Sample records for esox lucius foraging

  1. Standard Weight Equation for Tiger Muskellunge (Esox lucius x Esox masquinongy)

    Microsoft Academic Search

    Kevin B. Rogers; Keith D. Koupal

    1997-01-01

    Weight and length data for tiger muskellunge Esox lucius x Esox masquinongy were solicited from biologists across the continent to develop a 75th-percentile standard weight (Ws) equation for the hybrid. Only 27 populations (N = 1,124 fish) from 9 states yielded adequate data sets for this process. We used a bootstrap technique to demonstrate that the limited number of populations

  2. L'organe pinal du Brochet (Esox lucius L.) III. Voies intrapinales de conduction

    E-print Network

    Paris-Sud XI, Université de

    ; bipolar neurons were seen in the distal and proximal pineal. At the level of the subcommissural organL'organe pinéal du Brochet (Esox lucius L.) III. Voies intrapinéales de conduction des messages organ of the pike (Esox lucius, L.). II1. lntrapineal pathways for conduction of photosensory messages

  3. Temporal stability in size distributions and growth rates of three Esox lucius L. populations.

    E-print Network

    Roos, André M. de

    trajectories for three stream living pike Esox lucius populations were studied for 7 years. All three to differences in prey:predator size ratios. The pike populations in the more open and larger streams grew, available online at http://www.blackwell-synergy.com 461 # 2006 The Authors Journal compilation # 2006

  4. Physiological ecology of larval muskellunge and norlunge: temperature tolerance and growth rates under hatchery conditions. [Esox masquinongy, E. lucius

    Microsoft Academic Search

    Bonin

    1976-01-01

    Critical Thermal Maxima (CTM) and growth rates of larval muskellunge (Esox masquinongy) and norlunge (E. masquinongy female x E. lucius male) were determined under hatchery conditions. Two groups of fish were maintained at ambient water temperatures with natural photoperiod. Weekly water samples were collected to monitor the troughs. Parameters measured were dissolved oxygen, pH, and ammonia which were within normal

  5. Behavioral variation in pelvic phenotypes of brook stickleback, Culaea inconstans , in response to predation by northern pike, Esox lucius

    Microsoft Academic Search

    James D. Reist

    1983-01-01

    Populations ofCulaea inconstans, from Alberta and Saskatchewan, Canada exhibit phenotypic variation in expression of the pelvic skeleton and associated spines, from complete presence (with) through intermediate forms to complete absence (without). Such variation influences predation byEsox lucius which prefer the least spiny prey. Behavioral differences were investigated before and during pike predation. These differences may be associated either with the

  6. Hematological parameters associated with parasitism in pike, Esox lucius caught from Anzali wetland.

    PubMed

    Fallah, Farzin Jamalzad; Khara, Hossein; Rohi, Javad Daghigh; Sayadborani, Mohammad

    2015-06-01

    This study involved 120 pike, Esox lucius, captured from Anzali wetland. Parasite fauna were identified in captured fish. Also, changes of haematological parameters were compared both infected and uninfected fish. Parasitological inspections revealed the following infestations: Skin: Lernea cyprinacea, Argulus foliaceus (Crustacean) and Tricodina sp. (Ciliatea). Gill: Dactylogyrus sp. (Digenea) and Tetraonchus monenteron (Monogenea). Eye: Diplostomum spathaceum (Digenea). Gut: Eustrongylides exises, Rhipdocotyle illense, Raphidascaris acus (Nematode), Corynosoma Strumosum (Acanthocephala). Most prevalence and intensity were related to Eustrongylides exises and Rhipdocotyle illense. Following haematological parameters were evaluated: haematocrit, haemoglobin concentration, erythrocyte and leukocyte counts, mean cell volume (MCV), mean cell haemoglobin, mean cell haemoglobin concentration lymphocytes, monocytes and eosinophils. Significant difference was found for MCV between infected and uninfected fish. PMID:26064009

  7. Age and growth of pike (Esox lucius) in Chivyrkui Bay, Lake Baikal

    USGS Publications Warehouse

    Owens, Randall W.; Pronin, Nikolai M.

    2000-01-01

    The purpose of this study was to describe age and growth of pike (Esox lucius) in Lake Baikal. Pike were collected with gill nets and by angling in Chivyrkui Bay in late July-early August 1993 and by gill nets in June 1995. Total length (mm), weight (g), and sex were recorded and scales and cleithra were collected for aging. In 1993, pike, ages 1 to 3, ranged in length from 331 to 810 mm and in 1995 , pike, ages 2 to 10, ranged in length from 365 to 1,111 mm but only three percent were age 7 or older. Most growth in length occurred during the first two years of life. The length-weight relation for pike from Chivyrkui Bay was similar to that of pike from the St. Lawrence River. Calculated total length of pike from Lake Baikal equalled or exceeded the lengths of pike from lakes Erie or Ontario. Good agreement was found between ages from cleithra and from scales. Lengths at age in June 1995 (N=108) varied widely among pike. Females were generally larger than males at a given age among fish age-3 and older. When compared with the circumpolar growth standard, based on the von Bertalanffy growth curve, growth of Lake Baikal pike exceeded all other Asian populations, and equalled or exceeded many other northern hemisphere populations.

  8. Bioenergetics and growth of young-of the-year northern pike ( Esox lucius) and burbot ( Lota lota) exposed to metal mining effluent

    Microsoft Academic Search

    Pamela M. Bennett; David M. Janz

    2007-01-01

    We hypothesized that exposure to metal mining effluent would reduce the ability of young-of-the-year fishes to accumulate energy reserves to survive the overwinter period (known as “winter stress syndrome”) in a Canadian boreal forest watershed. Northern pike (Esox lucius) and burbot (Lota lota) were collected immediately before and after winter from a reference lake and two lakes receiving effluent. Unexpectedly,

  9. Biomarkers of contaminant exposure in northern pike (Esox lucius) from the Yukon River Basin, Alaska

    USGS Publications Warehouse

    Hinck, J.E.; Blazer, V.S.; Denslow, N.D.; Myers, M.S.; Gross, T.S.; Tillitt, D.E.

    2007-01-01

    As part of a larger investigation, northern pike (n = 158; Esox lucius) were collected from ten sites in the Yukon River Basin (YRB), Alaska, to document biomarkers and their correlations with organochlorine pesticide (total p,p'-DDT, total chlordane, dieldrin, and toxaphene), total polychlorinated biphenyls (PCBs), and elemental contaminant (arsenic, cadmium, copper, lead, total mercury, selenium, and zinc) concentrations. A suite of biomarkers including somatic indices, hepatic 7-ethoxyresorufin O-deethylase (EROD) activity, vitellogenin concentrations, steroid hormone (17B- ustradiol and 16-kebtestosteront) concentrations, splenic macrophage aggregates (MAs), oocyte atresia, and other microscopic anomalies in various tissues were documented in YRB pike. Mean condition factor (0.50 to 0.68), hepatosomatic index (1.00% to 3.56%), and splenosomatic index (0.09% to 0.18%) were not anomalous at any site nor correlated with any contaminant concentration. Mean EROD activity (0.71 to 17.51 pmol/min/mg protein) was similar to basal activity levels previously measured in pike and was positively correlated with selenium concentrations (r = 0.88, P 0.01 mg/mL in male pike from multiple sites indicated exposure to estrogenic compounds. Mean steroid hormone concentrations and percent oocyte atresia were not anomalous in pike from any YRB site. Few site differences were significant for mean MA density (1.86 to 6.42 MA/mm2), size (812 to 1481 ??m2), and tissue occupied (MA-%; 0.24% to 0.75%). A linear regression between MA-% and total PCBs was significant, although PCB concentrations were generally low in YRB pike (???63 ng/g), and MA-% values in female pike (0.24% to 0.54%) were lower than in male pike (0.32% to 0.75%) at similar PCB concentrations. Greater numbers of MAs were found as zinc concentrations increased in YRB female pike, but it is unlikely that this is a causative relationship. Histological abnormalities observed in gill, liver, spleen, and kidney tissues were not likely a result of contaminant exposure but provide information on the general health of YRB pike. The most common histologic anomalies were parasitic infestations in various organs and developing nephrons and nephrocalcinosis in posterior kidney tissues. Overall, few biomarker responses in YRB pike were correlated with chemical contaminant concentrations, and YRB pike generally appeared to be healthy with no site having multiple anomalous biomarker responses. ?? 2007 Springer Science+Business Media, LLC.

