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Sample records for owls bubo bubo

  1. 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. PMID:25162495

  2. Pulmonary carcinoma in a great horned owl (Bubo virginianus).

    PubMed

    Rettenmund, Christy; Sladky, Kurt K; Rodriguez, Daniel; Petersen, Michael; Pinkerton, Marie E; Rao, Deepa

    2010-03-01

    Pulmonary carcinoma was diagnosed in an 18+-year-old captive female great horned owl (Bubo virginianus). The owl presented with a history of progressive weakness and sudden onset of frank blood in the droppings. On physical examination, the owl had multiple white to yellow plaques in the oral cavity, decreased air sac sounds on the right side, dyspnea (during manual restraint), and reduced pectoral musculature. Whole-body radiographs revealed obliteration of the right-sided air sacs, a soft tissue plaque/density in the left caudal thoracic air sac, soft tissue opacity over the coelomic organs, and increased medullary opacity in the distal right humerus. The owl died during anesthetic recovery, and the body was submitted for necropsy. Although the clinical signs, physical examination results, radiographic signs, and gross pathology supported a diagnosis of mycotic infection, such as aspergillosis, histopathology confirmed pulmonary carcinoma with metastases to the air sacs and humerus. PMID:20722257

  3. Cytogenetic analysis of great horned owls (Bubo virginianus).

    PubMed

    Biederman, B M; Florence, D; Lin, C C

    1980-01-01

    A chromosome analysis of seven great honored owls (Bubo virginianus, Gmelin) has been performed on peripheral lymphocytes. The modal chromosome number was found to be 2n = 82. Measurements of relative lengths and arm ratios of the macrochromosomes were made. All chromosomes contain a region of constitutive heterochromatin in a centromeric location, with the W chromosome being composed almost entirely of this material. Chromosome replication, as demonstrated by the BudR-acridine orange method, showed synchronous replication of the two Z chromosomes of the male and late replication of the W chromosome of the female. In this species, functional regions of nucleolar organization appear to be localized to the microchromosomes. PMID:7449439

  4. 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.

  5. Presumptive electric cataracts in a Great Horned owl (Bubo virginianus).

    PubMed

    Dees, D Dustin; MacLaren, Nicole E

    2013-01-01

    This case report describes suspected electrocution in a juvenile female Great Horned owl (Bubo virginianus) with subsequent bilateral cataract formation. The bird flew into a high-voltage power line and was immediately rescued. Burn wounds of the head and ataxia with apparent blindness were noted. Initial ophthalmic examination 5 days after the incident revealed bilaterally symmetrical anterior subcapsular vacuolar cataracts with absence of intraocular inflammation and a predominantly clear view to the normal appearing fundus. The bird appeared to be nonvisual. No ophthalmic medications were prescribed at initial examination. Subsequent recheck examination at 8 weeks revealed moderate resolution of the cataracts and improved vision. To the authors' knowledge, this is the first published report of suspected electric cataracts in an avian species. PMID:22432797

  6. Chronic myelogenous leukemia in a great horned owl (Bubo virginianus).

    PubMed

    Wiley, Jennifer L; Whittington, Julia K; Wilmes, Christine M; Messick, Joanne B

    2009-03-01

    A free-ranging adult female great horned owl (Bubo virginianus) was presented to the Wildlife Medical Clinic at the University of Illinois after being observed with anorexia and decreased activity. A severe leukocytosis (212 400 cells/microl), primarily comprised of mature heterophils, was found at presentation. Results of various diagnostic tests including radiographs, Chlamydophila serologic testing, measurement of Aspergillus antibody and antigen titers, plasma protein electrophoresis, fecal culture and acid-fast staining, coelioscopy, endoscopy, tracheoscopy, exploratory coelomotomy, nuclear scintigraphy, tissue cultures, bone marrow biopsy, and histopathology revealed no underlying cause for the persistent leukocytosis. No response to treatment with antibiotics or antifungal agents was observed, although a transient, significant decrease in the leukocyte count (6200 cells/microl) was observed after treatment with fenbendazole. A presumptive diagnosis of chronic myelogenous leukemia was made based on 3 factors: disease duration of greater than 3 months, a lack of identifiable foci of inflammation, and a lack of response to conventional therapy. The diagnosis was confirmed based on postmortem examination and testing 177 days after initial presentation. PMID:19530405

  7. Disseminated lymphoma of presumptive T-cell origin in a great horned owl (Bubo virginianus).

    PubMed

    Malka, Shachar; Crabbs, Torrie; Mitchell, Elizabeth B; Zehnder, Ashley; Kent, Michael S; Lowenstine, Linda J; Hawkins, Michelle G

    2008-09-01

    A geriatric male great horned owl (Bubo virginianus) that was a resident at a raptor center was presented for examination because of stridor and weight loss. Results of physical examination, diagnostic imaging, and biopsy were consistent with disseminated lymphoma involving the oropharynx, neck region (including thyroid and parathyroid glands), keel, spleen, and liver. Attempts to treat the owl with chlorambucil failed, and the owl was euthanatized 5 months later. Neoplastic cells from this owl were immunoreactive to CD-3 antibody, suggesting the lymphoma was of T-cell origin. PMID:19014096

  8. Organohalogen exposure in a Eurasian Eagle owl (Bubo bubo) population from Southeastern Spain: temporal-spatial trends and risk assessment.

    PubMed

    Gómez-Ramírez, P; Martínez-López, E; García-Fernández, A J; Zweers, A J; van den Brink, N W

    2012-08-01

    Polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs) and organochlorine insecticides (OCs) were analysed in 58 Eurasian Eagle owl (Bubo bubo) unhatched eggs collected between 2004 and 2009 in Southeastern Spain. Levels of p,p'-DDE were found to be higher than in eggs laid by other European owls in the same decade, probably due to the greater agricultural activity in our study area. Compared to other European raptors, exposure to PCBs can be considered intermediate, but low to PBDEs. Land use differences and prey availability were the rationale to divide the study area in two subareas in further assessments. Temporal trends of HCB, p,p'-DDE, β-HCH, PCBs and PBDEs were significantly different in each subarea, generally increasing over time in the Southern but decreasing or remaining stable in the Northern. On the contrary, levels of cyclodienes tended to decrease in both subareas. Dietary shifts with a greater amount of birds are suggested as a cause for increasing organochlorine loads in raptors. This may explain the increasing trend in the Southern territories. However, due to the proximity of most of these nests to Cartagena, an important industrial city, increasing environmental pollution cannot be ruled out. Although average levels of the compounds analysed are below threshold levels, 17% of the samples exceeded 400 pg g(-1)ww (wet weight), the LOAEC for Total TEQs. Moreover, a negative correlation between TEQ concentrations and the metabolizable fraction of PCBs (F(prob)=0.0018) was found when TEQs values were above 10 pg g(-1)ww. This could be indicative of hepatic enzymes induction in the birds exposed at higher concentrations, which are mainly breeding in the Southern subarea. These females could be suffering from Ah-receptor-related toxic effects, some of which have been related to altered bird reproduction. Finally, a significant negative correlation between p,p'-DDE levels and eggshell thickness (r=-0.469, p<0.001) was observed, with

  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. PMID:22942441

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

    PubMed Central

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

    2012-01-01

    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. PMID:22942441

  11. 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.

  12. Penetrating keratoplasty for treatment of corneal protrusion in a great horned owl (Bubo virginianus).

    PubMed

    Andrew, Stacy E; Clippinger, Tracy L; Brooks, Dennis E; Helmick, Kelly E

    2002-09-01

    A young adult great horned owl (Bubo virginianus) was examined following presumed trauma. The owl had soft tissue injury to its left wing as well as corneal protrusion, lens subluxation, and iridodialysis of the right eye. The bird's eye was treated surgically with a large, rectangular penetrating keratoplasty. Following escape from housing, the bird was found with partial wound dehiscence and iris prolapse 12 days post operation. Surgical repair was performed and healing progressed for 14 days, at which time the transplant dehisced and the globe was exenterated. The patient rehabilitated well until escaping from its cage again 4 weeks later, at which time it sustained an open comminuted humeral fracture and was euthanized. PMID:12236872

  13. Sarcocystis falcatula-associated encephalitis in a free-ranging great horned owl (Bubo virginianus).

    PubMed

    Wünschmann, Arno; Rejmanek, Daniel; Cruz-Martinez, Luis; Barr, Bradd C

    2009-03-01

    A great horned owl (Bubo virginianus) was admitted to a rehabilitation clinic with severe neurologic signs that were unresponsive to supportive care. The animal was euthanatized because of a poor prognosis. Marked granulomatous encephalitis with focal brainstem malacia was detected microscopically. The brainstem was the most severely affected brain location and the only place in which schizonts and merozoites, morphologically compatible with Sarcocystis spp., were detected. Immunohistochemistry with the use of polyclonal antisera indicated the presence of Sarcocystis falcatula. The species identification of the protozoa as S. falcatula was confirmed by polymerase chain reaction. To the author's knowledge, this is the first report of spontaneous S. falcatula-associated encephalitis in a great horned owl. PMID:19286517

  14. 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.

  15. 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.

  16. The humeroscapular bone of the great horned owl (Bubo virginianus) and other raptors.

    PubMed

    Smith, B J; Smith, S A

    1992-03-01

    A small, separate, bony density dorsal to the shoulder joint is radiographically visible in several species of large hawks and owls. Gross dissection and histological examination show the bone to lie on the deep surface of the major deltoid muscle in intimate association with the dorsal coracohumeral ligament of the shoulder joint. The tendon of the supracoracoideus muscle passes immediately cranial to the humeroscapular bone. Two ligaments distinct from the shoulder joint capsule attach the humeroscapular bone to the proximal humerus: one passes to the proximal edge of the pectoral crest of the humerus, and the other passes to the ventral tubercle of the humerus. The bone was described as the humeroscapular bone in reference to a similar fibrocartilaginous structure possessed by some birds. The humeroscapular bone is present in the great horned owl (Bubo virginianus), the screech owl (Otus asio), the barred owl (Strix varia), the red-tailed hawk (Buteo jamaicencis), the Cooper's hawk (Accipiter cooperii), and the sharp-shinned hawk (Accipiter striatus). The bone is absent in the barn owl (Tyto alba), the osprey (Pandion haliaetus), the golden eagle (Aquila chysaetos), and the turkey vulture (Cathartes aura), though some of these species possessed a similar fibrocartilaginous structure. Whether the humeroscapular structure develops as bone or cartilage in a given species may be related to other morphological features of the wing, and/or to characteristics of the predatory behavior of the species. Clinicians and anatomists dealing with birds of prey must be aware of the presence of the humeroscapular bone to avoid misinterpreting it as a fracture fragment. PMID:1585989

  17. PHARMACOKINETIC PROPERTIES OF A SINGLE ADMINISTRATION OF ORAL GABAPENTIN IN THE GREAT HORNED OWL (BUBO VIRGINIANUS).

    PubMed

    Yaw, Taylor J; Zaffarano, Bianca A; Gall, Andrew; Olds, June E; Wulf, Larry; Papastavros, Efthimia; Coetzee, Johann F

    2015-09-01

    Gabapentin (1-[aminomethyl] cyclohexane acetic acid) is a γ-aminobutyric acid analogue that has been shown to be efficacious for neuropathic pain control in humans. Plasma gabapentin concentrations >2 μg/ml are considered effective in treating epilepsy in humans and are suggested to provide analgesia for neuropathic pain. This study investigated the pharmacokinetics of a single oral dose of gabapentin suspension (11 mg/kg) in great horned owls ( Bubo virginianus ). Plasma gabapentin concentrations were determined in six healthy birds for 48 hr using high-performance liquid chromatography with mass spectrometric detection. Plasma gabapentin concentrations were estimated by noncompartmental pharmacokinetic analysis. The harmonic mean (±SD) maximum concentration (Cmax), time to maximum concentration (Tmax), and elimination half-life (tv2λZ) for gabapentin (11 mg/kg) were 6.17±0.83 μg/ml, 51.43±5.66 min, and 264.60±69.35 min, respectively. In this study, plasma gabapentin concentrations were maintained above 2 μg/ml for 528 min (8.8 hr), suggesting that gabapentin administered orally every 8 hr may be appropriate in great horned owls. PMID:26352959

  18. Pharmacokinetics of piperacillan after intramuscular injection in red-tailed hawks (Buteo jamaicensis) and great horned owls (Bubo virginianus).

    PubMed

    Robbins, P K; Tell, L A; Needham, M L; Craigmill, A L

    2000-03-01

    This study characterized and compared the pharmacokinetics of piperacillin after single 100 mg/kg i.m. injections in nine red-tailed hawks (Buteo jamaicensis) and five great horned owls (Bubo virginianus) over 48 hr by a modified agar well diffusion microbial inhibition assay. The mean maximum plasma piperacillin concentrations were 204 microg/ml and 221 microg/ml for the hawks and owls, respectively, and times of maximum concentrations were 15 min and 30 min, respectively. The calculated mean terminal elimination half-lives were 77 min in the hawks and 118 min in the owls. Area-under-the-curve values were 218 +/- 52 microg x hr/ml in the hawks and 444 +/- 104 microg x hr/ml in the owls. On the basis of the most common minimal inhibitory concentration (90%) for various bacterial isolates from clinical samples of 8 microg/ml, analysis of the data suggests that the maximum dosing interval for piperacillin at 100 mg/kg in medium sized raptors should be 4-6 hr. PMID:10884123

  19. 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. PMID:27010284

  20. Great horned owl (Bubo virginianus) dietary exposure to PCDD/DF in the Tittabawassee River floodplain in Midland, Michigan, USA.

    PubMed

    Coefield, Sarah J; Zwiernik, Matthew J; Fredricks, Timothy B; Seston, Rita M; Nadeau, Michael W; Tazelaar, Dustin L; Moore, Jeremy N; Kay, Denise P; Roark, Shaun A; Giesy, John P

    2010-10-01

    Soils and sediments in the floodplain of the Tittabawassee River downstream of Midland, Michigan, USA contain elevated concentrations of polychlorinated dibenzofurans (PCDF) and polychlorinated dibenzo-p-dioxins (PCDD). As a long-lived, resident top predator, the great horned owl (Bubo virginianus; GHO) has the potential to be exposed to bioaccumulative compounds such as PCDD/DF. Site-specific components of the GHO diet were collected along 115 km of the Tittabawassee, Pine, Chippewa, and Saginaw Rivers during 2005 and 2006. The site-specific GHO biomass-based diet was dominated by cottontail rabbits (Sylvilagus floridanus) and muskrats (Ondatra zibethicus). Incidental soil ingestion and cottontail rabbits were the primary contributors of PCDD/DF to the GHO diet. The great horned owl daily dietary exposure estimates were greater in the study area (SA) (3.3 to 5.0 ng 2,3,7,8-TCDD equivalents (TEQ(WHO-avian))/kg body wt/d) than the reference area (RA) (0.07 ng TEQ(WHO-Avian)/kg body wt/d). Hazard quotients (HQs) based on central tendency estimates of the average daily dose and no-observable-adverse effect level (NOAEL) for the screech owl and uncertainty factors were <1.0 for both the RA and the SA. Hazard quotients based on upper end estimates of the average daily dose and NOAEL were <1.0 in the RA and up to 3.4 in the SA. PMID:20872700

  1. 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. PMID:18689078

  2. A new oligacanthorhynchid acanthocephalan described from the great horned owl, Bubo virginianus (Strigidae), and red-tailed hawk, Buteo jamaicensis (Accipitridae), from central Arizona, U.S.A.

    PubMed

    Bolette, David P

    2007-02-01

    Oligacanthorhynchus nickoli n. sp. (Acanthocephala: Oligacanthorhynchidae) is described from the great-horned owl, Bubo virginianus (Gmelin, 1788) (type host), and red-tailed hawk, Buteojamaicensis (Gmelin, 1788), collected in central Arizona. The new species is most similar to Oligacanthorhynchus iheringi and Oligacanthorhynchus minor, but it differs from all congeners primarily by trunk length, proboscis size and armature, egg size, geographical range, and host species. It is distinguished from the 9 Oligacanthorhynchus species occurring in avian hosts from both the Western and Eastern Hemispheres. Descriptions of juvenile forms of O. nickoli from the intestine of B. jamaicensis are provided from recently ingested cystacanths with everted proboscides. PMID:17436950

  3. Risk assessment methodologies for exposure of great horned owls (Bubo virginianus) to PCBs on the Kalamazoo River, Michigan.

    PubMed

    Strause, Karl D; Zwiernik, Matthew J; Newsted, John L; Neigh, Arianne M; Millsap, Stephanie D; Park, Cyrus S; Moseley, Pamela P; Kay, Denise P; Bradley, Patrick W; Jones, Paul D; Blankenship, Alan L; Sikarskie, James G; Giesy, John P

    2008-01-01

    Dietary exposures of great horned owls (GHO; Bubo virginianus) to polychlorinated biphenyls (PCBs) in the terrestrial food web at the Kalamazoo River, Michigan, USA, were examined. Average potential daily doses (APDD) in GHO diets were 7- to 10-fold and 3-fold greater at the more contaminated location versus a reference location for site-specific exposures quantified as total PCBs and 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQ(WHO-Avian)), respectively. Wetland/aquatic prey contributed significantly to PCB exposure and APDD. Estimates of risk based on comparison of modeled dietary intake (e.g., APDD) to toxicity reference values (TRVs), using a hazard quotient (HQ) methodology, varied between diet composition methods (mass basis vs numeric basis). Mass-basis compositions yielded greater HQs at all sites. Potential risks associated with dietary exposures ("bottom-up" risk assessment methodology) were less than (HQ < 1) benchmarks for effects. This result is consistent with risk estimates based on concentrations in tissues ("top-down" risk assessment methodology), and indicated PCBs posed no significant risk to terrestrial raptor species. Colocated and concurrent studies that evaluated GHO reproductive performance (nestling productivity) and relative abundance were consistent with results of the risk assessment. Measures of risk based on HQs were consistent with direct measures of ecologically relevant endpoints (reproductive fitness). Uncertainty in risk estimates is contributed during the selection of TRVs for effects in GHO based on TEQ(WHO-Avian) because of the absence of species-specific, dose-response thresholds. This evaluation indicated that a multiple-lines-of-evidence approach provided the best estimate of risk. PMID:18260206

  4. Mechanism of pellet egestion in great-horned owls (Bubo virginianus).

    PubMed

    Duke, G E; Evanson, O A; Redig, P T; Rhoades, D D

    1976-12-01

    To study the mechanism of oral pellet egestion in great-horned owls, bipolar electrodes and strain-gauge transducers were chronically implanted in the esophagus, muscular stomach, and duodenum of six owls. Recordings from conscious owls plus simultaneous radiographic observations revealed characteristic gastrointestinal motility patterns associated with egestion. Beginning at about 12 min before egestion, gastric contractions formed the final shape of the pellet and pushed it into the lower esophagus. The pellet was moved out of the esophagus by antiperistalsis during the last 8--10 s before egestion. During pellet egestion, contractions of abdominal muscles were not detected. Pellet egestion appears to be unlike either emesis in mammals with a simple stomach or regurgitation in ruminants. PMID:1052819

  5. Risk assessment of great horned owls (Bubo virginianus) exposed to polychlorinated biphenyls and DDT along the Kalamazoo River, Michigan, USA.

    PubMed

    Strause, Karl D; Zwiernik, Matthew J; Im, Sook Hyeon; Bradley, Patrick W; Moseley, Pamela P; Kay, Denise P; Park, Cyrus S; Jones, Paul D; Blankenship, Alan L; Newsted, John L; Giesy, John P

    2007-07-01

    The great horned owl (GHO; Bubo virginianus) was used in a multiple lines of evidence study of polychlorinated biphenyls (PCBs) and p,p'-dichlorodiphenyltrichloroethane (DDT) exposures at the Kalamazoo River Superfund Site (KRSS), Kalamazoo, Michigan, USA. The study examined risks from total PCBs, including 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TEQWorld Health Organization [WHO]-Avian Toxicity Equivalency Factor [TEF]), and total DDTs (sum of DDT, dichlorodiphenyldichloroethylene [DDE], and dichlorodiphenyldichloroethane [DDD]; sigmaDDT) by measuring concentrations in eggs and nestling blood plasma in two regions of the KRSS (upper, lower) and an upstream reference area (RA). An ecological risk assessment compared concentrations of the contaminants of concern (COCs) in eggs or plasma to toxicity reference values. Productivity and relative abundance measures for KRSS GHOs were compared with other GHO populations. Egg shell thickness was measured to assess effects of p,p'-DDE. The concentrations of PCBs in eggs were as great as 4.7 x 10(2) and 4.0 x 10(4) ng PCB/g, wet weight at the RA and combined KRSS sites, respectively. Egg TEQ(WHO-Avian) calculated from aryl hydrocarbon receptor-active PCB congeners and WHO TEFs ranged to 8.0 and 1.9 x 10(2) pg TEQ(WHO-Avian)/g, (wet wt) at the RA and combined KRSS, respectively. Egg sigmaDDT concentrations were as great as 4.2 x 10(2) and 5.0 x 10(3) ng sigmaDDT/g (wet wt) at the RA and combined KRSS, respectively. Hazard quotients (HQs) for the upper 95% confidence interval (UCI) (geometric mean) and least observable adverse effect concentration (LOAEC) for COCs in eggs were < or = 1.0 for all sites. Hazard quotient values based on the no observable adverse effect concentration (NOAEC) 95% UCI in eggs were < or = 1.0, except at the LKRSS (PCB HQ = 3.1; TEQ(WHO-Avian) HQ = 1.3). Productivity and relative abundance measures indicated no population level effects in the UKRSS. PMID:17665678

  6. 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. PMID:24158357

  7. Proventricular adenocarcinoma in a Humboldt penguin (Spheniscus humboldti) and a great horned owl (Bubo virginianus); identification of origin by mucin histochemistry.

    PubMed

    Yonemaru, Kayoko; Sakai, Hiroki; Asaoka, Yoshiji; Yanai, Tokuma; Fukushi, Hideto; Watanabe, Ken; Hirai, Katsuya; Masegi, Toshiaki

    2004-02-01

    Cases of proventricular neoplasm in a Humboldt penguin (Spheniscus humboldti) and a great horned owl (Bubo virginianus) were observed. Microscopically, the neoplastic cells formed branching tubules or acini in both cases. Galactose oxidase-Schiff (GOS) staining revealed that the cytoplasm of the normal surface epithelium and surface mucosubstances of the proventriculus adjacent to the neoplasm were positive in both cases. The neoplastic cells in both cases were also classified as GOS-positive. Therefore, the two proventricular neoplasms in this report were diagnosed as proventricular adenocarcinoma that arose from the proventricular surface epithelium. This study suggests that the mucosubstances, which the neoplastic cells produced, were a useful index for identifying the origin of the neoplastic cells in the birds. PMID:14681071

  8. The identity of Pennant's 'Wapacuthu owl' and the subspecific name for the population of Bubo virginianus from the western Hudson Bay

    USGS Publications Warehouse

    Browning, M.R.; Banks, R.C.

    1991-01-01

    The name Strix wapacuthu Gmelin, often used for the subspecies of Bubo virginianus west of Hudson Bay, cannot be associated with certainty with either B. virginianus or Nyctea scandiaca. The subspecific name of the population of B. virginianus from Mackenzie to central-eastern British Columbia and northern Ontario should be B. v. subarcticus Hoy.

  9. 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. PMID:24344511

  10. Ecological risk assessment of great horned owls (Bubo virginianus) exposed to PCDD/DF in the Tittabawassee River floodplain in Midland, Michigan, USA.

    PubMed

    Coefield, Sarah J; Fredricks, Timothy B; Seston, Rita M; Nadeau, Michael W; Tazelaar, Dustin L; Kay, Denise P; Newsted, John; Giesy, John P; Zwiernik, Matthew J

    2010-10-01

    Soils and sediments downstream of Midland, Michigan, USA have elevated polychlorinated dibenzofuran (PCDF) and polychlorinated dibenzo-p-dioxin (PCDD) concentrations. To determine if the PCDD/DF concentrations have the potential to adversely affect terrestrial avian predators, a site-specific, multiple lines of evidence risk assessment was conducted for the great horned owl (Bubo virginianus; GHO). As long-lived resident top predators, the GHO has the potential to be exposed to relatively great concentrations of bioaccumulative compounds such as PCDD/DF. From 2005 to 2008, concentrations of PCDD/DF were measured in blood plasma of adult and nestling GHOs and addled eggs. Indicators of the condition of the population, including abundance and reproductive success, were collected along 115 km of river corridor. Fifty-five active 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) equivalents (TEQ(WHO-Avian)) nests were monitored in 21 breeding territories from 2005 to 2008. The geometric mean concentration in blood plasma of GHOs was greater in the study area (SA) than in the reference area (RA) for both adults (RA: 3.1; SA: 9.4 ng TEQ(WHO-Avian)/kg) and nestlings (RA: 0.82 ng TEQ(WHO-Avian)/kg, SA: 2.1 ng TEQ(WHO-Avian)/kg) GHOs, but less than concentrations expected to cause adverse effects based on laboratory studies. Concentrations of TEQ(WHO-Avian) in addled GHO eggs were also greater in the SA than the RA (50 and 7.3 ng/kg, wet weight, respectively), but were less than concentrations expected to cause adverse effects. The GHO population condition and productivity were both greater in the study area than in the reference area and were similar to other GHO populations. This result suggests the GHO population in the Tittabawassee River floodplain is consistent with what would be expected for this area. PMID:20872699

  11. 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

  12. Isolated tuberculous lymphadenitis presenting as bilateral buboes

    PubMed Central

    Palanisamy, Arun Prasath; Samuel, Soumya; Vadivel, Sivasubramanian; Kothandapany, Srivenkateswaran

    2015-01-01

    Inguinal and femoral buboes are defined as localized enlargement of lymph nodes in the groin that are painful, and may or may not be fluctuant. We report a case of 42-year-old female who presented with bilateral inguinal swelling of 6 months duration. After a complete evaluation, she was found to be a case of isolated inguinal tuberculous lymphadenitis. There was complete resolution with standard antituberculous therapy. Isolated inguinal tuberculous lymphadenitis though a rare entity in developed countries is not uncommon in developing nations. In this era of syndromic management of sexually transmitted diseases, which carries its own pros and cons, this case report emphasizes the need to look beyond the venereal causes and calls for thorough evaluation and management. PMID:26392662

  13. A cephalic influence on gastric motility upon seeing food in domestic turkeys (Melagris gallopavo), great-horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis).

