting factor for avian reproduction. In altricial birds, food limitation is assumed to be more severe during the nestling stage than during laying or incubation, but this has yet to be adequately tested. Using food-supplementation experiments over a 5-year period, we determined the degree and timing of food limitation for burrowing owls (Athene cunicularia) breeding in Canada. Burrowing owls are an endangered species and food limitation during the nestling stage could influence reproductive performance of this species at the northern extent of their range. Supplemented pairs fledged on average 47% more owlets than unfed pairs, except during a year when natural food was not limiting (i.e., a prey irruption year). The difference in fledgling production resulted from high nestling mortality in unfed broods, with 96% of all nestling deaths being attributed to food shortage. Supplemental feeding during the nestling period also increased fledgling structural size. Pairs fed from the start of laying produced the same number of hatchlings as pairs that received no supplemental food before hatch. Furthermore, pairs supplemented from egg laying to fledging and pairs supplemented during the nestling period alone had the same patterns of nestling survival, equal numbers of fledglings, and similar fledgling mass and structural size. Our results provide empirical support for the hypothesis that the nestling period is the most food-limited phase of the breeding cycle. The experimental design we introduce here could be used with other altricial species to examine how the timing of food limitation differs among birds with a variety of life-history strategies. For burrowing owls, and other species with similar life histories, long-term, large-scale, and appropriately timed habitat management increasing prey abundance or availability is critical for conservation. Our results provide empirical support for the hypothesis that the nestling

  6. OWL: an eyesafe 1.5-μm laser radar system for military applications

    NASA Astrophysics Data System (ADS)

    Eibert, Max; Scherbarth, Stefan

    1998-10-01

    The paper reports on current advances in the development of the Dornier Obstacle Warning System (OWS) for helicopters, with particular emphasis on the Obstacle Warning Ladar (OWL). Here both segments, development and application of the 1.5 micrometer imaging laser radar (LADAR) will be represented. It will be shown how advances in the eyesafe LADAR technology resulted in Obstacle Warning Ladar optimized for wire detection leading to a system family platform covering the range from the commercial needs up to the military requirements.

  7. Induced Oral Infection of the Owl Monkey (Aotus trivirgatus) with Hepatitis A Virus.

    DTIC Science & Technology

    1985-05-01

    0 **W.H. Bancroft, **L.N. Binn g. PERFORMING ORGANIZATION NAME AND ADORSS8 A0 ASW1SiIN .. E OjW ASK *SGRD.JJI **Dept Virus Diseases AR Div, USAMRIID...A’. * . ... - 7. -t . A- 7 - -W -U Induced Oral Infection of the Owl Monkey (Aotus trivirgatus) with Hepatitis A Virus Creighton J. Trahan, James W...Research Institute of Infectious Diseases (USAMRIID) (Trahan, LeDuc, Staley) Ft. Detrick, Frederick, MD 21701-5011 and Department of Virus Diseases

  8. Experimental West Nile virus infection in Eastern Screech Owls (Megascops asio)

    USGS Publications Warehouse

    Nemeth, N.M.; Hahn, D.C.; Gould, D.H.; Bowen, R.A.

    2006-01-01

    Eastern Screech Owls (EASOs) were experimentally infected with the pathogenic New York 1999 strain of West Nile virus (WNV) by subcutaneous injection or per os. Two of nine subcutaneously inoculated birds died or were euthanatized on 8 or 9 days postinfection (DPI) after <24 hr of lethargy and recumbency. All subcutaneously inoculated birds developed levels of viremia that are likely infectious to mosquitoes, with peak viremia levels ranging from 105.0 to 109.6 plaque-forming units/ml. Despite the viremia, the remaining seven birds did not display signs of illness. All birds alive beyond 5 DPI seroconverted, although the morbid birds demonstrated significantly lower antibody titers than the clinically normal birds. Cagemates of infected birds did not become infected. One of five orally exposed EASOs became viremic and seroconverted, whereas WNV infection in the remaining four birds was not evident. All infected birds shed virus via the oral and cloacal route. Early during infection, WNV targeted skin, spleen, esophagus, and skeletal muscle. The two morbid owls had myocardial and skeletal muscle necrosis and mild encephalitis and nephritis, whereas some of the clinically healthy birds that were sacrificed on 14 DPI had myocardial arteritis and renal phlebitis. WNV is a significant pathogen of EASOs, causing pathologic lesions with varying clinical outcomes.

  9. European monitoring for raptors and owls: state of the art and future needs.

    PubMed

    Kovács, András; Mammen, Ubbo C C; Wernham, Chris V

    2008-09-01

    Sixty-four percent of the 56 raptor and owl species that occur in Europe have an unfavorable conservation status. As well as requiring conservation measures in their own right, raptors and owls function as useful sentinels of wider environmental "health," because they are widespread top predators, relatively easy to monitor, and sensitive to environmental changes at a range of geographical scales. At a time of global acknowledgment of an increasing speed of biodiversity loss, and new, forward-looking and related European Union biodiversity policy, there is an urgent need to improve coordination at a pan-European scale of national initiatives that seek to monitor raptor populations. Here we describe current initiatives that make a contribution to this aim, particularly the current "MEROS" program, the results of a questionnaire survey on the current state of national raptor monitoring across 22 BirdLife Partners in Europe, the challenges faced by any enhanced pan-European monitoring scheme for raptors, and some suggested pathways for efficiently tapping expertise to contribute to such an initiative.

  10. Influence of double stimulation on sound-localization behavior in barn owls.

    PubMed

    Kettler, Lutz; Wagner, Hermann

    2014-12-01

    Barn owls do not immediately approach a source after they hear a sound, but wait for a second sound before they strike. This represents a gain in striking behavior by avoiding responses to random incidents. However, the first stimulus is also expected to change the threshold for perceiving the subsequent second sound, thus possibly introducing some costs. We mimicked this situation in a behavioral double-stimulus paradigm utilizing saccadic head turns of owls. The first stimulus served as an adapter, was presented in frontal space, and did not elicit a head turn. The second stimulus, emitted from a peripheral source, elicited the head turn. The time interval between both stimuli was varied. Data obtained with double stimulation were compared with data collected with a single stimulus from the same positions as the second stimulus in the double-stimulus paradigm. Sound-localization performance was quantified by the response latency, accuracy, and precision of the head turns. Response latency was increased with double stimuli, while accuracy and precision were decreased. The effect depended on the inter-stimulus interval. These results suggest that waiting for a second stimulus may indeed impose costs on sound localization by adaptation and this reduces the gain obtained by waiting for a second stimulus.

  11. Local adaptation and matching habitat choice in female barn owls with respect to melanic coloration.

    PubMed

    Dreiss, A N; Antoniazza, S; Burri, R; Fumagalli, L; Sonnay, C; Frey, C; Goudet, J; Roulin, Alexandre

    2012-01-01

    Local adaptation is a major mechanism underlying the maintenance of phenotypic variation in spatially heterogeneous environments. In the barn owl (Tyto alba), dark and pale reddish-pheomelanic individuals are adapted to conditions prevailing in northern and southern Europe, respectively. Using a long-term dataset from Central Europe, we report results consistent with the hypothesis that the different pheomelanic phenotypes are adapted to specific local conditions in females, but not in males. Compared to whitish females, reddish females bred in sites surrounded by more arable fields and less forests. Colour-dependent habitat choice was apparently beneficial. First, whitish females produced more fledglings when breeding in wooded areas, whereas reddish females when breeding in sites with more arable fields. Second, cross-fostering experiments showed that female nestlings grew wings more rapidly when both their foster and biological mothers were of similar colour. The latter result suggests that mothers should particularly produce daughters in environments that best match their own coloration. Accordingly, whiter females produced fewer daughters in territories with more arable fields. In conclusion, females displaying alternative melanic phenotypes bred in habitats providing them with the highest fitness benefits. Although small in magnitude, matching habitat selection and local adaptation may help maintain variation in pheomelanin coloration in the barn owl.

  12. Hunting increases phosphorylation of calcium/calmodulin-dependent protein kinase type II in adult barn owls.

    PubMed

    Nichols, Grant S; DeBello, William M

    2015-01-01

    Juvenile barn owls readily adapt to prismatic spectacles, whereas adult owls living under standard aviary conditions do not. We previously demonstrated that phosphorylation of the cyclic-AMP response element-binding protein (CREB) provides a readout of the instructive signals that guide plasticity in juveniles. Here we investigated phosphorylation of calcium/calmodulin-dependent protein kinase II (pCaMKII) in both juveniles and adults. In contrast to CREB, we found no differences in pCaMKII expression between prism-wearing and control juveniles within the external nucleus of the inferior colliculus (ICX), the major site of plasticity. For prism-wearing adults that hunted live mice and are capable of adaptation, expression of pCaMKII was increased relative to prism-wearing adults that fed passively on dead mice and are not capable of adaptation. This effect did not bear the hallmarks of instructive information: it was not localized to rostral ICX and did not exhibit a patchy distribution reflecting discrete bimodal stimuli. These data are consistent with a role for CaMKII as a permissive rather than an instructive factor. In addition, the paucity of pCaMKII expression in passively fed adults suggests that the permissive default setting is "off" in adults.

  13. Acute toxicity of four anticholinesterase insecticides to American kestrels, eastern screech-owls and northern bobwhites

    USGS Publications Warehouse

    Wiemeyer, Stanley N.; Sparling, D.W.

    1991-01-01

    American kestrels (Falco sparverius), eastern screech-owls (Otus asio), and northern bobwhites (Colinus virginianus) were given single acute oral doses of four widely diverse anticholinesterase pesticides: EPN, fenthion, carbofuran, and monocrotophos. LD50s, based on birds that died within 5 d of dosage, were computed for each chemical in each species. Sex differences in the sensitivity of northern bobwhites in reproductive condition were examined. American kestrels were highly sensitive to all chemicals tested (LD50s 0.6--4.0 mg/kg). Eastern screech-owls were highly tolerant to EPN (LD50 274 mg/kg) but sensitive to the remaining chemicals (LD50s 1.5-3.9 mg/kg). Northern bobwhites were highly sensitive to monocrotophos (LD50 0.8 mg/kg) and less sensitive to the remaining chemicals (LD50s 4.6--31 mg/kg). Female bobwhites (LD50 3.1 mg/kg) were more sensitive to fenthion than males (LD50 7.0 mg/kg). Mean percent depression of brain cho[inesterase (ChE) of birds that died on the day of dosing exceeded 65% for all chemicals in all species. The response of one species to a given pesticide should not be used to predict the sensitivity of other species to the same pesticide. The need for research on several topics is discussed

  14. Integrating reasoning and clinical archetypes using OWL ontologies and SWRL rules.

    PubMed

    Lezcano, Leonardo; Sicilia, Miguel-Angel; Rodríguez-Solano, Carlos

    2011-04-01

    Semantic interoperability is essential to facilitate the computerized support for alerts, workflow management and evidence-based healthcare across heterogeneous electronic health record (EHR) systems. Clinical archetypes, which are formal definitions of specific clinical concepts defined as specializations of a generic reference (information) model, provide a mechanism to express data structures in a shared and interoperable way. However, currently available archetype languages do not provide direct support for mapping to formal ontologies and then exploiting reasoning on clinical knowledge, which are key ingredients of full semantic interoperability, as stated in the SemanticHEALTH report [1]. This paper reports on an approach to translate definitions expressed in the openEHR Archetype Definition Language (ADL) to a formal representation expressed using the Ontology Web Language (OWL). The formal representations are then integrated with rules expressed with Semantic Web Rule Language (SWRL) expressions, providing an approach to apply the SWRL rules to concrete instances of clinical data. Sharing the knowledge expressed in the form of rules is consistent with the philosophy of open sharing, encouraged by archetypes. Our approach also allows the reuse of formal knowledge, expressed through ontologies, and extends reuse to propositions of declarative knowledge, such as those encoded in clinical guidelines. This paper describes the ADL-to-OWL translation approach, describes the techniques to map archetypes to formal ontologies, and demonstrates how rules can be applied to the resulting representation. We provide examples taken from a patient safety alerting system to illustrate our approach.

  15. Patterns of maternal yolk hormones in eastern screech owl eggs (Megascops asio)

    USGS Publications Warehouse

    Hahn, D. Caldwell

    2011-01-01

    Owl clutches typically hatch asynchronously, and brood size hierarchies develop. In this study, we describe intra-clutch variation of testosterone, androstenedione, estradiol, and corticosterone in Eastern screech owl egg yolks. In order to assess whether these hormones may have originated in the follicle, we also characterize variation of testosterone, androstenedione, and corticosterone within the exterior, intermediate, and interior regions of the yolk. Concentrations of testosterone and androstenedione were distributed relatively evenly across egg lay order with the exception of first-laid eggs that had significantly lower concentrations of both androgens than eggs later in the laying sequence. Corticosterone and estradiol did not vary with laying order. Our results suggest that when food is abundant, yolk hormones are deposited in patterns that minimize sibling differences except to reduce dominance by the first-hatching chick. Testosterone and androstenedione concentrations varied throughout the yolk, while corticosterone was evenly distributed throughout the yolk. This supports a follicular origin for both yolk androgens, and an adrenal origin for yolk corticosterone.

  16. Reconnaissance and economic geology of Copper Mountain metamorphic complex, Owl Creek Mountains, Wyoming

    SciTech Connect

    Hausel, W.D.

    1983-08-01

    The Copper Mountain metamorphic complex lies within a westerly trending belt of Precambrian exposures known as the Owl Creek Mountains uplift. The metamorphic complex at Copper Mountain is part of a larger complex known as the Owl Creek Mountains greenstone belt. Until more detailed mapping and petrographic studies can be completed, the Copper Mountain area is best referred to as a complex, even though it has some characteristics of a greestone belt. At least three episodes of Precambrian deformation have affected the supracrustals, and two have disturbed the granites. The final Precambrian deformation event was preceded by a weak thermal event expressed by retrogressive metamorphism and restricted metasomatic alteration. During this event, a second phase of pegmatization was accompanied by hydrothermal solutions. During the Laramide orogeny, Copper Mountain was again modified by deformation. Laramide deformation produced complex gravity faults and keystone grabens. Uranium deposits were formed following major Laramide deformation. The genesis of these deposits is attributable to either the leaching of granites or the leaching of overlying tuffaceous sediments during the Tertiary. Production of metals and industrial minerals has been limited, although some gold, copper, silver, tungsten, beryl, feldspar, and lithium ore have been shipped from Copper Mountain. A large amount of uranium was produced from the Copper Mountain district in the 1950s.