  10. Post-glacial dispersal patterns of Northern pike inferred from an 8800 year old pike (Esox cf. lucius) skull from interior Alaska

    NASA Astrophysics Data System (ADS)

    Wooller, Matthew J.; Gaglioti, Benjamin; Fulton, Tara L.; Lopez, Andres; Shapiro, Beth

    2015-07-01

    The biogeography of freshwater fish species during and after late-Pleistocene glaciations relate to how these species are genetically organized today, and the management of these often disjunct populations. Debate exists concerning the biogeography and routes of dispersal for Northern pike (Esox lucius) after the last glaciation. A hypothesis to account for the relatively low modern genetic diversity for E. lucius is post-glacial radiation from refugia, including lakes from within the un-glaciated portions of eastern Beringia. We report the remains of a Northern pike (E. cf. lucius) skull, including bones, teeth, bone collagen and ancient DNA. The remains were preserved at a depth of between 440 and 446 cm in a 670 cm long core of sediment from Quartz Lake, which initiated at ?11,200 cal yr BP in interior Alaska. A calibrated accelerator mass spectrometer (AMS) radiocarbon age of the collagen extracted from the preserved bones indicated that the organism was dated to 8820 cal yr BP and is bracketed by AMS values from analyses of terrestrial plant macrofossils, avoiding any potential aquatic reservoir effect that could have influenced the radiocarbon age of the bones. Scanning electron microscope images of the specimen show the hinged tooth anatomy typically of E. lucius. Molar C:N (3.5, 1? = 0.1) value of the collagen from the specimen indicated well-preserved collagen and its mean stable nitrogen isotope value is consistent with the known predatory feeding ecology of E. lucius. Ancient DNA in the bones showed that the specimen was identical to modern E. lucius. Our record of E. lucius from interior Alaska is consistent with a biogeographic scenario involving rapid dispersal of this species from glacial refugia in the northern hemisphere after the last glaciation.

  11. Spatial analysis of Cd and Pb in the Pike (Esox lucius) from Western Anzali wetlands of Iran.

    PubMed

    Zamani-Ahmadmahmoodi, R; Esmaili-Sari, A; Mohammadi, J; Riyahi Bakhtiari, A; Savabieasfahani, M

    2013-04-01

    Geostatistical studies are used to estimate pollution burden in aquatic ecosystems and to plan large-scale control programs to protect these environments. Geostatistical studies allow us to predicted pollutant concentrations for areas that have not been sampled. This is done by taking into account the spatial correlations between estimated and sampled points and by minimizing the variance of estimation error. The use of geostatistical techniques in biomonitoring of fish species can illuminate extent and source of pollution, thereby providing an effective tool for developing intervention strategies to protect such environments. This study investigates the spatial distribution patterns of cadmium and lead in the Pike (Esox lucius). Fish were captured in the western parts of the Anzali wetlands located on the Caspian Sea in Iran. The muscle tissue of Anzali Pike had 5 ± 0.25 and 168 ± 18.4 (ng/g dw) cadmium and lead, respectively. Positive relationships were detected between Pike's length and weight (r = 0.85, p < 0.05), length and age (r = 0.35, p < 0.05), and muscle cadmium and lead (r = 0.45, p < 0.05). By contrast, there was a negative relationship between lead levels and weight in Pike (r = -0.36, p < 0.05). For both metals, the resulting metal concentration maps indicated higher pollutant concentrations in the southeast parts of the study area. Considerable boat traffic activity and agricultural activity contribute to the pollution in these areas, undermining the integrity of local habitat for fish survival and reproduction. PMID:23292487

  12. Investigation of first year biotic and abiotic influences on the recruitment of pike Esox lucius over 48 years in Windermere, UK.

    PubMed

    Paxton, C G M; Winfield, I J; Fletcher, J M; George, D G; Hewitt, D P

    2009-07-01

    Estimated pike Esox lucius recruitment varied by a factor of 16 for females from 1944 to 1991 and by a factor of 27 for males from 1943 to 1990 in Windermere, a temperate, mesotrophic U.K. lake. No significant stock-recruitment relationships were found, but analysis with general additive models (GAMs) revealed that early autumnal water temperature, strength and direction of the North Atlantic Oscillation displacement (corresponding to different climatic conditions in winter) and zooplankton abundance but above all, late summer water temperature were important explanatory variables over the entire time series. Female recruitment was also influenced by young-of-the-year winter temperature. There was no evidence that perch Perca fluviatilis year-class strength, lake level or the summer position of the Gulf Stream influenced recruitment. The fitted models explained up to c. 65% of the overall observed variation between years. PMID:20735553

  13. Bioenergetics and growth of young-of the-year northern pike (Esox lucius) and burbot (Lota lota) exposed to metal mining effluent.

    PubMed

    Bennett, Pamela M; Janz, David M

    2007-09-01

    We hypothesized that exposure to metal mining effluent would reduce the ability of young-of-the-year fishes to accumulate energy reserves to survive the overwinter period (known as "winter stress syndrome") in a Canadian boreal forest watershed. Northern pike (Esox lucius) and burbot (Lota lota) were collected immediately before and after winter from a reference lake and two lakes receiving effluent. Unexpectedly, total body lipid and triglyceride, and liver triglyceride levels were greater in effluent-exposed pike and burbot in both fall and spring. However, there were no lake or season differences in growth indices of length, weight, muscle RNA/DNA ratio, or muscle protein levels in pike. In addition, total lipids and triglycerides in burbot were greater in spring compared to fall, while no seasonal differences were observed in pike, suggesting that burbot continued to feed during winter. Findings do not support the winter stress syndrome hypothesis and suggest possible direct and indirect effects of metal mining effluent on lipid dynamics of juvenile fishes. PMID:17368537

  14. Diplostomatid Eye Flukes in Young-of-the-Year and Forage Fishes in the St. Lawrence River, Quebec

    Microsoft Academic Search

    David J. Marcogliese; Sacha Compagna

    1999-01-01

    Sixteen species of young-of-the year and forage fishes (alewife Alosa pseudoharengus, northern pike Esox lucius, common carp Cyprinus carpio, emerald shiner Notropis atherinoides, rosyface shiner Notropis rubellus, white sucker Catostomus commersoni, silver redhorse Moxostoma anisurum, brown bullhead Ameirurus nebulosus, trout-perch Percopsis omiscomaycus, rock bass Ambloplitis rupestris, pumpkinseed Lepomis gibbosus, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis

  15. Molecular and Phenotypic Evidence of a New Species of Genus Esox (Esocidae, Esociformes, Actinopterygii): The Southern Pike, Esox flaviae

    PubMed Central

    Lucentini, Livia; Puletti, Maria Elena; Ricciolini, Claudia; Gigliarelli, Lilia; Fontaneto, Diego; Lanfaloni, Luisa; Bilò, Fabiana; Natali, Mauro; Panara, Fausto

    2011-01-01

    We address the taxonomic position of the southern European individuals of pike, performing a series of tests and comparisons from morphology, DNA taxonomy and population genetics parameters, in order to support the hypothesis that two species of pike, and not only one, exist in Europe. A strong relationship emerged between a northern genotype supported by COI, Cytb, AFLP and specific fragments, and a phenotype with round spot skin colour pattern and a large number of scales in the lateral line, clearly separated from a southern genotype with other skin colour pattern and a low number of scales in the lateral line. DNA taxonomy, based on a coalescent approach (GMYC) from phylogenetic reconstructions on COI and Cytb together with AFLP admixture analysis, supported the existence of two independently evolving entities. Such differences are not simply due to geographic distances, as northern European samples are more similar to Canadian and Chinese samples than the southern Europe ones. Thus, given that the differences between the two groups of European pike are significant at the phenotypic, genotypic and geographical levels, we propose the identification of two pike species: the already known northern pike (Esox lucius) and the southern pike (E. flaviae n.sp.). The correct identification of these two lineages as independent species should give rise to a ban on the introduction of northern pikes in southern Europe for recreational fishing, due to potential problems of hybridisation. PMID:22164201

  16. Esox lucius k = (y2 -y1) / (x2 -x1)

    E-print Network

    Aslan, Turkey, PhD Student Pavel Bína, Czech Republic, Fauna Volunteer Monitoring Coordinator Backcover. This is achieved by research, education and environmental monitoring and assessment, in collaboration, as well as environmental monitoring and assessment, are carried out at several research stations

  17. Reduction of cannibalism in pike (Esox lucius) fry by isolation of full-sib families

    E-print Network

    Paris-Sud XI, Université de

    . Environmental parameters, such as depth and extent of the banks, may also affect growth and survival. Our, especially temperature change ; 2) nature and quantity of available food : zooplankton, invertebrates, fry on the availability of food : pond fertilization (Colas, 1938), supply of plankton (Arrignon, 1972 ; Huet, 1976

  18. OCCURRENCE OF 'ESOX NIGER' IN SANTA ROSA SOUND, FLORIDA

    EPA Science Inventory

    This is the first report of Esox niger collected from the normally saline portion of the lower Pensacola estuary. A 109 mm standard length chain pickerel was seined on 7 August 1975 from Santa Rosa Sound, in Santa Rosa County, Florida, from Thalassia beds about 300 m W. of the N....

  19. Spatial relations of mercury contents in Pike (Esox lucius) and sediments concentration of the Anzali wetland, along the southern shores of the Caspian Sea, Iran.