    PubMed

    Duke, G E; Evanson, O A; Redig, P T

    1976-11-01

    Strain gage transducers were permanently implanted on the muscular stomachs of 13 turkeys, 3 great-horned owls and 2 red-tailed hawks to monitor gastric motility before, during and after eating. Following fasting, the sight of food resulted in significant increases in gastric contractile activity in all three species. Gastric motility further increased when the birds were allowed to eat. In raptors, however, a brief interruption in gastric motility occurred immediately after eating. This is apparently analogous to receptive relaxation which occurs in the stomach of mammals. PMID:1019075

  14. Heavy-metal concentrations in three owl species from Korea.

    PubMed

    Kim, Jungsoo; Lee, Hang; Koo, Tae-Hoe

    2008-01-01

    This study presents concentrations of heavy metals (iron, zinc, manganese, copper, lead, and cadmium) in livers of three owl species from Korea. Essential trace elements (iron, zinc, manganese, and copper) did not differ among the owl species. We suggest that the essential elements are within the normal range and are maintained by normal homeostatic mechanisms. Lead and cadmium concentrations in Eurasian Eagle Owls (Bubo bubo) were significantly lower than in Brown Hawk Owls (Nixos scutulata) and Collared Scops Owls (Otus lempiji). Lead and cadmium concentrations in Korean owl species were at background levels; lead concentrations in two Collared Scops Owls were above background concentrations. Lead and cadmium concentrations were similar to concentrations previously reported in owls from other parts of the world. We suggest that lead and cadmium concentrations in Korean owls are below toxic concentrations. PMID:17955366

  15. Trichomoniasis in great horned owls.

    PubMed

    Jessup, D A

    1980-07-01

    Three cases of Trichomonas gallinae infection of deep tissues of the skull or of unusual tissues in great horned owls (Bubo virginianus), refractory to recommended doses but responsive to higher doses of dimetridazole, are discussed. Trichomonads were isolated from the lesions. PMID:7432340

  16. Mortality in fledgling great horned owls from black fly hematophaga and leucocytozoonosis.

    PubMed

    Hunter, D B; Rohner, C; Currie, D C

    1997-07-01

    Black fly feeding alone and in concert with Leucocytozoon spp. infection caused mortality in fledgling great horned owls (Bubo virginianus) in the Yukon, Canada 1990 to 1991. These mortalities occurred during a year of food shortage corresponding with a decline in the population of snowshoe hare (Lepus americanus), the main prey for great horned owls. We hypothesize an interaction between food availability and the consequences of host-parasite interactions. PMID:9249694

  17. Inclusion body disease in a great horned owl.

    PubMed

    Sileo, L; Carlson, H C; Crumley, S C

    1975-01-01

    The carcass of a great horned owl (Bubo virginianus), which had been found moribund in southern Ontario, was presented for necropsy. Throughout the liver and spleen were numerous white foci 1-2 mm in diameter; also noted were white plaques in the mucosae of the pharyngeal papillae and intestine. Results of light and electron microscopic studies and experimental transmission to two captive great horned owls suggested that this was a herpvirus disease similar and possibly indentical to the owl disease reported by other workers in Wiconsin and Australia. PMID:163384

  18. Experimental rabies in a great horned owl.

    PubMed

    Jorgenson, R D; Gough, P M; Graham, D L

    1976-07-01

    A great horned owl (Bubo virginianus) was fed the carcass of an experimentally infected rabid skunk. The bird developed antibody titer to rabies, detected by passive haemagglutination, 27 days after oral inoculation by ingestion. The owl suppressed the infection until corticosteroid administration, after which a maximum antibody titer was attained. Evidence of active rabies viral infection was seen by fluorescent antibody staining of oral swabs, corneal impression smears and histologic tissue smears, by suckling mouse inoculation of oral swab washings, and by transmission electron microcopy. No clinical signs of rabies virus infection were observed. PMID:16498892

  19. 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.

  20. 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

  1. 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

  2. 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.

  3. Effects of pesticides on owls in North America

    USGS Publications Warehouse

    Blus, L.J.

    1996-01-01

    A literature review of the effects of pesticides on owls in North America showed that relatively few studies have been undertaken. Owls used in experiments seem as sensitive to organochlorine pesticides (OCs) as other birds of prey, but wild owls experienced few serious problems, primarily because they were exposed to lower residues in their predominately mammalian or invertebrate prey. For example, the great horned owl ( Bubo virginianus ) and the common barn-owl ( Tyto alba ) neither experienced marked changes in mortality or recruitment rates nor was there any evidence of population decreases even during the maximum period of OC pesticide use. Also, eggshell thinning was not a widespread problem. There were adverse effects on individual owls including verified records of 74 owls of six species that died from secondary or tertiary poisoning related to strychnine, organochlorines, anticholinesterases (antiChEs) and anticoagulants in 16 states within the U.S. and one province in Canada. Most of the pesticide-related deaths occurred during the 1980s, although this probably does not represent a true temporal distribution. Verified mortalities of owls probably represent a small fraction of the actual number that died from pesticides. Incidence of mortality seems biased geographically toward areas such as New York that have active ecotoxicological programs. Burrowing owl ( Speotyto cunicularia ) populations currently are decreasing throughout much of the range in the U.S. and Canada. Studies in Canada indicate that antiChE pesticides, particularly carbofuran, were responsible for the declines there.

  4. 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. PMID:19826750

  5. 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. PMID:19005679

  6. Clinical and pathologic features of West Nile virus infection in native North American owls (Family strigidae).

    PubMed

    Fitzgerald, S D; Patterson, J S; Kiupel, M; Simmons, H A; Grimes, S D; Sarver, C F; Fulton, R M; Steficek, B A; Cooley, T M; Massey, J P; Sikarskie, J G

    2003-01-01

    Since the initial report of West Nile virus in the northeastern United States in 1999, the virus has spread rapidly westward and southward across the country. In the summer of 2002, several midwestern states reported increased cases of neurologic disease and mortality associated with West Nile virus infection in various native North American owl species. This report summarizes the clinical and pathologic findings for 13 captive and free-ranging owls. Affected species were all in the family Strigidae and included seven snowy owls (Nyctea scandiaca), four great-horned owls (Bubo virginianus), a barred owl (Strix varia), and a short-eared owl (Asio flammeus). Neurologic signs identified included head tilt, uncoordinated flight, paralysis, tremors, and seizures. Owls that died were screened for flaviviral proteins by immunohistochemical staining of formalin-fixed tissues, followed by specific polymerase chain reaction assay to confirm West Nile virus with fresh tissues when available. Microscopic lesions were widespread, involving brain, heart, liver, kidney, and spleen, and were typically nonsuppurative with infiltration by predominantly lymphocytes and plasma cells. Lesions in owls were much more severe than those previously reported in corvids such as crows, which are considered highly susceptible to infection and are routinely used as sentinel species for monitoring for the presence and spread of West Nile virus. This report is the first detailed description of the pathology of West Nile virus infection in Strigiformes and indicates that this bird family is susceptible to natural infection with West Nile virus. PMID:14562887

  7. 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.

  8. Response of great horned owls given the optical isomers of ketamine.

    PubMed

    Redig, P T; Larson, A A; Duke, G E

    1984-01-01

    The relative anesthetic effects of the 2 purified isomers and the racemic mixture of ketamine were compared in 6 great horned owls (Bubo virginianus), a species in which racemic ketamine is poorly tolerated. Other investigators have reported that the L(-) form is only a 3rd as potent as the D(+) form with respect to analgesic action in mammals. Accordingly, the racemic and the - forms were given at 2 X and 3 X, respectively, the dose of the + form in an attempt to achieve a potentially equivalent state of anesthesia. At these dose levels, there was no difference observed in the average duration of anesthesia with the 3 ketamine preparations. The - isomer yielded a poorer anesthetic response characterized by inadequate muscle relaxation, cardiac arrhythmias, and marked excitatory behavior during recovery. With the dosages used, the + form and the racemate were comparable in degree of muscle relaxation produced. The + form yielded smoother inductions and less cardiac arrhythmia than did the racemate. PMID:6703445

  9. 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.

  10. 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

  11. 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. PMID:26920901

  12. Spatial selectivity and binaural responses in the inferior colliculus of the great horned owl.

    PubMed

    Volman, S F; Konishi, M

    1989-09-01

    In this study we have investigated the processing of auditory cues for sound localization in the great horned owl (Bubo virginianus). Previous studies have shown that the barn owl, whose ears are asymmetrically oriented in the vertical plane, has a 2-dimensional, topographic representation of auditory space in the external division of the inferior colliculus (ICx). As in the barn owl, the great horned owl's ICx is anatomically distinct and projects to the optic tectum. Neurons in ICx respond over only a small range of azimuths (mean = 32 degrees), and azimuth is topographically mapped. In contrast to the barn owl, the great horned owl has bilaterally symmetrical ears and its receptive fields are not restricted in elevation. The binaural cues available for sound localization were measured both with cochlear microphonic recordings and with a microphone attached to a probe tube in the auditory canal. Interaural time disparity (ITD) varied monotonically with azimuth. Interaural intensity differences (IID) also changed with azimuth, but the largest IIDs were less than 15 dB, and the variation was not monotonic. Neither ITD nor IID varied systematically with changes in the vertical position of a sound source. We used dichotic stimulation to determine the sensitivity of ICx neurons to these binaural cues. Best ITD of ICx units was topographically mapped and strongly correlated with receptive-field azimuth. The width of ITD tuning curves, measured at 50% of the maximum response, averaged 72 microseconds. All ICx neurons responded only to binaural stimulation and had nonmonotonic IID tuning curves. Best IID was weakly, but significantly, correlated with best ITD (r = 0.39, p less than 0.05). The IID tuning curves, however, were broad (mean 50% width = 24 dB), and 67% of the units had best IIDs within 5 dB of 0 dB IID. ITD tuning was sensitive to variations in IID in the direction opposite to that expected for time-intensity trading, but the magnitude of this effect was only

  13. 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.

  14. Use of whole blood lymphocyte stimulation test for immunocompetency studies in bald eagles, red-tailed hawks, and great horned owls.

    PubMed

    Redig, P T; Dunnette, J L; Sivanandan, V

    1984-11-01

    Mitogen-induced whole blood lymphocyte stimulation tests for immunocompetency studies in bald eagles (Haliaeetus leucocephalus), red-tailed hawks (Buteo jamaicensis), and great horned owls (Bubo virginianus) were developed. Combinations of incubation times, blood dilutions, concentrations of [3H]thymidine and [125I]2-deoxyuridine, antibiotics, phytohemagglutinin-P, and concanavalin A were tested for their effects on the stimulation index (SI). An antibiotic combination of gentamicin plus amphotericin B yielded low SI with lymphocytes from bald eagles, but not with lymphocytes from great horned owls or red-tailed hawks. Penicillin plus streptomycin caused no such depression of SI. Lymphocytes from all 3 species yielded maximum responses with a 48-hour prelabel and 12- to- 16 hour postlabel incubation period at 41 C and 1:20 blood dilution. Optimal mitogen concentrations for lymphocytes from bald eagles, red-tailed hawks, and great horned owls were 25 micrograms, 10 micrograms, and 10 micrograms of phytohemagglutinin-P/well, respectively, and 2.5 micrograms, 10 micrograms, and 10 micrograms of concanavalin A/well, respectively. Differences in SI were not seen between the 2 radioactive labels. The optimal concentration of the [3H]thymidine label ranged from 0.06 to 0.125 microCi/well. PMID:6524727

  15. 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. PMID:17665679

  16. Lead in hawks, falcons and owls downstream from a mining site on the Coeur d'Alene River, Idaho.

    PubMed

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

    1994-02-01

    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 µg/g, wet wt) than the nearby reference area (0.087 µg/g). A 35% inhibition of blood δ-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 µg/g, and nestling 0.24 vs. 0.09 µg/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. PMID:24221348

  17. 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.

  18. 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.)

  19. 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.…

  20. Snowy owl

    USGS Publications Warehouse

    Smith, D.G.; Ellis, D.H.

    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.

  1. 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…

  2. 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.

  3. 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)

  4. 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

  5. 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,…

  6. 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)

  7. Synovial chondromatosis in raptors.

    PubMed

    Stone, E G; Walser, M M; Redig, P T; Rings, B; Howard, D J

    1999-01-01

    Fourteen raptors, consisting of 13 great horned owls (Bubo virginianus) and one red-tailed hawk (Buteo jamaicensis), from central and north central Minnesota, western Wisconsin, and eastern South Dakota (USA) were admitted to a raptor rehabilitation center between June 1992 and June 1995, with perisynovial and synovial chondromatosis affecting multiple joints. Birds were severely debilitated primarily due to loss of shoulder motion. The etiology of these lesions in raptors is unknown. PMID:10073365

  8. Fatal pox infection in a rough-legged hawk.

    PubMed

    Pearson, G L; Pass, D A; Beggs, E C

    1975-04-01

    Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation rsulting from inability to capture prey and to blood loss from foot lesions. PMID:167207

  9. Fatal pox infection in a rough-legged hawk

    USGS Publications Warehouse

    Pearson, G.L.; Pass, D.A.; Beggs, E.C.

    1975-01-01

    Natural pox infection occurred in a free-living rough-legged hawk (Buteo lagopus) in northeastern North Dakota. Gross, histological and electron microscopic findings were typical of pox infection, and characteristic lesions developed in red-tailed hawks (Buteo jamaicensis) but not in great horned owls (Bubo virginianus) following inoculation with case material. Death of the rough-legged hawk was attributed to starvation resulting from inability to capture prey and to blood loss from foot lesions.

  10. 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…

  11. 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.…

  12. 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

  13. 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.

  14. Burrowing Owls, Pulex irritans, and Plague.

    PubMed

    Belthoff, James R; Bernhardt, Scott A; Ball, Christopher L; Gregg, Michael; Johnson, David H; Ketterling, Rachel; Price, Emily; Tinker, Juliette K

    2015-09-01

    Western Burrowing Owls (Athene cunicularia hypugaea) are small, ground-dwelling owls of western North America that frequent prairie dog (Cynomys spp.) towns and other grasslands. Because they rely on rodent prey and occupy burrows once or concurrently inhabited by fossorial mammals, the owls often harbor fleas. We examined the potential role of fleas found on burrowing owls in plague dynamics by evaluating prevalence of Yersinia pestis in fleas collected from burrowing owls and in owl blood. During 2012-2013, fleas and blood were collected from burrowing owls in portions of five states with endemic plague-Idaho, Oregon, Washington, Colorado, and South Dakota. Fleas were enumerated, taxonomically identified, pooled by nest, and assayed for Y. pestis using culturing and molecular (PCR) approaches. Owl blood underwent serological analysis for plague antibodies and nested PCR for detection of Y. pestis. Of more than 4750 fleas collected from owls, Pulex irritans, a known plague vector in portions of its range, comprised more than 99.4%. However, diagnostic tests for Y. pestis of flea pools (culturing and PCR) and owl blood (PCR and serology) were negative. Thus, even though fleas were prevalent on burrowing owls and the potential for a relationship with burrowing owls as a phoretic host of infected fleas exists, we found no evidence of Y. pestis in sampled fleas or in owls that harbored them. We suggest that studies similar to those reported here during plague epizootics will be especially useful for confirming these results. PMID:26367482

  15. 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

  16. Lead and arsenic in bones of birds of prey from Spain.

    PubMed

    Mateo, R; Taggart, M; Meharg, A A

    2003-01-01

    The bones (humerus and/or femur) of 229 birds of prey from 11 species were analyzed for Pb and As to evaluate their exposure to Pb shot. The species with the highest mean Pb levels were red kite (Milvus milvus) and Eurasian griffon (Gyps fulvus), and the species with the lowest levels were Eurasian buzzard (Buteo buteo) and booted eagle (Hieraaetus pennatus). Red kite also had the highest mean As level, an element present in small amounts in Pb shot. Elevated bone Pb concentrations (>10 microg/g dry weight) were found in 10 birds from six species. Clinical signs compatible with lethal Pb poisoning and/or excessive bone Pb concentrations (>20 microg/g) were observed in one Eurasian eagle-owl (Bubo bubo), one red kite, and one Eurasian griffon. Pb poisoning has been diagnosed in eight upland raptor species in Spain to date. PMID:12860107

  17. 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.

  18. 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

  19. 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

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. Noninvasive measures of reproductive function and disturbance in the barred owl, great horned owl, and northern spotted owl.

    PubMed

    Wasser, Samuel K; Hunt, Kathleen E

    2005-06-01

    There is an urgent need for noninvasive methods to study reproduction and environmental stress in at-risk species such as the northern spotted owl (Strix occidentalis caurina). Two related owl species (barred owl and great horned owl) were used as surrogates to validate hormone assays for fecal metabolites of progesterone, 17beta-estradiol, testosterone, and corticosterone. Infusions of radiolabeled hormones showed that the owls excreted most hormone within 6 h. Feces and urine contained roughly equal amounts of hormone, and most fecal hormone metabolites were quite polar. The testosterone and corticosterone assays in this study bound to the major excreted metabolites of these hormones, but two progesterone assays did not appreciably bind to the major progesterone metabolites. All assays showed excellent parallelism with hydrolyzed and unhydrolyzed samples and with previously dried or undried fecal samples. Thus, samples do not require hydrolysis or prior drying. Samples from a female barred owl had significantly higher fecal estrogen, lower fecal testosterone, and higher fecal estrogen/testosterone ratio than samples from two male barred owls. The fecal estrogen/testosterone ratio was the most accurate predictor of owl gender, particularly if two or more samples are available from the same individual. Fecal corticosterone metabolites also demonstrated considerable utility for wild northern spotted owls. Fecal glucocorticoid levels varied by gender and breeding stage, being highest in male northern spotted owls early in the breeding season and highest in females when nestlings were fledging. Collectively, these studies show that noninvasive fecal hormone measurements show great promise for noninvasive assessment of reproduction and stress in wild owls. PMID:16055847

  5. 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)

  6. 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. PMID:23500818

  7. 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…

  8. Visualization of OWL DL using ORM

    NASA Astrophysics Data System (ADS)

    Pan, Wen-Lin; Liu, Da-Xin

    2011-12-01

    The OWL (Web Ontology Language) is the de facto standard ontology description language used by the Semantic Web. Because OWL is mainly designed for use by applications that need to process the content of information, it is difficult to read and understand by domain experts to build or verify domain ontologies expressed by OWL. ORM (Object Role Modeling) is a conceptual modeling language with graphical notations, its models/schemas can be translated into pseudo natural language that make it easier, also for domain experts who is a non-IT specialist, to create, check and adapt the knowledge about the UoD (Universe of Domain). Based on formal logic analysis of OWL DL and ORM and extending ORM notations, mapping rules has been presented to visualize OWL DL ontologies with ORM.

  9. Visualization of OWL DL using ORM

    NASA Astrophysics Data System (ADS)

    Pan, Wen-lin; Liu, Da-xin

    2012-01-01

    The OWL (Web Ontology Language) is the de facto standard ontology description language used by the Semantic Web. Because OWL is mainly designed for use by applications that need to process the content of information, it is difficult to read and understand by domain experts to build or verify domain ontologies expressed by OWL. ORM (Object Role Modeling) is a conceptual modeling language with graphical notations, its models/schemas can be translated into pseudo natural language that make it easier, also for domain experts who is a non-IT specialist, to create, check and adapt the knowledge about the UoD (Universe of Domain). Based on formal logic analysis of OWL DL and ORM and extending ORM notations, mapping rules has been presented to visualize OWL DL ontologies with ORM.

  10. Protein electrophoresis as a diagnostic and prognostic tool in raptor medicine.

    PubMed

    Tatum, L M; Zaias, J; Mealey, B K; Cray, C; Bossart, G D

    2000-12-01

    Plasma proteins of 139 healthy adult birds of prey from 10 species were separated by electrophoresis to characterize and document normal reference ranges and species-specific electrophoretic patternsand to evaluate the value of this technique for health screening, disease diagnosis, and prognostic indication. Species studied included bald eagle (Haliaeetus leucocephalus), red-tailed hawk (Buteo jamaicensis), barn owl (Tyto alba), great horned owl (Bubo virginianus), turkey vulture (Cathartes aura), Harris' hawk (Parabuteo unicinctus), Stellar's sea eagle (Haliaeetus pelagicus), barred owl (Strix varia), screech owl (Otus asio), and black vulture (Coragyps atratus). Several clinical cases show the diagnostic/therapeutic value of protein electrophoresis in raptors. This study establishes species-specific reference ranges for several birds of prey and discusses the benefit of electrophoresis as a diagnostic technique in health screens, as a diagnostic aid in conjunction with other tests, and as a prognostic indicator in clinical evaluation of raptors. PMID:11428396

  11. 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

  12. Formal analysis of ORM using OWL DL

    NASA Astrophysics Data System (ADS)

    Pan, Wen-lin; Liu, Da-xin

    2012-01-01

    ORM (Object Role Modeling), current version is 2.0, is a fully communication oriented information modeling method. Currently, ORM has been used in ontology engineering to model domain ontologies. To ensure the semantics of ORM model is consistent, it needs using reasoning engines to check semantic conflicts and redundancy. Furthermore, only publish ORM domain ontologies on the Semantic Web described by OWL can it is shared by different applications. Therefore, it needs to map ORM models into OWL DL. Several methods to transform ORM models have been considered and a series of general OWL DL formalization rules have been proposed.

  13. Formal analysis of ORM using OWL DL

    NASA Astrophysics Data System (ADS)

    Pan, Wen-Lin; Liu, Da-Xin

    2011-12-01

    ORM (Object Role Modeling), current version is 2.0, is a fully communication oriented information modeling method. Currently, ORM has been used in ontology engineering to model domain ontologies. To ensure the semantics of ORM model is consistent, it needs using reasoning engines to check semantic conflicts and redundancy. Furthermore, only publish ORM domain ontologies on the Semantic Web described by OWL can it is shared by different applications. Therefore, it needs to map ORM models into OWL DL. Several methods to transform ORM models have been considered and a series of general OWL DL formalization rules have been proposed.

  14. Inclusion body disease (herpesvirus infection) of falcons (IBDF).

    PubMed

    Graham, D L; Mare, C J; Ward, F P; Peckham, M C

    1975-01-01

    Inclusion body disease of falcons (IBDF) is caused by a herpesvirus. The clinical course is short, 24 to 72 hours in duration, and is characterized by mild to severe depression and weakness often accompanied by anorexia. The disease is invariably fatal. The virus has a marked affinity for the reticuloendothelial system and hepatocytes,producing focal to diffuse necrosis of infected tissues accompanied by the formation of intranuclear inclusion bodies. The virus is pathogenic for American kestrels (Falco sparverius) and great horned owls (Bubo virginianus) in which typical lesions of IBDF are reproduced. The lesions of IBDF are similar to those produced by some herpesvirus infections in other avian species. PMID:163383

  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

    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..

  18. 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.

  19. 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.

  20. 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.

  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. Paraconsistent Reasoning for OWL 2

    NASA Astrophysics Data System (ADS)

    Ma, Yue; Hitzler, Pascal

    A four-valued description logic has been proposed to reason with description logic based inconsistent knowledge bases. This approach has a distinct advantage that it can be implemented by invoking classical reasoners to keep the same complexity as under the classical semantics. However, this approach has so far only been studied for the basic description logic mathcal{ALC}. In this paper, we further study how to extend the four-valued semantics to the more expressive description logic mathcal{SROIQ} which underlies the forthcoming revision of the Web Ontology Language, OWL 2, and also investigate how it fares when adapted to tractable description logics including mathcal{EL++}, DL-Lite, and Horn-DLs. We define the four-valued semantics along the same lines as for mathcal{ALC} and show that we can retain most of the desired properties.

  3. 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. PMID:26029157

  4. Owls and Larks in Mice

    PubMed Central

    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. PMID:26029157

  5. 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

  6. 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. PMID:24283140

  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. PMID:26662578

  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

    ...We, the U.S. Fish and Wildlife Service, announce the availability of the record of decision (ROD) for the final environmental impact statement (Final EIS) for experimental removal of barred owls to benefit threatened northern spotted owls. We completed a thorough analysis of the environmental, social, and economic considerations and presented it in our Final EIS, which we released to the......

  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. Comparative physiology of sound localization in four species of owls.

    PubMed

    Volman, S F; Konishi, M

    1990-01-01

    Bilateral ear asymmetry is found in some, but not all, species of owls. We investigated the neural basis of sound localization in symmetrical and asymmetrical species, to deduce how ear asymmetry might have evolved from the ancestral condition, by comparing the response properties of neurons in the external nucleus of the inferior colliculus (ICx) of the symmetrical burrowing owl and asymmetrical long-eared owl with previous findings in the symmetrical great horned owl and asymmetrical barn owl. In the ICx of all of these owls, the neurons had spatially restricted receptive fields, and auditory space was topographically mapped. In the symmetrical owls, ICx units were not restricted in elevation, and only azimuth was mapped in ICx. In the barn owl, the space map is two-dimensional, with elevation forming the second dimension. Receptive fields in the long-eared owl were somewhat restricted in elevation, but their tuning was not sharp enough to determine if elevation is mapped. In every species, the primary cue for azimuth was interaural time difference, although ICx units were also tuned for interaural intensity difference (IID). In the barn owl, the IIDs of sounds with frequencies between about 5 and 8 kHz vary systematically with elevation, and the IID selectivity of ICx neurons primarily encodes elevation. In the symmetrical owls, whose ICx neurons do not respond to frequencies above about 5 kHz, IID appears to be a supplementary cue for azimuth. We hypothesize that ear asymmetry can be exploited by owls that have evolved the higher-frequency hearing necessary to generate elevation cues. Thus, the IID selectivity of ICx neurons in symmetrical owls may preadapt them for asymmetry; the neural circuitry that underlies IID selectivity is already present in symmetrical owls, but because IID is not absolutely required to encode azimuth it can come to encode elevation in asymmetrical owls. PMID:2279234

  12. Standardizing Legal Content with OWL and RDF

    NASA Astrophysics Data System (ADS)

    Hondros, Constantine

    Wolters Kluwer is one of the largest legal publishers in the world. Its various publishing units use a multitude of different formats to mark up what is effectively similar content. We describe a common content architecture based on OWL, RDF and XHTML that is used to build a standard representation of legal content, allowing publishable assets to be integrated across the enterprise. This architecture is governed by an OWL ontology that models the (occasionally complex) behaviour of legal documents and acts as a domain model of common legal metadata. How do OWL and RDF scale up to real-world publishing? We describe practical issues in producing and validating RDF on an industrial scale; in performance management; in handling fragmented ontologies; and the challenge of using RDF in a performant XSLT pipeline.

  13. 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.

  14. 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.

  15. 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...

  16. Owl Nebula (M97, NGC 3587)

    NASA Astrophysics Data System (ADS)

    Murdin, P.

    2000-11-01

    A planetary nebula in the constellation Ursa Major, position RA 11 h 14.8 m, dec. +55° 01'. The Owl is 3' across and gets its name from two adjacent dark patches that have the appearance of large eyes. The nebula is eleventh magnitude, and the central star is a faint magnitude 16....

  17. 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)

  18. 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,…

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

    PubMed

    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

  20. 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

  1. 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.

  2. 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. PMID:26545716

  3. 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.

  4. Efficient Query Answering for OWL 2

    NASA Astrophysics Data System (ADS)

    Pérez-Urbina, Héctor; Horrocks, Ian; Motik, Boris

    The QL profile of OWL 2 has been designed so that it is possible to use database technology for query answering via query rewriting. We present a comparison of our resolution based rewriting algorithm with the standard algorithm proposed by Calvanese et al., implementing both and conducting an empirical evaluation using ontologies and queries derived from realistic applications. The results indicate that our algorithm produces significantly smaller rewritings in most cases, which could be important for practicality in realistic applications.

  5. Habitat Suitability Index Models: Barred Owl

    USGS Publications Warehouse

    Allen, Arthur W.

    1987-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the barred owl (Strix varia). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  6. Habitat Suitability Index Models: Spotted Owl

    USGS Publications Warehouse

    Laymon, Stephen A.; Salwasser, Hal; Barrett, Reginald H.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the spotted owl (Strix occidentalis). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  7. 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. PMID:23971220

  8. 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.

  9. How the owl resolves auditory coding ambiguity.

    PubMed

    Mazer, J A

    1998-09-01

    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

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

    USGS Publications Warehouse

    Haig, Susan M.; Wennerberg, L.; 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.