  17. Integration of an OWL-DL knowledge base with an EHR prototype and providing customized information.

    PubMed

    Jing, Xia; Kay, Stephen; Marley, Tom; Hardiker, Nicholas R

    2014-09-01

    When clinicians use electronic health record (EHR) systems, their ability to obtain general knowledge is often an important contribution to their ability to make more informed decisions. In this paper we describe a method by which an external, formal representation of clinical and molecular genetic knowledge can be integrated into an EHR such that customized knowledge can be delivered to clinicians in a context-appropriate manner.Web Ontology Language-Description Logic (OWL-DL) is a formal knowledge representation language that is widely used for creating, organizing and managing biomedical knowledge through the use of explicit definitions, consistent structure and a computer-processable format, particularly in biomedical fields. In this paper we describe: 1) integration of an OWL-DL knowledge base with a standards-based EHR prototype, 2) presentation of customized information from the knowledge base via the EHR interface, and 3) lessons learned via the process. The integration was achieved through a combination of manual and automatic methods. Our method has advantages for scaling up to and maintaining knowledge bases of any size, with the goal of assisting clinicians and other EHR users in making better informed health care decisions.

  18. Burrow Occupancy Patterns of the Western Burrowing Owl in Southern Nevada

    SciTech Connect

    Paul D. Greger and Derek B. Hall

    2009-09-01

    Understanding long-term patterns of burrow occupancy for the Western Burrowing Owl (Athene cunicularia hypugaea) is necessary for the conservation of this species, especially in arid, desert ecosystems where burrow occupancy data are lacking. Monthly burrow monitoring was conducted over a 4-year period (1997–2001) in southern Nevada to determine burrow occupancy patterns of Burrowing Owls and to evaluate the effects of burrow type and desert region on burrow occupancy. Burrow occupancy occurred year-round and was most consistent in the Transition region and tended to be lowest in the Mojave Desert region. Peak burrow occupancy occurred during March through May, followed by a gradual decline in occupancy through the summer and fall until January and February, when occupancy was lowest. Occupancy was significantly higher at sites with both culvert and pipe burrows than at sites with earthen burrows in disturbed habitat or earthen burrows in natural habitat. Breeding-season occupancy was not significantly higher in wetter, cooler portions (e.g., Great Basin desert region) of the study area. Results suggest that occupancy is influenced by habitat features—such as suitable burrows in open areas with low vegetation—and climatic regime.

  19. Reprising the taxonomy of Cyprus Scops Owl Otus (scops) cyprius, a neglected island endemic.

    PubMed

    Flint, Peter; Whaley, David; Kirwan, Guy M; Charalambides, Melis; Schweizer, Manuel; Wink, Michael

    2015-11-11

    The endemic Cyprus Scops Owl Otus (scops) cyprius has been treated as a subspecies of the widespread Eurasian Scops Owl O. scops since at least the 1940s. However, its song is distinct from that of all other subspecies of O. scops in being double-noted, rather than single-noted. Its plumage also differs, most obviously in being consistently darker than other subspecies and in lacking a rufous morph. However, it shows no biometric differences from O. s. cycladum and southern populations of O. s. scops. It is also unusual among scops (s. l.) populations in being at least partially resident, although two specimens showing characters of this taxon were collected in Israel in early spring, and the numbers of birds that are resident on Cyprus appear to vary, with few recent winter records. It differs from O. s. scops by one synapomorphic nucleotide exchange in the analysed mitochondrial marker, indicating a recent separation. Given that large numbers of O. s. scops and O. s. cycladum pass through Cyprus on spring migration, and that the latter breeds in adjacent countries, it seems probable that cycladum would colonize the island, but for the presence of cyprius. That it does not do so, and that cyprius retains its distinctive song and plumage, suggests that isolating mechanisms exist. We recommend that cyprius be considered specifically distinct, as are other distinctively voiced insular Otus populations.

  20. Dynamic vortex interactions with flexible fibers and edges for prediction of owl noise suppression

    NASA Astrophysics Data System (ADS)

    Korykora, Sarah; Jaworski, Justin

    2015-11-01

    The compliant trailing-edge fringe of owls and the soft downy material on their upper wing surfaces are thought to enable their silent flight by weakening the interaction of boundary layer turbulence with these flexible structures. Previous analysis of turbulence noise generation by wave-bearing elastic edges have shown that the far-field acoustic power scaling can be weakened by up to the square of the Mach number relative to a rigid edge. However, it is unclear whether or not the wave-bearing feature or simply the flexible nature of the edge scatterer produces this noise suppression. To assess this distinction, a dynamic vortex interaction model is developed whereby the motion of a line vortex round a rigid but elastically-restrained wall-mounted fiber or trailing edge is determined numerically. Special attention is paid to the dynamic interaction between the flexible structure and vortex, which is accomplished via a conformal mapping relationship determined in closed form. Results from this analysis seek to develop a vortex sound model to discern the effect of flexible versus wave-bearing scatterers on turbulence noise suppression and help explain the mechanisms of silent owl flight.

  1. Regional and Seasonal Diet of the Western Burrowing Owl in South-Central Nevada

    SciTech Connect

    Derek B. Hall, Paul D. Greger, Jeffrey R. Rosier

    2009-04-01

    We examined diets of Western Burrowing Owls (Athene cunicularia hypugaea) based on contents of pellets and large prey remains collected year-round at burrows in each of the 3 regions in south central Nevada (Mojave Desert, Great Basin Desert, and Transition region). The most common prey items, based on percent frequency of occurrence, were crickets and grasshoppers, beetles, rodents, sun spiders, and scorpions. The most common vertebrate prey was kangaroo rats (Dipodomys spp.). True bugs (Hemiptera), scorpions, and western harvest mice (Reithrodontomys megalotis) occurred most frequently in pellets from the Great Basin Desert region. Kangaroo rats (Dipodomys spp.) and pocket mice (Perognathinae) were the most important vertebrate prey items in the Transition and Mojave Desert regions, respectively. Frequency of occurrence of any invertebrate prey was high (>80%) in samples year-round but dropped in winter samples, with scorpions and sun spiders exhibiting the steepest declines. Frequency of occurrence of any vertebrate prey peaked in spring samples, was intermediate for winter and summer samples, and was lowest in fall samples. With the possible exception of selecting for western harvest mice in the Great Basin Desert region, Western Burrowing Owls in our study appeared to be opportunistic foragers with a generalist feeding strategy.

  2. Effects of fluoride on screech owl reproduction: Teratological evaluation, growth, and blood chemistry in hatchlings

    USGS Publications Warehouse

    Hoffman, D.J.; Pattee, O.H.; Wiemeyer, Stanley N.

    1985-01-01

    The effects on reproduction in screech owls (Otus asio) of chronic dietary sodium fluoride administration at 0, 40, and 200 ppm were examined. Fluoride at 40 ppm resulted in a significantly smaller egg volume, while 200 ppm also resulted in lower egg weights and lengths. Day-one hatchlings in the 200 ppm group weighed almost 10% less than controls and had shorter crown-rump lengths. No gross abnormalities were apparent. Skeletal clearing and staining revealed significantly shorter tibiotarsus lengths in the 40 ppm and 200 ppm groups and a shorter radius-ulna length in the 200 ppm group. By 7 days of age, body weights and lengths did not differ from controls, but the tibiotarsus in the 200 ppm group remained shorter. No significant differences were detected in hematocrit, hemoglobin, plasma calcium or alkaline phosphatase. Plasma phosphorus levels were higher in the 40 ppm group than in controls. These results, in combination with the findings of Pattee et al. [25], revealed significant impairment of overall reproduction, suggesting that sodium fluoride could cause slight to moderate reproduction disorders in owls in fluoride-polluted areas.

  3. A link between eumelanism and calcium physiology in the barn owl.

    PubMed

    Roulin, Alexandre; Dauwe, Tom; Blust, Ronny; Eens, Marcel; Beaud, Michel

    2006-09-01

    In many animals, melanin-based coloration is strongly heritable and is largely insensitive to the environment and body condition. According to the handicap principle, such a trait may not reveal individual quality because the production of different melanin-based colorations often entails similar costs. However, a recent study showed that the production of eumelanin pigments requires relatively large amounts of calcium, potentially implying that melanin-based coloration is associated with physiological processes requiring calcium. If this is the case, eumelanism may be traded-off against other metabolic processes that require the same elements. We used a correlative approach to examine, for the first time, this proposition in the barn owl, a species in which individuals vary in the amount, size, and blackness of eumelanic spots. For this purpose, we measured calcium concentration in the left humerus of 85 dead owls. Results showed that the humeri of heavily spotted individuals had a higher concentration of calcium. This suggests either that plumage spottiness signals the ability to absorb calcium from the diet for both eumelanin production and storage in bones, or that lightly spotted individuals use more calcium for metabolic processes at the expense of calcium storage in bones. Our study supports the idea that eumelanin-based coloration is associated with a number of physiological processes requiring calcium.

  4. A link between eumelanism and calcium physiology in the barn owl

    NASA Astrophysics Data System (ADS)

    Roulin, Alexandre; Dauwe, Tom; Blust, Ronny; Eens, Marcel; Beaud, Michel

    2006-09-01

    In many animals, melanin-based coloration is strongly heritable and is largely insensitive to the environment and body condition. According to the handicap principle, such a trait may not reveal individual quality because the production of different melanin-based colorations often entails similar costs. However, a recent study showed that the production of eumelanin pigments requires relatively large amounts of calcium, potentially implying that melanin-based coloration is associated with physiological processes requiring calcium. If this is the case, eumelanism may be traded-off against other metabolic processes that require the same elements. We used a correlative approach to examine, for the first time, this proposition in the barn owl, a species in which individuals vary in the amount, size, and blackness of eumelanic spots. For this purpose, we measured calcium concentration in the left humerus of 85 dead owls. Results showed that the humeri of heavily spotted individuals had a higher concentration of calcium. This suggests either that plumage spottiness signals the ability to absorb calcium from the diet for both eumelanin production and storage in bones, or that lightly spotted individuals use more calcium for metabolic processes at the expense of calcium storage in bones. Our study supports the idea that eumelanin-based coloration is associated with a number of physiological processes requiring calcium.

  5. Heptachlor seed treatment contaminates hawks, owls, and eagles of Columbia Basin, Oregon

    USGS Publications Warehouse

    Henny, C.J.; Blus, L.J.; Kaiser, T.E.

    1984-01-01

    We evaluated organochlorine residues in 12 species of hawks. owls, and eagles from the Columbia Basin of Oregon between 1978 and 1981. Companion studies showed that heptachlor epoxide (HE) induced adult mortality and reduced productivity of the Canada Goose (Branta canadensis) and American Kestrel (Falco sparverius).ln this study, brain tissue from raptors found dead and sample eggs from 90 nests were analyzed for organochlorines. The primary concern was HE that entered raptor food chains through the ingestion of heptachlor-treated seed by their prey. HE residues were detected in eggs from 9 of 10 species and ranged as high as 4.75 ppm (wet wt), but no definite effects of HE on productivity were readily apparent from the limited series of nests. However, the hazard of heptachlor seed treatments to birds of prey was demonstrated by the occurrence of lethal residues of HE in brain tissue of 3 Golden Eagles (Aquila chrysaetos) and 1 Rough-legged Hawk (Buteo lagopus). Other organochlorine pesticides were present in the eggs and significant relationships were found between DDE and eggshell thickness for the Swainson's Hawk (Buteo swainsoni) and Western Screech-Owl (Otus kennicotti), although shell thinning (9.6% and 7.4%) was below the generally accepted range where reproductive problems have been known to occur.

  6. Why do territorial male Tengmalm's owls fail to obtain a mate?

    PubMed

    Hakkarainen, Harri; Korpimäki, Erkki

    1998-05-01

    Non-breeding may occur because non-breeders are immature or somehow physiologically incapable of breeding, or because of a lack of resources (e.g. food resources, mating partners) needed to breed. There is, however, a lack of experimental evidence on whether bachelor males possessing territories and nest-sites are able to breed when supplemented with extra food or provided with mating partners. In vole-eating Tengmalm's owl, Aegolius funereus, we provided supplementary food and transferred females in nest-boxes of non-breeding males. Bachelor males that we supplemented with food did not attract mates at a higher frequency than unfed control males, which suggests that a lack of food did not influence the ability to attract a mating partner. In contrast, bachelor males presented with a female seemed to breed more frequently than bachelor males in the control group without mate addition. This suggests that scarcity of females may be an important reason for the high proportion of non-breeding males in the population (c. 25%) and excludes the possibility that non-breeding males are physiologically unable to breed. The operational sex ratio of the owl population at the time of mating may be male-biased, and some males may thus remain unpaired. Habitat and nest-box quality also seemed to be lower among bachelors than among breeding males.

  7. Lifetime reproduction of a forest-dwelling owl increases with age and area of forests.

    PubMed

    Laaksonen, Toni; Hakkarainen, Harri; Korpimäki, Erkki

    2004-12-07

    Loss and alteration of habitats by human actions are the largest worldwide hazard to biodiversity and viability of populations. In boreal forests of Eurasia and North America the natural habitat is changing, mainly because of forestry practices and agriculture. Although there is evidence that the diversity and abundance of animal species are lower in intensively managed than in natural forests, very little is known about how the changes in habitat composition affect reproduction and survival. The best available measure of individual performance in the wild is lifetime reproductive success (LRS), the number of offspring produced during a lifetime, because it combines both survival and reproductive success to a single measure. We show that the LRS of forest-dwelling Tengmalm's owls (Aegolius funereus) increases with the proportion of old forest in the territory because of a higher number of breeding attempts, whereas it decreases with the proportion of agricultural land because of declining fledging success in years when prey populations crashed during owl breeding. These unique results provide an interesting insight into how human influence on the landscape can affect life-history traits of animals through various pathways.

  8. Pathology of hepatitis A infection in the owl monkey (Aotus trivirgatus).

    PubMed Central

    Keenan, C. M.; Lemon, S. M.; LeDuc, J. W.; McNamee, G. A.; Binn, L. N.

    1984-01-01

    Sequential liver biopsies of owl monkeys that had been experimentally infected with one of two strains of hepatitis A virus (HM-175 or PA-33) were examined for histopathologic alterations. Preinoculation biopsies were normal with only occasional minimal mononuclear cell infiltrates in portal tracts and hepatic lobular parenchyma. Histopathologic features that were present in biopsies taken during the period of elevated serum alanine aminotransferase activity (16-43 days after the intravenous inoculation of virus) included infiltration of predominantly mononuclear inflammatory cells into portal tracts and surrounding parenchyma, degeneration and necrosis of hepatocytes, and hypertrophy of Kupffer cells. Changes were similar in monkeys infected with either HM-175 or PA-33 virus strains. Convalescent biopsies (147-186 days after inoculation) showed resolving lesions with mild portal inflammation and occasional focal collections of inflammatory cells in the parenchyma. These histologic changes are similar to those associated with hepatitis A infection in man, chimpanzees, and several species of marmosets, and support the further use of the owl monkey as a model of human hepatitis A. Images Figure 1 Figure 2-4 Figure 5-6 Figure 7 PMID:6711675

  9. Neuroethology of prey capture in the barn owl (Tyto alba L.).

    PubMed

    Wagner, Hermann; Kettler, Lutz; Orlowski, Julius; Tellers, Philipp

    2013-01-01

    Barn owls are a model system for studying prey capture. These animals can catch mice by hearing alone, but use vision whenever light conditions allow this. The silent flight, the frontally oriented eyes, and the facial ruffs are specializations that evolved to optimize prey capture. The auditory system is characterized by high absolute sensitivity, a use of interaural time difference for azimuthal sound-localization over almost the total hearing range up to at least 9 kHz, and the use of interaural level difference for elevational sound localization in the upper frequency range. Response latencies towards auditory targets were shortened by covert attention, while overt attention helped to orient towards salient visual objects. However, only 20% of the fixation movements could be explained by the saliency of the fixated objects, suggesting a top-down control of attention. In a visual-search experiment the birds turned earlier and more often towards and spent more time at salient objects. The visual system also exhibits high absolute sensitivity, while the spatial resolution is not particularly high. Last but not least, head movements may be classified as fixations, translations, and rotations combined with translations. These motion primitives may be combined to complex head-movement patterns. With the expected easy availability of genetic techniques for specialists in the near future and the possibility to apply the findings in biomimetic devices prey capture in barn owls will remain an exciting field in the future.