    PubMed

    Zamani-Ahmadmahmoodi, Rasool; Bakhtiari, Alireza Riyahi; Rodríguez Martín, José Antonio

    2014-07-15

    In recent decades, the Anzali wetland has been threatened and destroyed by environmental pollution from several sources. The purpose of this study was to determine the possible relationships between mercury concentrations in Pike and their respective sediments within the assumed multiple activity center scales of Pike (100, 250 and 500 m in radius). To gain a better understanding spatial distribution pattern of Hg in sediments and to pursue the main purpose of this study, kriging (geostatistic spatial interpolation method) was applied. Poor relationships were found between mercury concentrations of Pike and sediments within the assumed multiple activity center scales of Pike. The mercury sediment influence diminished with the increasing radii of assumed activity centers. The results of the present study indicate that fish and sediment mercury concentrations in western parts of the Anzali wetland were low in comparison with the concentrations reported in the literature from other regions. PMID:24933165

  20. EVALUATION OF THE E-SOX PROCESS ON THE EPA PILOT ELECTROSTATIC PRECIPITATOR

    EPA Science Inventory

    The report gives results of a small pilot-scale evaluation of the E-SOx process, undertaken to obtain information needed to conduct a planned 5 MWe field pilot demonstration. he process uses an electrostatic precipitator (ESP) for combined sulfur dioxide (SO2) removal and particu...

  1. Bioaccumulation of Heavy Metals and Microelements in Silver Bream (Brama brama L.), Northern Pike (Esox lucius L.), Sterlet (Acipenser ruthenus L.), and Common Carp (Cyprinus carpio L.) From Tisza River, Serbia.

    PubMed

    Štrbac, Snežana; Kašanin-Grubin, Milica; Jovan?i?evi?, Branimir; Simonovi?, Predrag

    2015-01-01

    The aim of this study was to determine the concentrations of Al, As, B, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, Sr, and Zn in liver, gills, gonads, and brain of four ecologically different fish species in Serbia: piscivorous northern pike, benthivorous sterlet and silver bream, and omnivorous common carp. Fish were caught at four sites along the stretch of the River Tisza in the Pannonian part of Serbia during October 2010. Results revealed that heavy metals and microelements with the highest values in fish samples were Fe, Al, and Zn. The highest concentration of heavy metals and microelements was recorded in omnivorous common carp, and organs that most intensively accumulated the greatest number of metals were liver and gills, whereas the locality did not exert a marked impact on level of bioaccumulation. PMID:26039743

  2. Proceedings of the South Dakota Academy of Science,Vol. 85 (2006) 247 RECENT RANGE EXTENSIONS,

    E-print Network

    2006-01-01

    dace, Phoxinus eos, southern redbelly dace, P. erythrogaster, shorthead redhorse, Moxostoma macrolepidotum, yellow bullhead, Ameiurus na- talis, northern pike, Esox lucius, Iowa darter, Etheostoma exile

  3. Foraging Behaviour

    Microsoft Academic Search

    Mark Fellowes; Jacques Alphen; Mark Jervis

    In this chapter, we consider practical aspects of the foraging behaviour of insect natural enemies in its widest sense. Initially,\\u000a most insect natural enemies must locate the habitat where potential victims may be found. Within that habitat, the victims\\u000a themselves must be discovered. Once a patch of potential targets is identified, the predator or parasitoid must choose its\\u000a victim. Furthermore,

  4. Balancing Forage Demand with Forage Supply 

    E-print Network

    Troxel, Tom R.; White, Larry D.

    1995-09-25

    remaining forage. Seasonal quality varia- tions can be overcome by supplementation. Shortages in forage supply are more likely dur- ing the late fall and winter period, except dur- ing drought. Adjusting the livestock production cycle to best coincide..., the amount of forage required to support livestock can be calculated and compared to the amount of forage available. Often only past experience is used to estab- lish or adjust stocking rates. This may result in an overstocked ranch that is forced to sell...

  5. Foraging Behavior Thomas Caraco

    E-print Network

    Caraco, Thomas

    . Optimal foraging theory Optimal foraging theory (OFT) asks how behaviors governing the acquisition can be subject to optimizing (i.e., stabilizing) selection. Given this premise, foraging theory as social foraging theory (SFT). For clarity, this distinction is adopted here; some questions concerning

  6. Foraging & Optimality ... economic decisions

    E-print Network

    Blouin-Demers, Gabriel

    · For foraging, we can use energy as a common currency 2 Foraging & Predation · 2 themes · How to find food (foraging) · How to avoid becoming food (predator-rey interactions) · Evolutionary survey · Predator, but requires time and, thus, some compromises · Selection should favour efficient foraging behaviours

  7. Interactions of multiple predators with different foraging modes in an aquatic food web.

    PubMed

    Carey, Michael P; Wahl, David H

    2010-02-01

    Top predators can have different foraging modes that may alter their interactions and effects on food webs. Interactions between predators may be non-additive resulting from facilitation or interference, whereas their combined effects on a shared prey may result in emergent effects that are risk enhanced or risk reduced. To test the importance of multiple predators with different foraging modes, we examined the interaction between a cruising predator (largemouth bass, Micropterus salmoides) and an ambush predator (muskellunge, Esox masquinongy) foraging on a shared prey (bluegill sunfish, Lepomis macrochirus) with strong anti-predator defense behaviors. Additive and substitution designs were used to compare individual to combined predator treatments in experimental ponds. The multiple predator interaction facilitated growth of the cruising predator in the combined predator treatments, whereas predator species had substitutable effects on the growth of the ambush predator. The combined predator treatments created an emergent effect on the prey; however, the direction was dependent on the experimental design. The additive design found a risk-reducing effect, whereas the substitution design found a risk-enhancing effect for prey fish. Indirect effects from the predators weakly extended to lower trophic levels (i.e., zooplankton community). Our results highlight the need to consider differences in foraging mode of top predators, interactions between predators, and emergent effects on prey to understand food webs. PMID:19777265

  8. Muskie Lunacy: does the lunar cycle influence angler catch of muskellunge (Esox masquinongy)?

    PubMed

    Vinson, Mark R; Angradi, Ted R

    2014-01-01

    We analyzed angling catch records for 341,959 muskellunge (Esox masquinongy) from North America to test for a cyclic lunar influence on the catch. Using periodic regression, we showed that the number caught was strongly related to the 29-day lunar cycle, and the effect was consistent across most fisheries. More muskellunge were caught around the full and new moon than at other times. At night, more muskellunge were caught around the full moon than the new moon. The predicted maximum relative effect was ?5% overall. Anglers fishing exclusively on the peak lunar day would, on average, catch 5% more muskellunge than anglers fishing on random days. On some lakes and at night, the maximum relative effect was higher. We obtained angler effort data for Wisconsin, Mille Lacs (MN), and Lake Vermilion (MN). For Lake Vermilion there was a significant effect of the lunar cycle on angler effort. We could therefore not conclude that the lunar effect on catch was due to an effect on fish behavior alone. Several factors affected the amount of variation explained by the lunar cycle. The lunar effect was stronger for larger muskellunge (>102 cm) than for smaller fish, stronger in midsummer than in June or October, and stronger for fish caught at high latitudes (>48°N) than for fish caught further south. There was no difference in the lunar effect between expert and novice muskellunge anglers. We argue that this variation is evidence that the effect of the lunar cycle on catch is mediated by biological factors and is not due solely to angler effort and reflects lunar synchronization in feeding. This effect has been attributed to variation among moon phases in lunar illumination, but our results do not support that hypothesis for angler-caught muskellunge. PMID:24871329

  9. Forages for Biofuel

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage crops are an important potential renewable fuel resource. Perennial forages can produce large yields of renewable feedstock biomass, require relatively low nutrient inputs compared to row crops, and generate accessory benefits such as erosion stabilization, carbon sequestration, soil remediat...

  10. Fish, FADs and Forage (and Foraging Behavior)

    E-print Network

    Hawai'i at Manoa, University of

    Fish, FADs and Forage (and Foraging Behavior) Kim Holland, David Itano, Laurent Dagorn, Dean Grubbs · The Associative dynamics of tropical tuna to a large-scale anchored FAD array · Scaling up: Linking FAD-associated local behavior of tuna to regional scale movements and distribution #12;#12;#12;#12;= Instrumented FAD

  11. Life History of the Colorado Squawfish, Ptychocheilus lucius, and the Colorado Chub, Gila robusta, in the Green River in Dinosaur National Monument, 1964–1966

    Microsoft Academic Search

    C. David Vanicek; Robert H. Kramer

    1969-01-01

    Investigations of the ecology and life history of the Colorado squawfish, Ptychocheilus lucius, and the Colorado chub, Gila robusta, in the Green River in Dinosaur National Monument, Colorado-Utah, were conducted from May 1964, to October 1966. A total of 1,469 squawfish and 2,393 chubs was collected with gill nets, seines, fry gear, and an electric shocker. The operation of Flaming

  12. Grasses and Forage Plants.

    E-print Network

    Pittuck, B. C.