  11. Normal fasting plasma glucose levels in some birds of prey.

    PubMed

    O'Donnell, J A; Garbett, R; Morzenti, A

    1978-10-01

    Blood samples taken from five great horned owls (Bubo virginianus), eight red-tailed hawks (Buteo jamaicensis), four marsh hawks (Circus cyaneus), two prairie falcons (Falco mexicanus), five golden eagles (Aquila chrysaetos), and five white leghorn chickens (Gallus domesticus) that had been fasted for 24 h were used to determine plasma levels of glucose by the glucose oxidase method. The mean plasma glucose levels were: great horned owls 374.6 mg/100 ml, red-tailed hawks 346.5 mg/00 ml, marsh hawks 369.3 mg/100 ml, prairie falcons 414.5 mg/100 ml, golden eagles 368.4 mg/100 ml, and white Leghorn chickens 218.2 mg/100 ml. The plasma glucose levels obtained for the raptorial birds in this study were considerably higher than those found for the chickens. These values are discussed in relation to the carnivorous food habits of raptors. PMID:739587

  12. 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. PMID:24481981

  13. 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…

  14. Hypopi (Acari:Hypoderatidae) from owls (Aves:Strigiformes:Strigidae).

    PubMed

    Pence, D B; Bergan, J F

    1996-09-01

    Hypopi (deutonymphs) of the family Hypoderatidae were found in a barn owl, Tyto alba (Scopoli), and a burrowing owl, Speotyto cunicularia (Molina), from Texas. A redescription is provided for mature specimens of the hypopus of Tytodectes (Tytodectes) tyto Fain from the subcutaneous adipose tissues of the pelvic region in the barn owl. The hypopus of Tytodectes (Tytodectes) speotyto n. sp. is described from specimens in the subcutaneous adipose tissues of the pelvic region and in the adipose tissues of the intermuscular fasciae of the ankle in the burrowing owl. T. (T.) speotyto appears most similar in size and chaetotaxy to T. (T.) glaucidii Cerný described from the Cuban pygmy owl, Glaucidium siju (d'Orbigny), in Cuba, but differs in the presence of a spine on tibia IV, which also occurs in T. (T.) tyto. Both of the former species have the anterior apodemes of coxae I fused in a simple V and lack a sternum. They differ from T. (T.) tyto which has the anterior apodemes of coxae I fused in a Y and there is a well developed sternum. Based on the above 3 described hypopi, the hypoderatids of owls represent an assemblage of small closely related, but easily differentiated, species. The occurrence of a few specimens of Neottialges evansi Fain in the barn owl and Hypodectes (Hypodectoides) propus (Nitzsch) in the burrowing owl probably represent examples of host capture by hypopi that normally occur in cormorants and pigeons, herons or egrets, respectively. PMID:8840691

  15. 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

    ... loss and degradation (55 FR 26114). As a result, conservation efforts for the northern spotted owl have... largely unknown at that time (55 FR 26114, p. 26190). The Recovery Plan summarized information available... Register (74 FR 65546), to solicit participation of: Federal, State, and local agencies; Tribes; and...

  16. Mapping between the OBO and OWL ontology languages

    PubMed Central

    2011-01-01

    Background Ontologies are commonly used in biomedicine to organize concepts to describe domains such as anatomies, environments, experiment, taxonomies etc. NCBO BioPortal currently hosts about 180 different biomedical ontologies. These ontologies have been mainly expressed in either the Open Biomedical Ontology (OBO) format or the Web Ontology Language (OWL). OBO emerged from the Gene Ontology, and supports most of the biomedical ontology content. In comparison, OWL is a Semantic Web language, and is supported by the World Wide Web consortium together with integral query languages, rule languages and distributed infrastructure for information interchange. These features are highly desirable for the OBO content as well. A convenient method for leveraging these features for OBO ontologies is by transforming OBO ontologies to OWL. Results We have developed a methodology for translating OBO ontologies to OWL using the organization of the Semantic Web itself to guide the work. The approach reveals that the constructs of OBO can be grouped together to form a similar layer cake. Thus we were able to decompose the problem into two parts. Most OBO constructs have easy and obvious equivalence to a construct in OWL. A small subset of OBO constructs requires deeper consideration. We have defined transformations for all constructs in an effort to foster a standard common mapping between OBO and OWL. Our mapping produces OWL-DL, a Description Logics based subset of OWL with desirable computational properties for efficiency and correctness. Our Java implementation of the mapping is part of the official Gene Ontology project source. Conclusions Our transformation system provides a lossless roundtrip mapping for OBO ontologies, i.e. an OBO ontology may be translated to OWL and back without loss of knowledge. In addition, it provides a roadmap for bridging the gap between the two ontology languages in order to enable the use of ontology content in a language independent manner

  17. 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.

  18. OWL-Orbital Wide-angle Light-collector for the air watch program, and multiple OWL

    NASA Astrophysics Data System (ADS)

    Ebisuzaki, Toshikazu; Takahashi, Yoshiyuki; Mohri, Mamoru; Dimmock, John O.; Hillman, Lloyd W.; Hadaway, James B.; Lamb, David J.; Handa, Toshihiro

    2000-01-01

    The International Space Station (ISS) will revolutionize scientific experimentation by providing a platform upon which some of the most ambitious projects yet conceived may be constructed, operated, and deployed. The Orbiting Wide-angle Light-collector (OWL-Airwatch) is a proposed space-based extensive air shower observatory which will detect a significant number of cosmic rays with energies above 1020 eV (Takahashi, 1996; Streitmatter, 1998; DeMarzo, 1998). A complete understanding of the origins and propagation of these particles may only be possible by introducing new and exotic physical mechanisms, and OWL-Airwatch may provide the first definitive evidence for the existence and decay of topological defects and other such exotic phenomena. There also exists the possibility of detecting high energy neutrinos as well as observing the effects of quantum gravity with the OWL-Airwatch instrument. Although the first OWL-Airwatch mission is planned as a free-flying observatory, its scientific abilities can be greatly enhanced by moving to a so-called multi-OWL configuration with the resources available on the ISS. The current OWL-Airwatch mission will observe nitrogen fluorescence resulting from cosmic ray induced extensive air showers in the earth's atmosphere. Observing from space enables a large enough portion of the earth to be viewed such that a statistically significant number of the rare highest energy events can be detected within the life span of the mission. A second phase multi-OWL system fabricated and assembled on the ISS would further increase the threshold and statistics of the OWL-Airwatch mission. In this scheme, as many as seven OWL-Airwatch instruments would be assembled and deployed from the ISS. These seven units would cover the entire horizon of the earth's atmosphere at an orbit of 1000 km and would accurately map the cosmic ray spectrum beyond 1021 eV. .

  19. 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. PMID:27066328

  20. 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.

  1. Biomechanics of dromaeosaurid dinosaur claws: application of X-ray microtomography, nanoindentation, and finite element analysis.

    PubMed

    Manning, Phillip L; Margetts, Lee; Johnson, Mark R; Withers, Philip J; Sellers, William I; Falkingham, Peter L; Mummery, Paul M; Barrett, Paul M; Raymont, David R

    2009-09-01

    Dromaeosaurid theropod dinosaurs, such as Velociraptor, possess strongly recurved, hypertrophied and hyperextensible ungual claws on the pes (digit II) and manus. The morphology of these unguals has been linked to the capture and despatching of prey. However, the mechanical properties or, more importantly, the mechanical potential of these structures have not been explored. Generation of a 3D finite element (FE) stress/strain contour map of a Velociraptor manual ungual has allowed us to evaluate quantitatively the mechanical behavior of a dromaeosaurid claw for the first time. An X-ray microtomography scan allowed construction of an accurate 3D FE mesh. Analogue material from an extant avian theropod, the pedal digit and claw of an eagle owl (Bubo bubo), was analyzed to provide input data for the Velociraptor claw FE model (FEM). The resultant FEM confirms that dromaeosaurid claws were well-adapted for climbing as they would have been resistant to forces acting in a single (longitudinal) plane, in this case due to gravity. However, the strength of the unguals was limited with respect to forces acting tangential to the long-axis of the claw. The tip of the claw functioned as the puncturing and gripping element of the structure, whereas the expanded proximal portion transferred the load stress through the trabeculae and cortical bone. Enhanced climbing abilities of dromaeosaurid dinosaurs supports a scansorial phase in the evolution of flight. PMID:19711472

  2. 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. PMID:18766791

  3. 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

  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. How do owls localize interaurally phase-ambiguous signals?

    PubMed

    Saberi, K; Farahbod, H; Konishi, M

    1998-05-26

    Owls and other animals, including humans, use the difference in arrival time of sounds between the ears to determine the direction of a sound source in the horizontal plane. When an interaural time difference (ITD) is conveyed by a narrowband signal such as a tone, human beings may fail to derive the direction represented by that ITD. This is because they cannot distinguish the true ITD contained in the signal from its phase equivalents that are ITD +/- nT, where T is the period of the stimulus tone and n is an integer. This uncertainty is called phase-ambiguity. All ITD-sensitive neurons in birds and mammals respond to an ITD and its phase equivalents when the ITD is contained in narrowband signals. It is not known, however, if these animals show phase-ambiguity in the localization of narrowband signals. The present work shows that barn owls (Tyto alba) experience phase-ambiguity in the localization of tones delivered by earphones. We used sound-induced head-turning responses to measure the sound-source directions perceived by two owls. In both owls, head-turning angles varied as a sinusoidal function of ITD. One owl always pointed to the direction represented by the smaller of the two ITDs, whereas a second owl always chose the direction represented by the larger ITD (i.e., ITD - T). PMID:9600989

  8. Moving Objects in the Barn Owl's Auditory World.

    PubMed

    Langemann, Ulrike; Krumm, Bianca; Liebner, Katharina; Beutelmann, Rainer; Klump, Georg M

    2016-01-01

    Barn owls are keen hunters of moving prey. They have evolved an auditory system with impressive anatomical and physiological specializations for localizing their prey. Here we present behavioural data on the owl's sensitivity for discriminating acoustic motion direction in azimuth that, for the first time, allow a direct comparison of neuronal and perceptual sensitivity for acoustic motion in the same model species. We trained two birds to report a change in motion direction within a series of repeating wideband noise stimuli. For any trial the starting point, motion direction, velocity (53-2400°/s), duration (30-225 ms) and angular range (12-72°) of the noise sweeps were randomized. Each test stimulus had a motion direction being opposite to that of the reference stimuli. Stimuli were presented in the frontal or the lateral auditory space. The angular extent of the motion had a large effect on the owl's discrimination sensitivity allowing a better discrimination for a larger angular range of the motion. In contrast, stimulus velocity or stimulus duration had a smaller, although significant effect. Overall there was no difference in the owls' behavioural performance between "inward" noise sweeps (moving from lateral to frontal) compared to "outward" noise sweeps (moving from frontal to lateral). The owls did, however, respond more often to stimuli with changing motion direction in the frontal compared to the lateral space. The results of the behavioural experiments are discussed in relation to the neuronal representation of motion cues in the barn owl auditory midbrain. PMID:27080662

  9. 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.

  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. PMID:25973627

  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. High seroprevalence of antibodies to Toxoplasma gondii in wild animals from Portugal.

    PubMed

    Lopes, Ana Patrícia; Sargo, Roberto; Rodrigues, Manuela; Cardoso, Luís

    2011-05-01

    We report an investigation of antibodies to Toxoplasma gondii in 52 wild birds and 20 wild mammals from northern and central areas of Portugal by using the modified agglutination test. The birds comprised 26 common buzzards (Buteo buteo), five tawny owls (Strix aluco), four white storks (Ceconia ceconia), three Eurasian eagle owls (Bubo bubo), three northern goshawks (Accipiter gentilis), two booted eagles (Hieraaetus pennatus), two common barn owls (Tyto alba), two Eurasian sparrowhawks (Accipiter nisus), two short-toed eagles (Circaetus gallicus), one black kite (Milvus migrans), one Griffin vulture (Gyps fulvus), and one peregrine falcon (Falco peregrinus). The mammals were eight wild boars (Sus scrofa), six red foxes (Vulpes vulpes), two common genets (Genetta genetta), two European badgers (Meles meles), one European roe deer (Capreolus capreolus), and one Iberian wolf (Canis lupus signatus). Fifty percent of the wild birds and 90% of the wild mammals were seropositive; the overall seroprevalence of infection was 61.1%. When comparing the prevalence of antibodies in birds and mammals from northern Portugal, a significant difference was found, but the same was not true for birds and mammals from central Portugal. Seroprevalence levels were 30.0% in juvenile and 62.5% in adult birds (p=0.046), 0.0% in juvenile and 94.7% in adult mammals (p=0.100), 80.0% in female and 66.7% in male birds (p=1.000), and 81.8% in female and 100% in male mammals (p=0.479). This is the first study performed on T. gondii in birds of prey, white storks, and wild carnivores in Portugal. PMID:21104273

  13. Intraguild predation leads to cascading effects on habitat choice, behaviour and reproductive performance.

    PubMed

    Mueller, Anna-Katharina; Chakarov, Nayden; Heseker, Hanna; Krüger, Oliver

    2016-05-01

    Intraguild predation (IGP) is a commonly recognized mechanism influencing the community structure of predators, but the complex interactions are notoriously difficult to disentangle. The mesopredator suppression hypothesis predicts that a superpredator may either simultaneously repress two mesopredators, restrain the dominant one and thereby release the subdominant mesopredator, or elicit different responses by both mesopredators. We show the outcome arising from such conditions in a three-level predator assemblage (Eurasian eagle owl Bubo bubo L., northern goshawk Accipiter gentilis L. and common buzzard Buteo buteo L.) studied over 25 years. In the second half of the study period, the eagle owl re-colonized the study area, thereby providing a natural experiment of superpredator introduction. We combined this set-up with detailed GIS analysis of habitat use and a field experiment simulating intrusion by the superpredator into territories of the subdominant mesopredator, the buzzard. Although population trends were positive for all three species in the assemblage, the proportion of failed breeding attempts increased significantly in both mesopredators after the superpredator re-colonized the area. We predicted that superpredator-induced niche shifts in the dominant mesopredator may facilitate mesopredator coexistence in superpredator-free refugia. We found significant changes in nesting habitat choice in goshawk, but not in buzzard. Since competition for enemy-free refugia and the rapid increase in population density may have constrained niche shifts of the subdominant mesopredator, we further predicted behavioural changes in response to the superpredator. The field experiment indeed showed a significant increase in aggressive response of buzzards towards eagle owl territory intrusion over the course of 10 years, probably due to phenotypic plasticity in the response towards superpredation risk. Overall, our results show that intraguild predation can be a powerful

  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. PMID:22216719

  16. 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.

  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. 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. PMID:26602354

  19. 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.

  20. 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.

  1. Traffic noise reduces foraging efficiency in wild owls.

    PubMed

    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

  2. A high absorption coefficient DL-MPP imitating owl skin

    NASA Astrophysics Data System (ADS)

    Guo, Lijun; Zhao, Zhan; Kong, Deyi; Wu, Shaohua; Du, Lidong; Fang, Zhen

    2012-11-01

    This paper proposes a high absorption coefficient micro-perforated panel (MPP) imitating owl skin structure for acoustic noise reduction. Compared to the traditional micro-perforated panel, this device has two unique characteristics-simulating the owl skin structure, its radius of perforated apertures even can be as small as 55μ, and its material is silicon and fabricated by micro-electrical mechanical system (MEMS) technology; So that its absorption coefficients of acoustic noise for normal incidence sound wave whose frequencies arrange from 1.5 kHz to 6.0 kHz are all above 0.8 which is the owl's hunts sensitivity frequency band. Double leaf MPP fabricated by MEMS technology is an absolutely bionic success in functional-imitation.

  3. Representing lexical components of medical terminologies in OWL.

    PubMed

    Supekar, Kaustubh; Chute, Christopher G; Solbrig, Harold

    2005-01-01

    Medical Terminologies play a vital role in clinical data capture, reporting, information integration, indexing and retrieval. The Web Ontology language (OWL) provides an opportunity for the medical community to leverage the capabilities of OWL semantics and tools to build formal, sound and consistent medical terminologies, and to provide a standard web accessible medium for inter-operability,access and reuse. One of the tasks facing the medical community today is to represent the extensive terminology content that already exists into this new medium. This paper addresses one aspect of this challenge - how to incorporate multilingual, structured lexical information such as definitions, synonyms, usage notes, etc. into the OWL ontology model in a standardized, consistent and useful fashion. PMID:16779134

  4. 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.

  5. 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

  6. Nanostructures Enabled by On-Wire Lithography (OWL)

    PubMed Central

    Braunschweig, Adam B.; Schmucker, Abrin L.; Wei, Wei David; Mirkin, Chad A.

    2010-01-01

    Nanostructures fabricated by a novel technique, termed On-Wire-Lithography (OWL), can be combined with organic and biological molecules to create systems with emergent and highly functional properties. OWL is a template-based, electrochemical process for forming gapped cylindrical structures on a solid support, with feature sizes (both gap and segment length) that can be controlled on the sub-100 nm length scale. Structures prepared by this method have provided valuable insight into the plasmonic properties of noble metal nanomaterials and have formed the basis for novel molecular electronic, encoding, and biological detection devices. PMID:20396668

  7. Cross: An OWL Wrapper for Reasoning on Relational Databases

    NASA Astrophysics Data System (ADS)

    Champin, Pierre-Antoine; Houben, Geert-Jan; Thiran, Philippe

    One of the challenges of the Semantic Web is to integrate the huge amount of information already available on the standard Web, usually stored in relational databases. In this paper, we propose a formalization of a logic model of relational databases, and a transformation of that model into OWL, a Semantic Web language. This transformation is implemented in Cross, as an open-source prototype. We prove a relation between the notion of legal database state and the consistency of the corresponding OWL knowledge base. We then show how that transformation can prove useful to enhance databases, and integrate them in the Semantic Web.

  8. 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

  9. Axonal delay lines for time measurement in the owl's brainstem.

    PubMed

    Carr, C E; Konishi, M

    1988-11-01

    Interaural time difference is an important cue for sound localization. In the barn owl (Tyto alba) neuronal sensitivity to this disparity originates in the brainstem nucleus laminaris. Afferents from the ipsilateral and contralateral magnocellular cochlear nuclei enter the nucleus laminaris through its dorsal and ventral surfaces, respectively, and interdigitate in the nucleus. Intracellular recordings from these afferents show orderly changes in conduction delay with depth in the nucleus. These changes are comparable to the range of interaural time differences available to the owl. Thus, these afferent axons act as delay lines and provide anatomical and physiological bases for a neuronal map of interaural time differences in the nucleus laminaris. PMID:3186725

  10. Complete OWL-DL Reasoning Using Relational Databases

    NASA Astrophysics Data System (ADS)

    Del Mar Roldan-Garcia, Maria; Aldana-Montes, Jose F.

    Real Semantic Web applications, such as biological tools, use large ontologies, that is, ontologies with a large number (millions) of instances. Due to the increasing development of such applications, it is necessary to provide scalable and efficient ontology querying and reasoning systems. DBOWL is a Persistent and Scalable OWL reasoner which stores ontologies and implements reasoning using a relational database. In this paper we present an extension of DBOWL that implements all inference rules for OWL-DL. Furthermore, we describe briefly the reasoning algorithms and their completeness proofs.

  11. 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. PMID:3914842

  12. 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.

    2016-01-01

    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.

  13. Vaccinia recombinant virus expressing the rabies virus glycoprotein: safety and efficacy trials in Canadian wildlife.

    PubMed Central

    Artois, M; Charlton, K M; Tolson, N D; Casey, G A; Knowles, M K; Campbell, J B

    1990-01-01

    Twenty-six meadow voles (Microtus pennsylvanicus), ten woodchucks (Marmota monax), thirteen grey squirrels (Sciurus carolinensis), thirteen ring-billed gulls (Larus delawarensis), six red-tailed hawks (Buteo jamaicensis) and eight great horned owls (Bubo virginianus) received vaccinia virus recombinant expressing the rabies virus glycoprotein (V-RG) by direct instillation into the oral cavity. Each of ten coyotes (Canis latrans) received the virus in two vaccine-laden baits. Several voles and most of the gulls died from diseases unrelated to vaccination during the observation period, but all other animals remained healthy and survived. These deaths from causes other than vaccination and the absence of any lesions suggestive of vaccinia infection indicate that it is unlikely that any animal suffered or died as a result of V-RG administration. In addition several animals showed an unexpected high level of rabies neutralizing antibodies. PMID:2249183

  14. 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. PMID:3586207

  15. The fine structure of elongate gametocytes of Leucocytozoon ziemanni (Laveran).

    PubMed

    Kocan, A A; Kocan, K M

    1978-12-01

    In an effort to establish comparative data within the genus Leucocytozoon, elongate gametocytes of L. ziemanni from naturally infected great horned owls (Bubo virginianus) were examined by electron microscopy. Micro- and macrogametocytes proved to be easily distinguishable at the electron microscopic level due to dramatic dimorphism at maturity and cytoplasmic and nuclear morphology. The parasite membrane architecture, number and type of cytoplasmic ribosomes of both micro- and macrogametocytes, presence and arrangement of osmiophilic bodies and electron dense spheres, mitochondrial morphology, endoplasmic reticulum cisternae morphology, mitochondria containing pocket infoldings of the nuclear membrane of the microgametocytes, and cytostome and food vacuole formation compare favorably with available information on L. simondi and L. smithi. Comparative variations exist only in that L. ziemanni gametocytes apparently lack compartmentalization of the cytoplasm by aligned unit membranes and parasite induced separations of the host cell nucleus as reported for L. simondi. PMID:105117

  16. Vaccinia recombinant virus expressing the rabies virus glycoprotein: safety and efficacy trials in Canadian wildlife.

    PubMed

    Artois, M; Charlton, K M; Tolson, N D; Casey, G A; Knowles, M K; Campbell, J B

    1990-10-01

    Twenty-six meadow voles (Microtus pennsylvanicus), ten woodchucks (Marmota monax), thirteen grey squirrels (Sciurus carolinensis), thirteen ring-billed gulls (Larus delawarensis), six red-tailed hawks (Buteo jamaicensis) and eight great horned owls (Bubo virginianus) received vaccinia virus recombinant expressing the rabies virus glycoprotein (V-RG) by direct instillation into the oral cavity. Each of ten coyotes (Canis latrans) received the virus in two vaccine-laden baits. Several voles and most of the gulls died from diseases unrelated to vaccination during the observation period, but all other animals remained healthy and survived. These deaths from causes other than vaccination and the absence of any lesions suggestive of vaccinia infection indicate that it is unlikely that any animal suffered or died as a result of V-RG administration. In addition several animals showed an unexpected high level of rabies neutralizing antibodies. PMID:2249183

  17. 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.

  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. PMID:22856203

  19. Mesopredator Release by an Emergent Superpredator: A Natural Experiment of Predation in a Three Level Guild

    PubMed Central

    Chakarov, Nayden; Krüger, Oliver

    2010-01-01

    Background Intraguild predation (IGP) is widespread but it is often neglected that guilds commonly include many layers of dominance within. This could obscure the effects of IGP making unclear whether the intermediate or the bottom mesopredator will bear higher costs from the emergence of a new top predator. Methodology/Principal Findings In one of the most extensive datasets of avian IGP, we analyse the impact of recolonization of a superpredator, the eagle owl Bubo bubo on breeding success, territorial dynamics and population densities of two mesopredators, the northern goshawk Accipiter gentilis and its IG prey, the common buzzard Buteo buteo. The data covers more than two decades and encompass three adjacent plots. Eagle owls only recolonized the central plot during the second decade, thereby providing a natural experiment. Both species showed a decrease in standardized reproductive success and an increase in brood failure within 1.5 km of the superpredator. During the second decade, territory dynamics of goshawks was significantly higher in the central plot compared to both other plots. No such pattern existed in buzzards. Goshawk density in the second decade decreased in the central plot, while it increased in both other plots. Buzzard density in the second decade rapidly increased in the north, remained unchanged in the south and increased moderately in the center in a probable case of mesopredator release. Conclusions/Significance Our study finds support for top-down control on the intermediate mesopredator and both top-down and bottom-up control of the bottom mesopredator. In the face of considerable costs of IGP, both species probably compete to breed in predator-free refugia, which get mostly occupied by the dominant raptor. Therefore for mesopredators the outcome of IGP might depend directly on the number of dominance levels which supersede them. PMID:21151912

  20. 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.

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

    PubMed

    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. PMID:25847092

  2. 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

  3. Mapping ORM 2.0 into OWL 2

    NASA Astrophysics Data System (ADS)

    Pan, Wen-lin; Liu, Da-xin

    2011-12-01

    ORM (Object Role Modeling) has been used as an ontology modeling language to model domain ontologies. In order to publish domain ontologies modeled in ORM on the Semantic Web, it needs to translate ORM models into OWL 2, the latest standard Web Ontology Language. Several equivalent transformation methods for ORM model have been considered and a series of mapping rules have been presented.

  4. 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 experiences). (JC)

  5. 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…

  6. 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…

  7. 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.

  8. Spatiotemporal frequency and speed tuning in the owl visual wulst.

    PubMed

    Pinto, Lucas; Baron, Jerome

    2009-10-01

    The avian visual wulst is hodologically equivalent to the mammalian primary visual cortex (V1). In contrast to most birds, owls have a massive visual wulst, which shares striking functional similarities with V1. To provide a better understanding of how motion is processed within this area, we used sinusoidal gratings to characterize the spatiotemporal frequency and speed tuning profiles of 131 neurones recorded from awake burrowing owls. Cells were found to be clearly tuned to both spatial and temporal frequencies, and in a way that is similar to what has been reported in the striate cortex of primates and carnivores. Our results also suggest the presence of spatial frequency tuning domains in the wulst. Speed tuning was assessed by several methods devised to measure the degree of dependence between spatial and temporal frequency tuning. Although many neurones were found to be independently tuned, a significant proportion of cells showed at least some degree of dependence, compatible with the idea that some kind of initial transformation towards an explicit representation of speed is being carried out by the owl wulst. Interestingly, under certain constraints, a higher incidence of spatial frequency-invariant speed tuned profiles was obtained by combining our experimentally measured responses using a recent cortical model of speed tuning. Overall, our findings reinforce the notion that, like V1, the owl wulst is an important initial stage for motion processing, a function that is usually attributed to areas of the tectofugal pathway in lateral-eyed birds. PMID:19788573

  9. Prevalence of encysted Toxoplasma gondii in raptors from Alabama.

    PubMed

    Lindsay, D S; Smith, P C; Hoerr, F J; Blagburn, B L

    1993-12-01

    Little is known about the prevalence of encysted Toxoplasma gondii in wild birds. We examined the hearts and breast muscles from 101 raptors for encysted T. gondii. All of the raptors had been submitted for necropsy to the State Veterinary Diagnostic Laboratory, Auburn, Alabama. Tissues were digested in acid-pepsin solution and inoculated into groups of 3-5 laboratory mice. Toxoplasma gondii was isolated from 27 of 101 (26.7%) raptors: 8 of 12 (66.7%) red-shouldered hawks (Buteo lineatus), 13 of 27 (41.1%) red-tailed hawks (Buteo jamaicensis), 1 of 4 (25%) Cooper's hawks (Accipiter cooperi), 1 of 5 (20%) great horned owls (Bubo virginianus), 4 of 15 (26.7%) barred owls (Strix varia), and 1 of 3 (33.3%) kestrels (Falco sparverius). Toxoplasma gondii was not isolated from 3 broad-winged hawks (Buteo platypterus), 3 sharp-shinned hawks (Accipiter striatus), 6 barn owls (Tyto alba), 9 screech owls (Asio otus), a Mississippi kite (Ictinia misisippiensis), 2 golden eagles (Aquila chrysaetos), a bald eagle (Haliaeetus leucocephalus), 4 ospreys (Pandion haliaetus), 4 turkey vultures (Cathartes aura), or 2 black vultures (Coragyps atratus). No significant difference (P > 0.05) in prevalence was detected based on sex using chi-square analysis. Chi-square analysis of the data demonstrated that adult raptors had encysted stages of T. gondii significantly (P < 0.05) more often than did immature raptors. PMID:8277379

  10. Prevalence of encysted apicomplexans in muscles of raptors.

    PubMed

    Lindsay, D S; Blagburn, B L

    1999-01-28

    An acid-pepsin digestion technique was used to examine portions of breast muscle and heart from raptors for encysted protozoans. Apicomplexan zoites were present in 52 (45.6%) of the 114 samples examined: 11 of 12 (91.7%) red-shouldered hawks (Buteo lineatus), 20 of 34 (58.8%) red-tailed hawks (Buteo jamaicensis), two of seven (28.6%) Cooper's hawks (Accipiter cooperi), three of four (75%) sharp-shinned hawks (Accipiter striatus), one (100%) Mississippi kites (Ictinia misisippiensis), one of two (50%) American kestrels (Falco sparverius), one bald eagle (Haliaeetus leucocephalus), one of two (50%) golden eagles (Aquila chrysaetos), one of three (33%) turkey vultures (Cathartes aura), two of three (66.7%) black vultures (Coragyps atratus), three of six (50%) great-horned owls (Bubo virginianus), five of 15 (33.3%) barred owls (Strix varia), and one of 12 (8.3%) screech owls (Asio otus). Encysted protozoans were not observed in digests of tissues from three broad-winged hawks (Buteo platypterus), four ospreys (Pandion haliaetus), and five barn owls (Tyto alba). Apicomplexan cysts resembling Sarcocystis species were observed in tissue sections of muscles from 28 (37.8%) of 74 raptors. PMID:9950339

  11. 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. PMID:23296024

  12. 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.