  10. Nestling barn owls assess short-term variation in the amount of vocally competing siblings.

    PubMed

    Ruppli, Charlène A; Dreiss, Amélie N; Roulin, Alexandre

    2013-11-01

    Assessing the amount of rivals is crucial to optimally adjust investment into a contest. If laboratory animals show numerical abilities, little is known about the ecological implications particularly in young animals. The two to nine barn owl (Tyto alba) siblings vocally compete for priority of access to food resources before parents actually deliver them. In dyads, the individual that vocalizes at the highest rate in the absence of parents deters its siblings from competing for next delivered prey. We tested the novel hypothesis that to optimally adjust vocal investment, barn owl nestlings assess how many of their siblings are currently competing. To singleton owlets, we broadcasted a fixed global number of calls emitted by one, two or four pre-recorded unfamiliar nestlings. We could thus distinguish the independent effect on singletons' vocal behavior of the global number of calls produced by a brood from the number of competitors that produced these calls. Overall, nestlings retreated more from vocal contest when facing more competitors. However, in front of one highly motivated competitor, nestlings refrained from vocalizing to a larger extent than when competing against more but less motivated individuals. Therefore, young animals assess variation in the number of currently competing siblings based on individual-specific vocal cues.

  11. Spatiotemporal frequency tuning dynamics of neurons in the owl visual wulst.

    PubMed

    Pinto, Lucas; Baron, Jerome

    2010-06-01

    The transformation of spatial (SF) and temporal frequency (TF) tuning functions from broad-band/low-pass to narrow band-pass profiles is one of the key emergent properties of neurons in the mammalian primary visual cortex (V1). The mechanisms underlying such transformation are still a matter of ongoing debate. With the aim of providing comparative insights into the issue, we analyzed various aspects of the spatiotemporal tuning dynamics of neurons in the visual wulst of four awake owls. The wulst is the avian telencephalic target of the retinothalamofugal pathway and, in owls, bears striking functional analogy with V1. Most neurons in our sample exhibited fast and large-magnitude adaptation to the visual stimuli with response latencies very similar to those reported for V1. Moreover, latency increased as a function of stimulus SF but not TF, which suggests that parvo- and magno-like geniculate inputs could be converging onto single wulst neurons. No net shifts in preferred SF or TF were observed along the initial second of stimulation, but bandwidth decreased roughly during the first 200 ms after response latency for both stimulus dimensions. For SF, this occurred exclusively as a consequence of low-frequency suppression, whereas suppression was observed both at the low- and high-frequency limbs of TF tuning curves. Overall these results indicate that SF and TF tuning curves in the wulst are shaped by both feedforward and intratelencephalic suppressive mechanisms, similarly to what seems to be the case in the mammalian striate cortex.

  12. Comparison of metabolic substrates in alligators and several birds of prey.

    PubMed

    Sweazea, Karen L; McMurtry, John P; Elsey, Ruth M; Redig, Patrick; Braun, Eldon J

    2014-08-01

    On average, avian blood glucose concentrations are 1.5-2 times those of mammals of similar mass and high concentrations of insulin are required to lower blood glucose. Whereas considerable data exist for granivorous species, few data are available for plasma metabolic substrate and glucoregulatory hormone concentrations for carnivorous birds and alligators. Birds and mammals with carnivorous diets have higher metabolic rates than animals consuming diets with less protein whereas alligators have low metabolic rates. Therefore, the present study was designed to compare substrate and glucoregulatory hormone concentrations in several birds of prey and a phylogenetically close relative of birds, the alligator. The hypothesis was that the combination of carnivorous diets and high metabolic rates favored the evolution of greater protein and fatty acid utilization leading to insulin resistance and high plasma glucose concentrations in carnivorous birds. In contrast, it was hypothesized that alligators would have low substrate utilization attributable to a low metabolic rate. Fasting plasma substrate and glucoregulatory hormone concentrations were compared for bald eagles (Haliaeetus leucocephalus), great horned owls (Bubo virginianus), red-tailed hawks (Buteo jamaicensis), and American alligators (Alligator mississippiensis). Avian species had high circulating β-hydroxybutyrate (10-21 mg/dl) compared to alligators (2.81 ± 0.16 mg/dl). In mammals high concentrations of this byproduct of fatty acid utilization are correlated with insulin resistance. Fasting glucose and insulin concentrations were positively correlated in eagles whereas no relationship was found between these variables for owls, hawks or alligators. Additionally, β-hydroxybutyrate concentrations were low in alligators. Similar to carnivorous mammals, ingestion of a high protein diet may have favored the utilization of fatty acids and protein for energy thereby promoting the development of insulin

  13. Distributional changes in the western Burrowing Owl (Athene cunicularia hypugaea) in North America from 1967 to 2008

    USGS Publications Warehouse

    Macias-Duarte, Alberto; Conway, Courtney J.

    2015-01-01

    The quantification of shifts in bird distributions in response to climate change provides an opportunity to gain a deeper understanding of the processes that influence species persistence. We used data from the North American Breeding Bird Survey (BBS) to document changes in the distributional limits of the western Burrowing Owl (Athene cunicularia hypugaea) from 1967 to 2008. We used logistic regression to model presence probability (p) as a function of longitude, latitude, and year. We modeled a linear trend in logit(p) through time with slope and intercept modeled as a double Fourier series of longitude and latitude. We found that the western Burrowing Owl has experienced an intriguing southward shift in the northern half of its breeding range, contrary to what is predicted by most species niche models and what has been observed for many other species in North America. The breeding range of the Burrowing Owl has been shrinking near its northern, western, and eastern edges. Our model detected the population declines that were observed in California and eastern Washington, in locations where maps based on route-specific estimating equations had predicted significant population increases. We suggest that the northern boundary of the breeding distribution of the western Burrowing Owl has contracted southward and the southern boundary of the species' breeding distribution has expanded southward into areas of northern Mexico that were formerly used only by wintering migrants.

  14. Hematocrit and plasma chemistry values in adult collared scops owls (Otus lettia) and crested serpent eagles (Spilornis cheela hoya).

    PubMed

    Chan, Fang-Tse; Lin, Pei-I; Chang, Geng-Ruei; Wang, Hsien-Chi; Hsu, Tien-Huan

    2012-07-01

    In this study, we report hematocrit and plasma chemistry values for adult captive collared scops owls (Otus lettia) and crested serpent eagles (Spilornis cheela hoya). In particular, we address the gender-specific differences within these values. We measured hematocrit (HCT) and plasma chemistry values for uric acid (UA), plasma urea nitrogen (BUN), total protein (TP), albumin (ALB), glucose (GLU), cholesterol (CHO), triglyceride (TG), aspartate aminotransferase (AST), alanine aminotransferase (ALT), lactate dehydrogenase (LDH), alkaline phosphatase (ALP), total bilirubin (TBIL), creatine (CRE), creatine phosphokinase (CPK), amylase (AMY), calcium (CA), ionic phosphorous (IP) and sodium (NA), potassium (K) and chloride ions (CL) in 37 adult captive collared scops owls and 39 adult captive crested serpent eagles. Significant differences between the sexes were found for UA, GLU and CPK in the collared scope owls. UA and GLU concentrations were significantly higher (P<0.01 and P<0.05) among males than females, while the CPK concentration was significantly lower (P<0.05) in males. There were no significant differences in of all of the measured parameters between male and female eagles. These finding suggested that HCT and plasma chemistry values of raptors vary individually according to species and sex. Our results provide the 1st available reference data for ranges of plasma values in adult captive collared scops owls and crested serpent eagles, making them a potentially useful complementary diagnostic tool for veterinary care of individuals for both species in captivity.

  15. Reverse correlation analysis of auditory-nerve fiber responses to broadband noise in a bird, the barn owl.

    PubMed

    Fontaine, Bertrand; Köppl, Christine; Peña, Jose L

    2015-02-01

    While the barn owl has been extensively used as a model for sound localization and temporal coding, less is known about the mechanisms at its sensory organ, the basilar papilla (homologous to the mammalian cochlea). In this paper, we characterize, for the first time in the avian system, the auditory nerve fiber responses to broadband noise using reverse correlation. We use the derived impulse responses to study the processing of sounds in the cochlea of the barn owl. We characterize the frequency tuning, phase, instantaneous frequency, and relationship to input level of impulse responses. We show that, even features as complex as the phase dependence on input level, can still be consistent with simple linear filtering. Where possible, we compare our results with mammalian data. We identify salient differences between the barn owl and mammals, e.g., a much smaller frequency glide slope and a bimodal impulse response for the barn owl, and discuss what they might indicate about cochlear mechanics. While important for research on the avian auditory system, the results from this paper also allow us to examine hypotheses put forward for the mammalian cochlea.

  16. A comparison of positive reinforcement training techniques in owl and squirrel monkeys: time required to train to reliability.

    PubMed

    Rogge, Jessica; Sherenco, Katrina; Malling, Rachel; Thiele, Erica; Lambeth, Susan; Schapiro, Steve; Williams, Lawrence

    2013-01-01

    Positive reinforcement training (PRT) techniques enhance the psychological well being of nonhuman primates by increasing the animal's control over his or her environment and desensitizing the animal to stressful stimuli. However, the literature on PRT in neotropical primates is limited. Here PRT data from owl monkeys and squirrel monkeys are presented, including the length of time to train subjects to target, present hand, and present foot, important responses that can be used to aid in health inspection and treatment. A high percentage of the squirrel and owl monkeys were successfully trained on target and present hand. Present foot, a less natural response, was harder to train and maintain. Although squirrel monkeys did learn to target significantly faster than owl monkeys, the 2 genera did not differ on time to train on subsequent behavior. These data demonstrate that although owl monkeys may require slightly more time to acclimate to a PRT program, it is still possible to establish a PRT program with neotropical primates, and once animals have been introduced to the program, they can learn new responses in a relatively few short sessions.

  17. U.S. EPA OPTIMAL WELL LOCATOR (OWL): A SCREENING TOOL FOR EVALUATING LOCATIONS OF MONITORING WELLS (ROCKY GAP, MD)

    EPA Science Inventory

    The Optimal Well Locator (OWL): uses linear regression to fit a plane to the elevation of the water table in monitoring wells in each round of sampling. The slope of the plane fit to the water table is used to predict the direction and gradient of ground water flow. Along with ...

  18. Muscular Arrangement and Muscle Attachment Sites in the Cervical Region of the American Barn Owl (Tyto furcata pratincola).

    PubMed

    Boumans, Mark L L M; Krings, Markus; Wagner, Hermann

    2015-01-01

    Owls have the largest head rotation capability amongst vertebrates. Anatomical knowledge of the cervical region is needed to understand the mechanics of these extreme head movements. While data on the morphology of the cervical vertebrae of the barn owl have been provided, this study is aimed to provide an extensive description of the muscle arrangement and the attachment sites of the muscles on the owl's head-neck region. The major cervical muscles were identified by gross dissection of cadavers of the American barn owl (Tyto furcata pratincola), and their origin, courses, and insertion were traced. In the head-neck region nine superficial larger cervical muscles of the craniocervical, dorsal and ventral subsystems were selected for analysis, and the muscle attachment sites were illustrated in digital models of the skull and cervical vertebrae of the same species as well as visualised in a two-dimensional sketch. In addition, fibre orientation and lengths of the muscles and the nature (fleshy or tendinous) of the attachment sites were determined. Myological data from this study were combined with osteological data of the same species. This improved the anatomical description of the cervical region of this species. The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far. Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies.

  19. Tuberculosis-like lesions arising from the use of Freund's complete adjuvant in an owl monkey (Aotus sp)

    SciTech Connect

    Malaga, Carlos A.; Weller, Richard E.; Broderson, J R.; Gozalo, Alfonso S.

    2004-04-01

    An apparently normal, non-tuberculin-reacting, splenectomized owl monkey presented tuberculosis-like lesions of the lung at necropsy. Histological and bacteriological examination failed to demonstrate the presence of acid-fast organisms. Retrospective inquiry showed the animal had been inoculated using complete Freund's Adjuvant during a malaria vaccine trial. Lesions observed were compatible with lipid embolism of the adjuvant in the lungs.

  20. The Scientific Basis for Modeling Northern Spotted Owl Habitat: A Response to Loehle, Irwin, Manly, and Merrill

    EPA Science Inventory

    The U.S. Fish and Wildlife Service recently revised the recovery plan (USFWS 2011) and designated Critical Habitat (USFWS 2012a) for the Northern Spotted Owl (Strix occidentalis caurina). The Critical Habitat designation was based in part on a map of relative habitat suitability...

  1. 77 FR 14061 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Northern Spotted Owl

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-08

    ...The U.S. Fish and Wildlife Service (Service) proposes to revise the designated critical habitat for the northern spotted owl (Strix occidentalis caurina) under the Endangered Species Act of 1973, as amended (Act). Consistent with the best scientific data available, the standards of the Act, our regulations, and agency practice, we have initially identified, for public comment, approximately......

  2. Lineage-specific diversification of killer cell Ig-like receptors in the owl monkey, a New World primate.

    PubMed

    Cadavid, Luis F; Lun, Cheng-Man

    2009-01-01

    Killer cell Ig-like receptors (KIRs) modulate the cytotoxic effects of natural killer cells. In primates, the KIRs are highly diverse as a consequence of variation in gene content, alternative domain composition, and loci polymorphism. We analyzed a bacterial artificial chromosome (BAC) clone draft sequence spanning the owl monkey KIR cluster. The draft sequence had seven ordered yet unconnected contigs containing six full-length and two partial gene models, flanked by the LILRB and FcAR framework genes. Gene models were predicted to encode KIRs with inhibitory, activating, or dual functionality. Four gene models encoded three Ig domain receptors, while three others encoded molecules with four Ig domains. The additional domain resulted from an insertion in tandem of a 2,101 bp fragment containing the last 289 bp of intron 2, exon 3, and intron 3, resulting in molecules with two D0 domains. Re-screening of the owl monkey BAC library and sequencing of partial cDNAs from an owl monkey yielded five additional KIRs, four of which encoded receptors with short cytoplasmic domains with premature stop codons due to either a single nucleotide substitution or deletion or the absence of exon 8. Phylogenetic analysis by domains showed that owl monkey KIRs were monophyletic, clustering independently from other primate KIR lineages. Retroelements found in introns, however, were shared by KIRs from different primate lineages. This suggests that the owl monkey inherited a KIR cluster with a rich history of exon shuffling upon which positive selection for ligand binding operated to diversify the receptors in a lineage-specific fashion.