    1898-01-01

    forage. Seed may be obtained from J. M. Thorburn & Co., New York. L . sylvestris (F lat Pea). Bulletin No. 2 , U . S. Dept. Agr., Jared G. Sm ith . GRASSES AND FORAGE PLANTS. 1029 SPERGULA. S. arvensis (Spurrey).?Annual. Germinated March 23 to fair...

  13. Forage Sorghums in Texas.

    E-print Network

    Quinby, John Roy

    1934-01-01

    cooperation with U. S. Department of A~riculture. $In ,cooperation with Texas ~xtension service.' va tht The sorghums are the most important source of roughage from ltivated crops in Texas since they furnish the bulk of the hay, bundle forage, and silage... good farming practices. This Bulletin reports the results with varieties, rates and dates of planting, and other practices affecting pro- duction of forage sorghums in Texas. ~t Agronomist. Division of Forage Crops and ~is&s&; U. S. Department of be...

  14. Foraging Experiences with Children

    ERIC Educational Resources Information Center

    Russell, Helen Ross

    1976-01-01

    Provided are foraging experiences and wild foods information for utilization in the urban school curriculum. Food uses are detailed for roses, dandelions, wild onions, acorns, cattails, violets and mints. (BT)

  15. Forage Quality Photo Guide 

    E-print Network

    Lyons, Robert K.; Machen, Richard V.; Stuth, Jerry W.

    2000-08-18

    The relationship between forage quality and the physical appearance of feces of grazing cattle is explained. Four photographs provide a quick and easy visual reference for evaluating the diet quality of grazing beef cattle....

  16. Detection of viral hemorrhagic septicemia virus-IVb antibodies in sera of muskellunge Esox masquinongy using competitive ELISA.

    PubMed

    Millard, Elena V; Brenden, Travis O; LaPatra, Scott E; Marcquenski, Susan; Faisal, Mohamed

    2014-04-01

    A competitive enzyme-linked immunosorbent assay (cELISA) was developed for the detection of antibodies to viral hemorrhagic septicemia virus genotype IVb (VHSV-IVb) in fish sera. Assay conditions were standardized using known negative and positive muskellunge Esox masquinongy. A positive-negative threshold of 14.6% inhibition was established based on analysis of sera of 60 muskellunge with no previous exposure to VHSV-IVb. The cELISA was then used to investigate immune responses of wild muskellunge sampled from 5 water bodies in Michigan and Wisconsin, USA, between 2005 and 2012. Antibodies were detected in fish from Lake St. Clair, Michigan, and Lower Fox River/Green Bay, Wisconsin. Both water systems were considered enzootic for VHSV-IVb. Additionally, antibodies were detected in muskellunge from Thornapple Lake, a Michigan inland lake previously considered negative for VHSV-IVb based on virus isolation methods. Muskellunge populations from Lake Hudson, Michigan, and Butternut Lake, Wisconsin, lacked evidence of an immune response to VHSV-IVb. When results of the cELISA were compared to the 50% plaque neutralization test for several groups of fish, there was 78.4% agreement between the tests for antibody presence. The cELISA is a rapid and efficient test for the detection of binding antibodies to VHSV-IVb and will be a useful non-lethal tool for monitoring the spread of this serious pathogen. PMID:24695232

  17. Foraging search: Prototypical intelligence

    NASA Astrophysics Data System (ADS)

    Mobus, George

    2000-05-01

    We think because we eat. Or as Descartes might have said, on a little more reflection, "I need to eat, therefore I think." Animals that forage for a living repeatedly face the problem of searching for a sparsely distributed resource in a vast space. Furthermore, the resource may occur sporadically and episodically under conditions of true uncertainty (nonstationary, complex and non-linear dynamics). I assert that this problem is the canonical problem solved by intelligence. It's solution is the basis for the evolution of more advanced intelligence in which the space of search includes that of concepts (objects and relations) encoded in cortical structures. In humans the conscious experience of searching through concept space we call thinking. The foraging search model is based upon a higher-order autopoeitic system (the forager) employing anticipatory processing to enhance its success at finding food while avoiding becoming food or having accidents in a hostile world. I present a semi-formal description of the general foraging search problem and an approach to its solution. The latter is a brain-like structure employing dynamically adaptive neurons. A physical robot, MAVRIC, embodies some principles of foraging. It learns cues that lead to improvements in finding targets in a dynamic and nonstationary environment. This capability is based on a unique learning mechanism that encodes causal relations in the neural-like processing element. An argument is advanced that searching for resources in the physical world, as per the foraging model, is a prototype for generalized search for conceptual resources as when we think. A problem represents a conceptual disturbance in a homeostatic sense. The finding of a solution restores the homeostatic balance. The establishment of links between conceptual cues and solutions (resources) and the later use of those cues to think through to solutions of quasi-isomorphic problems is, essentially, foraging for ideas. It is a quite natural extension of the fundamental foraging model.

  18. Foraging bats avoid noise.

    PubMed

    Schaub, Andrea; Ostwald, Joachim; Siemers, Björn M

    2008-10-01

    Ambient noise influences the availability and use of acoustic information in animals in many ways. While much research has focused on the effects of noise on acoustic communication, here, we present the first study concerned with anthropogenic noise and foraging behaviour. We chose the greater mouse-eared bat (Myotis myotis) as a model species because it represents the especially vulnerable group of gleaning bats that rely on listening for prey rustling sounds to find food (i.e. 'passive listening'). In a choice experiment with two foraging compartments, we investigated the influence of background noise on foraging effort and foraging success. We tested the hypotheses that: (1) bats will avoid foraging areas with particularly loud background noise; and (2) the frequency-time structure of the noise will determine, in part, the degree to which it deters bats. We found a clear effect of the type of noise on the allocation of foraging effort to the compartments and on the distribution of prey capture events. When playing back silence, the bats made equal use of and were equally successful in both compartments. In the other three treatments (where a non-silent sound was played back), the bats avoided the playback compartment. The degree to which the background noise deterred bats from the compartment increased from traffic noise to vegetation movement noise to broadband computer-generated noise. Vegetation noise, set 12 dB below the traffic noise amplitude, had a larger repellent effect; presumably because of its acoustic similarity with prey sounds. Our experimental data suggest that foraging areas very close to highways and presumably also to other sources of intense, broadband noise are degraded in their suitability as foraging areas for such 'passive listening' bats. PMID:18805817

  19. Understanding Forage Quality Analysis

    E-print Network

    Stokes, Sandra R.; Prostko, Eric P.

    1998-03-23

    to dairies. Forage quality indicators important to dairy produc- ers include protein, neutral detergent fiber (NDF), acid detergent fiber (ADF), net energy for lactation (NE l ), and relative feed value (RFV). Protein. Crude protein (CP) can be a... components, NDF and ADF, which nutritionists use to more accurately formulate dairy rations. *Extension Dairy Specialist and Extension Agronomist,The Texas A&M University System Neutral Detergent Fiber measures all the fiber found in forage (hemicellulose...

  20. Why Range Forage Quality Changes

    E-print Network

    Lyons, Robert K.; Machen, Richard V.; Forbes, T. D. A.

    1999-02-15

    Range plants vary in nutritional quality. Forage quality is determined by the plant part eaten, plant age, season, soils and range sites, stocking rates, and other factors. Periods of high animal nutritional demand must match periods of high forage...

  1. Collective foraging in heterogeneous landscapes.

    PubMed

    Bhattacharya, Kunal; Vicsek, Tamás

    2014-11-01

    Animals foraging alone are hypothesized to optimize the encounter rates with resources through Lévy walks. However, the issue of how the interactions between multiple foragers influence their search efficiency is still not completely understood. To address this, we consider a model to study the optimal strategy for a group of foragers searching for targets distributed heterogeneously. In our model, foragers move on a square lattice containing immobile but regenerative targets. At any instant, a forager is able to detect only those targets that happen to be in the same site. However, we allow the foragers to have information about the state of other foragers. A forager who has not detected any target walks towards the nearest location, where another forager has detected a target, with a probability exp(-?d), where d is the distance between the foragers and ? is a parameter characterizing the propensity of the foragers to aggregate. The model reveals that neither overcrowding (? ? 0) nor independent searching (? ? ?) is beneficial for the foragers. For a patchy distribution of targets, the efficiency is maximum for intermediate values of ?. In addition, in the limit ? ? 0, the length of the walks can become scale-free. PMID:25165596

  2. The Physics of Foraging

    NASA Astrophysics Data System (ADS)

    Viswanathan, Gandhimohan. M.; da Luz, Marcos G. E.; Raposo, Ernesto P.; Stanley, H. Eugene

    2011-06-01

    Part I. Introduction: Movement: 1. Empirical motivation for studying movement; 2. Statistical physics of biological motion; 3. Random walks and Lévy flights; 4. Wandering albatrosses; Part II. Experimental Findings: 5. Early studies; 6. Evidence of anomalous diffusion; 7. Human dispersal; 8. How strong is the evidence?; Part III. Theory of Foraging: 9. Optimizing encounter rates; 10. Lévy flight foraging; 11. Other search models; Part IV. Finale: A Broader Context: 12. Superdiffusive random searches; 13. Adaptational versus emergent superdiffusion; 14. Perspectives and open problems; Appendices; References; Index.