  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. 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. PMID:26262167

  15. Detecting West Nile Virus in Owls and Raptors by an Antigen-capture Assay

    PubMed Central

    Campbell, Douglas G.; Barker, Ian K.; Lindsay, Robbin; Hunter, Bruce

    2004-01-01

    We evaluated a rapid antigen-capture assay (VecTest) for detection of West Nile virus in oropharyngeal and cloacal swabs, collected at necropsy from owls (N = 93) and raptors (N = 27). Sensitivity was 93.5%–95.2% for northern owl species but <42.9% for all other species. Specificity was 100% for owls and 85.7% for raptors. PMID:15663862

  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. Acoustic surveys for Mexican spotted owls (Strix occidentalis lucida): An analysis

    NASA Astrophysics Data System (ADS)

    Bowles, Ann E.; Martindell, Chris; Plotkin, Kenneth J.; Ikelheimer, Bruce; Lavallee, Tim

    2002-05-01

    During acoustic surveys for Mexican spotted owls, the effective detection range is presumed to be 0.25 mi (433 m). However, variations within and between surveys are observed, leading to a variance in owl density estimates. While owl behavior may explain some variation, topography and ambient noise are also likely to be important. To determine the influence of these factors, data from acoustic surveys for Mexican spotted owls in the Gila National Forest (April-July, 2000-2001) were examined. Measurements of owl and human call levels were made with a Sony TCD-10 Pro II DAT equipped with an ACO 7013 microphone. Ambient noise was collected using 40 Larson-Davis 820 and 824 sound level meters in owl activity centers. Wyle Laboratories NMSIM software was used to model propagation of owl and human calls. Owls produced calls with estimated maximum source levels of 92-98-dB SPL. Human callers produced maximum source levels of 88-95-dB SPL. Detection was possible out to more than 2 km under ideal conditions, but topography and ambient noise had a large effect. Corrections for these factors would greatly improve estimates of area surveyed, and thus owl density estimates. [Work supported by the U.S. Air Force, Air Combat Command.

  19. 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.

  20. Density and habitat associations of Barred Owls at the edge of their range in Oklahoma

    USGS Publications Warehouse

    Winton, Brian R.; Leslie, David M., Jr.

    2004-01-01

    We assessed breeding-pair density and habitat associations of Barred Owls (Strix varia) at the edge of their range in north-central Oklahoma in 1995-1996. We played taped calls of Barred Owls to solicit and record responses (visual and auditory) and thereby determine density in our 1155-ha study area. Numbers of owls ranged from 7 pairs in 1995 to 11 pairs in 1996, or 1 Barred Owl pair/105-165 ha in a relatively contiguous bottomland forest. To assess habitat associations, we overlaid core areas of owl activity, as inferred from the locations of Barred Owl responses, on aerial photographs and quantified habitats in a 0.65-km2 cell surrounding owl core areas. Barred owl pairs were associated with closed-canopy forest (62.8%), fallow agricultural fields (10.6%), water (8.1%), and treeless (open) areas (6.2%), which differed from single owls (presumed nonbreeders) that showed a greater affinity for open-canopy forest and agricultural fields.

  1. Adaptation of the Panama II strain of Plasmodium falciparum to Panamanian owl monkeys.

    PubMed

    Rossan, R N; Baerg, D C

    1987-09-01

    The Panama II strain of Plasmodium falciparum, acquired at the second passage level in splenectomized Colombian owl monkeys, was adapted to owl monkeys of Panamanian origin. Patent infections were induced in 22 of 27 unaltered and 20 of 21 splenectomized recipients during 19 serial passages. The infections were significantly more virulent in splenectomized than normal Panamanian owl monkeys, however recrudescences in seven normal monkeys achieved peak parasitemias 48 times greater than in the primary attack. These results describe the first reproducible infections of indigenous falciparum malaria in Panamanian owl monkeys. PMID:3310680

  2. 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.

  3. 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.

  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. 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.

  7. Barn Owl Productivity Response to Variability of Vole Populations.

    PubMed

    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

  8. Auditory spatial discrimination by barn owls in simulated echoic conditions

    NASA Astrophysics Data System (ADS)

    Spitzer, Matthew W.; Bala, Avinash D. S.; Takahashi, Terry T.

    2003-03-01

    In humans, directional hearing in reverberant conditions is characterized by a ``precedence effect,'' whereby directional information conveyed by leading sounds dominates perceived location, and listeners are relatively insensitive to directional information conveyed by lagging sounds. Behavioral studies provide evidence of precedence phenomena in a wide range of species. The present study employs a discrimination paradigm, based on habituation and recovery of the pupillary dilation response, to provide quantitative measures of precedence phenomena in the barn owl. As in humans, the owl's ability to discriminate changes in the location of lagging sources is impaired relative to that for single sources. Spatial discrimination of lead sources is also impaired, but to a lesser extent than discrimination of lagging sources. Results of a control experiment indicate that sensitivity to monaural cues cannot account for discrimination of lag source location. Thus, impairment of discrimination ability in the two-source conditions most likely reflects a reduction in sensitivity to binaural directional information. These results demonstrate a similarity of precedence effect phenomena in barn owls and humans, and provide a basis for quantitative comparison with neuronal data from the same species.

  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. 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.

  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. 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…

  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. 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 ...

  17. 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…

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

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-05

    ... 28, 2012 [FR Doc. 2012-5369 Filed 3-2-12; 8:45 am] Billing code 4310-10-P ...#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...

  19. 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. PMID:22834547

  20. "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 participation of successive…

  1. 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.

  2. 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

  3. 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. PMID:22946375

  4. Tonometry of normal eyes in raptors.

    PubMed

    Stiles, J; Buyukmihci, N C; Farver, T B

    1994-04-01

    An applanation tonometer was used to estimate intraocular pressure in normal eyes of several species of raptors. No bird had active injury or illness, though some were nonreleasable to the wild because of previous injury. Mean (+/- SD) intraocular pressure was 20.6 (+/- 3.4) mm of Hg in red-tailed hawks (Buteo jamaicensis, n = 10), 20.8 (+/- 2.3) mm of Hg in Swainson's hawks (Buteo swainsoni, n = 6), 21.5 (+/- 3.0) mm of Hg in golden eagles (Aquila chrysaetos, n = 7), 20.6 (+/- 2.0) mm of Hg in bald eagles (Haliaeetus leucocephalus, n = 3), and 10.8 (+/- 3.6) mm of Hg in great horned owls (Bubo virginianus, n = 6). There was no significant difference in intraocular pressure between hawks and eagles. Mean pressure in great horned owls was significantly (P < 0.01) lower than pressure in hawks or eagles. Reliable intraocular pressure readings could not be obtained in barn owls (Tyto alba). PMID:8017692

  5. Plasmodium forresteri n. sp., from raptors in Florida and southern Georgia: its distinction from Plasmodium elongatum morphologically within and among host species and by vector susceptibility.

    PubMed

    Telford, S R; Nayar, J K; Foster, G W; Knight, J W

    1997-10-01

    Plasmodium forresteri n. sp. naturally infects eastern screech-owls (Otus asio), great horned owls (Bubo virginianus), barred owls (Strix varia), bald eagles (Haliaeetus leucocephalus), red-shouldered hawks (Buteo lineatus), broad-winged hawks (Buteo platypterus), and red-tailed hawks (Buteo jamaicensis) in Florida and southern Georgia. Schizonts occur in mature or nearly mature erythrocytes, produce 2-6 merozoites arranged most commonly in fan or cruciform configuration, with mean dimensions among host species varying from 3.7 to 4.8 x 2.5 to 3.4 microns. Gametocytes are elongate, with mean dimensions among host species varying from 11.5 to 13.1 x 2.0 to 2.4 microns. One or both gametocyte margins are irregular and often crenulate. Gametocytes seldom fill the space between the erythrocyte nucleus and margin. Species characteristics were maintained in isodiagnostic Japanese quail (Coturnix japonica) and Pekin ducks (Anas platyrhynchos). In mosquito infection studies, only Culex restuans could support sporogony of P. forresteri, in contrast to Plasmodium elongatum of raptor origin that completed sporogony in both Cx. restuans and Culex nigripalpus. PMID:9379302

  6. 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.

  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. PMID:27243150

  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. PMID:26668551

  10. Physical Structure of Planetary Nebulae. I. The Owl Nebula

    NASA Astrophysics Data System (ADS)

    Guerrero, Martín A.; Chu, You-Hua; Manchado, Arturo; Kwitter, Karen B.

    2003-06-01

    The Owl Nebula is a triple-shell planetary nebula with the outermost shell being a faint bow-shaped halo. We have obtained deep narrowband images and high-dispersion echelle spectra in the Hα, [O III], and [N II] emission lines to determine the physical structure of each shell in the nebula. These spatiokinematic data allow us to rule out hydrodynamic models that can reproduce only the nebular morphology. Our analysis shows that the inner shell of the main nebula is slightly elongated with a bipolar cavity along its major axis, the outer nebula is a filled envelope coexpanding with the inner shell at 40 km s-1, and the halo has been braked by the interstellar medium as the Owl Nebula moves through it. To explain the morphology and kinematics of the Owl Nebula, we suggest the following scenario for its formation and evolution. The early mass loss at the TP-AGB phase forms the halo, and the superwind at the end of the AGB phase forms the main nebula. The subsequent fast stellar wind compressed the superwind to form the inner shell and excavated an elongated cavity at the center, but this has ceased in the past. At the current old age the inner shell is backfilling the central cavity. Based on observations made with the William Herschel Telescope, operated on the island of La Palma by the Isaac Newton Group in the Spanish Observatorio del Roque de Los Muchachos of the Instituto de Astrofísica de Canarias, and with the Burrell Schmidt telescope of the Warner and Swasey Observatory, Case Western Reserve University.

  11. 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.

  12. Blood oxygen binding properties for the burrowing owl, Athene cunicularia.

    PubMed

    Maginniss, L A; Kilgore, D L

    1989-05-01

    Isocapnic O2 equilibrium curves (O2ECs) were generated for whole blood of 4 adult burrowing owls (Athene cunicularia) using thin film techniques. At in vivo pHa (7.49 +/- 0.02; mean +/- 1 SEM) and 41 degrees C, the PO2 at half saturation (P50) was 42.3 +/- 0.8 Torr. CO2 and fixed acid (H+) Bohr slopes (delta log P50/delta pH) were -0.46 +/- 0.01 and -0.42 +/- 0.02, respectively, demonstrating a small specific CO2 effect. CO2 and H+ Bohr slopes were saturation-independent between 0.1 and 0.9 S. Hill plots for Athene blood were non-linear; the Hill coefficient (n) increased from 2.6 below 0.4 S to 3.4 above 0.6 S. Owl equilibrium data were accurately described by the equation: S = [(7.7 x 10(6]/(P4 + 44P3 - 108P2 + 3.5 x 10(4)P) + 1]-1. This complex O2EC shape may result from Hb heterogeneity; isoelectric focusing showed 4 isoHbs with a molar ratio of 9:1:1:1. This study revealed no apparent adaptations of Athene blood for hypoxic and hypercapnic conditions. We conclude that the observed blood O2 binding properties promote tissue O2 delivery during periods of surface activity. While occupying its burrow, the owl compensates for moderate alterations in inspired gas composition partly through increased ventilation. PMID:2749025

  13. Temporal Map Formation in the Barn Owl's Brain

    NASA Astrophysics Data System (ADS)

    Leibold, Christian; Kempter, Richard; van Hemmen, J. Leo

    2001-12-01

    Barn owls provide an experimentally well-specified example of a temporal map, a neuronal representation of the outside world in the brain by means of time. Their laminar nucleus exhibits a place code of interaural time differences, a cue which is used to determine the azimuthal location of a sound stimulus, e.g., prey. We analyze a model of synaptic plasticity that explains the formation of such a representation in the young bird and show how in a large parameter regime a combination of local and nonlocal synaptic plasticity yields the temporal map as found experimentally. Our analysis includes the effect of nonlinearities as well as the influence of neuronal noise.

  14. Chemical residue content and hatchability of screech owl eggs

    USGS Publications Warehouse

    Klaas, E.E.; Swineford, D.M.

    1976-01-01

    Eggs of wild Screech Owls were collected from nests in northwestern Ohio in 1973. One egg was taken from each of 19 nests near the start of incubation. Mean shell thickness in these 19 eggs and mean thickness of 16 unhatched eggs did not differ from 49 archival eggs collected in Ohio and Pennsylvania prior to the widespread use of organochlorine pesticides. Residues were generally low although all eggs contained DDE and PCB?s. No relationship was found between hatching failures and the presence of organochlorine residues. Low residues are consistent with a long history of good nesting success and a stable population.

  15. 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.

  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. 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. PMID:23418422

  18. 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. PMID:26718884

  19. 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.

  20. 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.

  1. 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

  2. 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. PMID:26657360

  3. 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. PMID:25532198

  4. Reasoning about Resources and Hierarchical Tasks Using OWL and SWRL

    NASA Astrophysics Data System (ADS)

    Elenius, Daniel; Martin, David; Ford, Reginald; Denker, Grit

    Military training and testing events are highly complex affairs, potentially involving dozens of legacy systems that need to interoperate in a meaningful way. There are superficial interoperability concerns (such as two systems not sharing the same messaging formats), but also substantive problems such as different systems not sharing the same understanding of the terrain, positions of entities, and so forth. We describe our approach to facilitating such events: describe the systems and requirements in great detail using ontologies, and use automated reasoning to automatically find and help resolve problems. The complexity of our problem took us to the limits of what one can do with OWL, and we needed to introduce some innovative techniques of using and extending it. We describe our novel ways of using SWRL and discuss its limitations as well as extensions to it that we found necessary or desirable. Another innovation is our representation of hierarchical tasks in OWL, and an engine that reasons about them. Our task ontology has proved to be a very flexible and expressive framework to describe requirements on resources and their capabilities in order to achieve some purpose.

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

    PubMed

    Cox, Weston; Fischer, Brian J

    2015-07-01

    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

  6. Cross-correlation in the auditory coincidence detectors of owls.

    PubMed

    Fischer, Brian J; Christianson, G Björn; Peña, José Luis

    2008-08-01

    Interaural time difference (ITD) plays a central role in many auditory functions, most importantly in sound localization. The classic model for how ITD is computed was put forth by Jeffress (1948). One of the predictions of the Jeffress model is that the neurons that compute ITD should behave as cross-correlators. Whereas cross-correlation-like properties of the ITD-computing neurons have been reported, attempts to show that the shape of the ITD response function is determined by the spectral tuning of the neuron, a core prediction of cross-correlation, have been unsuccessful. Using reverse correlation analysis, we demonstrate in the barn owl that the relationship between the spectral tuning and the ITD response of the ITD-computing neurons is that predicted by cross-correlation. Moreover, we show that a model of coincidence detector responses derived from responses to binaurally uncorrelated noise is consistent with binaural interaction based on cross-correlation. These results are thus consistent with one of the key tenets of the Jeffress model. Our work sets forth both the methodology to answer whether cross-correlation describes coincidence detector responses and a demonstration that in the barn owl, the result is that expected by theory. PMID:18685035

  7. West Nile Virus Outbreak in North American Owls, Ontario, 2002

    PubMed Central

    Barker, Ian K.; Lindsay, Robbin; Dibernardo, Antonia; McKeever, Katherine; Hunter, Bruce

    2004-01-01

    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. PMID:15663850

  8. 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).

  9. 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.

  10. 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.

  11. Breeding-season food habits of burrowing owls (Athene cunicularia) in southwestern Dominican Republic

    USGS Publications Warehouse

    Wiley, J.W.

    1998-01-01

    Diet data from 20 Burrowing Owl (Athene cunicularia) nests were collected in southwestern Dominican Republic in 1976, 1982, and 1996. Invertebrates (53.3%) comprised the most numerous prey items (N = 396) delivered to nests by adult owls, but vertebrates (46.7%) were much better represented than in other studies of Burrowing Owl diet. Among vertebrates, birds (28.3% of all items) and reptiles (14.9%) were most important, whereas mammals (1.0%) and amphibians (2.5%) were less commonly delivered to nests. Vertebrates, however, comprised more than twice (69.2%) of the total biomass as invertebrates (30.8%), with birds (50.4%) and reptiles (12.8%) the most important of the vertebrate prey classes. A positive relationship was observed between bird species abundance and number of individuals taken as prey by Burrowing Owls.

  12. 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.

  13. 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.

  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. An Analysis of Spatial Clustering and Implications for Wildlife Management: A Burrowing Owl Example

    NASA Astrophysics Data System (ADS)

    Fisher, Joshua B.; Trulio, Lynne A.; Biging, Gregory S.; Chromczak, Debra

    2007-03-01

    Analysis tools that combine large spatial and temporal scales are necessary for efficient management of wildlife species, such as the burrowing owl ( Athene cunicularia). We assessed the ability of Ripley’s K-function analysis integrated into a geographic information system (GIS) to determine changes in burrowing owl nest clustering over two years at NASA Ames Research Center. Specifically, we used these tools to detect changes in spatial and temporal nest clustering before, during, and after conducting management by mowing to maintain low vegetation height at nest burrows. We found that the scale and timing of owl nest clustering matched the scale and timing of our conservation management actions over a short time frame. While this study could not determine a causal link between mowing and nest clustering, we did find that Ripley’s K and GIS were effective in detecting owl nest clustering and show promise for future conservation uses.

  16. Blood characteristics, tracheal volume and heart mass of burrowing owls (Athene cunicularia) and bobwhite (Colinus virginianus).

    PubMed

    Boggs, D F; Birchard, G F; Kilgore, D L

    1983-01-01

    1. Measurements of certain hematological and morphological characteristics were made in burrowing owls and bobwhite in search of features that could be associated with the previously described ventilatory adaptations of the burrowing owl to hypoxia and hypercarbia. 2. Values for burrowing owls and bobwhite, respectively, were: P50 = 44.9, 46.0 torr; Hct = 36.6, 38.8 vol%, Hb = 12, 12.3 (g/100 ml); RBC = 2.72 X 10(6), 3.02 X 10(6); log P50/pH = -0.412, -0.485; delta log PCO2/delta pH = -1.39, -1.585. 3. The owls had greater heart weights and smaller tracheal volumes than the bobwhite or the predicted value. 4. No hematological characteristics of the burrowing bird distinguish it from the non-burrowing bird. PMID:6132713

  17. An analysis of spatial clustering and implications for wildlife management: a burrowing owl example.

    PubMed

    Fisher, Joshua B; Trulio, Lynne A; Biging, Gregory S; Chromczak, Debra

    2007-03-01

    Analysis tools that combine large spatial and temporal scales are necessary for efficient management of wildlife species, such as the burrowing owl (Athene cunicularia). We assessed the ability of Ripley's K-function analysis integrated into a geographic information system (GIS) to determine changes in burrowing owl nest clustering over two years at NASA Ames Research Center. Specifically, we used these tools to detect changes in spatial and temporal nest clustering before, during, and after conducting management by mowing to maintain low vegetation height at nest burrows. We found that the scale and timing of owl nest clustering matched the scale and timing of our conservation management actions over a short time frame. While this study could not determine a causal link between mowing and nest clustering, we did find that Ripley's K and GIS were effective in detecting owl nest clustering and show promise for future conservation uses. PMID:17253092

  18. Clinical pathological findings in an owl (Athene noctua) with microfilaraemia in Italy.

    PubMed

    Bedin, M; Petterino, C; Gallo, E; Selleri, P; Morgante, M

    2007-04-01

    We report the first case of microfilaria infection in a free-flying owl Athene noctua in Italy. A macroparasite, about 10.1-mm long, was observed in the right chamber of the heart. On microscopic examination microfilariae were seen in liver, kidney, myocardium and lungs, although no cellular reaction was present in association with the parasites in any of these tissues. Because of the low pathogenicity of this parasite, infection with microfilaria may be not harmful in wild owls. PMID:17381675

  19. Pharmaceutical validation of medication orders using an OWL Ontology and Business Rules.

    PubMed

    Chniti, Amina; Boussadi, Abdelali; Degoulet, Patrice; Albert, Patrick; Charlet, Jean

    2012-01-01

    In this paper we present an application of pharmaceutical validation of medication based on an OWL ontology and business rules or more specifically clinical decision rules. This application has been developed based on a prototype that enables business users to author, execute and manage their Business Rules over OWL Ontology. This prototype is based on the Business Rule Management System (BRMS) IBM WebSphere ILOG JRules. PMID:22874408

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

    USGS Publications Warehouse

    Van Riper, Charles, III; 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.

  1. 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.

  2. 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.

  3. 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., III

    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.

  4. 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.

  5. Maps of interaural delay in the owl's nucleus laminaris.

    PubMed

    Carr, Catherine E; Shah, Sahil; McColgan, Thomas; Ashida, Go; Kuokkanen, Paula T; Brill, Sandra; Kempter, Richard; Wagner, Hermann

    2015-09-01

    Axons from the nucleus magnocellularis form a presynaptic map of interaural time differences (ITDs) in the nucleus laminaris (NL). These inputs generate a field potential that varies systematically with recording position and can be used to measure the map of ITDs. In the barn owl, the representation of best ITD shifts with mediolateral position in NL, so as to form continuous, smoothly overlapping maps of ITD with iso-ITD contours that are not parallel to the NL border. Frontal space (0°) is, however, represented throughout and thus overrepresented with respect to the periphery. Measurements of presynaptic conduction delay, combined with a model of delay line conduction velocity, reveal that conduction delays can account for the mediolateral shifts in the map of ITD. PMID:26224776

  6. Signaling of the strongest stimulus in the owl optic tectum.

    PubMed

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

    2011-04-01

    Essential to the selection of the next target for gaze or attention is the ability to compare the strengths of multiple competing stimuli (bottom-up information) and to signal the strongest one. Although the optic tectum (OT) has been causally implicated in stimulus selection, how it computes the strongest stimulus is unknown. Here, we demonstrate that OT neurons in the barn owl systematically encode the relative strengths of simultaneously occurring stimuli independently of sensory modality. Moreover, special "switch-like" responses of a subset of neurons abruptly increase when the stimulus inside their receptive field becomes the strongest one. Such responses are not predicted by responses to single stimuli and, indeed, are eliminated in the absence of competitive interactions. We demonstrate that this sensory transformation substantially boosts the representation of the strongest stimulus by creating a binary discrimination signal, thereby setting the stage for potential winner-take-all target selection for gaze and attention. PMID:21471353

  7. Maps of interaural delay in the owl's nucleus laminaris

    PubMed Central

    Shah, Sahil; McColgan, Thomas; Ashida, Go; Kuokkanen, Paula T.; Brill, Sandra; Kempter, Richard; Wagner, Hermann

    2015-01-01

    Axons from the nucleus magnocellularis form a presynaptic map of interaural time differences (ITDs) in the nucleus laminaris (NL). These inputs generate a field potential that varies systematically with recording position and can be used to measure the map of ITDs. In the barn owl, the representation of best ITD shifts with mediolateral position in NL, so as to form continuous, smoothly overlapping maps of ITD with iso-ITD contours that are not parallel to the NL border. Frontal space (0°) is, however, represented throughout and thus overrepresented with respect to the periphery. Measurements of presynaptic conduction delay, combined with a model of delay line conduction velocity, reveal that conduction delays can account for the mediolateral shifts in the map of ITD. PMID:26224776

  8. 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

  9. 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.

  10. 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.

  11. 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.

  12. Automated Transformation of openEHR Data Instances to OWL.

    PubMed

    Haarbrandt, Birger; Jack, Thomas; Marschollek, Michael

    2016-01-01

    Standard-based integration and semantic enrichment of clinical data originating from electronic medical records has shown to be critical to enable secondary use. To facilitate the utilization of semantic technologies on clinical data, we introduce a methodology to enable automated transformation of openEHR-based data to Web Ontology Language (OWL) individuals. To test the correctness of the implementation, de-identified data of 229 patients of the pediatric intensive care unit of Hannover Medical School has been transformed into 2.983.436 individuals. Querying of the resulting ontology for symptoms of the systemic inflammatory response syndrome (SIRS) yielded the same result set as a SQL query on an openEHR-based clinical data repository. PMID:27139386

  13. Hearing in the crepuscular owl butterfly (Caligo eurilochus, Nymphalidae).

    PubMed

    Lucas, Kathleen M; Mongrain, Jennifer K; Windmill, James F C; Robert, Daniel; Yack, Jayne E

    2014-10-01

    Tympanal organs are widespread in Nymphalidae butterflies, with a great deal of variability in the morphology of these ears. How this variation reflects differences in hearing physiology is not currently understood. This study provides the first examination of hearing organs in the crepuscular owl butterfly, Caligo eurilochus. We examined the tuning and sensitivity of the C. eurilochus hearing organ, called Vogel's organ, using laser Doppler vibrometry and extracellular neurophysiology. We show that the C. eurilochus ear responds to sound and is most sensitive to frequencies between 1 and 4 kHz, as confirmed by both the vibration of the tympanal membrane and the physiological response of the associated nerve branches. In comparison to the hearing of its diurnally active relative, Morpho peleides, C. eurilochus has a narrower frequency range with higher auditory thresholds. Hypotheses explaining the function of hearing in this crepuscular butterfly are discussed. PMID:25173833

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

    NASA Astrophysics Data System (ADS)

    Brittan-Powell, Elizabeth F.; Lohr, Bernard; Hahn, D. Caldwell; Dooling, Robert J.

    2005-07-01

    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.

  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. An anatomical basis for visual calibration of the auditory space map in the barn owl's midbrain.

    PubMed

    Feldman, D E; Knudsen, E I

    1997-09-01

    The map of auditory space in the external nucleus of the inferior colliculus (ICX) of the barn owl is calibrated by visual experience during development. ICX neurons are tuned for interaural time difference (ITD), the owl's primary cue for sound source azimuth, and are arranged into a map of ITD. When vision is altered by rearing owls with prismatic spectacles that shift the visual field in azimuth, ITD tuning in the ICX shifts adaptively. In contrast, ITD tuning remains unchanged in the lateral shell of the central nucleus of the inferior colliculus (ICCls), which provides the principal auditory input to the ICX, suggesting that the projection from the ICCls to the ICX is altered by prism-rearing. In this study, the topography of the ICCls-ICX projection was assessed in normal and prism-reared owls by retrograde labeling using biotinylated dextran amine. In juvenile owls at the age before prism attachment, and in normal adults, labeling patterns were consistent with a topographic projection, with each ICX site receiving input from a restricted region of the ICCls with similar ITD tuning. In prism-reared owls, labeling patterns were systematically altered: each ICX site received additional, abnormal input from a region of the ICCls where ITD tuning matched the shifted ITD tuning of the ICX neurons. These results indicate that anatomical reorganization of the ICCls-ICX projection contributes to the visual calibration of the ICX auditory space map. PMID:9254692

  17. 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.