  3. The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl.

    PubMed

    Baxter, Caitlin S; Nelson, Brian S; Takahashi, Terry T

    2013-02-01

    Echoes and sounds of independent origin often obscure sounds of interest, but echoes can go undetected under natural listening conditions, a perception called the precedence effect. How does the auditory system distinguish between echoes and independent sources? To investigate, we presented two broadband noises to barn owls (Tyto alba) while varying the similarity of the sounds' envelopes. The carriers of the noises were identical except for a 2- or 3-ms delay. Their onsets and offsets were also synchronized. In owls, sound localization is guided by neural activity on a topographic map of auditory space. When there are two sources concomitantly emitting sounds with overlapping amplitude spectra, space map neurons discharge when the stimulus in their receptive field is louder than the one outside it and when the averaged amplitudes of both sounds are rising. A model incorporating these features calculated the strengths of the two sources' representations on the map (B. S. Nelson and T. T. Takahashi; Neuron 67: 643-655, 2010). The target localized by the owls could be predicted from the model's output. The model also explained why the echo is not localized at short delays: when envelopes are similar, peaks in the leading sound mask corresponding peaks in the echo, weakening the echo's space map representation. When the envelopes are dissimilar, there are few or no corresponding peaks, and the owl localizes whichever source is predicted by the model to be less masked. Thus the precedence effect in the owl is a by-product of a mechanism for representing multiple sound sources on its map.

  4. A comparative study of the mechanics of the pectoralis muscle of the red-tailed hawk and the barred owl.

    PubMed

    Peters, Susan E; Dobbins, Charles S

    2012-03-01

    A comparison of the isometric forces and levers of the pectoralis muscle in red-tailed hawks (Buteo jamaicensis) and barred owls (Strix varia) was done to identify differences that may correlate with their different flight styles. The pectoralis consists of two heads, the anterior m. sternobrachialis (SB) and the posterior m. thoracobrachialis (TB). These are joined at an intramuscular tendon and are supplied by separate primary nerve branches. As in other birds, the two heads have distinct fiber orientations in red-tailed hawks and barred owls. SB's fiber orientation (posterolateral and mediolateral from origin to insertion) provides pronation and protraction of the humerus during adduction. Electromyographic studies in pigeons show that it is active in early downstroke and during level flight. TB is more active during take-off and landing in pigeons. The anterolateral orientation (from origin to insertion) of its fibers provides a retractive component to humeral adduction used to control the wing during landing. In our study, the maximum isometric force produced by the combined pectoralis heads did not differ significantly between the hawk and owl, however, the forces were distributed differently between the two muscle heads. In the owl, SB and TB were capable of producing equal amounts of force, but in the hawk, SB produced significantly less force than did TB. This may reflect the need for a large TB to control landing in both birds during prey-strike, with the owl maintaining both protractive (using SB) and retractive (using TB) abilities. Pronation and protraction may be less important in the flight behavior of the hawk, but its prey-strike behavior may require the maintenance of a substantial TB for braking and controlled stalling, as it initiates strike behavior.

  5. Relative Effects of Road Risk, Habitat Suitability, and Connectivity on Wildlife Roadkills: The Case of Tawny Owls (Strix aluco)

    PubMed Central

    Santos, Sara M.; Lourenço, Rui; Mira, António; Beja, Pedro

    2013-01-01

    Background Despite its importance for reducing wildlife-vehicle collisions, there is still incomplete understanding of factors responsible for high road mortality. In particular, few empirical studies examined the idea that spatial variation in roadkills is influenced by a complex interplay between road-related factors, and species-specific habitat quality and landscape connectivity. Methodology/Principal Findings In this study we addressed this issue, using a 7-year dataset of tawny owl (Strix aluco) roadkills recorded along 37 km of road in southern Portugal. We used a multi-species roadkill index as a surrogate of intrinsic road risk, and we used a Maxent distribution model to estimate habitat suitability. Landscape connectivity was estimated from least-cost paths between tawny owl territories, using habitat suitability as a resistance surface. We defined 10 alternative scenarios to compute connectivity, based on variation in potential movement patterns according to territory quality and dispersal distance thresholds. Hierarchical partitioning of a regression model indicated that independent variation in tawny owl roadkills was explained primarily by the roadkill index (70.5%) and, to a much lesser extent, by landscape connectivity (26.2%), while habitat suitability had minor effects (3.3%). Analysis of connectivity scenarios suggested that owl roadkills were primarily related to short range movements (<5 km) between high quality territories. Tawny owl roadkills were spatially autocorrelated, but the introduction of spatial filters in the regression model did not change the type and relative contribution of environmental variables. Conclusions Overall, results suggest that road-related factors may have a dominant influence on roadkill patterns, particularly in areas like ours where habitat quality and landscape connectivity are globally high for the study species. Nevertheless, the study supported the view that functional connectivity should be incorporated

  6. The importance of being spatial (and reserved): assessing northern spotted owl habitat relationships with hierarchical Bayesian models.

    PubMed

    Carroll, Carlos; Johnson, Devin S

    2008-08-01

    Regional conservation planning increasingly draws on habitat suitability models to support decisions regarding land allocation and management. Nevertheless, statistical techniques commonly used for developing such models may give misleading results because they fail to account for 3 factors common in data sets of species distribution: spatial autocorrelation, the large number of sites where the species is absent (zero inflation), and uneven survey effort. We used spatial autoregressive models fit with Bayesian Markov Chain Monte Carlo techniques to assess the relationship between older coniferous forest and the abundance of Northern Spotted Owl nest and activity sites throughout the species' range. The spatial random-effect term incorporated in the autoregressive models successfully accounted for zero inflation and reduced the effect of survey bias on estimates of species-habitat associations. Our results support the hypothesis that the relationship between owl distribution and older forest varies with latitude. A quadratic relationship between owl abundance and older forest was evident in the southern portion of the range, and a pseudothreshold relationship was evident in the northern portion of the range. Our results suggest that proposed changes to the network of owl habitat reserves would reduce the proportion of the population protected by up to one-third, and that proposed guidelines for forest management within reserves underestimate the proportion of older forest associated with maximum owl abundance and inappropriately generalize threshold relationships among subregions. Bayesian spatial models can greatly enhance the utility of habitat analysis for conservation planning because they add the statistical flexibility necessary for analyzing regional survey data while retaining the interpretability of simpler models.

  7. Adult male replacement and subsequent infant care by male and siblings in socially monogamous owl monkeys (Aotus azarai).

    PubMed

    Fernandez-Duque, Eduardo; Juárez, Cecilia Paola; Di Fiore, Anthony

    2008-01-01

    Owl monkeys (Aotus azarai) are small, territorial, socially monogamous primates that show intense infant care by the adult male in the group. It has been hypothesized that male care may be adaptive because it increases offspring survival and/or reduces the metabolic costs to the female of raising the offspring. Alternatively, males may provide care even when they are not related to the infants to increase future reproductive opportunities. We describe changes in infant care patterns that took place after the eviction of the resident male by a solitary male in an owl monkey population in the Argentinean Chaco. The resident male and mother provided all infant care during the first month of life of the infant, until the male was evicted. During the three-day male replacement event, care of the infant was shared among the mother, a four-year-old sister, and a one-year-old brother. The new male began contributing to infant care soon after entering the group, carrying, and interacting socially with the infant in much the same way as any male regularly does. However, despite receiving biparental care from both the original and new resident males, the infant disappeared at the age of four months and was presumed dead. These are the first reports of care by sibling and by non-putative fathers in wild owl monkeys. Given the significant amount of time that new pairs of owl monkeys spend before reproducing, it is possible that male care in owl monkeys functions as mating effort as much as or more than parenting effort.

  8. Social monogamy in wild owl monkeys (Aotus azarae) of Argentina: the potential influences of resource distribution and ranging patterns.

    PubMed

    Fernandez-Duque, Eduardo

    2016-03-01

    Using published and new data from a population of monogamous owl monkeys in the Argentinean Chaco, I examine the hypothesis that social monogamy is a default social system imposed upon males because the spatial and/or temporal distribution of resources and females makes it difficult for a single male to defend access to more than one mate. First, I examine a set of predictions on ranging patterns, use of space, and population density. This first section is followed by a second one considering predictions related to the abundance and distribution of food. Finally, I conclude with a section attempting to link the ranging and ecological data to demographic and life-history parameters as proxies for reproductive success. In support of the hypothesis, owl monkey species do live at densities (7-64 ind/km(2) ) that are predicted for monogamous species, but groups occupy home ranges and core areas that vary substantially in size, with pronounced overlap of home ranges, but not of core areas. There are strong indications that the availability of food sources in the core areas during the dry season may be of substantial importance for regulating social monogamy in owl monkeys. Finally, none of the proxies for the success of groups were strongly related to the size of the home range or core area. The results I present do not support conclusively any single explanation for the evolution of social monogamy in owl monkeys, but they help us to better understand how it may function. Moreover, the absence of conclusive answers linking ranging, ecology, and reproductive success with the evolution of social monogamy in primates, offer renewed motivation for continuing to explore the evolution of monogamy in owl monkeys.

  9. Population dynamics of the California Spotted Owl (Strix occidentalis occidentalis): a meta-analysis

    USGS Publications Warehouse

    Franklin, A.B.; Gutierrez, R.J.; Nichols, J.D.; Seamans, M.E.; White, Gary C.; Zimmerman, G.S.; Hines, J.E.; Munton, T.E.; LaHaye, W.S.; Blakesley, J.A.; Steger, G.N.; Noon, B.R.; Shaw, D.W.H.; Keane, J.J.; McDonald, T.L.; Britting, S.

    2004-01-01

    We conducted a meta-analysis to provide a current assessment of the population characteristics of California Spotted Owls (Strix occidentalis occidentalis) resident on four study areas in the Sierra Nevada and one study area in southern California. Our meta-analysis followed rigorous a priori analysis protocols, which we derived through extensive discussion during a week-long analysis workshop. Because there is great interest in the owl?s population status, we used state-of-the-art analytical methods to obtain results as precise as possible. Our meta-analysis included data from five California study areas located on the Lassen National Forest (1990-2000), Eldorado National Forest (1986-2000), Sierra National Forest (1990-2000), Sequoia and Kings Canyon national parks (1990-2000), and San Bernardino National Forest (1987-1998). Four of the five study areas spanned the length of the Sierra Nevada, whereas the fifth study area encompassed the San Bernardino Mountains in southern California. Study areas ranged in size from 343 km2 (Sequoia and Kings Canyon) to 2,200 km (Lassen). All studies were designed to use capture-recapture methods and analysis. We used survival in a meta-analysis because field methods were very similar among studies. However, we did not use reproduction in a meta-analysis because it was not clear if variation among individual study-area protocols used to assess reproductive output of owls would confound results. Thus, we analyzed fecundity only by individual study area. We examined population trend using the reparameterized Jolly-Seber capture-recapture estimator (8t) We did not estimate juvenile survival rates because of estimation problems and potential bias because of juvenile emigration from study areas. We used mark-recapture estimators under an information theoretic framework to assess apparent survival rates of adult owls. The pooled estimate for adult apparent survival for the five study areas was 0.833, which was lower than pooled adult

  10. Depth of artificial Burrowing Owl burrows affects thermal suitability and occupancy

    USGS Publications Warehouse

    Nadeau, Christopher P.; Conway, Courtney J.; Rathbun, Nathan

    2015-01-01

    Many organizations have installed artificial burrows to help bolster local Burrowing Owl (Athene cunicularia) populations. However, occupancy probability and reproductive success in artificial burrows varies within and among burrow installations. We evaluated the possibility that depth below ground might explain differences in occupancy probability and reproductive success by affecting the temperature of artificial burrows. We measured burrow temperatures from March to July 2010 in 27 artificial burrows in southern California that were buried 15–76 cm below the surface (measured between the surface and the top of the burrow chamber). Burrow depth was one of several characteristics that affected burrow temperature. Burrow temperature decreased by 0.03°C per cm of soil on top of the burrow. The percentage of time that artificial burrows provided a thermal refuge from above-ground temperature decreased with burrow depth and ranged between 50% and 58% among burrows. The percentage of time that burrow temperature was optimal for incubating females also decreased with burrow depth and ranged between 27% and 100% among burrows. However, the percentage of time that burrow temperature was optimal for unattended eggs increased with burrow depth and ranged between 11% and 95% among burrows. We found no effect of burrow depth on reproductive success across 21 nesting attempts. However, occupancy probability had a non-linear relationship with burrow depth. The shallowest burrows (15 cm) had a moderate probability of being occupied (0.46), burrows between 28 and 40 cm had the highest probability of being occupied (>0.80), and burrows >53 cm had the lowest probability of being occupied (<0.43). Burrowing Owls may prefer burrows at moderate depths because these burrows provide a thermal refuge from above-ground temperatures, and are often cool enough to allow females to leave eggs unattended before the onset of full-time incubation, but not too cool for incubating females that

  11. Pulsed resources affect the timing of first breeding and lifetime reproductive success of tawny owls.

    PubMed

    Millon, A; Petty, S J; Lambin, X

    2010-03-01

    1. According to life-history theory, environmental variability and costs of reproduction account for the prevalence of delayed reproduction in many taxa. Empirical estimates of the fitness consequences of different ages at first breeding in a variable environment are few however such that the contributions of environmental and individual variability remains poorly known. 2. Our objectives were to elucidate processes that underpin variation in delayed reproduction and to assess lifetime consequences of the age of first breeding in a site-faithful predator, the tawny owl Strix aluco L. subjected to fluctuating selection linked to cyclical variation in vole density (typically 3-year cycles with low, increasing and decreasing vole densities in successive years). 3. A multistate capture-recapture model revealed that owl cohorts had strikingly different juvenile survival prospects, with estimates ranging from 0.08 to 0.33 respectively for birds born in Decrease and Increase phases of the vole cycle. This resulted in a highly skewed population structure with >75% of local recruits being reared during Increase years. In contrast, adult survival remained constant throughout a vole cycle. The probability of commencing reproduction was lower at age 1 than at older ages, and especially so for females. From age 2 onwards, pre-breeders had high probabilities of entering the breeding population. 4. Variation in lifetime reproductive success was driven by the phase of the vole cycle in which female owls started their breeding career (26-47% of variance explained, whether based on the number of local recruits or fledglings), more than by age at first breeding or by conditions experienced at birth. Females who postponed reproduction to breed for the first time at age 3 during an Increase phase, produced more recruits, even when accounting for birds that may have died before reproduction. No such effects were detected for males. 5. Sex-specific costs of early reproduction may have

  12. Status and trends in demography of northern spotted owls, 1985-2003

    USGS Publications Warehouse

    Anthony, R.G.; Forsman, E.D.; Franklin, A.B.; Anderson, D.R.; Burnham, K.P.; White, Gary C.; Schwarz, C.J.; Nichols, J.D.; Hines, J.E.; Olson, G.S.; Ackers, S.H.; Andrews, L.S.; Biswell, B.L.; Carlson, P.C.; Diller, L.V.; Dugger, K.M.; Fehring, K.E.; Fleming, T.L.; Gerhardt, R.P.; Gremel, S.A.; Gutierrez, R.J.; Happe, P.J.; Herter, D.R.; Higley, J.M.; Horn, R.B.; Irwin, L.L.; Loschl, P.J.; Reid, J.A.; Sovern, S.G.; Krausman, P.R.