  3. Foraging bats avoid noise

    Microsoft Academic Search

    Andrea Schaub; Joachim Ostwald; Björn M. Siemers

    2008-01-01

    SUMMARY Ambient noise influences the availability and use of acoustic information in animals in many ways. While much research has focused on the effects of noise on acoustic communication, here, we present the first study concerned with anthropogenic noise and foraging behaviour. We chose the greater mouse-eared bat (Myotis myotis) as a model species because it represents the especially vulnerable

  4. Journal of Chemical Ecology, Vol. 23, No. 4, 1997 REACTIONS OF Gammarus lacustris TO CHEMICAL

    E-print Network

    Wisenden, Brian D.

    and to chemical stimuli from two types of natural predators: dragonfly larvae (Aeshna eremita) and northern pike, alarm pheromone, kairomone, predator avoidance, antipredator behavior, Esox lucius, Aeshna eremita pheromone decreases the capture efficiency of predatory larvaldragonflies (Aeshna umbrosa) (Hews, 1988

  5. I. Fish..........................................................................................................................................2 A) Fish native to both Europe and North America (not analyzed) ........................................2

    E-print Network

    Jeschke, Jonathan

    autumnalis 2. Esox lucius 3. Gasterosteus aculeatus 4. Lampetra richardsoni 5. Lethenteron japonicum 6. Lota lota 7. Petromyzon marinus 8. Pungitius pungitius 9. Salmo salar 10. Salvelinus alpinus 11. Stenodus

  6. Selective Predation by Three Esocids: The Role of Prey Behavior and Morphology

    Microsoft Academic Search

    DAVID H. WAHL; ROY A. STEIN

    1988-01-01

    We documented differential vulnerability of fathead minnows Pimephales promelas, gizzard shad Dorosoma cepedianum. and bluegills Lepomis macrochirus to predation by muskel- lunge Esox masquinongy. northern pike E. lucius. and tiger muskellunge £\\

  7. Auditory exostoses and evidence for fishing at Vlasac

    E-print Network

    Frayer, David W.

    1988-01-01

    % of the vertebrate fauna recovered at Vlasac is fish. Species identified in clude pike (Esox lucius), carp (Cyprinus carpio), and catfish (Silurus glanis). Bokonyi does not give minimum individual counts but does note that catfish were the most important...

  8. Journal of Fish Biology (1997) 50, 799808 The effect of physical condition and shoalmate familiarity on

    E-print Network

    Wisenden, Brian D.

    1997-01-01

    for review) and only one, attraction of secondary predators, has been demonstrated convincingly. Pike Esox lucius L., and predatory diving beetles (Dytiscidae) are attracted to chemical cues from injured minnow

  9. COOK, A. F., N. E. STACEY, AND R. E. PETER. 1980. Periovulatory changes in serum cortisol levels in

    E-print Network

    in the goldfish, Carassius auratus. Gen. Compo Endocri- no\\. 40:507-510. HIROSE, K. 1976. Endocrine control pike(Esox lucius), and goldfish (Carassius auratus). J. Fish. Res. Board Can. 33:974-988. KAYA, C. M

  10. Understanding Forage Intake in Range Animals 

    E-print Network

    Lyons, Robert K.; Machen, Richard V.; Forbes, T. D. A.

    1999-02-08

    Forage quality influences the performance of range livestock and wildlife, and it is often assumed that, if forage quality meets animal nutrient requirements, animal performance will meet expectations. However, forage intake can be at least... production potential. ? Forage quality. ? Supplemental feed. ? Forage availability. ? Environmental factors. Considering these factors can help you better understand the relationship between rangeland resources and herbivore production. Herbivore Species...

  11. Wide home ranges for widely foraging lizards

    Microsoft Academic Search

    Dave Verwaijen; Raoul Van Damme

    2008-01-01

    Space usage by animals may be influenced by a range of factors. In this study we investigate whether foraging behaviour affects the home range size of lizards. Two distinct tactics of foraging have been recognized in predators: sit-and-wait foraging (SW) and active foraging (AF). Foraging activity level of a data set of lizard species, mainly compiled from literature, is compared

  12. Irrigation Systems for Forage Crops.

    E-print Network

    Henggeler, Joseph C.

    1988-01-01

    &M University System ? College Station, Texas (Blank Pa,ge -In. O-riIIJIal BuIIetinl . 1?? .. , * ): . Irrigation Systems for Forage Crops Joseph C. Henggeler* Several types of irrigation systems can be chosen for irrigating forage crops for grazing...

  13. Behavior of fish predators and their prey: habitat choice between open water and dense vegetation

    USGS Publications Warehouse

    Savino, Jacqueline F.; Stein, Roy A.

    1989-01-01

    Behavior of largemouth bass, Micropterus salmoides , and northern pike, Esox lucius, foraging on fathead minnows, Pimephales promelas, or bluegills, Lepomis macrochirus, was quantified in pools with 50% cover (half the pool had artificial stems at a density of 1000 stems n-2). Both predators spent most of their time in the vegetation. Largemouth bass searched for bluegills and ambushed minnows, whereas the relatively immobile northern pike ambushed all prey. Minnows were closer to predators and were captured more frequently than bluegills. Even when minnows dispersed, they moved continually and eventually wandered within striking distance of a predator. Bluegills dispersed in the cover with predators. Bass captured the few bluegills that strayed into the open and pike captured those that approached too closely in the cover. The ability of predators to capture prey while residing in habitats containing patches of dense cover may explain their residence in areas often considered to be poor ones for foraging.

  14. Annual Summer Forages for West Texas Including Brown Mid-Rib (BMR) and Photoperiod Sensitive Forages

    E-print Network

    Mukhtar, Saqib

    ) and Acid Detergent Fiber (ADF)} of the forage. Thus BMR forage has higher feed value and forage of developing BMR), but you may pay an additional $3-4 per acre for the hybrids of large national seed companies

  15. Root Foraging Influences Plant Growth Responses to Earthworm Foraging

    PubMed Central

    Cameron, Erin K.; Cahill, James F.; Bayne, Erin M.

    2014-01-01

    Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited examination of the direct effects of earthworm burrowing on plant growth. Here we show a novel second pathway exists, whereby earthworms (Lumbricus terrestris L.) impact plant root foraging. In a mini-rhizotron experiment, roots occurred more frequently in burrows and soil cracks than in the soil matrix. The roots of Achillea millefolium L. preferentially occupied earthworm burrows, where nutrient availability was presumably higher than in cracks due to earthworm excreta. In contrast, the roots of Campanula rotundifolia L. were less likely to occur in burrows. This shift in root behaviour was associated with a 30% decline in the overall biomass of C. rotundifolia when earthworms were present. Our results indicate earthworm impacts on plant foraging can occur indirectly via physical and chemical changes to the soil and directly via root consumption or abrasion and thus may be one factor influencing plant growth and community change following earthworm invasion. More generally, this work demonstrates the potential for interactions to occur between the foraging behaviours of plants and soil animals and emphasizes the importance of integrating behavioural understanding in foraging studies involving plants. PMID:25268503

  16. Root foraging influences plant growth responses to earthworm foraging.

    PubMed

    Cameron, Erin K; Cahill, James F; Bayne, Erin M

    2014-01-01

    Interactions among the foraging behaviours of co-occurring animal species can impact population and community dynamics; the consequences of interactions between plant and animal foraging behaviours have received less attention. In North American forests, invasions by European earthworms have led to substantial changes in plant community composition. Changes in leaf litter have been identified as a critical indirect mechanism driving earthworm impacts on plants. However, there has been limited examination of the direct effects of earthworm burrowing on plant growth. Here we show a novel second pathway exists, whereby earthworms (Lumbricus terrestris L.) impact plant root foraging. In a mini-rhizotron experiment, roots occurred more frequently in burrows and soil cracks than in the soil matrix. The roots of Achillea millefolium L. preferentially occupied earthworm burrows, where nutrient availability was presumably higher than in cracks due to earthworm excreta. In contrast, the roots of Campanula rotundifolia L. were less likely to occur in burrows. This shift in root behaviour was associated with a 30% decline in the overall biomass of C. rotundifolia when earthworms were present. Our results indicate earthworm impacts on plant foraging can occur indirectly via physical and chemical changes to the soil and directly via root consumption or abrasion and thus may be one factor influencing plant growth and community change following earthworm invasion. More generally, this work demonstrates the potential for interactions to occur between the foraging behaviours of plants and soil animals and emphasizes the importance of integrating behavioural understanding in foraging studies involving plants. PMID:25268503

  17. CROP & SOIL SCIENCES Forage Breeding

    E-print Network

    Arnold, Jonathan

    CROP & SOIL SCIENCES Forage Breeding Committee Membership Dr. Joseph Bouton - committee chair Dr. Brian Schwartz Department of Crop & Soil Sciences Department of Crop & Soil Sciences University & Soil Sciences Department of Crop & Soil Sciences University of Georgia University of Georgia Center

  18. FLOCK SIZE AND FORAGING DECISIONS IN CENTRAL PLACE FORAGING WHITE STORKS, CICONIA CICONIA

    E-print Network

    Carrascal, Luis M.