  18. 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. PMID:18082246

  19. Through a barn owl's eyes: interactions between scene content and visual attention.

    PubMed

    Ohayon, Shay; Harmening, Wolf; Wagner, Hermann; Rivlin, Ehud

    2008-02-01

    In this study we investigated visual attention properties of freely behaving barn owls, using a miniature wireless camera attached to their heads. The tubular eye structure of barn owls makes them ideal subjects for this research since it limits their eye movements. Video sequences recorded from the owl's point of view capture part of the visual scene as seen by the owl. Automated analysis of video sequences revealed that during an active search task, owls repeatedly and consistently direct their gaze in a way that brings objects of interest to a specific retinal location (retinal fixation area). Using a projective model that captures the geometry between the eye and the camera, we recovered the corresponding location in the recorded images (image fixation area). Recording in various types of environments (aviary, office, outdoors) revealed significant statistical differences of low level image properties at the image fixation area compared to values extracted at random image patches. These differences are in agreement with results obtained in primates in similar studies. To investigate the role of saliency and its contribution to drawing the owl's attention, we used a popular bottom-up computational model. Saliency values at the image fixation area were typically greater than at random patches, yet were only 20% out of the maximal saliency value, suggesting a top-down modulation of gaze control. PMID:18066583

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

    PubMed Central

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

    2012-01-01

    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. PMID:22279165

  1. Ventilatory and intrapulmonary chemoreceptor sensitivity to CO2 in the burrowing owl.

    PubMed

    Kilgore, D L; Faraci, F M; Fedde, M R

    1985-12-01

    We measured the ventilatory response of anesthetized, unidirectionally ventilated pigeons and burrowing owls to changes in intrapulmonary CO2 concentration and the static CO2 sensitivity of intrapulmonary chemoreceptors (IPC) in these species and the domestic goose. Compared with pigeons, burrowing owls showed a significantly reduced respiratory frequency and amplitude response to increases in FICO2 from 0.05 to 0.10, which corroborates similar findings in intact, awake individuals of the same species. The average static CO2 sensitivity of IPC in geese, pigeons, and burrowing owls, as reflected by the average slope of the linear regressions of receptor discharge frequency on ln(PICO2), was -7.96, -11.1 and -6.87 imp/sec . ln(PICO2), respectively. The sensitivities of individual receptors were normally distributed in geese and pigeons, but skewed in burrowing owls. Therefore, the median CO2 sensitivity [-5.50 imp/sec . ln(PICO2)] is a more appropriate measure of the typical CO2 sensitivity of IPC in burrowing owls. The static CO2 sensitivity of IPC in burrowing owls is the lowest reported for euthermic birds with a normal acid-base balance and may materially contribute to the blunted ventilatory response of these birds to the elevated CO2 levels they encounter in nature. PMID:3937191

  2. Adaptation in the auditory space map of the barn owl.

    PubMed

    Gutfreund, Yoram; Knudsen, Eric I

    2006-08-01

    Auditory neurons in the owl's external nucleus of the inferior colliculus (ICX) integrate information across frequency channels to create a map of auditory space. This study describes a powerful, sound-driven adaptation of unit responsiveness in the ICX and explores the implications of this adaptation for sensory processing. Adaptation in the ICX was analyzed by presenting lightly anesthetized owls with sequential pairs of dichotic noise bursts. Adaptation occurred in response even to weak, threshold-level sounds and remained strong for more than 100 ms after stimulus offset. Stimulation by one range of sound frequencies caused adaptation that generalized across the entire broad range of frequencies to which these units responded. Identical stimuli were used to test adaptation in the lateral shell of the central nucleus of the inferior colliculus (ICCls), which provides input directly to the ICX. Compared with ICX adaptation, adaptation in the ICCls was substantially weaker, shorter lasting, and far more frequency specific, suggesting that part of the adaptation observed in the ICX was attributable to processes resident to the ICX. The sharp tuning of ICX neurons to space, along with their broad tuning to frequency, allows ICX adaptation to preserve a representation of stimulus location, regardless of the frequency content of the sound. The ICX is known to be a site of visually guided auditory map plasticity. ICX adaptation could play a role in this cross-modal plasticity by providing a short-term memory of the representation of auditory localization cues that could be compared with later-arriving, visual-spatial information from bimodal stimuli. PMID:16707713

  3. 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

  4. 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. PMID:23246613

  5. 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

  6. 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

  7. Sensitive and critical periods for visual calibration of sound localization by barn owls.

    PubMed

    Knudsen, E I; Knudsen, P F

    1990-01-01

    This study describes developmental changes in the capacity of owls to adjust sound localization in response to chronic prismatic displacement of the visual field and to recover accurate sound localization following the restoration of normal vision. Matched, binocular displacing prisms were mounted over the eyes of 19 barn owls (Tyto alba) beginning at ages ranging from 10 to 272 d. In nearly all cases, the visual field was shifted 23 degrees to the right. Sound localization was assessed on the basis of head orientations to sound sources, measured in a darkened sound chamber with a search coil system. Chronic exposure to a displaced visual field caused the owls to alter sound localization in the direction of the visual field displacement, thereby inducing a sound-localization error. The size of the sound-localization error that resulted depended on the age of the animal when prism experience began. Maximal errors of about 20 degrees were induced only when prism experience began by 21 d of age. As prism experience began at later ages, the magnitude of induced errors decreased. A bird that wore prisms beginning at 102 d of age, altered sound localization by only 6 degrees. An adult owl, when exposed chronically to a displaced visual field, altered sound localization by about 3 degrees. We refer to the early period in life when displaced vision induces exceptionally large sound-localization errors (relative to those induced in the adult) as a sensitive period. The capacity to recover accurate sound localization following restoration of normal vision was tested in 7 owls that had been raised wearing prisms. Four owls that had prisms removed by 182 d of age recovered accurate localization rapidly (over a period of weeks), whereas 3 owls that were older when the prisms were removed did not recover accurate localization when tested for up to 7 months after prism removal. Adjustment of sound localization slowed greatly or ceased at about 200 days of age, referred to here as

  8. 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. PMID

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

    PubMed

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

    2014-05-15

    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. PMID:24656750

  10. 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.

  11. 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. PMID:16699143

  12. 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

  13. Automating generation of textual class definitions from OWL to English

    PubMed Central

    2011-01-01

    Background Text definitions for entities within bio-ontologies are a cornerstone of the effort to gain a consensus in understanding and usage of those ontologies. Writing these definitions is, however, a considerable effort and there is often a lag between specification of the main part of an ontology (logical descriptions and definitions of entities) and the development of the text-based definitions. The goal of natural language generation (NLG) from ontologies is to take the logical description of entities and generate fluent natural language. The application described here uses NLG to automatically provide text-based definitions from an ontology that has logical descriptions of its entities, so avoiding the bottleneck of authoring these definitions by hand. Results To produce the descriptions, the program collects all the axioms relating to a given entity, groups them according to common structure, realises each group through an English sentence, and assembles the resulting sentences into a paragraph, to form as ‘coherent’ a text as possible without human intervention. Sentence generation is accomplished using a generic grammar based on logical patterns in OWL, together with a lexicon for realising atomic entities. We have tested our output for the Experimental Factor Ontology (EFO) using a simple survey strategy to explore the fluency of the generated text and how well it conveys the underlying axiomatisation. Two rounds of survey and improvement show that overall the generated English definitions are found to convey the intended meaning of the axiomatisation in a satisfactory manner. The surveys also suggested that one form of generated English will not be universally liked; that intrusion of too much ‘formal ontology’ was not liked; and that too much explicit exposure of OWL semantics was also not liked. Conclusions Our prototype tools can generate reasonable paragraphs of English text that can act as definitions. The definitions were found acceptable

  14. 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

  15. Multiple sites of adaptive plasticity in the owl's auditory localization pathway.

    PubMed

    DeBello, William M; Knudsen, Eric I

    2004-08-01

    In the midbrain auditory localization pathway of the barn owl, a map of auditory space is relayed from the external nucleus of the inferior colliculus (ICX) to the deep and intermediate layers of the optic tectum (OT) and from these layers to the superficial layers. Within the OT, the auditory space map aligns with a visual map of space. Raising young barn owls with a prismatic displacement of the visual field leads to progressive changes in auditory tuning in the OT that tend to realign the auditory space map with the prismatically displaced visual space map. The only known site of this adaptive plasticity is in the ICX, in which the auditory system first creates a map of space. In this study, we identified an additional site of plasticity in the OT. In owls that experienced prisms beginning late in the juvenile period, adaptive shifts in auditory tuning in the superficial layers of the OT exceeded the adaptive shifts that occurred in the deep layers of the OT or in the ICX. Anatomical results from these owls demonstrated that the topography of intrinsic OT connections was systematically altered in the adaptive direction. In juvenile owls, plasticity in the OT increased as plasticity in the ICX decreased. Because plasticity at both sites has been shown to decline substantially in adults, these results suggest that an age-dependent decrease in auditory map plasticity occurs first in the ICX and later at the higher level, in the OT. PMID:15295019

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

    USGS Publications Warehouse

    Willey, D.W.; van Riper, Charles, III

    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.

  17. 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.

  18. 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.

  19. 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 ...

  20. 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

  1. OWL site survey: first seeing measurement with ADIMM

    NASA Astrophysics Data System (ADS)

    Benkhaldoun, Zouhair; Abahamid, Abdelouahed; El Azhari, Youssef; Siher, El Arbi

    2004-10-01

    The ESO OWL site survey plan includes the analysis of the astronomical quality of the Atlas mountains in Morocco. In this paper we are presenting the first long time measurement of optical turbulence at Oukaimeden site. For this work we built an instrument called ADIMM for an Automated Differencial Image Motion Monitor, and we use it to the measure the optical turbulence at the Oukaimeden Site. We are describing the instrument and reporting the first results obtained after six month of working on this project. The results of night-time seeing measurements carried out during the period from Jun 14 up to October 01 2003 are presented. The median and mean values of the seeing for the entire period of observations are respectively 0.75" and 0.84". This work was organized in the framework of contract Num.69651/ODG/02/9005/GWI between the European Southern Observatory (ESO) and Astrophysics and Physics of High Energy Laboratory of the Faculty of Sciences, Cadi Ayyad University (LPHEA).

  2. 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

  3. 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. PMID:25056556

  4. Visual modulation of auditory responses in the owl inferior colliculus.

    PubMed

    Bergan, Joseph F; Knudsen, Eric I

    2009-06-01

    The barn owl's central auditory system creates a map of auditory space in the external nucleus of the inferior colliculus (ICX). Although the crucial role visual experience plays in the formation and maintenance of this auditory space map is well established, the mechanism by which vision influences ICX responses remains unclear. Surprisingly, previous experiments have found that in the absence of extensive pharmacological manipulation, visual stimuli do not drive neural responses in the ICX. Here we investigated the influence of dynamic visual stimuli on auditory responses in the ICX. We show that a salient visual stimulus, when coincident with an auditory stimulus, can modulate auditory responses in the ICX even though the same visual stimulus may elicit no neural responses when presented alone. For each ICX neuron, the most effective auditory and visual stimuli were located in the same region of space. In addition, the magnitude of the visual modulation of auditory responses was dependent on the context of the stimulus presentation with novel visual stimuli eliciting consistently larger response modulations than frequently presented visual stimuli. Thus the visual modulation of ICX responses is dependent on the characteristics of the visual stimulus as well as on the spatial and temporal correspondence of the auditory and visual stimuli. These results demonstrate moment-to-moment visual enhancements of auditory responsiveness that, in the short-term, increase auditory responses to salient bimodal stimuli and in the long-term could serve to instruct the adaptive auditory plasticity necessary to maintain accurate auditory orienting behavior. PMID:19321633

  5. 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

  6. 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. PMID:24244622

  7. 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

  8. Low glucokinase activity and high rates of gluconeogenesis contribute to hyperglycemia in barn owls (Tyto alba) after a glucose challenge.

    PubMed

    Myers, M R; Klasing, K C

    1999-10-01

    Barn owls (Tyto alba) and leghorn chickens were fed a low protein high glucose (33.44% protein, 23.67% glucose) or a high protein low glucose (55.35% protein, 1.5% glucose) diet. After an intravenous glucose infusion, the peak in plasma glucose was not affected by diet in either species and was 22.6 and 39.4 mmol/L in chickens and barn owls, respectively. Glucose levels returned to normal within 30 min in chickens, but remained elevated for 3.5 h in barn owls. An oral glucose challenge also resulted in greater and longer hyperglycemia in barn owls than in chickens. The activities of hepatic glucokinase, malic enzyme and phosphoenolpyruvate carboxykinase of barn owls were 16, 35, and 333% of the levels in chickens. Malic enzyme (P = 0.024) was less affected by dietary glucose level in barn owls than in chickens. Cultured hepatocytes from chickens produced 43% more glucose from lactate than hepatocytes from barn owls and, conversely, barn owl hepatocytes produced 87% more glucose from threonine than chickens (P = 0.001). Gluconeogenesis from lactate was greatly suppressed by high media glucose in chicken hepatocytes but not in those of barn owls (P = 0.0001 for species by glucose level interaction). When threonine was the substrate, gluconeogenesis was suppressed by increased glucose in both species but to a greater relative extent in chickens (P = 0.007 for species by glucose level interaction). Owls were glucose intolerant at least in part because of low hepatic glucokinase activity and an inadequate suppression of gluconeogenesis in the presence of exogenous glucose, apparently because they evolved with large excesses of amino acids and limited glucose in their normal diet. PMID:10498765

  9. Heterochromatin Blocks Constituting the Entire Short Arms of Acrocentric Chromosomes of Azara's Owl Monkey: Formation Processes Inferred From Chromosomal Locations

    PubMed Central

    Prakhongcheep, Ornjira; Chaiprasertsri, Nampech; Terada, Shoko; Hirai, Yuriko; Srikulnath, Kornsorn; Hirai, Hirohisa; Koga, Akihiko

    2013-01-01

    Centromeres and telomeres of higher eukaryotes generally contain repetitive sequences, which often form pericentric or subtelomeric heterochromatin blocks. C-banding analysis of chromosomes of Azara's owl monkey, a primate species, showed that the short arms of acrocentric chromosomes consist mostly or solely of constitutive heterochromatin. The purpose of the present study was to determine which category, pericentric, or subtelomeric is most appropriate for this heterochromatin, and to infer its formation processes. We cloned and sequenced its DNA component, finding it to be a tandem repeat sequence comprising 187-bp repeat units, which we named OwlRep. Subsequent hybridization analyses revealed that OwlRep resides in the pericentric regions of a small number of metacentric chromosomes, in addition to the short arms of acrocentric chromosomes. Further, in the pericentric regions of the acrocentric chromosomes, OwlRep was observed on the short-arm side only. This distribution pattern of OwlRep among chromosomes can be simply and sufficiently explained by assuming (i) OwlRep was transferred from chromosome to chromosome by the interaction of pericentric heterochromatin, and (ii) it was amplified there as subtelomeric heterochromatin. OwlRep carries several direct and inverted repeats within its repeat units. This complex structure may lead to a higher frequency of chromosome scission and may thus be a factor in the unique distribution pattern among chromosomes. Neither OwlRep nor similar sequences were found in the genomes of the other New World monkey species we examined, suggesting that OwlRep underwent rapid amplification after the divergence of the owl monkey lineage from lineages of the other species. PMID:23761219

  10. An OWL Meta-Ontology for Representing the Clinical Element Model

    PubMed Central

    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. PMID:22195200

  11. Spatial cue reliability drives frequency tuning in the barn Owl's midbrain.

    PubMed

    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. PMID:25531067

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

    PubMed Central

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

    2011-01-01

    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. PMID:21536886

  13. 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. PMID:26365667

  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. 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. PMID:24810326

  17. OPTIMAL WELL LOCATOR (OWL) : SOFTWARE TO EVALUATE AND SELECT MONITORING WELL LOCATIONS

    EPA Science Inventory

    OWL is currently in pre-Beta form and possesses a user- friendly graphical user interface (GUI) which enables easy data entry, program execution and visualization of results. In fiscal year 2001, the GUI programming and user's manual for the Beta Version will be completed throug...

  18. 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…

  19. 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...

  20. Representing the NCI Thesaurus in OWL DL: Modeling tools help modeling languages

    PubMed Central

    Noy, Natalya F.; de Coronado, Sherri; Solbrig, Harold; Fragoso, Gilberto; Hartel, Frank W.; Musen, Mark A.

    2009-01-01

    The National Cancer Institute’s (NCI) Thesaurus is a biomedical reference ontology. The NCI Thesaurus is represented using Description Logic, more specifically Ontylog, a Description logic implemented by Apelon, Inc. We are exploring the use of the DL species of the Web Ontology Language (OWL DL)—a W3C recommended standard for ontology representation—instead of Ontylog for representing the NCI Thesaurus. We have studied the requirements for knowledge representation of the NCI Thesaurus, and considered how OWL DL (and its implementation in Protégé-OWL) satisfies these requirements. In this paper, we discuss the areas where OWL DL was sufficient for representing required components, where tool support that would hide some of the complexity and extra levels of indirection would be required, and where language expressiveness is not sufficient given the representation requirements. Because many of the knowledge-representation issues that we encountered are very similar to the issues in representing other biomedical terminologies and ontologies in general, we believe that the lessons that we learned and the approaches that we developed will prove useful and informative for other researchers. PMID:19789731

  1. 75 FR 63800 - Information Collection; Commercial Use of the Woodsy Owl Symbol

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-18

    ... children discover the natural world and join in life- long actions to care for that world. The USDA Forest... Forest Service Information Collection; Commercial Use of the Woodsy Owl Symbol AGENCY: Forest Service... 1995, the Forest Service is seeking comments from all interested individuals and organizations on...

  2. Interactive effects of prey and p,p'-DDE on burrowing owl population dynamics.

    PubMed

    Gervais, Jennifer A; Hunter, Christine M; Anthony, Robert G

    2006-04-01

    We used population models to explore the effects of the organochlorine contaminant p,p'-DDE and fluctuations in vole availability on the population dynamics of Burrowing Owls (Athene cunicularia). Previous work indicated an interaction between low biomass of voles in the diet and moderate levels of p,p'-DDE in Burrowing Owl eggs that led to reproductive impairment. We constructed periodic and stochastic matrix models that incorporated three vole population states observed in the field: average, peak, and crash years. We modeled varying frequencies of vole crash years and a range of impairment of owl demographic rates in vole crash years. Vole availability had a greater impact on owl population growth rate than did reproductive impairment if vole populations peaked and crashed frequently. However, this difference disappeared as the frequency of vole crash years declined to once per decade. Fecundity, the demographic rate most affected by p,p'-DDE, had less impact on population growth rate than adult or juvenile survival. A life table response experiment of time-invariant matrices for average, peak, and crash vole conditions showed that low population growth under vole crash conditions was due to low adult and juvenile survival rates, whereas the extremely high population growth under vole peak conditions was due to increased fecundity. Our results suggest that even simple models can provide useful insights into complex ecological interactions. This is particularly valuable when temporal or spatial scales preclude manipulative experimental work in the field or laboratory. PMID:16711053

  3. 77 FR 74688 - Final Recovery Plan, First Revision; Mexican Spotted Owl

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-12-17

    ... Region. We made the draft plan available via a Federal Register notice published on June 24, 2011 (76 FR... Mexican spotted owl as a threatened species under the Act on March 16, 1993 (58 FR 14248). We designated critical habitat on August 31, 2004 (69 FR 53182). We originally completed a recovery plan for the...

  4. 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 Schoenherr--the…

  5. Experimental analysis of the flow field over a novel owl based airfoil

    NASA Astrophysics Data System (ADS)

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

    2009-05-01

    The aerodynamics of a newly constructed wing model the geometry of which is related to the wing of a barn owl is experimentally investigated. Several barn owl wings are scanned to obtain three-dimensional surface models of natural wings. A rectangular wing model with the general geometry of the barn owl but without any owl-specific structure being the reference case for all subsequent measurements is investigated using pressure tabs, oil flow pattern technique, and particle-image velocimetry. The main flow feature of the clean wing is a transitional separation bubble on the suction side. The size of the bubble depends on the Reynolds number and the angle of attack, whereas the location is mainly influenced by the angle of attack. Next, a second model with a modified surface is considered and its influence on the flow field is analyzed. Applying a velvet onto the suction side drastically reduces the size of this separation at moderate angles of attack and higher Reynolds numbers.

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

    PubMed

    Suárez, William; Olson, Storrs L

    2015-01-01

    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. PMID:26624114

  7. Effects of Kelthane? on reproduction of captive eastern screech-owls

    USGS Publications Warehouse

    Wiemeyer, Stanley N.; Spann, J.W.; Bunck, C.M.; Krynitsky, A.J.

    1989-01-01

    Eastern screech-owls were fed diets containing 10 ppm Kelthane? with 3.4% DDT-related contaminants, 10 ppm Kelthane? with no detectable DDT contaminants, or a control diet. Food consumption, adult weight and date of initiation of egg laying were similar for birds in control and dosed treatment groups.

  8. 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

    ...' History We listed the Mexican spotted owl as a threatened species under the Act on March 16, 1993 (58 FR 14248). We designated critical habitat on August 31, 2004 (69 FR 53182). We originally completed and... peer review of recovery plans (July 1, 1994; 59 FR 34270). In an appendix to the approved recovery...

  9. 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)

  10. 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.…

  11. 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…

  12. 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)

  13. 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 ...

  14. 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…

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

    USGS Publications Warehouse

    Willey, D.W.; van Riper, Charles, III

    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).

  16. 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.

  17. 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…

  18. 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)

  19. 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

    ... spotted owl (77 FR 14062; March 8, 2012). These lands are being considered for exclusion from the final... Safe Harbor policy (64 FR 32717; June 17, 1999) and Safe Harbor regulations (September 10, 2003, 68 FR 53320; May 3, 2004, 69 FR 24084) provide important terms and concepts for developing SHAs. The...

  20. Determining sex of eastern screech-owls using discriminant function analysis

    USGS Publications Warehouse

    Smith, D.G.; Wiemeyer, Stanley N.

    1992-01-01

    Seven morphometric characteristics and weight of males and females of a captive colony of Eastern Screech-Owls (Otus asio) were compared. Females were significantly larger than males in weight, total length, and length of tail, wing and bill. A discriminant function analysis based on weight, wing and tail length correctly identified the sex of 88% of the 77 birds.

  1. First report of Oxyspirura sp. from a captive fulvous owl (Strix fulvescens) in Mexico.

    PubMed

    Rodriguez-Tovar, L E; Casas-Martínez, A; Ramírez-Romero, R; Nevárez-Garza, A M; Zarate-Ramos, J J

    2008-12-01

    Nematodes similar to Oxyspirura sp. were recovered from the cornea and nictitating membrane of a fulvous owl (Strix fulvescens). The bird had been captive for several months, but died suddenly. It had no clinical history of prior diseases, including ocular lesions. PMID:18576870

  2. Moonstruck Primates: Owl Monkeys (Aotus) Need Moonlight for Nocturnal Activity in Their Natural Environment

    PubMed Central

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

    2010-01-01

    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

  3. 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

    2010-01-01

    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

  4. 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

  5. Hearing impairment induces frequency-specific adjustments in auditory spatial tuning in the optic tectum of young owls.

    PubMed

    Gold, J I; Knudsen, E I

    1999-11-01

    Bimodal, auditory-visual neurons in the optic tectum of the barn owl are sharply tuned for sound source location. The auditory receptive fields (RFs) of these neurons are restricted in space primarily as a consequence of their tuning for interaural time differences and interaural level differences across broad ranges of frequencies. In this study, we examined the extent to which frequency-specific features of early auditory experience shape the auditory spatial tuning of these neurons. We manipulated auditory experience by implanting in one ear canal an acoustic filtering device that altered the timing and level of sound reaching the eardrum in a frequency-dependent fashion. We assessed the auditory spatial tuning at individual tectal sites in normal owls and in owls raised with the filtering device. At each site, we measured a family of auditory RFs using broadband sound and narrowband sounds with different center frequencies both with and without the device in place. In normal owls, the narrowband RFs for a given site all included a common region of space that corresponded with the broadband RF and aligned with the site's visual RF. Acute insertion of the filtering device in normal owls shifted the locations of the narrowband RFs away from the visual RF, the magnitude and direction of the shifts depending on the frequency of the stimulus. In contrast, in owls that were raised wearing the device, narrowband and broadband RFs were aligned with visual RFs so long as the device was in the ear but not after it was removed, indicating that auditory spatial tuning had been adaptively altered by experience with the device. The frequency tuning of tectal neurons in device-reared owls was also altered from normal. The results demonstrate that experience during development adaptively modifies the representation of auditory space in the barn owl's optic tectum in a frequency-dependent manner. PMID:10561399

  6. On-line monitoring of adhesion and proliferation of cultured hepatoma cells using optical waveguide lightmode spectroscopy (OWLS).

    PubMed

    Hug, T S; Prenosil, J E; Maier, P; Morbidelli, M

    2002-01-01

    Monitoring of cell adhesion, cell spreading, and cell proliferation opens attractive perspectives in the on-line control of monolayer cell cultures in toxicity tests, in bioreactors as used for the serial production of skin grafts, or in extracorporeal liver devices. In this study the hepatoma Hep G2 cell adhesion and proliferation was monitored using an integrated optical method, optical waveguide lightmode spectroscopy (OWLS). This method is based upon refractive index measurements within a 100-nm thin layer above a Si(Ti)O(2) surface on which the cells were cultured and exposed to cytotoxic and cytostatic agents. The OWLS signal was proportional to cell density during the spreading period (4 h), and in long-term experiments (46 h) the OWLS signal correlated on a logarithmic scale with cell density. After administration of the protein synthesis inhibitor cycloheximide (4 microg/mL) to fully spread hepatoma cells, cell growth was arrested and change of the OWLS signal became noticeable within 6 h after drug administration. For exposure to increasing concentrations of the anticancer drug cyclophosphamide (2.5-20 mM) a concentration-dependent reduction of the OWLS signal was found. For cycloheximide and cyclophospamide the OWLS signal was also confirmed by cell viability measurements using the neutral red assay, the thiazolylblue tetrazoliumbromide assay, total protein measurements, and cell morphology. It was demonstrated that the OWLS signal detects minor changes in cell adhesion, which serve as indicators of metabolic state and growth behavior. OWLS is thus a quantitative tool to characterize impaired cell growth mediated by culture medium, by extracellular matrix, or after exposure to a toxin. PMID:12467478

  7. 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. PMID:24669722

  8. 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, III; 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.