    2006-01-01

    We analyzed demographic data from northern spotted owls (Strix occidentalis caurina) from 14 study areas in Washington, Oregon, and California for 1985-2003. The purpose of our analyses was to provide an assessment of the status and trends of northern spotted owl populations throughout most of their geographic range. The 14 study areas made up approximately 12% of the range of the subspecies and included federal, tribal, private, and mixed federal and private lands. The study areas also included all the major forest types that the subspecies inhabits. The analyses followed rigorous protocols that were developed a priori and were the result of extensive discussions and consensus among the authors. Our primary objectives were to estimate fecundity, apparent survival (??), and annual rate of population change (??) and to determine if there were any temporal trends in these population parameters. In addition to analyses of data from individual study areas, we conducted 2 meta-analyses on each demographic parameter. One meta-analysis was conducted on all 14 areas, and the other was restricted to the 8 areas that constituted the Effectiveness Monitoring Plan for northern spotted owls under the Northwest Forest Plan. The average number of years of reproductive data per study area was 14 (range = 5-19), and the average number of recapture occasions per study area was 13 (range = 4-18). Only 1 study area had 1 year old. We found no differences in apparent survival rates between sexes except for 1 area (Marin), which had only 6 years of data. Estimates of apparent survival from individual study areas indicated that there were differences among age classes with adults generally having higher survival than 1- and 2-year-olds. Apparent survival rates ranged from 0.750 (SE=0.026) to 0.886 (SE=0.010) for adults, 0.626 (SE=0.073) to 0.886 (SE=0.010) for 2-year-olds, and 0.415 (SE=0.111) to 0.860 (SE=0.017) for 1-year-olds. These estimates were comparable to survival rates from

  13. An Identification Key to Rodent Prey in Owl Pellets from the Northwestern and Southeastern United States: Employing Incisor Size to Distinguish among Genera

    ERIC Educational Resources Information Center

    Hager, Stephen B.; Cosentino, Bradley J.

    2006-01-01

    We present an identification key to the common rodent prey found in owl pellets from the Northwestern (NW) and Southeastern (SE) United States that is based on differences in incisor size (arc diameter) among genera.

  14. The impact of climate and cyclic food abundance on the timing of breeding and brood size in four boreal owl species.

    PubMed

    Lehikoinen, Aleksi; Ranta, Esa; Pietiäinen, Hannu; Byholm, Patrik; Saurola, Pertti; Valkama, Jari; Huitu, Otso; Henttonen, Heikki; Korpimäki, Erkki

    2011-02-01

    The ongoing climate change has improved our understanding of how climate affects the reproduction of animals. However, the interaction between food availability and climate on breeding has rarely been examined. While it has been shown that breeding of boreal birds of prey is first and foremost determined by prey abundance, little information exists on how climatic conditions influence this relationship. We studied the joint effects of main prey abundance and ambient weather on timing of breeding and reproductive success of two smaller (pygmy owl Glaucidium passerinum and Tengmalm's owl Aegolius funereus) and two larger (tawny owl Strix aluco and Ural owl Strix uralensis) avian predator species using long-term nation-wide datasets during 1973-2004. We found no temporal trend either in vole abundance or in hatching date and brood size of any studied owl species. In the larger species, increasing late winter or early spring temperature advanced breeding at least as much as did high autumn abundance of prey (voles). Furthermore, increasing snow depth delayed breeding of the largest species (Ural owl), presumably by reducing the availability of voles. Brood size was strongly determined by spring vole abundance in all four owl species. These results show that climate directly affects the breeding performance of vole-eating boreal avian predators much more than previously thought. According to earlier studies, small-sized species should advance their breeding more than larger species in response to increasing temperature. However, we found an opposite pattern, with larger species being more sensitive to temperature. We argue that this pattern is caused by a difference in the breeding tactics of larger mostly capital breeding and smaller mostly income breeding owl species.

  15. DataStaR: Bridging XML and OWL in Science Metadata Management

    NASA Astrophysics Data System (ADS)

    Lowe, Brian

    DataStaR is a science data “staging repository” developed by Albert R. Mann Library at Cornell University that produces semantic metadata while enabling the publication of data sets and accompanying metadata to discipline-specific data centers or to Cornell’s institutional repository. DataStaR, which employs OWL and RDF in its metadata store, serves as a Web-based platform for production and management of metadata and aims to reduce redundant manual input by reusing named ontology individuals. A key requirement of DataStaR is the ability to produce metadata records conforming to existing XML schemas that have been adopted by scientific communities. To facilitate this, DataStaR integrates ontologies that directly reflect XML schemas, generates HTML editing forms, and “lowers” ontology axioms into XML documents compliant with existing schemas. This paper describes our approach and implementation, and discusses the challenges involved.

  16. Effects of climatic variation on survival rates in northern spotted owls

    SciTech Connect

    Franklin, A.B.; Anderson, D.R.; Gutierrez, R.J. |

    1995-09-01

    We examined the effect of climate on the annual survival of marked northern spotted owls in northwest California between 1985 through 1994. We tested a priori predictions concerning the effects of precipitation and temperature during critical environmental and life history periods using mark-recapture models where logit(survival) was modeled as a function of the climatic covariates. Additional factors considered in models included sex, age and random time effects. We used Akaike`s Information Criterion to select parsimonious models in lieu of time effects. We used Akaike`s Information Criterion to select parsimonious models in lieu of a strict hypothesis-testing framework. Models incorporating climatic covariates, such as precipitation during the winter and nesting periods, explained variation in survival rates significantly better than models with time effects. These results have important implications for the life history of this species as well as it`s conservation as a threatened species.

  17. Avian wing geometry and kinematics of a free-flying barn owl in flapping flight

    NASA Astrophysics Data System (ADS)

    Wolf, Thomas; Konrath, Robert

    2015-02-01

    This paper presents results of high-resolution three-dimensional wing shape measurements performed on free-flying barn owls in flapping flight. The applied measurement technique is introduced together with a moving camera set-up, allowing for an investigation of the free flapping flight of birds with high spatial and temporal resolution. Based on the three-dimensional surface data, a methodology for parameterizing the wing profile along with wing kinematics during flapping flight has been developed. This allowed a description of the spanwise varying kinematics and aerodynamic parameters (e.g. effective angles of attack, camber, thickness) of the wing in dependence on the flapping phase. The results are discussed in detail using the data of a single flight, whereas a comparison of some kinematic parameters obtained from different flights is given too.

  18. Mineral resources of the Owl Creek Wilderness Study Area, Hot Springs County, Wyoming

    SciTech Connect

    Bove, D.J.; Carlson, R.R.; Kulik, D.M.; Lundby, W.

    1989-01-01

    At the request of the US Bureau of Land Management, 710 acres of the Owl Creek Wilderness Study Area were studied for mineral endowment. Field and laboratory studies were conducted by the US Geological Survey and the US Bureau of Mines. A search of US Bureau of Land Management, State, and County records showed no current or previous mining claim activity and, other than common-variety sand and gravel, no mineral resources were identified during field examination of this study area. Sand and gravel is classified as an inferred subeconomic resource; however, the remoteness of this area precludes much usage of this material. About two-thirds of this study area is under lease for oil and gas. This entire study area has a moderate resource potential for undiscovered oil and gas and a low resource potential for undiscovered metals, coal, zeolites, and geothermal energy.

  19. The complete mitochondrial genome of Brown wood owl Strix leptogrammica (Strigiformes: Strigidae).

    PubMed

    Liu, Gang; Zhou, Lizhi; Gu, Changming

    2014-10-01

    The mitochondrial genome of Brown wood owl is a 16,308-bp circular molecule, which contains 37 typical mitochondrial genes (13 protein-coding genes, 2 rRNAs and 22 tRNAs) and a 741-bp A+T-rich region. Its gene arrangement pattern is identical with typical bird species. All protein-coding genes start with an ATG codon. TAA is the most frequent stop codon, and TAG and T- are also occurred very common. The mtDNA sequence contains 12S rRNA and 16S rRNA of rRNA. Except for tRNA(Ser) ((AGY)) and tRNA(Leu) ((CUN)) without the dihydrouridine (DHU) arm, all tRNAs could be folded into canonical cloverleaf secondary structures.

  20. Mineral resources of the Owl Creek Wilderness Study Area, Hot Springs County, Wyoming

    SciTech Connect

    Bove, D.J.; Carlson, R.R.; Kulik, D.M.; Lundby, W.

    1989-01-01

    At the request of the U.S. Bureau of Land Management, 710 acres of the Owl Creek Wilderness Study Area were studied for mineral endowment. Field and labortory studies were conducted by the U.S. Geological Survey and the U.S. Bureau of Mines. A search of U.S. Bureau of Land Management, State, and county records showed no current or previous mining claim activity and, other than common-variety sand and gravel, no mineral resources were identified during field examination of the study area. Sand and gravel is classified as an inferred subeconomic resource; however, the remoteness of the area precludes much usage of the material. About two-thirds of the study area is under lease for oil and gas. The entire study area has moderate resource potential for undiscovered oil and gas and low resource potential for undiscovered metals, coal, zeolites, and geothermal energy.

  1. Miniature stereo radio transmitter for simultaneous recording of multiple single-neuron signals from behaving owls.

    PubMed

    Nieder, A

    2000-09-15

    Wireless radiotelemetric transmission of neuronal activity is an elegant technique to study brain-behavior interaction in unrestrained animals. In the current study, a miniature FM-stereo radio transmitter is described that permitted simultaneous recordings from two microelectrodes in behaving barn owls. Input from two independent channels is multiplexed to form a stereo composite signal that modulates a radio frequency carrier. The high quality of broadcasted extracellular signals enabled separation of single units based on differences in spike waveforms. Recording several single cells from different electrodes allows the possibility of investigating correlations between small, distributed neuronal ensembles. Multi-channel radiotelemetry that meets the demands of modern electrophysiology might open a new perspective for combined behavioral/neurophysiological approaches in freely-behaving animals.

  2. A female melanin ornament signals offspring fluctuating asymmetry in the barn owl.

    PubMed

    Roulin, Alexandre; Ducrest, Anne-Lyse; Balloux, François; Dijkstra, Cor; Riols, Christian

    2003-01-22

    Sexual selection theory predicts that males advertise quality by displaying extravagant ornaments. By contrast, whether phenotypic variation in females has a signalling function remains an open question. Here, to our knowledge, we provide the first evidence that a female plumage trait can signal fluctuating asymmetry in the offspring. We experimentally demonstrate in wild barn owls (Tyto alba) that the extent to which females display black spots on their plumage does not only signal offspring parasite resistance as shown in a previous study but also developmental homeostasis in the offspring. A greater number of spotted females produced offspring that had more symmetrical feathers during the period of growth. Males, that pair non-randomly with respect to female plumage spottiness therefore appear to gain substantial benefits by mating with heavily spotted females. Genetic variation in plumage spottiness is nevertheless maintained as the covariation between offspring body mass and mother plumage spottiness varies annually depending on environmental conditions.

  3. Transmission of hepatitis A virus among recently captured Panamanian owl monkeys.

    PubMed

    Lemon, S M; LeDuc, J W; Binn, L N; Escajadillo, A; Ishak, K G

    1982-01-01

    The presence of antibody to hepatitis A virus (anti-HAV) in 60% of procured owl monkeys (Aotus trivirgatus) held within the United States prompted a study of recently captured A trivirgatus in Panama. Only 2 of 145 newly captured monkeys, but all of 35 A trivirgatus held within a colony for over 100 days, were found to have anti-HAV. Of 41 sero-negative, newly captured monkeys followed prospectively, 25 became infected with hepatitis A virus (HAV) as evidenced by seroconversion or demonstration of virus in the liver at death. Only one monkey that survived over 60 days within the colony was not infected. HAV was identified in the feces of most infected monkeys prior to the development of antibody and was antigenically indistinguishable from human HAV in cross-blocking radioimmunoassays. This colony-centered epizootic provides strong evidence that A trivirgatus is susceptible to HAV and should be investigated further as a potential model of human hepatitis A.

  4. Breeding success of barn owls (Tyto alba) fed low levels of DDE and dieldrin

    USGS Publications Warehouse

    Mendenhall, V.M.; Klaas, E.E.; McLane, M.A.R.

    1983-01-01

    The relative importance of two organochlorine pesticides in the recent reproductive failure of raptors was investigated. Captive barn owls were fed 3.0 ppm DDE and 0.5 ppm dieldrin; doses were given separately and in combination for two years. Breeding success was followed from the laying of eggs through natural incubation and rearing of young. DDE was associated with significant eggshell thinning, egg breakage, embryo mortality, and reduced production per pair. Dieldrin alone was associated with slight but significant eggshell thinning, but not with reduction of breeding success. Ecological implications of the results are discussed; it is suggested that DDE had a much more severe effect on reproduction in wild raptors than dieldrin, which contributed to their decline primarily through adult mortality.

  5. Use of Artificial Burrows by Burrowing Owls (Athene cunicularia) at the HAMMER Facility on the U.S. Department of Energy Hanford Site

    SciTech Connect

    Alexander, Amanda K.; Sackschewsky, Michael R.; Duberstein, Corey A.

    2005-09-30

    In 2003 the U.S. Department of Energy (DOE) constructed an Emergency Vehicle Operations Course (EVOC) at the Hazardous Material Management and Emergency Response Training and Education Center (HAMMER) in the southern portion of the Hanford Site. Preliminary surveys during 2001 identified an active burrowing owl (Athene cunicularia) burrow and three burrowing owls within the proposed development area. Burrowing owls were classified as a federal species of concern, a Washington State ?candidate? species, a Washington Department of Fish and Wildlife priority species, and a Hanford Site Biological Resources Management Plan Level III resource. Therefore, the mitigation action plan for the project included the installation of twenty artificial burrows around EVOC in the spring of 2003. The mitigation plan established a success criterion of five percent annual use of the burrows by owls. In July 2005, a field survey of the EVOC burrow complex was conducted to determine use and demography at each site. Burrow locations were mapped and signs of activity (feces, owl tracks, castings, feathers) were recorded. Out of the twenty burrows, twelve were found to be active. Of the eight inactive burrows three appeared to have been active earlier in the 2005 breeding season. A total of nineteen owls were counted but demography could not be determined. It appears that the EVOC mitigation exceeded burrow use goals during 2005. Continued site monitoring and maintenance, according to mitigation plan guidelines should be conducted as prescribed.