    FLOCK SIZE AND FORAGING DECISIONS IN CENTRAL PLACE FORAGING WHITE STORKS, CICONIA CICONIA by JAVIER) Summary We studied the foraging decisions of six individually marked white storks at a breeding colony in central Spain. Storks behaved as central place foragers, gathering in flocks to feed. Travel distance

  19. Fish predation selects for reduced foraging activity

    Microsoft Academic Search

    Francis Strobbe; Mark A. McPeek; Marjan De Block; Robby Stoks

    2011-01-01

    Despite the importance of foraging activity for the growth\\/predation risk trade-off, studies that demonstrated predator-induced\\u000a survival selection on foraging activity under semi-natural conditions are relatively rare. Here, we tested for fish-induced\\u000a selection for reduced foraging activity in two larval Enallagma damselflies using a field enclosure experiment. Fish imposed considerable mortality in both damselfly species and survival\\u000a selection on foraging activity

  20. Ant Foraging Revisited Liviu Alexandru Panait1

    E-print Network

    Luke, Sean

    Ant Foraging Revisited Liviu Alexandru Panait1 and Sean Luke1 1. Department of Computer Science: lpanait@cs.gmu.edu Abstract Previous artificial (non-biological) ant foraging models have to date relied ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  1. Nocturnal foraging in the American White Pelican

    Microsoft Academic Search

    BLAIR F. MCMAHON; ROGER M. EVANS

    1992-01-01

    Nocturnal foraging was examined in American White Pelicans (Pelecanus erythrorhynchos) at the Dauphin River, about 50 km from a breeding colony on Lake Winnipeg, Manitoba, Canada. From two to three times as many pelicans foraged at night as in the daytime, with foraging flocks being larger at night. In contrast, more pelicans were present at adjacent loafing sites during the

  2. Age, growth, and food of northern pike in eastern Lake Ontario

    USGS Publications Warehouse

    Wolfert, David R.; Miller, Terence J.

    1978-01-01

    Northern pike (Esox lucius) from eastern Lake Ontario were sampled with gill nets and trap nets in 1972-1973. Fish of age-groups IV, V, and VI were predominant in the catch. Although males were slightly longer after the 1st yr of life, females gained a 25-mm advantage in the 2nd yr and a 30-mm advantage in the 3rd yr. In later years, the increments of growth of males and females were similar. All males were mature after 2 yr and females after 3 yr. The stomachs of northern pike contained only fish; the alewife (Alosa pseudoharengus) was the principal forage species consumed. Electivity indexes for alewives, white perch (Morone americana), and yellow perch (Perca flavescens), the three most common species in the diet, indicated a positive selection for alewives that increased from June to October during a period when the relative abundance of alewives steadily decreased.

  3. Breeding for increased forage quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage crops have a large number of benefits to society, including ecosystem services such as soil and water conservation, wildlife habitat, and diversification of the agricultural landscape. However, their principal function can only be realized when they are processed through livestock to produce ...

  4. Do You Have Enough Forage?

    E-print Network

    White, Larry D.

    1999-02-12

    and disappearance and livestock gains and losses. Some managers can just ?tell Do You Have Enough Forage? Larry D. White Extension Range Specialist ?Sir, you?re only outta patience, I?m outta grass, outta feed, outta water, and outta money!? Figure 1. This stressful...

  5. Handling manure on forage crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Manure application to alfalfa (and other perennial forages) is often necessary because of limited application windows during the year and limited land-to-livestock ratios to meet Comprehensive Nutrient Management Plan requirements. Manure applied before alfalfa planting or during production can impr...

  6. Why Range Forage Quality Changes 

    E-print Network

    Lyons, Robert K.; Machen, Richard V.; Forbes, T. D. A.

    1999-02-15

    Range livestock and wildlife have access to a tremendous diversity of forage plants which vary in nutritional quality. Range animals get the nutri- ents (protein, energy, vitamins, and minerals) required for growth, reproduction, and milk pro..., Texas AgriLife Extension Service; Assistant Professor and Extension Livestock Specialist, Texas AgriLife Extension Service; and Associate Professor, Grazing Ecology, Texas AgriLife Experiment Station, The Texas A&M University System. E-99 As plant cells...

  7. Nutritive characteristics of forage chemical components 

    E-print Network

    Buentello, Jose Luis

    1969-01-01

    of cellular 13 contents present in a forage can be regarded as completely digestible and its high correlation coefficient confirmed that same property for a variety of different forages. In contrast, the neutral-detergent fiber (cell wall fraction... and resultant sheep feces, at a specified level of intake, were collected and identified for subsequent chemical analysis. Forage and fecal samples were extracted with a neutral detergent solution yielding a residue (NDF) and an extract which was determined...

  8. Animal foraging: past, present and future.

    PubMed

    Perry, G; Pianka, E R

    1997-08-01

    Studies of foraging behaviour have proliferated over the past 30 years. Two schools of thought have emerged, one focusing on theoretical aspects (so-called 'optimal foraging theory'), the other on empirical studies. We summarize both, showing how they have evolved and begun to coalesce during the past decade. The emerging new framework is more complex than previous models, combining theory with observation. Modern phylogenetic methods promise new insights into how animal foraging has evolved. PMID:21238109

  9. Does Foraging Activity Affect Foraging Success in the Western Harvester Ant (Hymenoptera: Formicidae)?

    E-print Network

    Wiernasz, Diane C.

    BEHAVIOR Does Foraging Activity Affect Foraging Success in the Western Harvester Ant (Hymenoptera extensively studied in harvester ants (Hymenoptera: Formicidae); however, there is little information about) (Hymenoptera: Formicidae), col- onies with greater genetic diversity in the worker force begin foraging earlier

  10. Social foraging by honeybees: how colonies allocate foragers among patches of flowers

    Microsoft Academic Search

    Thomas D. Seeley

    1986-01-01

    To understand how a colony of honeybees keeps its forager force focussed on rich sources of food, and analysis was made of how the individual foragers within a colony decide to abandon or continue working (and perhaps even recruit to) patches of flowers. A nectar forager grades her behavior toward a patch in response to both the nectar intake rate

  11. Harvester ants use interactions to regulate forager activation and availability

    E-print Network

    Pinter-Wollman, Noa

    : collective behaviour complex system flexibility foraging interaction rate Pogonomyrmex barbatus regulation timescales. Here we examine how behavioural processes operating at two timescales regulate the foraging to food availability and predation. Previous work showed that the rate at which foragers return

  12. Boa constrictor (Boa constrictor): foraging behavior

    USGS Publications Warehouse

    Sorrell, G.G.; Boback, M.S.; Reed, R.N.; Green, S.; Montgomery, Chad E.; DeSouza, L.S.; Chiaraviglio, M.

    2011-01-01

    Boa constrictor is often referred to as a sit-and-wait or ambush forager that chooses locations to maximize the likelihood of prey encounters (Greene 1983. In Janzen [ed.], Costa Rica Natural History, pp. 380-382. Univ. Chicago Press, Illinois). However, as more is learned about the natural history of snakes in general, the dichotomy between active versus ambush foraging is becoming blurred. Herein, we describe an instance of diurnal active foraging by a B. constrictor, illustrating that this species exhibits a range of foraging behaviors.

  13. Social foraging with partial (public) information.

    PubMed

    Mann, Ofri; Kiflawi, Moshe

    2014-10-21

    Group foragers can utilize public information to better estimate patch quality and arrive at more efficient patch-departure rules. However, acquiring such information may come at a cost; e.g. reduced search efficiency. We present a Bayesian group-foraging model in which social foragers do not require full awareness of their companions' foraging success; only of their number. In our model, patch departure is based on direct estimates of the number of remaining items. This is achieved by considering all likely combinations of initial patch-quality and group foraging-success; given the individual forager's experience within the patch. Slower rates of information-acquisition by our 'partially-aware' foragers lead them to over-utilize poor patches; more than fully-aware foragers. However, our model suggests that the ensuing loss in long-term intake-rates can be matched by a relatively low cost to the acquisition of full public information. In other words, we suggest that group-size offers sufficient information for optimal patch utilization by social foragers. We suggest, also, that our model is applicable to other situations where resources undergo 'background depletion', which is coincident but independent of the consumer's own utilization. PMID:24911779

  14. Name ___________________________________________ Soil, Water and Forage Testing Laboratory

    E-print Network

    Name ___________________________________________ Soil, Water and Forage Testing Laboratory __________________________________________ City ____________________________State_____ Zip _____ County where sampled ___________________ Phone INFORMATION (Required) (See options listed below) Laboratory # Your Sample Sample Type and Usage: Livestock

  15. Heating effects on the quality of forage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The negative consequences of baling forages before they are dried adequately are widely known to hay producers. Generally, these responses include molding, spontaneous heating, losses of DM, and other changes in forage quality that are usually quite undesirable. Many changes in nutritive value are r...