  9. Neural maps of head movement vector and speed in the optic tectum of the barn owl.

    PubMed

    du Lac, S; Knudsen, E I

    1990-01-01

    1. This study investigates the contribution of the optic tectum in encoding the metric and kinetic properties of saccadic head movements. We describe the dependence of head movement components (size, direction, and speed) on parameters of focal electrical stimulation of the barn owl's optic tectum. The results demonstrate that both the site and the amount of activity can influence head saccade metrics and kinetics. 2. Electrical stimulation of the owl's optic tectum elicited rapid head movements that closely resembled natural head movements made in response to auditory and visual stimuli. The kinetics of these movements were similar to those of saccadic eye movements in primates. 3. The metrics and kinetics of head movements evoked from any given site depended strongly on stimulus parameters. Movement duration increased with stimulus duration, as did movement size. Both the size and the maximum speed of the movement increased to a plateau value with current strength and pulse rate. Movement direction was independent of stimulus parameters. 4. The initial position of the head influenced the size, direction, and speed of movements evoked from any given site: when the owl initially faced away from the direction of the induced saccade, the movement was larger and faster than when the owl initially faced toward the direction of the induced movement. 5. A characteristic movement of particular size, direction, and speed could be defined for each site by the use of stimulation parameters that elicited plateau movements with normal kinetic profiles and by having the head initially centered on the body. The size, direction, and speed of these characteristic movements varied systematically with the site of stimulation across the tectum. The map of head movement vector (size and direction) was aligned with the sensory representations of visual and auditory space, such that the movement elicited from a given site when the owl initially faced straight ahead brought the owl to

  10. Sensitive periods for visual calibration of the auditory space map in the barn owl optic tectum.

    PubMed

    Brainard, M S; Knudsen, E I

    1998-05-15

    Previous studies have identified sensitive periods for the developing barn owl during which visual experience has a powerful influence on the calibration of sound localization behavior. Here we investigated neural correlates of these sensitive periods by assessing developmental changes in the capacity of visual experience to alter the map of auditory space in the optic tectum of the barn owl. We used two manipulations. (1) We equipped owls with prismatic spectacles that optically displaced the visual field by 23 degrees to the left or right, and (2) we restored normal vision to prism-reared owls that had been raised wearing prisms. In agreement with previous behavioral experiments, we found that the capacity of abnormal visual experience to shift the tectal auditory space map was restricted to an early sensitive period. However, this period extended until later in life (approximately 200 d) than described previously in behavioral studies (approximately 70 d). Furthermore, unlike the previous behavioral studies that found that the capacity to recover normal sound localization after restoration of normal vision was lost at approximately 200 d of age, we found that the capacity to recover a normal auditory space map was never lost. Finally, we were able to reconcile the behaviorally and neurophysiologically defined sensitive periods by taking into account differences in the richness of the environment in the two sets of experiments. We repeated the behavioral experiments and found that when owls were housed in a rich environment, the capacity to adjust sound localization away from normal extended to later in life, whereas the capacity to recover to normal was never lost. Conversely, when owls were housed in an impoverished environment, the capacity to recover a normal auditory space map was restricted to a period ending at approximately 200 d of age. The results demonstrate that the timing and even the existence of sensitive periods for plasticity of a neural circuit

  11. Representation of frequency in the primary auditory field of the barn owl forebrain.

    PubMed

    Cohen, Y E; Knudsen, E I

    1996-12-01

    1. The primary auditory field (PAF) constitutes the first telencephalic stage of auditory information processing in the classical auditory pathway. In this study we investigated the frequency representation in the PAF of the barn owl, a species with a broad frequency range of hearing and a highly advanced auditory system. 2. Single- and multiunit sites were recorded extracellularly in ketamine-anesthetized owls. The frequency response properties of PAF sites were assessed with the use of digitally synthesized dichotic stimuli. PAF sites (n = 442) either were unresponsive to tonal stimulation (but responsive to noise stimuli), were tuned for frequency, or had multipeaked frequency response profiles. Tuned sites responded best to frequencies between 0.2 and 8.8 kHz, a range that encompasses nearly the entire hearing range of the barn owl. Most sites responding best to frequencies < 4 kHz had relatively broad frequency tuning, whereas sites responding best to higher frequencies had either broad or narrow frequency tuning. Sites with multipeaked frequency response profiles typically had two response peaks. The first peak was usually between 1 and 3 kHz and the second was usually between 5 and 8 kHz; there was no systematic relationship between the two peak frequencies. 3. In dorsoventral electrode penetrations that contained sites with tuned and/or multipeaked response profiles, a "common frequency" was identified that elicited a maximal response from all of the sites in the penetration. 4. The PAF contains a single tonotopic field. Units tuned to low frequencies are located caudomedially, whereas units tuned to high frequencies are located rostrolaterally. Compared with the frequency representation along the basilar papilla and in other auditory structures, the PAF overrepresents low frequencies (< 4 kHz) that are important for barn owl vocalizations. Conversely, high frequencies (> or = 4 kHz), which are necessary for precise sound localization, are underrepresented

  12. 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

  13. GAP analysis of state protection wetland bird diversity on the Sanjiang Plain

    NASA Astrophysics Data System (ADS)

    Liu, Jiping; Sheng, Lianxi; Wang, Haixi; Yu, Yang

    2008-12-01

    Sanjiang Plain was chosen as the study area in this paper, based on the relationship between species and their habitats, using principles of landscape ecology and protection biology, "3S" technique, same surface areas of hexagons as forecasting and evaluating units to analyze protection status of state protection wetlands birds and diversity of their habitats, to find the unprotected biodiversity hotspots there and then analyze the priority protection. The study results showed that nationally protected bird categories I, such as Ciconia boyciana and Haliaeetus albicilla have been protected well, the area which protects in the protected occupies its distribution area 41.5% and 31.2%, simply has obtained the very good protection. The Mergus squamatus, Grus japonensis and Aquila chrysaetos also occupy their always dispersal area in the protectorate dispersal area above 20%, but their main distribution area not in protectorate, mainly is nature or half natural ecosystem. Some birds under second class state protection as Bubo bubo, Falco peregrinus, Accipiter gentilis, Falco tinnunculu, and Strix uralensis have not been well protected. Specially Bubo bubo, only protects its dispersal area 0.6%, simply h as not obtained the very good protection. Looked from various ecosystem type that, the typical meadow and the island forest to protect well, but the islands, the Reed marshesand the rivers ecosystem to protect relatively bad. Thirteen hotspots have been discovered in this area, which are mainly distributed in surroundings near nature reserve and coast of some great rivers.

  14. 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. PMID:25238090

  15. 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. PMID:21481471

  16. Pathology and epidemiology of natural West Nile viral infection of raptors in Georgia.

    PubMed

    Ellis, Angela E; Mead, Daniel G; Allison, Andrew B; Stallknecht, David E; Howerth, Elizabeth W

    2007-04-01

    Carcasses from 346 raptors found between August 2001 and December 2004 were tested for West Nile virus (WNV) using virus isolation and immunohistochemistry; 40 were positive for WNV by one or both methods. Of these 40 birds, 35 had histologic lesions compatible with WNV infection, one had lesions possibly attributable to WNV, and four had no histologic evidence of WNV. The most common histologic lesions associated with WNV infection were myocardial inflammation, necrosis, and fibrosis; skeletal muscle degeneration, inflammation, and fibrosis; and lymphoplasmacytic encephalitis. Other lesions included hepatitis, lymphoid depletion in spleen and bursa, splenic and hepatic hemosiderosis, pancreatitis, and ganglioneuritis. Gross lesions included calvarial and leptomeningeal hemorrhage, myocardial pallor, and splenomegaly. Red-tailed hawks (Buteo jamaicensis) (10/56), sharp-shinned hawks (Accipiter striatus) (8/40), and Cooper's hawks (Accipiter cooperii) (10/103) were most commonly affected. Also affected were red-shouldered hawks (Buteo lineatus) (2/43), an osprey (Pandion haliaetus) (1/5), barred owls (Strix varia) (4/27), a great horned owl (Bubo virginianus) (1/18), and eastern screech owls (Megascops asio) (4/42). Although birds were examined throughout the year, positive cases occurred only during the summer and late fall (June-December). Yearly WNV mortality rates ranged from 7-15% over the four years of the study. This study indicates trends in infection rates of WNV in raptorial species over a significant time period and supports the available information regarding pathology of WNV infection in Strigiformes and Falconiformes. Although many species tested were positive for WNV infection, severity of lesions varied among species. PMID:17495305

  17. 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. PMID

  18. 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. PMID:26262392

  19. 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. PMID:15482841

  20. Friction drive and bogies for OWL's main axes, technological step backwards or cost effective alternative?

    NASA Astrophysics Data System (ADS)

    Brunetto, Enzo; Koch, Franz; Biancat Marchet, F.; Dimmler, Martin

    2003-01-01

    The drive and bearing technologies have a major impact on the static and dynamic performances of a steerable telescope. The costs related to the complexity of the design and its Reliability, Availability, Maintainability and Safety (RAMS) are not negligible. The design constraints of Extremely Large Telescopes (ELT) depart from those applicable to the current generation of 8 to 10 meter class telescopes, thus suggesting that alternative solutions should be investigated. This paper discusses the feasibility of implementing a design based on friction drives and bogies, tailored to OWL"s azimuthal and altitude degrees of freedom. The estimated static and dynamic performance of the mechanical structure, the achievable angular resolution, the optimal distribution of loads and stresses, the RAMS performance and finally its cost efficiency, make this solution particularly attractive.

  1. Leap and strike kinetics of an acoustically 'hunting' barn owl (Tyto alba).

    PubMed

    Usherwood, James R; Sparkes, Emily L; Weller, Renate

    2014-09-01

    Barn owls are effective hunters of small rodents. One hunting technique is a leap from the ground followed by a brief flight and a plummeting 'strike' onto an acoustically targeted - and potentially entirely hidden - prey. We used forceplate measurements to derive kinetics of the leap and strike. Leaping performance was similar to reported values for guinea fowl. This is likely achieved despite the owl's considerably smaller size because of its relatively long legs and use of wing upstroke. Strikes appear deliberately forceful: impulses could have been spread over larger periods during greater deflections of the centre of mass, as observed in leaping and an alighting landing measurement. The strike, despite forces around 150 times that of a mouse body weight, is not thought to be crucial to the kill; rather, forceful strikes may function primarily to enable rapid penetration of leaf litter or snow cover, allowing grasping of hidden prey. PMID:24948629

  2. 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. PMID:22471670

  3. Trends in North American small mammals found in common barn-owl (Tyto alba) dietary studies

    USGS Publications Warehouse

    Clark, D.R., Jr.; 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.

  4. Variability reduction in interaural time difference tuning in the barn owl.

    PubMed

    Fischer, Brian J; Konishi, Masakazu

    2008-08-01

    The interaural time difference (ITD) is the primary auditory cue used by the barn owl for localization in the horizontal direction. ITD is initially computed by circuits consisting of axonal delay lines from one of the cochlear nuclei and coincidence detector neurons in the nucleus laminaris (NL). NL projects directly to the anterior part of the dorsal lateral lemniscal nucleus (LLDa), and this area projects to the core of the central nucleus of the inferior colliculus (ICcc) in the midbrain. To show the selectivity of an NL neuron for ITD requires averaging of responses over several stimulus presentations for each ITD. In contrast, ICcc neurons detect their preferred ITD in a single burst of stimulus. We recorded extracellularly the responses of LLDa neurons to ITD in anesthetized barn owls and show that this ability is already present in LLDa, raising the possibility that ICcc inherits its noise reduction property from LLDa. PMID:18509071

  5. Spatial hearing in echoic environments: The role of the envelope in owls

    PubMed Central

    Nelson, Brian S.; Takahashi, Terry T.

    2010-01-01

    Summary 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. PMID:20797540

  6. 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.

  7. Inner vane fringes of barn owl feathers reconsidered: morphometric data and functional aspects

    PubMed Central

    Bachmann, Thomas; Wagner, Hermann; Tropea, Cameron

    2012-01-01

    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. PMID:22471670

  8. 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. PMID:25451101

  9. 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.

  10. 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. PMID:26552377

  11. 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

  12. Comparison of midbrain and thalamic space-specific neurons in barn owls.

    PubMed

    Pérez, María Lucía; Peña, José Luis

    2006-02-01

    Spatial receptive fields of neurons in the auditory pathway of the barn owl result from the sensitivity to combinations of interaural time (ITD) and level differences across stimulus frequency. Both the forebrain and tectum of the owl contain such neurons. The neural pathways, which lead to the forebrain and tectal representations of auditory space, separate before the midbrain map of auditory space is synthesized. The first nuclei that belong exclusively to either the forebrain or the tectal pathways are the nucleus ovoidalis (Ov) and the external nucleus of the inferior colliculus (ICx), respectively. Both receive projections from the lateral shell subdivision of the inferior colliculus but are not interconnected. Previous studies indicate that the owl's tectal representation of auditory space is different from those found in the owl's forebrain and the mammalian brain. We addressed the question of whether the computation of spatial cues in both pathways is the same by comparing the ITD tuning of Ov and ICx neurons. Unlike in ICx, the relationship between frequency and ITD tuning had not been studied in single Ov units. In contrast to the conspicuous frequency independent ITD tuning of space-specific neurons of ICx, ITD selectivity varied with frequency in Ov. We also observed that the spatially tuned neurons of Ov respond to lower frequencies and are more broadly tuned to ITD than in ICx. Thus there are differences in the integration of frequency and ITD in the two sound-localization pathways. Thalamic neurons integrate spatial information not only within a broader frequency band but also across ITD channels. PMID:16424454

  13. Primary closure of the corneas of two Great Horned owls after resection of nonhealing ulcers.

    PubMed

    Gionfriddo, Juliet R; Powell, Cynthia C

    2006-01-01

    Two Great Horned owls were presented to the Colorado State University Veterinary Teaching Hospital for evaluation of corneal lesions. Each bird had a corneal ulcer and bullous keratopathy. Following unsuccessful attempts at medical and surgical management, the corneal defects in each bird were treated with penetrating keratoplasties and conjunctival pedicle grafts. In each bird the cornea healed well and regained approximately its normal shape. Both birds fully recovered and have been released into the wild. PMID:16771761

  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. PMID:24014246

  15. 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

  16. 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.

  17. 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.

  18. Animal behaviour: use of dung as a tool by burrowing owls.

    PubMed

    Levey, Douglas J; Duncan, R Scot; Levins, Carrie F

    2004-09-01

    Reports of tool usage by birds tend to be anecdotal as only a few individuals may be involved and the behaviour observed can often be interpreted in other ways. Here we describe the widespread collection of mammalian dung by burrowing owls (Athene cunicularia) and show that they use this dung as a bait to attract dung beetles, a major item of prey. Our controlled investigation provides an unambiguous estimate of the importance of tool use in a wild animal. PMID:15343324

  19. Directional responses of visual wulst neurones to grating and plaid patterns in the awake owl.

    PubMed

    Baron, Jerome; Pinto, Lucas; Dias, Marcelo Oliveira; Lima, Bruss; Neuenschwander, Sergio

    2007-10-01

    The avian retinothalamofugal pathway reaches the telencephalon in an area known as visual wulst. A close functional analogy between this area and the early visual cortex of mammals has been established in owls. The goal of the present study was to assess quantitatively the directional selectivity and motion integration capability of visual wulst neurones, aspects that have not been previously investigated. We recorded extracellularly from a total of 101 cells in awake burrowing owls. From this sample, 88% of the units exhibited modulated directional responses to sinusoidal gratings, with a mean direction index of 0.74 +/- 0.03 and tuning bandwidth of 28 +/- 1.16 degrees . A direction index higher than 0.5 was observed in 66% of the cells, thereby qualifying them as direction selective. Motion integration was tested with moving plaids, made by adding two sinusoidal gratings of different orientations. We found that 80% of direction-selective cells responded optimally to the motion direction of the component gratings, whereas none responded to the global motion of plaids, whose direction was intermediate to that of the gratings. The remaining 20% were unclassifiable. The strength of component motion selectivity rapidly increased over a 200 ms period following stimulus onset, maintaining a relatively sustained profile thereafter. Overall, our data suggest that, as in the mammalian primary visual cortex, the visual wulst neurones of owls signal the local orientated features of a moving object. How and where these potentially ambiguous signals are integrated in the owl brain might be important for understanding the mechanisms underlying global motion perception. PMID:17897399

  20. 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. PMID:27377751

  1. 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. PMID:23615168

  2. Experimental analysis of the flow field over a novel owl based airfoil

    NASA Astrophysics Data System (ADS)

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

    The aerodynamics of a newly constructed wing model the geometry of which is related to the wing of a barn owl is experimentally investigated. Several barn owl wings are scanned to obtain three-dimensional surface models of natural wings. A rectangular wing model with the general geometry of the barn owl but without any owlspecific structure being the reference case for all subsequent measurements is investigated using pressure tabs, oil flow pattern technique, and particle-image velocimetry. The main flow feature of the clean wing is a transitional separation bubble on the suction side. The size of the bubble depends on the Reynolds number and the angle of attack, whereas the location is mainly influenced by the angle of attack. Next, a second model with a modified surface is considered and its influence on the flow field is analyzed. Applying a velvet onto the suction side drastically reduces the size of this separation at moderate angles of attack and higher Reynolds numbers.

  3. Acetylcholinesterase staining differentiates functionally distinct auditory pathways in the barn owl.

    PubMed

    Adolphs, R

    1993-03-15

    The aim of this study was to examine how the functional specialization of the barn owl's auditory brainstem might correlate with histochemical compartmentalization. The barn owl uses interaural intensity and time differences to encode, respectively, the vertical and azimuthal positions of sound sources in space. These two auditory cues are processed in parallel ascending pathways that separate from each other at the level of the cochlear nuclei. Sections through the auditory brainstem were stained for acetylcholinesterase (AChE) to examine whether nuclei that process different auditory cues stain differentially for this enzyme. Of the two cochlear nuclei, angularis showed more intense staining than nucleus magnocellularis. Nucleus angularis projects to all of the nuclei and subdivisions of nuclei that belong to the intensity processing pathway. Acetylcholinesterase stained all regions that contain terminal fields of nucleus angularis and thus provided discrimination between the time and intensity pathways. Moreover, staining patterns with acetylcholinesterase were complementary to those previously reported with an anti-calbindin antibody, which stains terminal fields of nucleus laminaris, and thus stains all the nuclei and subdivisions of nuclei that belong to the time pathway. Some of the gross staining patterns observed with AChE were similar to those reported with antibodies to glutamate decarboxylase. However, AChE is a more convenient and definitive marker in discriminating between these pathways than is calbindin or glutamate decarboxylase. Acetylcholinesterase staining of the intensity pathway in the owl may be related to encoding of sound intensity by spike rate over large dynamic ranges. PMID:7681456

  4. Disruption of auditory spatial working memory by inactivation of the forebrain archistriatum in barn owls.

    PubMed

    Knudsen, E I; Knudsen, P F

    1996-10-01

    Barn owls not only localize auditory stimuli with great accuracy, they also remember the locations of auditory stimuli and can use this remembered spatial information to guide their flight and strike. Although the mechanisms of sound localization have been studied extensively, the neurobiological basis of auditory spatial memory has not. Here we show that the ability of barn owls to orient their gaze towards and fly to the remembered location of auditory targets is lost during pharmacological inactivation of a small region in the forebrain, the anterior archistriatum. In contrast, archistriatal inactivation has no effect on stimulus-guided responses to auditory targets. The memory-dependent deficit is evident only for acoustic events that occur in the hemifield contralateral to the side that is inactivated. The data demonstrate that in the avian archistriatum, as in the mammalian frontal cortex, there exists a region that is essential for the expression of spatial working memory and that, in the barn owl, this region encodes auditory spatial memory. PMID:8837773

  5. Selective predation on hantavirus-infected voles by owls and confounding effects from landscape properties.

    PubMed

    Khalil, Hussein; Ecke, Frauke; Evander, Magnus; Hörnfeldt, Birger

    2016-06-01

    It has been suggested that predators may protect human health through reducing disease-host densities or selectively preying on infected individuals from the population. However, this has not been tested empirically. We hypothesized that Tengmalm's owl (Aegolius funereus) selectively preys on hantavirus-infected individuals of its staple prey, the bank vole (Myodes glareolus). Bank voles are hosts of Puumala hantavirus, which causes a form of hemorrhagic fever in humans. Selective predation by owls on infected voles may reduce human disease risk. We compared the prevalence of anti-Puumala hantavirus antibodies (seroprevalence), in bank voles cached by owls in nest boxes to seroprevalence in voles trapped in closed-canopy forest around each nest box. We found no general difference in seroprevalence. Forest landscape structure could partly account for the observed patterns in seroprevalence. Only in more connected forest patches was seroprevalence in bank voles cached in nest boxes higher than seroprevalence in trapped voles. This effect disappeared with increasing forest patch isolation, as seroprevalence in trapped voles increased with forest patch isolation, but did not in cached voles. Our results suggest a complex relationship between zoonotic disease prevalence in hosts, their predators, and landscape structure. Some mechanisms that may have caused the seroprevalence patterns in our results include higher bank vole density in isolated forest patches. This study offers future research potential to shed further light on the contribution of predators and landscape properties to human health. PMID:26873607

  6. 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.

  7. Comparative determination of two probiotics by QCM and OWLS-based immunosensors.

    PubMed

    Szalontai, Helga; Adányi, Nóra; Kiss, Attila

    2014-09-25

    The regular consumption of foods containing probiotic bacteria has beneficial physiological effects on the health and the digestion system. There is a need for novel analytical approaches for the determination of these bacteria that are faster than the classical plate counting method. For this purpose, two label-free biosensors were investigated and presented in this paper: Quartz Crystal Microbalance (QCM) and Optical Waveguide Lightmode Spectroscopy (OWLS) based direct immunosensors were developed for real-time direct detection of probiotic bacteria in fermented dairy products. Bifidobacterium bifidum O1356 and Lactobacillus acidophilus O1132 were detected by polyclonal anti-B. bifidum IgG and anti-L. acidophilus IgG immobilized on the sensors' surface. Sulfo-LC-SPDP cross linking agent was used to bind antibodies to the gold surface of the QCM's AT-cut quartz wafer. Concerning OWLS, antibodies were covalently bound to the amino groups of the silanized surface of the waveguide by glutaraldehyde. The dynamic measuring range was found between 1.0E+3 and 5.0E+5CFUmL(-1) in 100 fold diluted fermented milk products by QCM and with OWLS. Considering the current legislation of the probiotic content in probiotic products, the two developed immunosensors can be applied for rapid quantification of L. acidophilus and B. bifidum in fermented milk. These examinations offer effective alternatives to the microbiological plate counting method. PMID:24768869

  8. Cue Reliability Represented in the Shape of Tuning Curves in the Owl's Sound Localization System

    PubMed Central

    Fischer, Brian J.; Peña, Jose L.

    2016-01-01

    Optimal use of sensory information requires that the brain estimates the reliability of sensory cues, but the neural correlate of cue reliability relevant for behavior is not well defined. Here, we addressed this issue by examining how the reliability of spatial cue influences neuronal responses and behavior in the owl's auditory system. We show that the firing rate and spatial selectivity changed with cue reliability due to the mechanisms generating the tuning to the sound localization cue. We found that the correlated variability among neurons strongly depended on the shape of the tuning curves. Finally, we demonstrated that the change in the neurons' selectivity was necessary and sufficient for a network of stochastic neurons to predict behavior when sensory cues were corrupted with noise. This study demonstrates that the shape of tuning curves can stand alone as a coding dimension of environmental statistics. SIGNIFICANCE STATEMENT In natural environments, sensory cues are often corrupted by noise and are therefore unreliable. To make the best decisions, the brain must estimate the degree to which a cue can be trusted. The behaviorally relevant neural correlates of cue reliability are debated. In this study, we used the barn owl's sound localization system to address this question. We demonstrated that the mechanisms that account for spatial selectivity also explained how neural responses changed with degraded signals. This allowed for the neurons' selectivity to capture cue reliability, influencing the population readout commanding the owl's sound-orienting behavior. PMID:26888922

  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. Hydrogeologic features of the alluvial deposits in the Owl Creek Valley, Bighorn Basin, Wyoming

    USGS Publications Warehouse

    Cooley, M.E.; Head, W.J.

    1982-01-01

    The alluvial acquifer principally of the flood-plain alluvium and part of the Arapahoe Ranch terrace deposits and consists subordinately of alluvial-fan deposits. Thickness of the alluvial aquifer is generally 20 to 40 feet. Dissolved-solids concentration of water in the alluvial aquifer ranges from about 500 to more than 3,000 milligrams per liter. The most favorable areas for groundwater development are the flood-plain alluvium and part of the Arapahoe Ranch terrace deposits; however, in much of these units, the water contains more than 2,000 milligrams per liter of dissolved solids. Measurements of specific conductance of the flow of Owl Creek indicate a progressive increase in the down stream direction and range between 15 and 355 micromhos per centimeter at 25C per mile. The increases are due to return flow of irrigation water, inflow from tributaries, and inflow from groundwater. Conspicuous terraces in Owl Creek Valley included an unnamed terrace at 500 feet above Owl Creek, the Embar Ranch terrace 160 to 120 feet above the creek, and the Arapahoe Ranch terrace 50 to 20 feet above the creek. (USGS)

  11. 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.

  12. 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.

  13. 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

  14. 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.

  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. PMID:25786606

  16. Process model-based atomic service discovery and composition of composite semantic web services using web ontology language for services (OWL-S)

    NASA Astrophysics Data System (ADS)

    Paulraj, D.; Swamynathan, S.; Madhaiyan, M.

    2012-11-01

    Web Service composition has become indispensable as a single web service cannot satisfy complex functional requirements. Composition of services has received much interest to support business-to-business (B2B) or enterprise application integration. An important component of the service composition is the discovery of relevant services. In Semantic Web Services (SWS), service discovery is generally achieved by using service profile of Ontology Web Languages for Services (OWL-S). The profile of the service is a derived and concise description but not a functional part of the service. The information contained in the service profile is sufficient for atomic service discovery, but it is not sufficient for the discovery of composite semantic web services (CSWS). The purpose of this article is two-fold: first to prove that the process model is a better choice than the service profile for service discovery. Second, to facilitate the composition of inter-organisational CSWS by proposing a new composition method which uses process ontology. The proposed service composition approach uses an algorithm which performs a fine grained match at the level of atomic process rather than at the level of the entire service in a composite semantic web service. Many works carried out in this area have proposed solutions only for the composition of atomic services and this article proposes a solution for the composition of composite semantic web services.

  17. Dynamics of visually guided auditory plasticity in the optic tectum of the barn owl.

    PubMed

    Brainard, M S; Knudsen, E I

    1995-02-01

    1. In the optic tectum of normal barn owls, bimodal (auditory-visual) neurons are tuned to the values of interaural time difference (ITD) that are produced by sounds at the locations of their visual receptive fields (VRFs). The auditory tuning of tectal neurons is actively guided by visual experience during development: in the tectum of adult owls reared with an optically displaced visual field, neurons are tuned to abnormal values of ITD that are close to the values produced by sounds at the locations of their optically displaced VRFs. In this study we investigated the dynamics of this experience-dependent plasticity. 2. Owls were raised from shortly after eye-opening (14-22 days of age) with prismatic spectacles that displaced the visual field to the right or left. Starting at approximately 60 days of age, multiunit recordings were made to assess the tuning of tectal neurons to ITD presented via earphones. In the earliest recording sessions (ages 60-80 days), ITD tuning was often close to normal, even though the majority of the owls' previous experience was with an altered correspondence between ITD values and VRF locations. Subsequently, over a period of weeks, responses to the normal range of ITDs were gradually eliminated while responses to values of ITD corresponding with the optically displaced VRF were acquired. 3. At intermediate stages in this process, the ITD tuning at many sites became abnormally broad, so that responses were simultaneously present to both normal values of ITD and to values corresponding with the optically displaced VRF. At this stage the latencies and durations of newly acquired responses systematically exceeded the latencies and durations of the responses to normal values of ITD. 4. Dynamic changes in ITD tuning similar to those recorded in the optic tectum also occurred in the external nucleus of the inferior colliculus (ICX), which provides the major source of ascending auditory input to the tectum. 5. These results suggest the

  18. Identification of Owl Monkey CD4 Receptors Broadly Compatible with Early-Stage HIV-1 Isolates

    PubMed Central

    Meyerson, Nicholas R.; Sharma, Amit; Wilkerson, Gregory K.

    2015-01-01

    ABSTRACT Most HIV-1 variants isolated from early-stage human infections do not use nonhuman primate versions of the CD4 receptor for cellular entry, or they do so poorly. We and others have previously shown that CD4 has experienced strong natural selection over the course of primate speciation, but it is unclear whether this selection has influenced the functional characteristics of CD4 as an HIV-1 receptor. Surprisingly, we find that selection on CD4 has been most intense in the New World monkeys, animals that have never been found to harbor lentiviruses related to HIV-1. Based on this, we sampled CD4 genetic diversity within populations of individuals from seven different species, including five species of New World monkeys. We found that some, but not all, CD4 alleles found in Spix's owl monkeys (Aotus vociferans) encode functional receptors for early-stage human HIV-1 isolates representing all of the major group M clades (A, B, C, and D). However, only some isolates of HIV-1 subtype C can use the CD4 receptor encoded by permissive Spix's owl monkey alleles. We characterized the prevalence of functional CD4 alleles in a colony of captive Spix's owl monkeys and found that 88% of surveyed individuals are homozygous for permissive CD4 alleles, which encode an asparagine at position 39 of the receptor. We found that the CD4 receptors encoded by two other species of owl monkeys (Aotus azarae and Aotus nancymaae) also serve as functional entry receptors for early-stage isolates of HIV-1. IMPORTANCE Nonhuman primates, particularly macaques, are used for preclinical evaluation of HIV-1 vaccine candidates. However, a significant limitation of the macaque model is the fact that most circulating HIV-1 variants cannot use the macaque CD4 receptor to enter cells and have to be adapted to these species. This is particularly true for viral variants from early stages of infection, which represent the most relevant vaccine targets. In this study, we found that some individuals

  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. Sarcocystis sp. in mountain goats (Oreamnos americanus) in Washington: prevalence and search for the definitive host.