  6. Food partitioning between breeding White-tailed Kites (Elanus leucurus; Aves; Accipitridae) and Barn Owls (Tyto alba; Aves; Tytonidae) in southern Brazil.

    PubMed

    Scheibler, D R

    2007-02-01

    I examined the diet of breeding White-tailed Kites (Elanus leucurus; Aves; Accipitridae) and Barn Owls (Tyto alba; Aves; Tytonidae) in an agrarian area of southern Brazil by analyzing regurgitated prey remains. The objective was to evaluate how these raptors, which differ markedly in their hunting activity periods (owls are nocturnal and kites diurnal), share their mammalian food component. 2,087 prey consumed by Barn Owls and 1,276 by White-tailed Kites were identified. They presented a high overlap of food-niches (Piankas index was 0.98). Based on the daily activity period of their main small mammal prey, a lower overlap would be expected. The crepuscular/nocturnal Mus musculus was the main prey for the diet of breeding Barn Owls (81%) and White-tailed Kites (63%). This small exotic rodent provided 63% of the small mammal biomass ingested by owls and 44% by kites. Larger native small mammals were also considered important for the diet of kites, mainly because of their biomass contribution. Although these raptors differ markedly in their hunting activity periods, Barn Owls and White-tailed Kites are very similar predators in southern Brazil, overlapping their diets.

  7. Molecular cloning of pituitary glycoprotein alpha-subunit and follicle stimulating hormone and chorionic gonadotropin beta-subunits from New World squirrel monkey and owl monkey.

    PubMed

    Scammell, Jonathan G; Funkhouser, Jane D; Moyer, Felricia S; Gibson, Susan V; Willis, Donna L

    2008-02-01

    The goal of this study was to characterize the gonadotropins expressed in pituitary glands of the New World squirrel monkey (Saimiri sp.) and owl monkey (Aotus sp.). The various subunits were amplified from total RNA from squirrel monkey and owl monkey pituitary glands by reverse transcription-polymerase chain reaction and the deduced amino acid sequences compared to those of other species. Mature squirrel monkey and owl monkey glycoprotein hormone alpha-polypeptides (96 amino acids in length) were determined to be 80% homologous to the human sequence. The sequences of mature beta subunits of follicle stimulating hormone (FSHbeta) from squirrel monkey and owl monkey (111 amino acids in length) are 92% homologous to human FSHbeta. New World primate glycoprotein hormone alpha-polypeptides and FSHbeta subunits showed conservation of all cysteine residues and consensus N-linked glycosylation sites. Attempts to amplify the beta-subunit of luteinizing hormone from squirrel monkey and owl monkey pituitary glands were unsuccessful. Rather, the beta-subunit of chorionic gonadotropin (CG) was amplified from pituitaries of both New World primates. Squirrel monkey and owl monkey CGbeta are 143 and 144 amino acids in length and 77% homologous with human CGbeta. The greatest divergence is in the C terminus, where all four sites for O-linked glycosylation in human CGbeta, responsible for delayed metabolic clearance, are predicted to be absent in New World primate CGbetas. It is likely that CG secreted from pituitary of New World primates exhibits a relatively short half-life compared to human CG.

  8. The sensitive period for auditory localization in barn owls is limited by age, not by experience.

    PubMed

    Knudsen, E I; Knudsen, P F

    1986-07-01

    Early in life, the barn owl passes through a sensitive period during which it can interpret and make use of abnormal auditory cues for accurate sound localization. This capacity is lost at about 8 weeks of age, just after the head and ears reach adult size (knudsen et al. 1984a). The end of the sensitive period could be triggered either by an age-dependent process or by the exposure of the auditory system to stable or adult-like cues. To distinguish between these alternatives, we subjected baby owls to constant abnormal cues (chronic monaural occlusion) or to frequently changing abnormal cues (alternating monaural occlusion) throughout the sensitive period. In the first group of animals (n = 2), one ear was plugged continuously until 73 or 79 d of age, respectively, and then the earplug was switched to the opposite ear. Although these animals adjusted sound localization accuracy during the initial chronic monaural occlusion, they could not localize sounds at all after the earplug was switched to the opposite ear, and they remained unable to localize sounds as long as the opposite ear remained occluded (7 and 27 weeks, respectively). When the second monaural occlusion was finally removed, both birds localized sounds with errors that were similar to the errors they exhibited immediately after removal of the first monaural occlusion. One bird that was 127-d-old at the time the second earplug was removed corrected its localization error; the other bird, 250-d-old when the second earplug was removed, did not.(ABSTRACT TRUNCATED AT 250 WORDS)

  9. Hematologic and plasma biochemistry reference intervals of healthy adult barn owls (Tyto alba).

    PubMed

    Szabo, Zoltan; Klein, Akos; Jakab, Csaba

    2014-06-01

    Hematologic and plasma biochemistry parameters of barn owls (Tyto alba) were studied in collaboration by the Exotic Division of the Faculty of Veterinary Science of the Szent Istvan University and the Eötvös Loránd University, both in Budapest, Hungary. Blood samples were taken from a total of 42 adult barn owls kept in zoos and bird repatriation stations. The following quantitative and qualitative hematologic values were determined: packed cell volume, 46.2 +/- 4%; hemoglobin concentration, 107 +/- 15 g/L; red blood cell count, 3.2 +/- 0.4 x 10(12)/L; white blood cell count, 13.7 +/- 2.7 x 10(9)/L; heterophils, 56.5 +/- 11.5% (7.8 +/- 2 x 10(9)/L); lymphocytes, 40.3 +/- 10.9% (5.5 +/- 1.9 x 10(9)/L); monocytes, 1.8 +/- 2.1% (0.3 +/- 0.3 x 10(9)/ L); eosinophils, 1 +/- 1% (0.1 +/- 0.1 x 10(9)/L); and basophils, 0.6 +/- 0.5% (0.1 +/- 0.1 x 10(9)/L). The following plasma biochemistry values also were determined: aspartate aminotransferase, 272 +/- 43 U/L; L-gamma-glutamyltransferase, 9.5 +/- 4.7 U/L; lipase, 31.7 +/- 11.1 U/L; creatine kinase, 2228 +/- 578 U/L; lactate dehydrogenase, 1702 +/- 475 U/L; alkaline phosphatase, 358 +/- 197 U/L; amylase, 563 +/- 114 U/L; glutamate dehydrogenase, 7.5 +/- 2.5 U/L; total protein, 30.6 +/- 5.3 g/L; uric acid, 428 +/- 102 micromol/L; and bile acids, 43 +/- 18 micromol/L. These results provide reliable reference values for the clinical interpretation of hematologic and plasma biochemistry results for the species.

  10. In vivo Recordings from Low-Frequency Nucleus Laminaris in the Barn Owl.

    PubMed

    Palanca-Castan, Nicolas; Köppl, Christine

    2015-01-01

    Localization of sound sources relies on 2 main binaural cues: interaural time differences (ITD) and interaural level differences. ITD computing is first carried out in tonotopically organized areas of the brainstem nucleus laminaris (NL) in birds and the medial superior olive (MSO) in mammals. The specific way in which ITD are derived was long assumed to conform to a delay line model in which arrays of systematically arranged cells create a representation of auditory space, with different cells responding maximally to specific ITD. This model conforms in many details to the particular case of the high-frequency regions (above 3 kHz) in the barn owl NL. However, data from recent studies in mammals are not consistent with a delay line model. A new model has been suggested in which neurons are not topographically arranged with respect to ITD and coding occurs through assessment of the overall response of 2 large neuron populations – 1 in each brainstem hemisphere. Currently available data comprise mainly low-frequency (<1,500 Hz) recordings in the case of mammals and higher-frequency recordings in the case of birds. This makes it impossible to distinguish between group-related adaptations and frequency-related adaptations. Here we report the first comprehensive data set from low-frequency NL in the barn owl and compare it to data from other avian and mammalian studies. Our data are consistent with a delay line model, so differences between ITD processing systems are more likely to have originated through divergent evolution of different vertebrate groups.

  11. Architectonic subdivisions of the motor thalamus of owl monkeys: Nissl, acetylcholinesterase, and cytochrome oxidase patterns.

    PubMed

    Stepniewska, I; Preuss, T M; Kaas, J H

    1994-11-22

    As the first part of an investigation of the motor thalamus and its cortical connections in the owl monkey, a New World anthropoid primate, we studied thalamic architecture by using stains for Nissl, acetylcholinesterase (AChE), and cytochrome oxidase (CO), in order to identify subdivisions of the ventrolateral thalamic region as well as other nuclei with motor connections. Material was obtained from brains cut in the frontal, horizontal, and parasagittal planes. Our results indicate that the ventrolateral thalamic region (VL) of owl monkeys is a heterogeneous structure composed of several architectonic subdivisions that resemble divisions that have been described in macaques and other Old World anthropoids. All of these subdivisions are more readily distinguished in AChE than in Nissl or CO preparations. The anterior part of VL, VLa (VLo of Olszewski), is characterized by clusters of medium-sized, darkly stained neurons. VLa is also distinguished by AChE-positive cells embedded in a matrix of neurites as well as by a characteristic dark, irregular net of blood vessels. The posterior part of VL is rather uniform cytoarchitectonically and contains large, darkly stained, and sparsely distributed neurons. However, we were able to distinguish three subdivisions of posterior VL that closely correspond to structures described by Olszewski in macaques: a principal segment, VLp (VPLo of Olszewski), a medial segment, VLx ("area X" of Olszewski), and a dorsal segment, VLd (VLc and VLps of Olszewski). In AChE, VLd is much darker than the other divisions. The distinction between VLp and VLx, which together make up the largest part of VL, is less marked, although VLp is somewhat darker and more irregular in appearance in AChE than is VLx.

  12. The On-line Waste Library (OWL): Usage and Inventory Status Report

    SciTech Connect

    Sassani, David; Jang, Je-Hun; Mariner, Paul; Price, Laura L.; Rechard, Robert P.; Rigali, Mark J.; Rogers, Ralph; Stein, Emily; Walkow, Walter M.; Weck, Philippe F.

    2016-09-23

    The Waste Form Disposal Options Evaluation Report (SNL 2014) evaluated disposal of both Commercial Spent Nuclear Fuel (CSNF) and DOE-managed HLW and Spent Nuclear Fuel (DHLW and DSNF) in the variety of disposal concepts being evaluated within the Used Fuel Disposition Campaign. That work covered a comprehensive inventory and a wide range of disposal concepts. The primary goal of this work is to evaluate the information needs for analyzing disposal solely of a subset of those wastes in a Defense Repository (DRep; i.e., those wastes that are either defense related, or managed by DOE but are not commercial in origin). A potential DRep also appears to be safe in the range of geologic mined repository concepts but may have different concepts and features because of the very different inventory of waste that would be included. The focus of this status report is to cover the progress made in FY16 toward: (1) developing a preliminary DRep included inventory for engineering/design analyses; (2) assessing the major differences of this included inventory relative to that in other analyzed repository systems and the potential impacts to disposal concepts; (3) designing and developing an on-line waste library (OWL) to manage the information of all those wastes and their waste forms (including CSNF if needed); and (4) constraining post-closure waste form degradation performance for safety assessments of a DRep. In addition, some continuing work is reported on identifying potential candidate waste types/forms to be added to the full list from SNL (2014 – see Table C-1) which also may be added to the OWL in the future. The status for each of these aspects is reported herein.

  13. Adaptation in the auditory midbrain of the barn owl (Tyto alba) induced by tonal double stimulation.

    PubMed

    Singheiser, Martin; Ferger, Roland; von Campenhausen, Mark; Wagner, Hermann

    2012-02-01

    During hunting, the barn owl typically listens to several successive sounds as generated, for example, by rustling mice. As auditory cells exhibit adaptive coding, the earlier stimuli may influence the detection of the later stimuli. This situation was mimicked with two double-stimulus paradigms, and adaptation was investigated in neurons of the barn owl's central nucleus of the inferior colliculus. Each double-stimulus paradigm consisted of a first or reference stimulus and a second stimulus (probe). In one paradigm (second level tuning), the probe level was varied, whereas in the other paradigm (inter-stimulus interval tuning), the stimulus interval between the first and second stimulus was changed systematically. Neurons were stimulated with monaural pure tones at the best frequency, while the response was recorded extracellularly. The responses to the probe were significantly reduced when the reference stimulus and probe had the same level and the inter-stimulus interval was short. This indicated response adaptation, which could be compensated for by an increase of the probe level of 5-7 dB over the reference level, if the latter was in the lower half of the dynamic range of a neuron's rate-level function. Recovery from adaptation could be best fitted with a double exponential showing a fast (1.25 ms) and a slow (800 ms) component. These results suggest that neurons in the auditory system show dynamic coding properties to tonal double stimulation that might be relevant for faithful upstream signal propagation. Furthermore, the overall stimulus level of the masker also seems to affect the recovery capabilities of auditory neurons.