  16. Potential of energy production from conserved forages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forages have a potential role in meeting the demand for energy. Perennial forages are attractive for various reasons. One, both the monetary and energy cost of planting is spread over many years. Two, we already have the equipment for harvesting, storing and transporting this source of biomass. Thre...

  17. Polyphenol oxidase activity in annual forage clovers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Polyphenol oxidase (PPO)-mediated phenol reactions in red clover (Trifolium pratense L.) bind forage protein and reduce proteolysis, producing beneficial effects on forage protein degradability, silage fermentation, and soil-N cycling. We evaluated PPO activity in seven previously untested annual c...

  18. Visual perception and social foraging in birds

    Microsoft Academic Search

    Esteban Fernández-Juricic; Jonathan T. Erichsen; Alex Kacelnik

    2004-01-01

    Birds gather information about their environment mainly through vision by scanning their surroundings. Many prevalent models of social foraging assume that foraging and scanning are mutually exclusive. Although this assumption is valid for birds with narrow visual fields, these models have also been applied to species with wide fields. In fact, available models do not make precise predictions for birds

  19. Optimal Forager against Ideal Free Distributed Prey.

    PubMed

    Garay, József; Cressman, Ross; Xu, Fei; Varga, Zoltan; Cabello, Tomás

    2015-07-01

    The introduced dispersal-foraging game is a combination of prey habitat selection between two patch types and optimal-foraging approaches. Prey's patch preference and forager behavior determine the prey's survival rate. The forager's energy gain depends on local prey density in both types of exhaustible patches and on leaving time. We introduce two game-solution concepts. The static solution combines the ideal free distribution of the prey with optimal-foraging theory. The dynamical solution is given by a game dynamics describing the behavioral changes of prey and forager. We show (1) that each stable equilibrium dynamical solution is always a static solution, but not conversely; (2) that at an equilibrium dynamical solution, the forager can stabilize prey mixed patch use strategy in cases where ideal free distribution theory predicts that prey will use only one patch type; and (3) that when the equilibrium dynamical solution is unstable at fixed prey density, stable behavior cycles occur where neither forager nor prey keep a fixed behavior. PMID:26098343

  20. Increased carrying capacity with perennial forage kochia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Carrying capacity can be increased on grass-dominated rangeland pastures by including perennial forage kochia (Kochia prostrata) as one of the plant components. The objectives of the study reported here were to compare the differences of traditional winter pastures versus pastures with forage kochi...

  1. Foraging in groups affects giving-up densities: solo foragers quit sooner.

    PubMed

    Carthey, Alexandra J R; Banks, Peter B

    2015-07-01

    The giving-up density framework is an elegant and widely adopted mathematical approach to measuring animals' foraging decisions at non-replenishing artificial resource patches. Under this framework, an animal should "give up" when the benefits of foraging are outweighed by the costs (e.g., predation risk, energetic, and/or missed opportunity costs). However, animals of many species may forage in groups, and group size is expected to alter perceived predation risk and hence influence quitting decisions. Yet, most giving-up density studies assume either that individuals forage alone or that giving-up densities are not affected by group foraging. For animals that forage both alone and in groups, differences in giving-up densities due to group foraging rather than experimental variables may substantially alter interpretation. However, no research to date has directly investigated how group foraging affects the giving-up density. We used remote-sensing cameras to identify instances of group foraging in two species of Rattus across three giving-up density experiments to determine whether group foraging influences giving-up densities. Both Rattus species have been observed to vary between foraging alone and in groups. In all three experiments, solo foragers left higher giving-up densities on average than did group foragers. This result has important implications for studies using giving-up densities to investigate perceived risk, the energetic costs of searching, handling time, digestion, and missed opportunity costs, particularly if groups of animals are more likely to experience certain experimental treatments. It is critically important that future giving-up density studies consider the effects of group foraging. PMID:25740332

  2. Biomimicry of bacterial foraging for distributed optimization and control

    Microsoft Academic Search

    K. M. Passino

    2002-01-01

    We explain the biology and physics underlying the chemotactic (foraging) behavior of E. coli bacteria. We explain a variety of bacterial swarming and social foraging behaviors and discuss the control system on the E. coli that dictates how foraging should proceed. Next, a computer program that emulates the distributed optimization process represented by the activity of social bacterial foraging is

  3. Optimal Foraging by Birds: Experiments for Secondary & Postsecondary Students

    ERIC Educational Resources Information Center

    Pecor, Keith W.; Lake, Ellen C.; Wund, Matthew A.

    2015-01-01

    Optimal foraging theory attempts to explain the foraging patterns observed in animals, including their choice of particular food items and foraging locations. We describe three experiments designed to test hypotheses about food choice and foraging habitat preference using bird feeders. These experiments can be used alone or in combination and can…

  4. Perennial Forages as Second Generation Bioenergy Crops

    PubMed Central

    Sanderson, Matt A.; Adler, Paul R.

    2008-01-01

    The lignocellulose in forage crops represents a second generation of biomass feedstock for conversion into energy-related end products. Some of the most extensively studied species for cellulosic feedstock production include forages such as switchgrass (Panicum virgatum L.), reed canarygrass (Phalaris arundinacea L.), and alfalfa (Medicago sativa L.). An advantage of using forages as bioenergy crops is that farmers are familiar with their management and already have the capacity to grow, harvest, store, and transport them. Forage crops offer additional flexibility in management because they can be used for biomass or forage and the land can be returned to other uses or put into crop rotation. Estimates indicate about 22.3 million ha of cropland, idle cropland, and cropland pasture will be needed for biomass production in 2030. Converting these lands to large scale cellulosic energy farming could push the traditional forage-livestock industry to ever more marginal lands. Furthermore, encouraging bioenergy production from marginal lands could directly compete with forage-livestock production. PMID:19325783

  5. The presence of uric acid, an antioxidantive substance, in fish seminal plasma

    Microsoft Academic Search

    A. Ciereszko; K. Dabrowski; D. Kucharczyk; S. Dobosz; K. Goryczko; J. Glogowski

    1999-01-01

    High concentrations of uric acid in seminal plasma of a range of teleost fish species are reported for the first time. Concentrations of urate amounted to 223.4; 121.9–130.0, 355.9, 735.6, 124.0, 192.7 and 148.0 µM for rainbow trout (Oncorhynchus mykiss), yellow perch (Perca flavescens), muskellunge (Esox masquinongy), Northern pike (Esox lucius), carp koi (Cyprinus carpio), bream (Abramis brama), and tench (Tinca

  6. QTL mapping of forage yield and forage yield component traits in Sorghum bicolor x S. sudanense.

    PubMed

    Liu, Y L; Wang, L H; Li, J Q; Zhan, Q W; Zhang, Q; Li, J F; Fan, F F

    2015-01-01

    The sorghum-sudangrass hybrid (Sorghum bicolor x S. sudanense) is an important forage crop. However, little is known about the genetic mechanisms related to forage yield and the 4 forage yield component traits in this forage crop. In this study, a linkage map was constructed with 124 assigned SSR markers using an F2 mapping population derived from the crossing of sorghum Tx623A and sudangrass Sa. Nine quantitative trait loci (QTLs) were detected for forage yield and the 4 forage yield component traits using inclusive composite interval mapping. Five fresh weight QTLs were identified and contributed >50% of the total phenotypic variance. Of these QTLs, all showed additive and dominant effects, but most exhibited mainly dominant effects. These results will provide useful information for improvements in sorghum-sudangrass hybrid breeding. PMID:25966155

  7. Rangeland Risk Management for Texans: Forage Quality and Quantity 

    E-print Network

    Lyons, Robert K.

    2000-11-01

    and Correcting Forage Quality Problems Producers understand forage quality, especially crude protein content, in relation to livestock performance. Hay shows emphasize the importance of forage testing to determine quality, and demonstrate how forage quality can... and the need for supplemental feed. Know the quality of your forage. In winter hay feeding programs, information about for- age quality can be used 1) to ration scarce supplies of good quality hay to meet animal needs without over- feeding, 2) to match...

  8. Grass management for forage and seed production

    E-print Network

    Hendler, Richard John

    1979-01-01

    GRASS MANAGEMENT FOR FORAGE AND SEED PRODUCTION A Thesis by RICHARD JOHN HENDLER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1979 Major... Subject: Agronomy GRASS MANAGEMENT FOR FORAGE AND SEED PRODUCTION A Thesis by RICHARD JOHN HENDLER Approved as to style and content by: (Chairman of Committee) (Head of Department) (Member) Member) August 1979 ABSTRACT Grass Management...