    PubMed

    Foreyt, W J

    1989-10-01

    During October and November 1986, Sarcocystis sp. was detected in 24 of 56 (43%) tongues from hunter-killed mountain goats (Oreamnos americanus) in Washington (USA). Sarcocysts had an unusual sessile polyp-shaped branched wall. Mean size of 154 sarcocysts was 71.3 x 37.8 microns (range, 20 to 248 x 10 to 120 microns), and the mean intensity was 2.3 (range, 1 to 28). In an attempt to identify the definitive host, infected tongues were fed to four coyotes (Canis latrans), eight domestic dogs, four domestic cats, three bears (Ursus americanus), two raccoons (Procyon lotor), two martens (Martes americana), two fishers (Martes pennanti), three skunks (Mephitis mephitis), five mink (Mustela vison), five ferrets (Mustela putorius), one pigtail macaque (Macaca nemestrina), two red-tailed hawks (Buteo jamaicensis) and one great horned owl (Bubo virginianus). Oocysts or sporocysts were not detected in the feces of any host for less than or equal to 20 days after ingestion of the infected meat. The definitive host for Sarcocystis sp. in mountain goats was not identified. PMID:2509738

  1. Yersinia enterocolitica and related species isolated from wildlife in New York State.

    PubMed

    Shayegani, M; Stone, W B; DeForge, I; Root, T; Parsons, L M; Maupin, P

    1986-09-01

    Fecal specimens for Yersinia screening were obtained from a variety of wild mammals, birds, reptiles, fish, and invertebrates throughout New York State. One specimen from each of 1,426 animals was examined. A total of 148 isolates of Yersinia enterocolitica and related species were obtained from 133 (9.3%) of the animals. Y. enterocolitica was isolated from 100 (7%) of the animals tested, including 81 (10%) of 812 mammals and 19 (3.3%) of 573 birds. Y. intermedia, Y. frederiksenii, and Y. kristensenii were isolated from 39 (2.7%), 5 (0.35%), and 4 (0.28%) animals, respectively. The 81 Y. enterocolitica isolates from mammals belonged to 15 serogroups and included three pathogens: two isolates of typical serogroup 0:8, the "American strain," one from a gray fox (Urocyon cinereoargenteus) and one from a porcupine (Erethizon dorsatum); and one isolate of serogroup 0:3, bacteriophage type IXb, the "Canadian strain," from a gray fox. The most prevalent serogroups recovered from mammals were 0:6,31 (16 isolates) and 0:5,27 (6 isolates). The 19 isolates of Y. enterocolitica from birds belonged to nine serogroups and included one serogroup 0:6,31 isolate from a common grackle (Quiscalus quiscula) and two serogroup 0:5,27 isolates from great horned owls (Bubo virginianus). PMID:3767355

  2. Serologic evidence of West Nile virus infection in three wild raptor populations.

    PubMed

    Stout, William E; Cassini, Andrew G; Meece, Jennifer K; Papp, Joseph M; Rosenfield, Robert N; Reed, Kurt D

    2005-09-01

    We assayed for West Nile virus (WNV) antibodies to determine the presence and prevalence of WNV infection in three raptor populations in southeast Wisconsin during 2003-04. This study was conducted in the framework of ongoing population studies that started before WNV was introduced to the study area. For 354 samples, 88% of 42 adult Cooper's hawks (Accipiter cooperii), 2.1% of 96 nestling Cooper's hawks, 9.2% of 141 nestling red-tailed hawks (Buteo jamaicensis), and 12% of 73 nestling great horned owls (Bubo virginianus) tested positive for WNV antibodies by the constant virus-serum dilution neutralization test. Samples that tested positive for WNV antibodies were collected across a wide variety of habitat types, including urban habitats (both high and low density), roads, parking areas, recreational areas, croplands, pastures, grasslands, woodlands, and wetlands. Based on the increased prevalence and significantly higher WNV antibody titers in adults compared with nestlings, we suggest that nestlings with detectable antibody levels acquired these antibodies through passive transmission from the mother during egg production. Low levels of WNV antibodies in nestlings could serve as a surrogate marker of exposure in adult raptor populations. Based on breeding population densities and reproductive success over the past 15 yr, we found no apparent adverse effects of WNV infections on these wild raptor populations. PMID:16252490

  3. 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. PMID:17092880

  4. 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. PMID:17495304

  5. Poisoning of wildlife with anticoagulant rodenticides in New York.

    PubMed

    Stone, W B; Okoniewski, J C; Stedelin, J R

    1999-04-01

    From 1971 through 1997, we documented 51 cases (55 individual animals) of poisoning of non-target wildlife in New York (plus two cases in adjoining states) (USA) with anticoagulant rodenticides--all but two of these cases occurred in the last 8 yrs. Brodifacoum was implicated in 80% of the incidents. Diphacinone was identified in four cases, bromadiolone in three cases (once in combination with brodifacoum), and chlorophacinone and coumatetralyl were detected once each in the company of brodifacoum. Warfarin accounted for the three cases documented prior to 1989, and one case involving a bald eagle (Haliaeetus leucocephalus) in 1995. Secondary intoxication of raptors, principally great horned owls (Bubo virginianus) and red-tailed hawks (Buteo jamaicensis), comprised one-half of the cases. Gray squirrels (Sciurus carolinensis), raccoons (Procyon lotor) and white-tailed deer (Odocoileus virginianus) were the most frequently poisoned mammals. All of the deer originated from a rather unique situation on a barrier island off southern Long Island (New York). Restrictions on the use of brodifacoum appear warranted. PMID:10231745

  6. Retinal Structure of Birds of Prey Revealed by Ultra-High Resolution Spectral-Domain Optical Coherence Tomography

    PubMed Central

    Ruggeri, Marco; Major, James C.; McKeown, Craig; Knighton, Robert W.; Puliafito, Carmen A.

    2010-01-01

    Purpose. To reveal three-dimensional (3-D) information about the retinal structures of birds of prey in vivo. Methods. An ultra-high resolution spectral-domain optical coherence tomography (SD-OCT) system was built for in vivo imaging of retinas of birds of prey. The calibrated imaging depth and axial resolution of the system were 3.1 mm and 2.8 μm (in tissue), respectively. 3-D segmentation was performed for calculation of the retinal nerve fiber layer (RNFL) map. Results. High-resolution OCT images were obtained of the retinas of four species of birds of prey: two diurnal hawks (Buteo platypterus and Buteo brachyurus) and two nocturnal owls (Bubo virginianus and Strix varia). These images showed the detailed retinal anatomy, including the retinal layers and the structure of the deep and shallow foveae. The calculated thickness map showed the RNFL distribution. Traumatic injury to one bird's retina was also successfully imaged. Conclusions. Ultra-high resolution SD-OCT provides unprecedented high-quality 2-D and 3-D in vivo visualization of the retinal structures of birds of prey. SD-OCT is a powerful imaging tool for vision research in birds of prey. PMID:20554605

  7. A survey on the faunal diversity of Savar Upazila, Dhaka, Bangladesh.

    PubMed

    Hossain, Eftekhar; Chowdhury, Mohammad Mamun; Iqubal, Kazi Farhed

    2008-02-01

    A survey was conducted during January to December 2006 to assess the status of faunal diversity of Savar Upazila, Dhaka, Bangladesh. A total of 30 species of birds, 24 species of winter birds, 7 species of reptiles, 3 species of amphibians, 15 species of mammalians and 32 species of fishes were recorded. Relative abundance of those species were determined. Of the birds, House Sparrow (Passer domesticus) was abundant while Blyth's Kingfisher (Alcedo hercules), Rock Eagle Owl (Bubo bengalensis), Hooded Pitta (Pitta sordida), Black-headed Oriole (Oriolus xanthornus), White-winged Duck (Cairina seululala) and Duck (Anser indicus) were rare. The relative abundance of winter bird could not be assessed because of their migratory habit. Striped keelback (Amphiesma stolata) and Common Smooth Water Snake (Enhydris enhydris) were very common while Black pond turtle (Geoclyms hamiltonii) and Pond tortoise (Melanochelys trijuga) were recorded as endangered. Common Toad (Bufo melanostictus) were abundant but Bull Frog (Rana tigrina) was rare. Asiatic Wild Dog (Cuon alpinus) and House Mouse (Mus musculus) were abundant while Common Otter, Large Indian Civet, Irrawaddy River Dolphin, Indian Hare were rare. Carpu, Silver carp, Tilapia, Nilotica were abundant while, Freshwater Garfish, One stripe spinyeel and Grey Featherback were rare. Landfilling, deforestation, poaching, industrial effluents and current jal were identified as major threats to the faunal diversity of Savar area. PMID:18817158

  8. 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.

  9. 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.

  10. 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

  11. 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. PMID:22227859

  12. Parallel pathways mediating both sound localization and gaze control in the forebrain and midbrain of the barn owl.

    PubMed

    Knudsen, E I; Knudsen, P F; Masino, T

    1993-07-01

    The hypothesis that sound localization and gaze control are mediated in parallel in the midbrain and forebrain was tested in the barn owl. The midbrain pathway for gaze control was interrupted by reversible inactivation (muscimol injection) or lesion of the optic tectum. Auditory input to the forebrain was disrupted by reversible inactivation or lesion of the primary thalamic auditory nucleus, nucleus ovoidalis (homolog of the medial geniculate nucleus). Barn owls were trained to orient their gaze toward auditory or visual stimuli presented from random locations in a darkened sound chamber. Auditory and visual test stimuli were brief so that the stimulus was over before the orienting response was completed. The accuracy and kinetics of the orienting responses were measured with a search coil attached to the head. Unilateral inactivation of the optic tectum had immediate and long-lasting effects on auditory orienting behavior. The owls failed to respond on a high percentage of trials when the auditory test stimulus was located on the side contralateral to the inactivated tectum. When they did respond, the response was usually (but not always) short of the target, and the latency of the response was abnormally long. When the auditory stimulus was located on the side ipsilateral to the inactivated tectum, responses were reliable and accurate, and the latency of responses was shorter than normal. In a tectally lesioned animal, response probability and latency to contralateral sounds returned to normal within 2 weeks, but the increase in response error (due to undershooting) persisted for at least 12 weeks. Despite abnormalities in the response, all of the owls were capable of localizing and orienting to contralateral auditory stimuli on some trials with the optic tectum inactivated or lesioned. This was not true for contralateral visual stimuli. Immediately following tectal inactivation, the owls exhibited complete neglect for visual stimuli located more than 20

  13. 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

  14. 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.

  15. 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.

  16. A Pulse-type Hardware Level Difference Detection Model Based on Sound Source Localization Mechanism in Barn Owl

    NASA Astrophysics Data System (ADS)

    Sakurai, Tsubasa; Sekine, Yoshifumi

    Auditory information processing is very important in the darkness where vision information is extremely limited. Barn owls have excellent hearing information processing function. Barn owls can detect a sound source in the high accuracy of less than two degrees in both of the vertical and horizontal directions. When they perform the sound source localization, the barn owls use the interaural time difference for localization in the horizontal plane, and the interaural level difference for localization in the vertical plane. We are constructing the two-dimensional sound source localization model using pulse-type hardware neuron models based on sound source localization mechanism of barn owl for the purpose of the engineering application. In this paper, we propose a pulse-type hardware model for level difference detection based on sound source localization mechanism of barn owl. Firstly, we discuss the response characteristics of the mathematical model for level difference detection. Next we discuss the response characteristics of the hardware mode. As a result, we show clearly that this proposal model can be used as a sound source localization model of vertical direction.

  17. Particle-image velocimetry investigation of the fluid-structure interaction mechanisms of a natural owl wing.

    PubMed

    Winzen, A; Roidl, B; Schröder, W

    2015-10-01

    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. PMID:26372422

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. Site of auditory plasticity in the brain stem (VLVp) of the owl revealed by early monaural occlusion.

    PubMed

    Mogdans, J; Knudsen, E I

    1994-12-01

    1. The optic tectum of the barn owl contains a physiological map of interaural level difference (ILD) that underlies, in part, its map of auditory space. Monaural occlusion shifts the range of ILDs experienced by an animal and alters the correspondence of ILDs with source locations. Chronic monaural occlusion during development induces an adaptive shift in the tectal ILD map that compensates for the effects of the earplug. The data presented in this study indicate that one site of plasticity underlying this adaptive adjustment is in the posterior division of the ventral nucleus of the lateral lemniscus (VLVp), the first site of ILD comparison in the auditory pathway. 2. Single and multiple unit sites were recorded in the optic tecta and VLVps of ketamine-anesthetized owls. The owls were raised from 4 wk of age with one ear occluded with an earplug. Auditory testing, using digitally synthesized dichotic stimuli, was carried out 8-16 wk later with the earplug removed. The adaptive adjustment in ILD coding in each bird was quantified as the shift from normal ILD tuning measured in the optic tectum. Evidence of adaptive adjustment in the VLVp was based on statistical differences between the VLVp's ipsilateral and contralateral to the occluded ear in the sensitivity of units to excitatory-ear and inhibitory-ear stimulation. 3. The balance of excitatory to inhibitory influences on VLVp units was shifted in the adaptive direction in six out of eight owls. In three of these owls, adaptive differences in inhibition, but not in excitation, were found. For this group of owls, the patterns of response properties across the two VLVps can only be accounted for by plasticity in the VLVp. For the other three owls, the possibility that the difference between the two VLVps resulted from damage to one of the VLVps could not be eliminated, and for one of these, plasticity at a more peripheral site (in the cochlea or cochlear nucleus) could also explain the data. In the remaining two

  3. 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. PMID:24881152

  4. Learning drives differential clustering of axodendritic contacts in the barn owl auditory system.

    PubMed

    McBride, Thomas J; Rodriguez-Contreras, Adrian; Trinh, Angela; Bailey, Robert; Debello, William M

    2008-07-01

    Computational models predict that experience-driven clustering of coactive synapses is a mechanism for information storage. This prediction has remained untested, because it is difficult to approach through time-lapse analysis. Here, we exploit a unique feature of the barn owl auditory localization pathway that permits retrospective analysis of prelearned and postlearned circuitry: owls reared wearing prismatic spectacles develop an adaptive microcircuit that coexists with the native one but can be analyzed independently based on topographic location. To visualize the clustering of axodendritic contacts (potential synapses) within these zones, coactive axons were labeled by focal injection of fluorescent tracer and their target dendrites labeled with an antibody directed against CaMKII (calcium/calmodulin-dependent protein kinase type II, alpha subunit). Using high-resolution confocal imaging, we measured the distance from each contact to its nearest neighbor on the same branch of dendrite. We found that the distribution of intercontact distances for the adaptive zone was shifted dramatically toward smaller values compared with distributions for either the maladaptive zone of the same animals or the adaptive zone of normal juveniles, which indicates that a dynamic clustering of contacts had occurred. Moreover, clustering in the normal zone was greater in normal juveniles than in prism-adapted owls, indicative of declustering. These data demonstrate that clustering is bidirectionally adjustable and tuned by behaviorally relevant experience. The microanatomical configurations in all zones of both experimental groups matched the functional circuit strengths that were assessed by in vivo electrophysiological mapping. Thus, the observed changes in clustering are appropriately positioned to contribute to the adaptive strengthening and weakening of auditory-driven responses. PMID:18596170

  5. Representation of interaural time difference in the central nucleus of the barn owl's inferior colliculus.

    PubMed

    Wagner, H; Takahashi, T; Konishi, M

    1987-10-01

    This paper investigates the role of the central nucleus of the barn owl's inferior colliculus in determination of the sound-source azimuth. The central nucleus contains many neurons that are sensitive to interaural time difference (ITD), the cue for azimuth in the barn owl. The response of these neurons varies in a cyclic manner with the ITD of a tone or noise burst. Response maxima recur at integer multiples of the period of the stimulating tone, or, if the stimulus is noise, at integer multiples of the period corresponding to the neuron's best frequency. Such neurons can signal, by means of their relative spike rate, the phase difference between the sounds reaching the left and right ears. Since an interaural phase difference corresponds to more than one ITD, these neurons represent ITD ambiguously. We call this phenomenon phase ambiguity. The central nucleus is tonotopically organized and its neurons are narrowly tuned to frequency. Neurons in an array perpendicular to isofrequency laminae form a physiological and anatomical unit; only one ITD, the array-specific ITD, activates all neurons in an array at the same relative level. We, therefore, may say that, in the central nucleus, an ITD is conserved in an array of neurons. Array-specific ITDs are mapped and encompass the entire auditory space of the barn owl. Individual space-specific neurons of the external nucleus, which receive inputs from a wide range of frequency channels (Knudsen and Konishi, 1978), are selective for a unique ITD. Space-specific neurons do not show phase ambiguity when stimulated with noise (Takahashi and Konishi, 1986). Space-specific neurons receive inputs from arrays that are selective for the same ITD. The collective response of the neurons in an array may be the basis for the absence of phase ambiguity in space-specific neurons. PMID:3668618

  6. 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. PMID:27455406

  7. 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.

  8. Energy metabolism and body temperature of barn owls fasting in the cold.

    PubMed

    Thouzeau, C; Duchamp, C; Handrich, Y

    1999-01-01

    Energetic adaptation to fasting in the cold has been investigated in a nocturnal raptor, the barn owl (Tyto alba), during winter. Metabolic rate and body temperature (Tb) were monitored in captive birds, (1) after acute exposure to different ambient temperatures (Ta), and (2) during a prolonged fast in the cold (4 degrees C), to take into account the three characteristic phases of body fuel utilization that occur during a long-term but reversible fast. In postabsorptive birds, metabolic rate in the thermoneutral zone was 4. 1+/-0.1 W kg-1 and increased linearly below a lower critical temperature of 23 degrees C. Metabolic rate was 70% above basal at +4 degrees C Ta. Wet thermal conductance was 0.22 W kg-1 degrees C-1. During fasting in the cold, the mass-specific resting metabolic rate decreased by 16% during the first day (phase I) and remained constant thereafter. The amplitude of the daily rhythm in Tb was only moderately increased during phase II, with a slight lowering (0. 6 degrees C) in minimal diurnal Tb, but rose markedly in phase III with a larger drop (1.4 degrees C) in minimal diurnal Tb. Refeeding the birds ended phase III and reversed the observed changes. These results indicate that diurnal hypothermia may be used in long-term fasting barn owls and could be triggered by a threshold of body lipid depletion, according to the shift from lipid to protein fuel metabolism occurring at the phase II/phase III transition. The high cost of regulatory thermogenesis and the limited use of hypothermia during fasting may contribute to the high mortality of barn owls during winter. PMID:10068620

  9. 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

  10. 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. PMID:25905920

  11. Auditory tuning for spatial cues in the barn owl basal ganglia.

    PubMed

    Cohen, Y E; Knudsen, E I

    1994-07-01

    1. The basal ganglia are known to contribute to spatially guided behavior. In this study, we investigated the auditory response properties of neurons in the barn owl paleostriatum augmentum (PA), the homologue of the mammalian striatum. The data suggest that the barn owl PA is specialized to process spatial cues and, like the mammalian striatum, is involved in spatial behavior. 2. Single- and multiunit sites were recorded extracellularly in ketamine-anesthetized owls. Spatial receptive fields were measured with a free-field sound source, and tuning for frequency and interaural differences in timing (ITD) and level (ILD) was assessed using digitally synthesized dichotic stimuli. 3. Spatial receptive fields measured at nine multiunit sites were tuned to restricted regions of space: tuning widths at half-maximum response averaged 22 +/- 9.6 degrees (mean +/- SD) in azimuth and 54 +/- 22 degrees in elevation. 4. PA sites responded strongly to broadband sounds. When frequency tuning could be measured (n = 145/201 sites), tuning was broad, averaging 2.7 kHz at half-maximum response, and tended to be centered near the high end of the owl's audible range. The mean best frequency was 6.2 kHz. 5. All PA sites (n = 201) were selective for both ITD and ILD. ITD tuning curves typically exhibited a single, large "primary" peak and often smaller, "secondary" peaks at ITDs ipsilateral and/or contralateral to the primary peak. Three indices quantified the selectivity of PA sites for ITD. The first index, which was the percent difference between the minimum and maximum response as a function of ITD, averaged 100 +/- 29%. The second index, which represented the size of the largest secondary peak relative to that of the primary peak, averaged 49 +/- 23%. The third index, which was the width of the primary ITD peak at half-maximum response, averaged only 66 +/- 35 microseconds. 6. The majority (96%; n = 192/201) of PA sites were tuned to a single "best" value of ILD. The widths of ILD

  12. 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

  13. Surgical removal of a thymoma in a burrowing owl (Athene cunicularia).

    PubMed

    Kinney, Matthew E; Hanley, Christopher S; Trupkiewicz, John G

    2012-06-01

    A 12-year-old male burrowing owl (Athene cunicularia) was presented for evaluation of a mass in the right cervical region. A thymoma was diagnosed after surgical resection and histopathologic evaluation. Extensive adherence of the thymoma to the esophagus and suspected invasion into the right jugular vein contributed to a poor postsurgical outcome. Diagnosis and treatment of thymomas in avian species is similar to that in mammals. Surgical removal of noninvasive thymomas is usually curative. Thymomas are rarely reported in avian species and this is the first report in a strigiform bird. PMID:22872980

  14. Comparing food limitation among three stages of nesting: supplementation experiments with the burrowing owl.

    PubMed

    Wellicome, Troy I; Danielle Todd, L; Poulin, Ray G; Holroyd, Geoffrey L; Fisher, Ryan J

    2013-08-01

    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 period is

  15. 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. PMID:21118725

  16. 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.

  17. Endogenous New World primate type C viruses isolated from owl monkey (Aotus trivirgatus) kidney cell line.

    PubMed Central

    Todaro, G J; Sherr, C J; Sen, A; King, N; Daniel, M D; Fleckenstein, B

    1978-01-01

    A type C virus (OMC-1) detected in a culture of owl monkey kidney cells resembled typical type C viruses morphologically, but was slightly larger than previously characterized mammalian type C viruses. OMC-1 can be transmitted to bat lung cells and cat embryo fibroblasts. The virions band at a density of 1.16 g/ml in isopycnic sucrose density gradients and contain reverse transcriptase and a 60-65S RNA genome composed of approximately 32S subunits. The reverse transcriptase is immunologically and biochemically distinct from the polymerases of othe retroviruses. Radioimmunoassays directed to the interspecies antigenic determinants of the major structure proteins of other type C viruses do not detect a related antigen in OMC-1. Nucleic acid hybridization experiments using labeled viral genomic RNA or proviral cDNA transcripts to normal cellular DNA of different species show that OMC-1 is an endogenous virus with multiple virogene copies (20-50 per haploid genome) present in normal owl monkey cells and is distinct from previously isolated type C and D viruses. Sequences related to the OMC-1 genome can be detected in other New World monkeys. Thus, similar to the Old World primates (e.g., baboons as a prototype), the New World monkeys contain endogenous type C viral genes that appear to have been transmitted in the primate germ line. Images PMID:76312

  18. Reproduction and survival of tawny owls in relation to persistent organic pollutants.

    PubMed

    Yoccoz, Nigel G; Bustnes, Jan O; Bangjord, Georg; Skaare, Jannech Utne

    2009-01-01

    The potential effects of organochlorines (OCs) and brominated flame retardants on reproduction and survival were studied in tawny owls (Strix aluco) in Central Norway over a period of 19 years (1986-2004). Concentrations of 14 OCs and five polybrominated diphenyl ethers (PBDEs) were measured in eggs (n=104), and Principal Component Analysis was used to produce composite measurements of pollutants; i.e. PC1 and PC2, which accounted for 85% of the variation in contaminant concentrations. There was no evidence for adverse associations between pollutants (PC scores) and life-history traits such as clutch size, probability of producing fledglings and survival, when controlling for potentially confounding variables. Moreover, there was no evidence for interactions between pollutants and vole abundance suggesting no synergistic effects of food stress and pollutants on these life-history traits. There was, however, some evidence for a non-linear negative association between p,p'-DDE (1,1-dichloro-2,2-bis (p-chlorophenyl) ethylene) and eggshell thickness. This suggests that the concentrations of pollutants in this ecosystem were too low to affect reproduction and survival in an owl predominantly consuming prey at low trophic levels, but may be sufficient to cause eggshell thinning at the highest concentrations. PMID:18930319

  19. 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.

  20. 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

  1. 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. PMID:22510644

  2. 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. PMID:23604690

  3. Adaptive visual and auditory map alignment in barn owl superior colliculus and its neuromorphic implementation.

    PubMed

    Huo, Juan; Murray, Alan; Wei, Dongqing

    2012-09-01

    Adaptation is one of the most important phenomena in biology. A young barn owl can adapt to imposed environmental changes, such as artificial visual distortion caused by wearing a prism. This adjustment process has been modeled mathematically and the model replicates the sensory map realignment of barn owl superior colliculus (SC) through axonogenesis and synaptogenesis. This allows the biological mechanism to be transferred to an artificial computing system and thereby imbue it with a new form of adaptability to the environment. The model is demonstrated in a real-time robot environment. Results of the experiments are compared with and without prism distortion of vision, and show improved adaptability for the robot. However, the computation speed of the embedded system in the robot is slow. A digital and analog mixed signal very-large-scale integration (VLSI) circuit has been fabricated to implement adaptive sensory pathway changes derived from the SC model at higher speed. VLSI experimental results are consistent with simulation results. PMID:24807931

  4. Hunting Increases Phosphorylation of Calcium/Calmodulin-Dependent Protein Kinase Type II in Adult Barn Owls

    PubMed Central

    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. PMID:25789177

  5. Preservation of spectrotemporal tuning between the nucleus laminaris and the inferior colliculus of the barn owl.

    PubMed

    Christianson, G Björn; Peña, José Luis

    2007-05-01

    Performing sound recognition is a task that requires an encoding of the time-varying spectral structure of the auditory stimulus. Similarly, computation of the interaural time difference (ITD) requires knowledge of the precise timing of the stimulus. Consistent with this, low-level nuclei of birds and mammals implicated in ITD processing encode the ongoing phase of a stimulus. However, the brain areas that follow the binaural convergence for the computation of ITD show a reduced capacity for phase locking. In addition, we have shown that in the barn owl there is a pooling of ITD-responsive neurons to improve the reliability of ITD coding. Here we demonstrate that despite two stages of convergence and an effective loss of phase information, the auditory system of the anesthetized barn owl displays a graceful transition to an envelope coding that preserves the spectrotemporal information throughout the ITD pathway to the neurons of the core of the central nucleus of the inferior colliculus. PMID:17314241

  6. Noise reduction of coincidence detector output by the inferior colliculus of the barn owl.

    PubMed

    Christianson, G Björn; Peña, José Luis

    2006-05-31

    A recurring theme in theoretical work is that integration over populations of similarly tuned neurons can reduce neural noise. However, there are relatively few demonstrations of an explicit noise reduction mechanism in a neural network. Here we demonstrate that the brainstem of the barn owl includes a stage of processing apparently devoted to increasing the signal-to-noise ratio in the encoding of the interaural time difference (ITD), one of two primary binaural cues used to compute the position of a sound source in space. In the barn owl, the ITD is processed in a dedicated neural pathway that terminates at the core of the inferior colliculus (ICcc). The actual locus of the computation of the ITD is before ICcc in the nucleus laminaris (NL), and ICcc receives no inputs carrying information that did not originate in NL. Unlike in NL, the rate-ITD functions of ICcc neurons require as little as a single stimulus presentation per ITD to show coherent ITD tuning. ICcc neurons also displayed a greater dynamic range with a maximal difference in ITD response rates approximately double that seen in NL. These results indicate that ICcc neurons perform a computation functionally analogous to averaging across a population of similarly tuned NL neurons. PMID:16738236

  7. Top-down control of multimodal sensitivity in the barn owl optic tectum.

    PubMed

    Winkowski, Daniel E; Knudsen, Eric I

    2007-11-28

    We studied the effects of electrically microstimulating a gaze-control area in the owl's forebrain, the arcopallial gaze fields (AGFs), on the responsiveness of neurons in the optic tectum (OT) to visual and auditory stimuli. Microstimulation of the AGF enhanced the visual and auditory responsiveness and stimulus discriminability of OT neurons representing the same location in space as that represented at the microstimulation site in the AGF. At such OT sites, AGF microstimulation also sharpened auditory receptive fields and shifted them toward the location represented at the AGF stimulation site. At the same time, AGF microstimulation suppressed the responsiveness of OT neurons that represented visual or auditory stimuli at other locations in space. The top-down influences of this forebrain gaze-control area on sensory responsiveness in the owl OT are strikingly similar to the space-specific regulation of visual responsiveness in the monkey visual cortex produced by voluntary attention as well as by microstimulation of the frontal eye fields. This experimental approach provides a means for discovering mechanisms that underlie the top-down regulation of sensory responses. PMID:18045922

  8. Sensitivity to spectral interaural intensity difference cues in space-specific neurons of the barn owl.

    PubMed

    Arthur, B J

    2004-02-01

    Barn owls use interaural intensity differences to localize sounds in the vertical plane. At a given elevation the magnitude of the interaural intensity difference cue varies with frequency, creating an interaural intensity difference spectrum of cues which is characteristic of that direction. To test whether space-specific cells are sensitive to spectral interaural intensity difference cues, pure-tone interaural intensity difference tuning curves were taken at multiple different frequencies for single neurons in the external nucleus of the inferior colliculus. For a given neuron, the interaural intensity differences eliciting the maximum response (the best interaural intensity differences) changed with the frequency of the stimulus by an average maximal difference of 9.4+/-6.2 dB. The resulting spectral patterns of these neurally preferred interaural intensity differences exhibited a high degree of similarity to the acoustic interaural intensity difference spectra characteristic of restricted regions in space. Compared to stimuli whose interaural intensity difference spectra matched the preferred spectra, stimuli with inverted spectra elicited a smaller response, showing that space-specific neurons are sensitive to the shape of the spectrum. The underlying mechanism is an inhibition for frequency-specific interaural intensity differences which differ from the preferred spectral pattern. Collectively, these data show that space-specific neurons are sensitive to spectral interaural intensity difference cues and support the idea that behaving barn owls use such cues to precisely localize sounds. PMID:14669025

  9. 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.