  14. The representation of sound localization cues in the barn owl's inferior colliculus

    PubMed Central

    Singheiser, Martin; Gutfreund, Yoram; Wagner, Hermann

    2012-01-01

    The barn owl is a well-known model system for studying auditory processing and sound localization. This article reviews the morphological and functional organization, as well as the role of the underlying microcircuits, of the barn owl's inferior colliculus (IC). We focus on the processing of frequency and interaural time (ITD) and level differences (ILD). We first summarize the morphology of the sub-nuclei belonging to the IC and their differentiation by antero- and retrograde labeling and by staining with various antibodies. We then focus on the response properties of neurons in the three major sub-nuclei of IC [core of the central nucleus of the IC (ICCc), lateral shell of the central nucleus of the IC (ICCls), and the external nucleus of the IC (ICX)]. ICCc projects to ICCls, which in turn sends its information to ICX. The responses of neurons in ICCc are sensitive to changes in ITD but not to changes in ILD. The distribution of ITD sensitivity with frequency in ICCc can only partly be explained by optimal coding. We continue with the tuning properties of ICCls neurons, the first station in the midbrain where the ITD and ILD pathways merge after they have split at the level of the cochlear nucleus. The ICCc and ICCls share similar ITD and frequency tuning. By contrast, ICCls shows sigmoidal ILD tuning which is absent in ICCc. Both ICCc and ICCls project to the forebrain, and ICCls also projects to ICX, where space-specific neurons are found. Space-specific neurons exhibit side peak suppression in ITD tuning, bell-shaped ILD tuning, and are broadly tuned to frequency. These neurons respond only to restricted positions of auditory space and form a map of two-dimensional auditory space. Finally, we briefly review major IC features, including multiplication-like computations, correlates of echo suppression, plasticity, and adaptation. PMID:22798945

  15. The effects of rain on acoustic communication: tawny owls have good reason for calling less in wet weather.

    PubMed Central

    Lengagne, Thierry; Slater, Peter J B

    2002-01-01

    Numerous attempts have been made to quantify ecological factors that affect the calling range of animal signals. The various processes leading signals to become distorted and embedded in background noise have been described in many habitats (ranging from forest to savannah) and the propagation path in these biomes has thereby been characterized. However, the impact of climatic factors on acoustic communication has been little studied. Surprisingly, to our knowledge, the importance of rain, a regular phenomenon occurring in all habitats except deserts, has never been investigated. Here, we describe a 69-fold advantage in area reached by the call of a territorial bird, the tawny owl (Strix aluco) in dry versus rainy conditions. In support of this, we found a marked reduction in the calling of tawny owls in rainy conditions. Constraints imposed by a rainy propagation path are likely to modify the reliability of acoustic information and thus calling behaviour of many animals. PMID:12396486

  16. Long-term data set of small mammals from owl pellets in the Atlantic-Mediterranean transition area.

    PubMed

    Escribano, Nora; Galicia, David; Ariño, Arturo H; Escala, Carmen

    2016-09-27

    We describe the pellet sampling data set from the Vertebrate Collection of the Museum of Zoology of the University of Navarra. This data set compiles all information about small mammals obtained from the analysis of owl pellets. The collection consists on skulls, mandibles, and some skeletons of 36 species of more than 72,000 georeferenced specimens. These specimens come from the Iberian Peninsula although most samples were collected in Navarra, a highly diverse transitional area of 10,000 kilometre square sitting across three biogeographical regions. The collection spans more than forty years and is still growing as a result of the establishment of a barn owl pellet monitoring network in 2015. The program will provide critical information about the evolution of the small mammals' community in this transition zone as it changes over time.

  17. Orbit Determination with Angle-only Data from the First Korean Optical Satellite Tracking System, OWL-Net

    NASA Astrophysics Data System (ADS)

    Choi, J.; Jo, J.

    2016-09-01

    The optical satellite tracking data obtained by the first Korean optical satellite tracking system, Optical Wide-field patrol - Network (OWL-Net), had been examined for precision orbit determination. During the test observation at Israel site, we have successfully observed a satellite with Laser Retro Reflector (LRR) to calibrate the angle-only metric data. The OWL observation system is using a chopper equipment to get dense observation data in one-shot over 100 points for the low Earth orbit objects. After several corrections, orbit determination process was done with validated metric data. The TLE with the same epoch of the end of the first arc was used for the initial orbital parameter. Orbit Determination Tool Kit (ODTK) was used for an analysis of a performance of orbit estimation using the angle-only measurements. We have been developing batch style orbit estimator.

  18. "Owl" Technique for All-Arthroscopic Augmentation of a Massive or Large Rotator Cuff Tear With Extracellular Matrix Graft.

    PubMed

    Narvani, A Ali; Consigliere, Paolo; Polyzois, Ioannis; Sarkhel, Tanaya; Gupta, Rohit; Levy, Ofer

    2016-08-01

    Despite the vast improvement in techniques and technology for arthroscopic rotator cuff surgery, repairs of massive and large tears remain challenging because they are associated with significantly high failure rates. In recent years, patch augmentation has gained popularity as a technique to decrease these high failure rates. Arthroscopic patch augmentation of rotator cuff repair, however, is technically difficult. The purpose of this report is to describe a simple and reproducible technique for all-arthroscopic extracellular matrix graft augmentation. With this technique, which we refer to as the "owl" technique because the prepared extracellular augment resembles an owl, there are relatively few suture ends involved; therefore, augment introduction is straightforward with a reduced risk of suture ends becoming tangled. In addition, the way in which our augmentation is prepared helps to prevent it from becoming bunched up when being secured.

  19. The effects of rain on acoustic communication: tawny owls have good reason for calling less in wet weather.

    PubMed

    Lengagne, Thierry; Slater, Peter J B

    2002-10-22

    Numerous attempts have been made to quantify ecological factors that affect the calling range of animal signals. The various processes leading signals to become distorted and embedded in background noise have been described in many habitats (ranging from forest to savannah) and the propagation path in these biomes has thereby been characterized. However, the impact of climatic factors on acoustic communication has been little studied. Surprisingly, to our knowledge, the importance of rain, a regular phenomenon occurring in all habitats except deserts, has never been investigated. Here, we describe a 69-fold advantage in area reached by the call of a territorial bird, the tawny owl (Strix aluco) in dry versus rainy conditions. In support of this, we found a marked reduction in the calling of tawny owls in rainy conditions. Constraints imposed by a rainy propagation path are likely to modify the reliability of acoustic information and thus calling behaviour of many animals.

  20. Long-term data set of small mammals from owl pellets in the Atlantic-Mediterranean transition area

    PubMed Central

    Escribano, Nora; Galicia, David; Ariño, Arturo H.; Escala, Carmen

    2016-01-01

    We describe the pellet sampling data set from the Vertebrate Collection of the Museum of Zoology of the University of Navarra. This data set compiles all information about small mammals obtained from the analysis of owl pellets. The collection consists on skulls, mandibles, and some skeletons of 36 species of more than 72,000 georeferenced specimens. These specimens come from the Iberian Peninsula although most samples were collected in Navarra, a highly diverse transitional area of 10,000 kilometre square sitting across three biogeographical regions. The collection spans more than forty years and is still growing as a result of the establishment of a barn owl pellet monitoring network in 2015. The program will provide critical information about the evolution of the small mammals’ community in this transition zone as it changes over time. PMID:27676217

  1. Sound-localization experiments with barn owls in virtual space: influence of interaural time difference on head-turning behavior.

    PubMed

    Poganiatz, I; Nelken, I; Wagner, H

    2001-03-01

    Specific cues in a sound signal are naturally linked to certain parameters in acoustic space. In the barn owl, interaural time difference (ITD) varies mainly with azimuth, while interaural level difference (ILD) varies mainly with elevation. Previous data suggested that ITD is indeed the main cue for azimuthal sound localization in this species, while ILD is an important cue for elevational sound localization. The exact contributions of these parameters could be tested only indirectly because it was not possible to generate a stimulus that contained all relevant spatial information on the one hand, and allowed for a clean separation of these parameters on the other hand. Virtual auditory worlds offer this opportunity. Here we show that barn owls responded to azimuthal variations in virtual space in the same way as to variations in free-field stimuli. We interpret the increase of turning angle with sound-source azimuths (up to +/- 140 degrees) such that the owls did not experience front/back confusions with virtual stimuli. We then separated the influence of ITD from the influence of all other stimulus parameters by fixing the overall ITD in virtual stimuli to a constant value (+100 micros or +100 micros) while leaving all other sound characteristics unchanged. This manipulation influenced both azimuthal and elevational components of head arms. Since the owls' azimuthal head-turn amplitude always resembled the value signified by the ITD, these data demonstrated that azimuthal sound localization is influenced only by ITD both in the frontal hemisphere and in large parts of the rear hemisphere. ILDs did not have an influence on azimuthal components of head turns. While response latency to normal virtual stimuli was found to be largely independent of stimulus position, response delays of the head turns became longer if the ITD information pointed into a different hemisphere as the other cues of the sounds.

  2. Muscular Arrangement and Muscle Attachment Sites in the Cervical Region of the American Barn Owl (Tyto furcata pratincola)

    PubMed Central

    Boumans, Mark L. L. M.; Krings, Markus; Wagner, Hermann

    2015-01-01

    Owls have the largest head rotation capability amongst vertebrates. Anatomical knowledge of the cervical region is needed to understand the mechanics of these extreme head movements. While data on the morphology of the cervical vertebrae of the barn owl have been provided, this study is aimed to provide an extensive description of the muscle arrangement and the attachment sites of the muscles on the owl’s head-neck region. The major cervical muscles were identified by gross dissection of cadavers of the American barn owl (Tyto furcata pratincola), and their origin, courses, and insertion were traced. In the head-neck region nine superficial larger cervical muscles of the craniocervical, dorsal and ventral subsystems were selected for analysis, and the muscle attachment sites were illustrated in digital models of the skull and cervical vertebrae of the same species as well as visualised in a two-dimensional sketch. In addition, fibre orientation and lengths of the muscles and the nature (fleshy or tendinous) of the attachment sites were determined. Myological data from this study were combined with osteological data of the same species. This improved the anatomical description of the cervical region of this species. The myological description provided in this study is to our best knowledge the most detailed documentation of the cervical muscles in a strigiform species presented so far. Our results show useful information for researchers in the field of functional anatomy, biomechanical modelling and for evolutionary and comparative studies. PMID:26222908

  3. Unravelling a biogeographical knot: origin of the 'leapfrog' distribution pattern of Australo-Papuan sooty owls (Strigiformes) and logrunners (Passeriformes).

    PubMed

    Norman, J A; Christidis, L; Joseph, L; Slikas, B; Alpers, D

    2002-10-22

    Molecular analysis of two Australo-Papuan rainforest birds exhibiting correlated 'leapfrog' patterns were used to elucidate the evolutionary origin of this unusual pattern of geographical differentiation. In both sooty owls (Tyto) and logrunners (Orthonyx), phenotypically similar populations occupy widely disjunct areas (central-eastern Australia and upland New Guinea) with a third, highly distinctive population, occurring between them in northeastern Queensland. Two mechanisms have been proposed to explain the origin of leapfrog patterns in avian distributions: recent shared ancestry of terminal populations and unequal rates or phenotypic change among populations. As the former should generate correlated patterns of phenotypic and genetic differentiation, we tested for a sister relationship between populations from New Guinea and central-eastern Australia using nuclear and mitochondrial DNA sequences. The resulting phylogenies not only refute recent ancestry as an explanation for the leapfrog pattern, but provide evidence of vastly different spatio-temporal histories for sooty owls and logrunners within the Australo-Papuan rainforests. This incongruence indicates that the evolutionary processes responsible for generating leapfrog patterns in these co-distributed taxa are complex, possibly involving a combination of selection and drift in sooty owls and convergence or retention of ancestral characteristics in logrunners.

  4. Unravelling a biogeographical knot: origin of the 'leapfrog' distribution pattern of Australo-Papuan sooty owls (Strigiformes) and logrunners (Passeriformes).

    PubMed Central

    Norman, J A; Christidis, L; Joseph, L; Slikas, B; Alpers, D

    2002-01-01

    Molecular analysis of two Australo-Papuan rainforest birds exhibiting correlated 'leapfrog' patterns were used to elucidate the evolutionary origin of this unusual pattern of geographical differentiation. In both sooty owls (Tyto) and logrunners (Orthonyx), phenotypically similar populations occupy widely disjunct areas (central-eastern Australia and upland New Guinea) with a third, highly distinctive population, occurring between them in northeastern Queensland. Two mechanisms have been proposed to explain the origin of leapfrog patterns in avian distributions: recent shared ancestry of terminal populations and unequal rates or phenotypic change among populations. As the former should generate correlated patterns of phenotypic and genetic differentiation, we tested for a sister relationship between populations from New Guinea and central-eastern Australia using nuclear and mitochondrial DNA sequences. The resulting phylogenies not only refute recent ancestry as an explanation for the leapfrog pattern, but provide evidence of vastly different spatio-temporal histories for sooty owls and logrunners within the Australo-Papuan rainforests. This incongruence indicates that the evolutionary processes responsible for generating leapfrog patterns in these co-distributed taxa are complex, possibly involving a combination of selection and drift in sooty owls and convergence or retention of ancestral characteristics in logrunners. PMID:12396487

  5. EXPLORATORY PLASMA BIOCHEMISTRY REFERENCE INTERVALS FOR URAL OWLS (STRIX URALENSIS, PALLAS 1771) FROM THE AUSTRIAN REINTRODUCTION PROJECT.

    PubMed

    Scope, Alexandra; Schwendenwein, Ilse; Stanclova, Gabriela; Vobornik, Angela; Zink, Richard

    2016-06-01

    The Ural owl (Strix uralensis) is the biggest forest-living owl in Austria; however, it became extinct in Austria through poaching and habitat loss more than half a century ago. The birds examined in the present study were breeding pairs from the reintroduction project with the aim of determining exploratory plasma biochemistry reference intervals in Ural owls and evaluating the amount of biological variation between seasons, sexes, and ages. A total of 45 birds were sampled, including 13 adult males, 14 adult females, and 18 juvenile birds. Remarkably, almost all of the analytes showed significant differences between the subgroups, primarily between seasons, followed by age and sex. Only creatinkinase, glucose, lactatdehydrogenase, and triglycerides did not show any significant variations. Despite partitioning of reference values into subgroups according to biological variation diminishing the number of reference individuals in the respective groups, the resulting smaller reference intervals will improve medical assessment. The results of the present study once again demonstrate that significant seasonal fluctuations must be expected and considered in the interpretation. It can be assumed that these differences are probably even greater in free-range birds with considerable changes in food quantity and quality during and between years.

  6. Preliminary risk assessment of the Mexican Spotted Owl under a spatially-weighted foraging regime at the Los Alamos National Laboratory

    SciTech Connect

    Gallegos, A.F.; Gonzales, G.J.; Bennett, K.D.; Pratt, L.E.

    1997-02-01

    The Record of Decision on the Dual Axis Radiographic Hydrodynamic Test Facility at the Los Alamos National Laboratory requires that the Department of Energy takes special precautions to protect the Mexican Spotted Owl (Strix occidentalis lucida). In order to do so, risk to the owl presented by radiological and nonradiological contaminants must be estimated. A preliminary risk assessment on the Mexican Spotted Owl in two Ecological Exposure Units (EEUs) was performed using a modified Environmental Protection Agency Quotient method, the FORTRAN model ECORSK4, and a geographic information system. Estimated doses to the owl under a spatially-weighted foraging regime were compared against toxicological reference doses generating hazard indices (HIs) and hazard quotients (HQs) for three risk source types. The average HI was 0.20 for EEU-21 and 0.0015 for EEU-40. Under the risk parameter assumptions made, hazard quotient results indicated no unacceptable risk to the owl, including a measure of cumulative effects from multiple contaminants that assumes a linear additive toxicity type. An HI of 1.0 was used as the evaluative criteria for determining the acceptability of risk. This value was exceeded (1.06) in only one of 200 simulated potential nest sites. Cesium-137, Ni, {sup 239}Pu, Al and {sup 234}U we`re among the constituents with the highest partial HQs. Improving model realism by weighting simulated owl foraging based on distance from potential nest sites decreased the estimated risk by 72% (0.5 HI units) for EEU-21 and by 97.6% (6.3E-02 HI units) for EEU-40. Information on risk by specific geographical location was generated, which can be used to manage contaminated areas, owl habitat, facility siting, and/or facility operations in order to maintain risk from contaminants at acceptably low levels.