  10. 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.

  11. 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.

  12. Site selection for OWL using past, present, and future climate information

    NASA Astrophysics Data System (ADS)

    Graham, Edward; Sarazin, Marc S.; Beniston, Martin; Collet, Claude; Hayoz, Michael; Neun, Moritz; Goyette, Stéphane

    2004-10-01

    Selection of an ideal site for the new generation of Overwhelmingly Large (OWL) telescopes is dependent on many climatological and meteorological parameters. Among these are cloud cover, atmospheric humidity, aerosol content, air temperature, airflow direction, strength and turbulence. Even relatively minor changes in weather patterns can have a significant effect on seeing conditions. A composite climatological database has been designed and built for the site selection task at the Department of Geosciences, University of Fribourg, Switzerland. The database is mainly composed of ECMWF and NCEP-NCAR reanalysis data at a global resolution of between 1° and 2.5° latitude / longitude. Using a Java based interface, codenamed "FriOWL", and programmed in the style of a Geographical Information System, all of this relevant information can be interrogated in order to find the best possible sites for the new telescope. Perhaps the most important variable in site selection is the interaction between air-flow and topography, as atmospheric turbulence greatly affects the image quality produced by the telescope. Global climate is changing and it will continue to do throughout the 21st century. Therefore, it is important to ascertain the effect of global warming on potential sites. An ideal site in today"s climate may not prove ideal within 20 to 50 years. It is therefore planned to update the database with future climate data, using output from global climate models. High resolution modeling of the critical parameters at preferred sites under future climates is also planned.

  13. Vortex Noise Reductions from a Flexible Fiber Model of Owl Down

    NASA Astrophysics Data System (ADS)

    Jaworski, Justin; Peake, Nigel

    2013-11-01

    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. The down is presently idealized as a collection of independent and rigid fibers, which emerge perpendicularly from a rigid plane and are allowed to rotate under elastic restraint. Noise generation from an isolated fiber is effected by its interaction with a point vortex, whose motion is induced by the presence of the rigid half-plane and the elastically-restrained fiber. Numerical evaluations of the vortex path and acoustic signature furnish a comparison with known analytical results for stationary fibers, and results from this primitive model seek to address how aerodynamic noise could be mitigated by flexible fibers.

  14. 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.

  15. 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.

  16. 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.

  17. 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

    2015-01-01

    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. PMID:26624667

  18. 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.

  19. Effectiveness of voluntary habitat stewardship in conserving grassland: case of operation burrowing owl in Saskatchewan.

    PubMed

    Warnock, Robert G; Skeel, Margaret A

    2004-03-01

    There have been no published performance evaluations of nongovernmental, voluntary habitat stewardship programs. The Operation Burrowing Owl (OBO) stewardship program, initiated in 1987, was evaluated for its effectiveness in conservation of grassland habitat during 1986-1993. The 108 OBO sites from 1987 to 88 and 98 randomly selected non-OBO sites that were grassland in 1986 in the Regina-Weyburn, Saskatchewan study area were classified by size and agricultural soil suitability. By 1993, 41 (38%) of the 108 OBO sites had been withdrawn from the program. The 1986 area of grassland was compared with grassland area calculated from digitized 1993 LANDSAT imagery. A correction for satellite inaccuracies was determined. Grassland retention in 1993 was significantly higher at OBO sites (66%) than at random sites (49%), demonstrating that the OBO voluntary program effectively conserved habitat. Also, grassland retention was significantly lower on sites with better agricultural soils, and for sites <12 ha in size. Site type (OBO or random), size and their interaction, followed by agricultural soil suitability, had the greatest effects on grassland retention. During an era of accelerated grassland loss, OBO strongly and positively (statistically significant) affected conservation of grassland sites most at risk: sites <12 ha in size and with good to excellent agricultural soils. This suggests that grassland conservation efforts focus on vulnerable sites (small size and/or good agricultural soils) to provide nesting habitat for burrowing owls. Our study demonstrates that a voluntary stewardship program can significantly increase conservation of habitat. PMID:15037954

  20. A neurophysiological determination of the vertical horopter in the cat and owl.

    PubMed

    Cooper, M L; Pettigrew, J D

    1979-03-01

    We have undertaken a determination of the vertical horopter in two species by simultaneously mapping the receptive field positions of binocular cortical neurons at various elevations along the zero azimuthal meridians. In the paralyzed cat our recordings show that the zero meridians of the two eyes are parallel and vertical under paralysis. Slit-pupil photographs demonstrate that paralysis induces an average net intorsin of 9 degrees between the two eyes. Correction back to the unparalyzed state results in the zero meridians themselves being out-torted with respect to each other. Since the two eyes' zero meridians define physiologically the positions of corresponding retinal points, this out-torsion results in a vertical horopter in the mid-sagittal plane which is tilted away from the alert, unparalyzed cat. The limited eye movements of the owl permit the use of an unparalyzed preparation; it is therefore possible to avoid the problem of the cyclotorsion under paralysis which occurs in the cat. The results of our physiological analysis in the burrowing owl (Speotyto cunicularia) also reveal a tilted horopter in this terrestrial avian species. PMID:762277

  1. A pathway for predation in the brain of the barn owl (Tyto alba)

    PubMed Central

    Wild, J. M.; Kubke, M. F.; Peña, J. L.

    2008-01-01

    The Wulst of birds, which is generally considered homologous with the isocortex of mammals, comprises an elevation on the dorsum of the telencephalon that is particularly prominent in predatory species, especially those with large, frontally placed eyes, such as owls. The Wulst, therefore, is largely visual, but a relatively small rostral portion is somatosensory in nature. In barn owls this rostral somatosensory part of the Wulst forms a unique physical protuberance dedicated to the representation of the contralateral claw. Here we investigate whether the input to this ‘claw area’ arises from dorsal thalamic neurons that, in turn, receive their somatosensory input from the gracile nucleus. Following injections of biotinylated dextran amine into the gracile nucleus and cholera toxin B-chain into the claw area, terminations from the former and retrogradely labeled neurons from the latter overlapped substantially in the thalamic nucleus dorsalis intermedius ventralis anterior. These results indicate the existence in this species of a ‘classical’ trisynaptic somatosensory pathway from the body periphery to the telencephalic Wulst, via the dorsal thalamus, one that is likely involved in the barn owl’s predatory behavior. The results are discussed in the context of somatosensory projections, primarily in this and other avian species. PMID:18461603

  2. 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

  3. 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......

  4. 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. PMID:26222908

  5. 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. PMID:25315358

  6. Early visual experience shapes the representation of auditory space in the forebrain gaze fields of the barn owl.

    PubMed

    Miller, G L; Knudsen, E I

    1999-03-15

    Auditory spatial information is processed in parallel forebrain and midbrain pathways. Sensory experience early in life has been shown to exert a powerful influence on the representation of auditory space in the midbrain space-processing pathway. The goal of this study was to determine whether early experience also shapes the representation of auditory space in the forebrain. Owls were raised wearing prismatic spectacles that shifted the visual field in the horizontal plane. This manipulation altered the relationship between interaural time differences (ITDs), the principal cue used for azimuthal localization, and locations of auditory stimuli in the visual field. Extracellular recordings were used to characterize ITD tuning in the auditory archistriatum (AAr), a subdivision of the forebrain gaze fields, in normal and prism-reared owls. Prism rearing altered the representation of ITD in the AAr. In prism-reared owls, unit tuning for ITD was shifted in the adaptive direction, according to the direction of the optical displacement imposed by the spectacles. Changes in ITD tuning involved the acquisition of unit responses to adaptive ITD values and, to a lesser extent, the elimination of responses to nonadaptive (previously normal) ITD values. Shifts in ITD tuning in the AAr were similar to shifts in ITD tuning observed in the optic tectum of the same owls. This experience-based adjustment of binaural tuning in the AAr helps to maintain mutual registry between the forebrain and midbrain representations of auditory space and may help to ensure consistent behavioral responses to auditory stimuli. PMID:10066282

  7. 77 FR 27010 - Endangered and Threatened Wildlife and Plants; Revised Critical Habitat for the Northern Spotted Owl

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ... amended (Act). The proposed rule was published in the Federal Register on March 8, 2012 (77 FR 14062), and is available online at www.regulations.gov and at http://www.gpo.gov/fdsys/pkg/FR-2012-03-08/pdf/2012...; Revised Critical Habitat for the Northern Spotted Owl AGENCY: Fish and Wildlife Service, Interior....

  8. 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...

  9. 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.

  10. 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 ...

  11. 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.

  12. Rodents in open space adjust their behavioral response to the different risk levels during barn-owl attack

    PubMed Central

    Edut, Shahaf; Eilam, David

    2003-01-01

    Background Previous studies have revealed that the response of prey species to predatory risk comprised either freezing (when the prey remained immobile), or fleeing (when it ran frantically in order to remove itself from the vicinity of the predator). Other studies, however, have suggested that the prey will adjust its behavior to risk level. The present study was designed to follow the attacks of a barn owl (Tyto alba) on common spiny mice (Acomys cahirinus) and social voles (Microtus socialis guntherei), in order to reveal the correspondence between the behavior of the owl, the risk level at each phase of the owl's attack, and the defensive behavior of the rodents. Results Spiny mice dramatically increased the traveled distance upon the appearance of the owl, and kept moving during its attack while taking long trajectories of locomotion. Defensive response in voles dichotomized: in some voles traveled distance dropped when the owl appeared, reaching zero during its attack. In other voles, traveled distance dramatically increased once the owl appeared and further increased under its attack. These defensive responses developed by gradual tuning of normal locomotor behavior in accordance with the level of risk. Conclusions The phenotypic difference in defensive behavior between voles and spiny mice probably stems from their different habitats and motor capacities. Agility and running capacity, together with a relatively sheltered natural habitat, make fleeing the most appropriate response for spiny mice during owl attack. Clumsiness and relatively limited motor capacities, together with an open natural habitat, account for the dichotomy to freezing or fleeing in voles. Thus, the apparent species-specific anti-predator response in spiny mice and voles is based on species-specific normal locomotor behavior, which depends on the species-specific ecology and motor capacity, and behaviors like defensive attack or escape jump that are specific to life threat. The latter

  13. 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

  14. Site selection for extremely large telescopes using the FriOWL software and global re-analysis climate data

    NASA Astrophysics Data System (ADS)

    Graham, E.; Sarazin, M.; Kurlandczyk, H.; Neun, M.; Matzler, C.

    2008-07-01

    FriOWL is a site selection tool for large or extremely large telescope projects. It consists of a graphical user interface and a large global climatic and geophysical database, and is directly accessible on the world wide web. A new version (version 3.1) of the software has recently been developed by scientists at the University of Bern (Switzerland; European Southern Observatory, Germany). The main feature of the new FriOWL database is the inclusion of ERA40 re-analysis data, giving access to over 40 years of long-term climate data. New software tools, programmed in the style of a Geographical Information System, include the capability of resampling layers and time series extraction. A new global seismic hazard layer has been introduced, as well as very high resolution (1km) topographic tiles. Reclassification and overlaying of layers is also possible. Although FriOWL is primarily designed for site selection projects, it can equally be used in other climate studies. It is especially important in the determination of the climatic stability of a potential site, and in the analysis of climatic anomalies and trends. The long-term astroclimatological seeing and photometric statistics for the Paranal and La Silla observatories can be used to validate FriOWL. A case study of ESO Paranal using FriOWL reveals that the deterioration in seeing conditions since 1998 is co-incident with a strong increase in 1000 hPa geopotential height to the south-east of the observatory; there may be a link with the Interdecadal Pacific Oscillation.

  15. 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. PMID:23175801

  16. Early auditory experience induces frequency-specific, adaptive plasticity in the forebrain gaze fields of the barn owl.

    PubMed

    Miller, G L; Knudsen, E I

    2001-05-01

    Binaural acoustic cues such as interaural time and level differences (ITDs and ILDs) are used by many species to determine the locations of sound sources. The relationship between cue values and locations in space is frequency dependent and varies from individual to individual. In the current study, we tested the capacity of neurons in the forebrain localization pathway of the barn owl to adjust their tuning for binaural cues in a frequency-dependent manner in response to auditory experience. Auditory experience was altered by raising young owls with a passive acoustic filtering device that caused frequency-dependent changes in ITD and ILD. Extracellular recordings were made in normal and device-reared owls to characterize frequency-specific ITD and ILD tuning in the auditory archistriatum (AAr), an output structure of the forebrain localization pathway. In device-reared owls, individual sites in the AAr exhibited highly abnormal, frequency-dependent variations in ITD tuning, and across the population of sampled sites, there were frequency-dependent shifts in the representation of ITD. These changes were in a direction that compensated for the acoustic effects of the device on ITD and therefore tended to restore a normal representation of auditory space. Although ILD tuning was degraded relative to normal at many sites in the AAr of device-reared owls, the representation of frequency-specific ILDs across the population of sampled sites was shifted in the adaptive direction. These results demonstrate that early auditory experience shapes the representation of binaural cues in the forebrain localization pathway in an adaptive, frequency-dependent manner. PMID:11353033

  17. 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. PMID:22025367

  18. The role of envelope shape in the localization of multiple sound sources and echoes in the barn owl

    PubMed Central

    Baxter, Caitlin S.; Takahashi, Terry T.

    2013-01-01

    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. PMID:23175801

  19. 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. PMID:25931263

  20. Maps of ITD in the nucleus laminaris of the barn owl.

    PubMed

    Carr, Catherine; Shah, Sahil; Ashida, Go; McColgan, Thomas; Wagner, Hermann; Kuokkanen, Paula T; Kempter, Richard; Köppl, Christine

    2013-01-01

    Axons from the nucleus magnocellularis (NM) and their targets in nucleus laminaris (NL) form the circuit responsible for encoding interaural time differences (ITDs). In barn owls, NL receives bilateral inputs from NM such that axons from the ipsilateral NM enter NL dorsally, while contralateral axons enter from the ventral side. These afferents and their synapses on NL neurons generate a tone-induced local field potential, or neurophonic, that varies systematically with position in NL. From dorsal to ventral within the nucleus, the best interaural time difference (ITD) of the neurophonic shifts from contralateral space to best ITDs around 0 µs. Earlier recordings suggested that in NL, iso-delay contours ran parallel to the dorsal and ventral borders of NL (Sullivan WE, Konishi M. Proc Natl Acad Sci U S A 83:8400-8404, 1986). This axis is orthogonal to that seen in chicken NL, where a single map of ITD runs from around 0 µs ITD medially to contralateral space laterally (Köppl C, Carr CE. Biol Cyber 98:541-559, 2008). Yet the trajectories of the NM axons are similar in owl and chicken (Seidl AH, Rubel EW, Harris DM, J Neurosci 30:70-80, 2010). We therefore used clicks to measure conduction time in NL and made lesions to mark the 0 µs iso-delay contour in multiple penetrations along an isofrequency slab. Iso-delay contours were not parallel to the dorsal and ventral borders of NL; instead the 0 µs iso-delay contour shifted systematically from a dorsal position in medial NL to a ventral position in lateral NL. Could different conduction delays account for the mediolateral shift in the representation of 0 µs ITD? We measured conduction delays using the neurophonic potential and developed a simple linear model of the delay-line conduction velocity. We then raised young owls with time-delaying earplugs in one ear (Gold JI, Knudsen EI, J Neurophysiol 82:2197-2209, 1999) to examine map plasticity. PMID:23716226

  1. 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.

    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

  2. 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

  3. 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.

  4. Functional Delay of Myelination of Auditory Delay Lines in the Nucleus Laminaris of the Barn Owl

    PubMed Central

    Cheng, Shih-Min; Carr, Catherine E.

    2012-01-01

    In the barn owl, maps of interaural time difference (ITD) are created in the nucleus laminaris (NL) by interdigitating axons that act as delay lines. Adult delay line axons are myelinated, and this myelination is timely, coinciding with the attainment of adult head size, and stable ITD cues. The proximal portions of the axons become myelinated in late embryonic life, but the delay line portions of the axon in NL remain unmyelinated until the first postnatal week. Myelination of the delay lines peaks at the third week posthatch, and myelinating oligodendrocyte density approaches adult levels by one month, when the head reaches its adult width. Migration of oligodendrocyte progenitors into NL and the subsequent onset of myelination may be restricted by a glial barrier in late embryonic stages and the first posthatch week, since the loss of tenascin-C immunoreactivity in NL is correlated with oligodendrocyte progenitor migration into NL. PMID:17918244

  5. 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.

  6. Dynamic shifts in the owl's auditory space map predict moving sound location.

    PubMed

    Witten, Ilana B; Bergan, Joseph F; Knudsen, Eric I

    2006-11-01

    The optic tectum of the barn owl contains a map of auditory space. We found that, in response to moving sounds, the locations of receptive fields that make up the map shifted toward the approaching sound. The magnitude of the receptive field shifts increased systematically with increasing stimulus velocity and, therefore, was appropriate to compensate for sensory and motor delays inherent to auditory orienting behavior. Thus, the auditory space map is not static, but shifts adaptively and dynamically in response to stimulus motion. We provide a computational model to account for these results. Because the model derives predictive responses from processes that are known to occur commonly in neural networks, we hypothesize that analogous predictive responses will be found to exist widely in the central nervous system. This hypothesis is consistent with perceptions of stimulus motion in humans for many sensory parameters. PMID:17013379

  7. Effects of dietary fluoride on reproduction in eastern screech-owls

    USGS Publications Warehouse

    Pattee, O.H.; Wiemeyer, Stanley N.; Swineford, D.M.

    1988-01-01

    Sixty-six eastern screech-owls (Otus asio) were paired and randomly assigned to dietary treatment groups of 0, 40, or 200 ppm (mg/kg) Ifluoride (as sodium fluoride) in November 1981. Hatching success was adversely affected at the 200 ppm (mg/kg) level, suggesting potential detrimental impacts to wild populations exposed to fluoride pollution. Eggshell thickness was unaffected. Although fluoride concentrations were elevated in bone and eggshells, large variations among individuals were observed as well as a trend for eggshell residues to increase with sequence of laying. Females had higher residues of fluoride in bone than males. Although fluoride levels in bone and eggshells are useful indicators of exposure, the variability in residues among individuals makes residue data from field collections of limited usefulness in assessing hazards in wild birds.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. OWL model of clinical trial eligibility criteria compatible with partially-known information

    PubMed Central

    2013-01-01

    Background Clinical trials are important for patients, for researchers and for companies. One of the major bottlenecks is patient recruitment. This task requires the matching of a large volume of information about the patient with numerous eligibility criteria, in a logically-complex combination. Moreover, some of the patient’s information necessary to determine the status of the eligibility criteria may not be available at the time of pre-screening. Results We showed that the classic approach based on negation as failure over-estimates rejection when confronted with partially-known information about the eligibility criteria because it ignores the distinction between a trial for which patient eligibility should be rejected and trials for which patient eligibility cannot be asserted. We have also shown that 58.64% of the values were unknown in the 286 prostate cancer cases examined during the weekly urology multidisciplinary meetings at Rennes’ university hospital between October 2008 and March 2009. We propose an OWL design pattern for modeling eligibility criteria based on the open world assumption to address the missing information problem. We validate our model on a fictitious clinical trial and evaluate it on two real clinical trials. Our approach successfully distinguished clinical trials for which the patient is eligible, clinical trials for which we know that the patient is not eligible and clinical trials for which the patient may be eligible provided that further pieces of information (which we can identify) can be obtained. Conclusions OWL-based reasoning based on the open world assumption provides an adequate framework for distinguishing those patients who can confidently be rejected from those whose status cannot be determined. The expected benefits are a reduction of the workload of the physicians and a higher efficiency by allowing them to focus on the patients whose eligibility actually require expertise. PMID:24034867

  14. The representation of sound localization cues in the barn owl's inferior colliculus.

    PubMed

    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. 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. PMID:26182962

  16. 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. PMID:22288481

  17. Emergence of multiplicative auditory responses in the midbrain of the barn owl.

    PubMed

    Fischer, Brian J; Peña, José Luis; Konishi, Masakazu

    2007-09-01

    Space-specific neurons in the barn owl's auditory space map gain spatial selectivity through tuning to combinations of the interaural time difference (ITD) and interaural level difference (ILD). The combination of ITD and ILD in the subthreshold responses of space-specific neurons in the external nucleus of the inferior colliculus (ICx) is well described by a multiplication of ITD- and ILD-dependent components. It is unknown, however, how ITD and ILD are combined at the site of ITD and ILD convergence in the lateral shell of the central nucleus of the inferior colliculus (ICcl) and therefore whether ICx is the first site in the auditory pathway where multiplicative tuning to ITD- and ILD-dependent signals occurs. We used extracellular recording of single neurons to determine how ITD and ILD are combined in ICcl of the anesthetized barn owl (Tyto alba). A comparison of additive, multiplicative, and linear-threshold models of neural responses shows that ITD and ILD are combined nonlinearly in ICcl, but the interaction of ITD and ILD is not uniformly multiplicative over the sample. A subset (61%) of the neural responses is well described by the multiplicative model, indicating that ICcl is the first site where multiplicative tuning to ITD- and ILD-dependent signals occurs. ICx, however, is the first site where multiplicative tuning is observed consistently. A network model shows that a linear combination of ICcl responses to ITD-ILD pairs is sufficient to produce the multiplicative subthreshold responses to ITD and ILD seen in ICx. PMID:17615132

  18. Transcriptome changes associated with instructed learning in the barn owl auditory localization pathway.

    PubMed

    Swofford, Janet A; DeBello, William M

    2007-09-15

    Owls reared wearing prismatic spectacles learn to make adaptive orienting movements. This instructed learning depends on re-calibration of the midbrain auditory space map, which in turn involves the formation of new synapses. Here we investigated whether these processes are associated with differential gene expression, using longSAGE. Newly fledged owls were reared for 8-36 days with prism or control lenses at which time the extent of learning was quantified by electrophysiological mapping. Transciptome profiles were obtained from the inferior colliculus (IC), the major site of synaptic plasticity, and the optic tectum (OT), which provides an instructive signal that controls the direction and extent of plasticity. Twenty-two differentially expressed sequence tags were identified in IC and 36 in OT, out of more than 35,000 unique tags. Of these, only four were regulated in both structures. These results indicate that regulation of two largely independent gene clusters is associated with synaptic remodeling (in IC) and generation of the instructive signal (in OT). Real-time PCR data confirmed the changes for two transcripts, ubiquitin/polyubiquitin and tyrosine 3-monooxgenase/tryotophan 5-monooxygenase activation protein, theta subunit (YWHAQ; also referred to as 14-3-3 protein). Ubiquitin was downregulated in IC, consistent with a model in which protein degradation pathways act as an inhibitory constraint on synaptogenesis. YWHAQ was up-regulated in OT, indicating a role in the synthesis or delivery of instructive information. In total, our results provide a path towards unraveling molecular cascades that link naturalistic experience with synaptic remodeling and, ultimately, with the expression of learned behavior. PMID:17526003

  19. Pharmacological specialization of learned auditory responses in the inferior colliculus of the barn owl.

    PubMed

    Feldman, D E; Knudsen, E I

    1998-04-15

    Neural tuning for interaural time difference (ITD) in the optic tectum of the owl is calibrated by experience-dependent plasticity occurring in the external nucleus of the inferior colliculus (ICX). When juvenile owls are subjected to a sustained lateral displacement of the visual field by wearing prismatic spectacles, the ITD tuning of ICX neurons becomes systematically altered; ICX neurons acquire novel auditory responses, termed "learned responses," to ITD values outside their normal, pre-existing tuning range. In this study, we compared the glutamatergic pharmacology of learned responses with that of normal responses expressed by the same ICX neurons. Measurements were made in the ICX using iontophoretic application of glutamate receptor antagonists. We found that in early stages of ITD tuning adjustment, soon after learned responses had been induced by experience-dependent processes, the NMDA receptor antagonist D, L-2-amino-5-phosphonopentanoic acid (AP-5) preferentially blocked the expression of learned responses of many ICX neurons compared with that of normal responses of the same neurons. In contrast, the non-NMDA receptor antagonist 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) blocked learned and normal responses equally. After long periods of prism experience, preferential blockade of learned responses by AP-5 was no longer observed. These results indicate that NMDA receptors play a preferential role in the expression of learned responses soon after these responses have been induced by experience-dependent processes, whereas later in development or with additional prism experience (we cannot distinguish which), the differential NMDA receptor-mediated component of these responses disappears. This pharmacological progression resembles the changes that occur during maturation of glutamatergic synaptic currents during early development. PMID:9526024

  20. Distribution within the barn owl's inferior colliculus of neurons projecting to the optic tectum and thalamus.

    PubMed

    Arthur, Ben J

    2005-11-01

    Behavioral studies in barn owls indicate that both the optic tectum (OT) and the auditory arcopallium (AAr) mediate sound localization through the presence of neurons that respond only when sound comes from a circumscribed direction in space. The early stages of the computations leading to these so-called space-specific neurons are shared in a common brainstem pathway, which then splits at the level of the inferior colliculus (IC) such that the last computational stage is thought to be duplicated. The study presented here addresses whether the space-specific neurons in OT and AAr are indeed partially independent of each other by using anatomical methods more precise than those used in previous studies. Specifically, projection neurons in IC were retrogradely labelled with injections of fluorescein- and rhodamine-conjugated dextran amines into OT and nucleus ovoidalis (OV), the thalamic nucleus leading to AAr. By labelling the OT-projecting and OV-projecting neurons in the same owl, it was confirmed that neurons in IC project to either OV or OT but not both. However, although a segregation was generally observed between the medially positioned OV-projecting neurons and the laterally positioned OT-projecting neurons, there was also a slight overlap between the two populations. Moreover, electrolytic lesions demarcating physiological tuning properties indicate that many OV-projecting neurons are within the area containing space-specific neurons. These results highlight the need for more detailed studies elucidating the microcircuitry and corresponding physiology of IC, such as have been done in the cortices of the mammalian cerebellum and cerebrum. PMID:16175562