  7. DNA barcoding as a tool for elucidating species delineation in wide-ranging species as illustrated by owls (Tytonidae and Strigidae).

    PubMed

    Nijman, Vincent; Aliabadian, Mansour

    2013-11-01

    The mitochondrial cytochrome c-oxidase subunit I (cox1) can serve as a fast and accurate marker for the identification of animal species, and for the discovery of new species across the tree of life. Distinguishing species using this universal molecular marker, a technique known as DNA barcoding, relies on the identifying the gap between intra- and interspecific divergence. One of the difficulties could be wide-ranging, cosmopolitan species that show large amounts of morphological variation. The barn owl Tyto alba is a case in point. It occurs worldwide and varies morphologically, leading to the recognition of many subspecies or, more recently, species. We analysed data from the cox1 gene for 31 individuals of seven subspecies, and compared this with 214 sequences from 29 other owl species. Phylogenetic analysis of the T. alba samples gives very strong support for an Old World alba-clade (three subspecies) and a New World furcata-clade (four subspecies) that are genetically equidistant. The amount of intraspecific variation within each of these clades ranges from 0.66-0.99%, but variation among these clades ranges from 5.33-6.20%. Combined these data suggest that barn owl of the Old World is indeed best considered a separate species different from that of the New World. For combined dataset, sample size of owl species (n between 1 and 21 sequences) increased with geographic range size but we did not find significant relationships between interspecific divergence and sample size or between interspecific divergence and geographic range. For 21/24 species of owls with sample sizes of n ≥4 the maximum interspecific divergences was ≤ 3.00%. However, similar to those found in barn owls, the largest amount of divergence (3.23-4.09%) was present in two other wide-ranging species (Strix nebulosa and Aegolius funereus) raising the possibility of multiple species in other wide-ranging owls as well.

  8. Morphological features of the tongue and laryngeal entrance in two predatory birds with similar feeding preferences: common kestrel (Falco tinnunculus) and Hume's tawny owl (Strix butleri).

    PubMed

    Abumandour, Mohamed M A; El-Bakary, Neveen E R

    2016-04-15

    The aim of this investigation was to describe the morphological characters of the tongue of two predatory birds with similar feeding preferences, i.e. the common kestrel and Hume's tawny owl. Descriptive information on the lingual morphology of these two birds, particularly Hume's tawny owl, is incomplete. We found that the lingual apex of the owl has an oval, concave, shovel-like form with a bifid lingual tip, while that of the kestrel has the shape of a horny tip-like spoon with a central process in addition to there being several filiform-like papillae on the dorsal surface of the apex and body. In the owl, the dorsal surface of the apex and body is subdivided into four U-shaped regions: lingual tip, two lateral regions and a median region. The two lateral regions are characterized by the presence of papillae and several openings of lingual glands, while the median region carries filiform-like papillae. In both birds, the papillary crest is located between the body and root. In the kestrel, there is an additional row of papillae rostral to crest, while in the owl there is a rostral lateral extension of papillae on the lateral lingual surface so the distribution pattern has a W-shape. In the kestrel, the posterior part of lingual body has several openings of glands, while the root lacks glands completely, although it has many taste buds. In the owl, the lingual root is folded and has a large number of gland openings. In the kestrel caudally to the glottis, there are two paramedian transverse rows of pharyngeal papillae with a pair of median huge papillae, while in the owl, there is only one transverse row of papillae. The dorsal and ventral lingual surfaces of both birds are lined with non-keratinized stratified squamous epithelium.

  9. Biomonitoring heavy metals using the barn owl (Tyto alba guttata): sources of variation especially relating to body condition.

    PubMed

    Esselink, H; van der Geld, F M; Jager, L P; Posthuma-Trumpie, G A; Zoun, P E; Baars, A J

    1995-05-01

    The feasibility of using the Barn Owl (Tyto alba guttata) to monitor environmental quality in the Netherlands was investigated, using Cd, Cu, Pb, Mn, and Fe as indicators for environmental contamination. Throughout 1992, bird-watchers, volunteers, and officials submitted 53 birds. The age and geographical distribution of these birds, formed a representative sample of the population. The following interrelationships were investigated: cause of death, nutrient reserve, age, time of death, place of death, body measurements, sex, condition, and heavy metal concentration in kidney, liver, and tibia. Twenty-eight animals had died after collisions. Fifteen Barn Owls died of exhaustion. In total, twenty-four birds were exhausted, with coccidiosis or other parasitic gastrointestinal infections. The condition of the birds showed that as the birds' condition worsened, fat reserves were depleted before protein reserves. Significant linear relationships were found between decreasing protein reserves and decreasing dry weights of the liver, kidney, flight muscle and heart, but not of the tibia. An asymptotic, nonlinear relation was observed between dry organ weight and fat reserve. This suggested that fat reserves were only found when protein reserves exceeded 15% of the body mass at starvation. Concentrations of Cu and Fe in liver and kidney rose as protein reserves fell; the total content of Cu and Fe per organ, however, remained constant. The Mn concentration of these organs remained constant; Mn content increased with increasing organ sizes. Neither Cd nor Pb showed a clear relationship with parameters of body condition. The ratio between the organ content of Pb or Cd and the dry organ weight, however, revealed some birds from contaminated habitats. The findings suggested that concentrations of environmental contaminants should be measured on a dry weight basis. Furthermore, depending on the pharmacokinetic characteristics of a contaminant, the total content of that

  10. Great science observatories in the space station era and OWL efforts in Japan

    NASA Astrophysics Data System (ADS)

    Takahashi, Yoshiyuki

    1998-06-01

    A concept of ``Space Factory'' on the International Space Station Alpha (ISSA) is described. By following the four great observatories that purposefully took advantage of the Space Transportation System (STS), the next generation of great observatories is considered. These new astronomical projects require a very large optical telescope whose diameter is of the order of 10 m. Space telescope of this size will require careful assembly and tuning by astronauts on orbit before deployment. Once built, it could visualize the universe to the earliest galaxies, and could explore the earth-like planet in other star-system. The ``Space Factory'' would permit other large-scale observatories for construction in space. A step-by-step advancement of the ``Space Factory'' is conceived by including four or five frontier astrophysics programs. Less demanding experiments would precede the construction project of the most demanding optical telescope. A study in Japan to observe the highest energy cosmic rays from space is synchronized with those being carried out by the OWL team in the USA and the AIRWATCH team in Italy. The Japanese efforts are coordinated in a larger program study of the Space SUBARU, which envisages a plan of orbital construction, fine-tuning and eventual deployment of large scale astrophysical instruments into the desired free-flying orbit. A space observatory of the highest energy cosmic rays can be maximized by a cluster of 6 or 7 units of the wide-angle OWL telescopes, each having a field-of-view (FOV) of ~60°. The ultimate viewing area could be up to 6,000 km×6,000 km, the entire horizon for a 1000 km orbit. Within this large detection area about 105 cosmic hadronic events at above 1020 eV would be observed in a year. It also makes possible to observe the highest energy neutrinos from the known source mechanisms; including cosmic photo-production. Neutrino events from Topological Defects, Gamma Ray Burst fireballs and Blazers are observable as frequently

  11. Assessment of toxicity and coagulopathy of brodifacoum in Japanese quail and testing in wild owls.

    PubMed

    Webster, Kirstin H; Harr, Kendal E; Bennett, Darin C; Williams, Tony D; Cheng, Kimberly M; Maisonneuve, France; Elliott, John E

    2015-07-01

    Based on detection of hepatic residues, scavenging and predatory non-target raptors are widely exposed to second generation anticoagulant rodenticides (SGARs). A small proportion, generally <10%, of tested birds are diagnosed as acutely poisoned. Little is known, however, of sub-lethal effects of SGARs, such as interaction of clotting capacity with traumatic injury. Assessment of coagulation function of birds submitted live to wildlife rehabilitators or veterinarians may provide a means of establishing the proportion of animals suffering sub-lethal coagulopathies, as well as identifying individuals requiring treatment. As a first step in exploring the potential of this approach, we dosed Japanese quail (Coturnix japonica) with the SGAR, brodifacoum, at 0, 0.8, 1.4, 1.9, and 2.5 mg/kg and sampled birds at 1, 3, 5 and 7 days post-dosing. Prothrombin time (PT), which measures the extrinsic coagulation pathway, was significantly prolonged in 98% of brodifacoum-exposed quail in a dose- and time-dependent manner. 50-fold prolongation of PT occurred at higher brodifacoum dosages and correlated to hemorrhage found at necropsy. Activated clotting time (ACT), a measure of the intrinsic pathway also increased with dose and time. Hemoglobin (Hb) and hematocrit (Hct) decreased dose- and time-dependently at doses ≥1.4 mg/kg with no significant change at 0.8 mg/kg. Reference intervals for PT (10.0-16.2 s), ACT (30-180 s), Hb (9.6-18.4 g/dl), and Hct (34-55%) were established in Japanese quail. Species-specific reference intervals are required as barn owl PT (17-29 s) and quail PT were different. The proportion of brodifacoum-exposed quail with hemorrhage was not correlated with liver residues, but was correlated with PT, suggesting that this assay is a useful indicator of avian anticoagulant rodenticide exposure. PTs measured in free-living barn owls sampled between April 2009 and August 2010 in the lower Fraser Valley of BC do not suggest significant exposure to SGARs.

  12. Ventilatory and metabolic responses of burrowing owls, Athene cunicularia, to moderate and extreme hypoxia: analysis of the hypoxic ventilatory threshold vs. hemoglobin oxygen affinity relationship in birds.

    PubMed

    Kilgore, Delbert L; Boggs, Dona F; Kilgore, Trevor J; Colby, Conrad; Williams, Burl R; Bavis, Ryan W

    2008-06-01

    We measured ventilation, oxygen consumption and blood gases in burrowing owls (Athene cunicularia) breathing moderate and extreme hypoxic gas mixtures to determine their hypoxic ventilatory threshold (HVT) and to assess if they, like other birds and mammals, exhibit a relationship between HVT and hemoglobin O2 affinity (P(50)) of their blood. An earlier report of an attenuated ventilatory responsiveness of this species to hypoxia was enigmatic given the low O2 affinity (high P(50)) of burrowing owl hemoglobin. In the current study, burrowing owls breathing 11% and 9% O2 showed a significantly elevated total ventilation. The arterial partial pressure of oxygen (PaO2) at which ventilation is elevated above normoxic values in burrowing owls was 58 mm Hg. This threshold value conforms well to expectations based on the high P(50) of their hemoglobin and the HVT vs. P(50) relationship for birds developed in this study. Correcting for phylogenetic relatedness in the multi-species analysis had no effect on the HVT vs. P(50) relationship. Also, because burrowing owls in this study did not show a hypometabolic response at any level of hypoxia (even at 9% O2); HVT described in terms of percent change in oxygen convection requirement is identical to that based on ventilation alone.

  13. Revisiting the “visible burrow system”: The impact of the group, social rank, and gender on voles under owl attack.

    PubMed

    Bodek, Sivan; Eilam, David

    2015-07-01

    In the present study, corticosterone levels and behavior were compared between voles (Microtus socialis) that were attacked by a barn owl (Tyto alba) and voles that did not experience such attack. Both female and male voles were exposed to the owl either together with their group mates or when socially isolated. As hypothesized, corticosterone levels were higher in voles after the owl attack, and were higher in females than in males. However, blood corticosterone was higher in voles that experienced the attack in groups compared with the socially-isolated voles. The latter result seems enigmatic, since group members usually benefit from the “social buffering” conferred by their group-mates. It is suggested that contagious vigilance among group members accounts for the higher mean corticosterone level in grouped compared to socially-isolated voles, overshadowing the possible impact of social buffering. We also found a negative correlation between body mass and corticosterone level, with more high-mass voles showing low corticosterone levels compared with low mass voles. This finding accords with a previous study in which the behavior of high-mass voles was less affected by owl attack compared to low-mass voles. The novelty of the present results therefore lies in supporting, at the hormonal level, past behavioral findings in rats and voles, and in demonstrating that high-mass voles, by virtue of their physical strength and perhaps also their life experience, are less stressed by the owl attack and become the leaders and stabilizers of their groups.

  14. 2017 European guideline for the management of chancroid.

    PubMed

    Lautenschlager, Stephan; Kemp, Michael; Christensen, Jens Jørgen; Mayans, Marti Vall; Moi, Harald

    2017-03-01

    Chancroid is a sexually acquired infection caused by Haemophilus ducreyi. The infection is characterized by one or more genital ulcers, which are soft and painful, and regional lymphadenitis, which may develop into buboes. The infection may easily be misidentified due to its rare occurrence in Europe and difficulties in detecting the causative pathogen. H. ducreyi is difficult to culture. Nucleic acid amplification tests can demonstrate the bacterium in suspected cases. Antibiotics are usually effective in curing chancroid.

  15. Input clustering in the normal and learned circuits of adult barn owls.

    PubMed

    McBride, Thomas J; DeBello, William M

    2015-05-01

    Experience-dependent formation of synaptic input clusters can occur in juvenile brains. Whether this also occurs in adults is largely unknown. We previously reconstructed the normal and learned circuits of prism-adapted barn owls and found that changes in clustering of axo-dendritic contacts (putative synapses) predicted functional circuit strength. Here we asked whether comparable changes occurred in normal and prism-removed adults. Across all anatomical zones, no systematic differences in the primary metrics for within-branch or between-branch clustering were observed: 95-99% of contacts resided within clusters (<10-20 μm from nearest neighbor) regardless of circuit strength. Bouton volumes, a proxy measure of synaptic strength, were on average larger in the functionally strong zones, indicating that changes in synaptic efficacy contributed to the differences in circuit strength. Bootstrap analysis showed that the distribution of inter-contact distances strongly deviated from random not in the functionally strong zones but in those that had been strong during the sensitive period (60-250 d), indicating that clusters formed early in life were preserved regardless of current value. While cluster formation in juveniles appeared to require the production of new synapses, cluster formation in adults did not. In total, these results support a model in which high cluster dynamics in juveniles sculpt a potential connectivity map that is refined in adulthood. We propose that preservation of clusters in functionally weak adult circuits provides a storage mechanism for disused but potentially useful pathways.

  16. Estimation and comparison of parameters in stochastic growth models for barn owls

    SciTech Connect

    White, G.C.; Brisbin, I.L. Jr.

    1980-06-01

    Alternative methods for parameter estimation and the incorporation of stochasticity into growth models are investigated and compared to the commonly used sampling error model in which error terms are simply added-on to the integrated form of growth equation. A process error model, in which the process of growth is assumed to have stochastic variation or error incorporated within it, was found to be more appropriate for use with nonlinear estimation procedures based on a minimization of ..sigma..e/sub i//sup 2/. The process error model tended to minimize and/or eliminate the autocorrelation of residuals, which were characteristic of the sampling error model. These analyses further suggest that while the commonly used sampling error growth model may indeed provide unbiased parameter estimates, the estimated variances of such estimates are likely to be unwarrantedly low,