  9. Aggressive and Foraging Behavioral Interactions Among Ruffe

    Microsoft Academic Search

    Jacqueline F. Savino; Melissa J. Kostich

    2000-01-01

    The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100?cm diameter, 15?cm water depth) were conducted to determine whether fish density (low=2, medium=4, high=6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated

  10. Seabird foraging behaviour indicates prey type

    Microsoft Academic Search

    Kyle Hamish Elliott; Kerry Woo; Anthony J. Gaston; Silvano Benvenuti; Luigi Dall' Antonia; Gail K. Davoren

    2008-01-01

    To investigate how a generalist marine predator modifies its foraging behaviour by prey type, we attached time-depth-temperature recorders to chick-rearing thick-billed murres (n = 204) at Coats Island, Nunavut, Canada from 1999 to 2007. Predators varied their behavior along 3 major 'axes': foraging effort, prey depth and prey lifestyle (benthic\\/pelagic). Dive behaviours for different prey — fish doctor, squid, sandlance,

  11. Foraging ‘enrichment’ as treatment for pterotillomania

    Microsoft Academic Search

    Johannes T. Lumeij; Caroline J. Hommers

    2008-01-01

    This study was performed to determine whether foraging ‘enrichment’ reduces self-directed psychogenic feather picking (pterotillomania) in parrots. A positive correlation between increased foraging time and improvement of feather score was hypothesised.Eighteen pterotillomanic African grey parrots (Psittacus erithacus) were randomly assigned to experimental and control groups in a crossover design for two 1-month-periods. The experimental group received food in pipe feeders,

  12. Aggressive and foraging behavioral interactions among ruffe

    USGS Publications Warehouse

    Savino, Jacqueline F.; Kostich, Melissa J.

    2000-01-01

    The ruffe, Gymnocephalus cernuus, is a nonindigenous percid in the Great Lakes. Ruffe are aggressive benthivores and forage over soft substrates. Laboratory studies in pools (100 cm in diameter, 15 cm water depth) were conducted to determine whether fish density (low = 2, medium = 4, high = 6 ruffe per pool) changed foraging and aggressive behaviors with a limited food supply of chironomid larvae. All fish densities demonstrated a hierarchy based on aggressive interactions, but ruffe were most aggressive at low and high fish densities. Time spent in foraging was lowest at the low fish density. The best forager at the low fish density was the most aggressive individual, but the second most aggressive fish at the medium and high fish density was the best forager and also the one chased most frequently. A medium fish density offered the best energetic benefits to ruffe by providing the lowest ratio of time spent in aggression to that spent foraging. Based on our results, ruffe should grow best at an intermediate density. With high ruffe densities, we would also expect disparity in size as the more aggressive fish are able to garner a disproportionate amount of the resources. Alternatively, as the Great Lakes are a fairly open system, ruffe could migrate out of one area to colonize another as populations exceed optimal densities.

  13. Phonation behavior of cooperatively foraging spinner dolphins.

    PubMed

    Benoit-Bird, Kelly J; Au, Whitlow W L

    2009-01-01

    Groups of spinner dolphins have been shown to cooperatively herd small prey. It was hypothesized that the strong group coordination is maintained by acoustic communication, specifically by frequency-modulated whistles. Observations of groups of spinner dolphins foraging at night within a sound-scattering layer were made with a multibeam echosounder while the rates of dolphin sounds were measured using four hydrophones at 6 m depth intervals. Whistles were only detected when dolphins were not foraging and when animals were surfacing. Differences in click rates were found between depths and between different foraging stages but were relatively low when observations indicated that dolphins were actively feeding despite the consistency of these clicks with echolocation signals. Highest click rates occurred within the scattering layer, during transitions between foraging states. This suggests that clicks may be used directly or indirectly to cue group movement during foraging, potentially by detecting other individuals' positions in the group or serving a direct communicative role which would be contrary to the existing assumption that echolocation and communication are compartmentalized. Communicating via clicks would be beneficial as the signal's characteristics minimize the chance of eavesdropping by competing dolphins and large fish. Our results are unable to support the established paradigm for dolphin acoustic communication and suggest an alternate coordination mechanism in foraging spinner dolphins. PMID:19173439

  14. Fishing amplifies forage fish population collapses

    PubMed Central

    Essington, Timothy E.; Moriarty, Pamela E.; Froehlich, Halley E.; Hodgson, Emma E.; Koehn, Laura E.; Oken, Kiva L.; Siple, Margaret C.; Stawitz, Christine C.

    2015-01-01

    Forage fish support the largest fisheries in the world but also play key roles in marine food webs by transferring energy from plankton to upper trophic-level predators, such as large fish, seabirds, and marine mammals. Fishing can, thereby, have far reaching consequences on marine food webs unless safeguards are in place to avoid depleting forage fish to dangerously low levels, where dependent predators are most vulnerable. However, disentangling the contributions of fishing vs. natural processes on population dynamics has been difficult because of the sensitivity of these stocks to environmental conditions. Here, we overcome this difficulty by collating population time series for forage fish populations that account for nearly two-thirds of global catch of forage fish to identify the fingerprint of fisheries on their population dynamics. Forage fish population collapses shared a set of common and unique characteristics: high fishing pressure for several years before collapse, a sharp drop in natural population productivity, and a lagged response to reduce fishing pressure. Lagged response to natural productivity declines can sharply amplify the magnitude of naturally occurring population fluctuations. Finally, we show that the magnitude and frequency of collapses are greater than expected from natural productivity characteristics and therefore, likely attributed to fishing. The durations of collapses, however, were not different from those expected based on natural productivity shifts. A risk-based management scheme that reduces fishing when populations become scarce would protect forage fish and their predators from collapse with little effect on long-term average catches. PMID:25848018

  15. Effects of artificial illumination on the nocturnal foraging of waders

    NASA Astrophysics Data System (ADS)

    Santos, Carlos D.; Miranda, Ana C.; Granadeiro, José P.; Lourenço, Pedro M.; Saraiva, Sara; Palmeirim, Jorge M.

    2010-03-01

    Large areas of natural and semi-natural habitats are exposed to artificial illumination from adjacent urban areas and roads. Estuarine and coastal wetlands are particularly exposed to such illumination because shorelines often are heavily utilized by man. However, the impact of artificial illumination on the waders that forage in these highly productive habitats is virtually unknown. We evaluated the effects of artificial illumination on the nocturnal habitat selection and foraging behaviour of six wader species with different feeding strategies: three visual foragers, two species that alternate visual and tactile strategies (mixed foragers), and one tactile forager. We quantified the number of birds and their foraging behaviour at sites affected and not affected by streetlights, and also before and after illuminating experimental sites. Areas illuminated by streetlights were used more during the night by visual foragers, and to a lesser extent by mixed foragers, than non-illuminated areas. Visual foragers increased their foraging effort in illuminated areas, and mixed foragers changed to more efficient visual foraging strategies. These behavioural shifts improved prey intake rate by an average of 83% in visual and mixed foragers. We have showed that artificial illumination has a positive effect on the nocturnal foraging of waders, but on the other hand may draw them to degraded areas close to urban centres, and potentially raises their exposure to predators. Our findings suggest that artificial illumination is worth investigation as a tool in the management of intertidal habitats for waders.

  16. EFFECTS OF FORAGE SPECIES ON RIB COMPOSITION, COLOR, AND PALATABILITY IN FORAGE-FINISHED BEEF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forty-seven Angus-crossbred steers were used to evaluate the effects of forage species grazed in the last 41 d of the finishing period on rib composition, color, and palatability in forage-finished beef and compared to traditional high concentrate finished. Steers grazed naturalized pastures (bluegr...

  17. Interactions of Forage Quality and Physiological State on Forage Intake of Grazing Beef Cows in Autumn

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Intake by grazing cattle is affected by quality and availability of forage and by physiological demands, such as lactation and gestation. However, limited information is available on how these factors interact. We tested the hypothesis that autumn forage intake is altered by the interaction of cow...

  18. Forage and bioenergy feedstock production from hybrid forage sorghum and sorghum x sudangrass hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As the bioenergy industry expands, producers choosing to shift current forage crop production to dedicated biomass crops will find it advantageous to grow low risk multi-purpose crops that maximize management options. Hybrid forage sorghums (HFS) and sorghum by sudangrass hybrids (SSG) are capable...

  19. Evolution of foraging behavior in Drosophilid larvae

    NASA Astrophysics Data System (ADS)

    Rivera-Alba, Marta; Kabra, Mayank; Branson, Kristin; Mirth, Christen

    2015-03-01

    Drosophilids, like other insects, go through a larval phase before metamorphosing into adults. Larvae increase their body weight by several orders of magnitude in a few days. We therefore hypothesized that foraging behavior is under strong evolutionary pressure to best fit the larval environment. To test our hypothesis we used a multidisciplinary approach to analyze foraging behavior across species and larval stages. First, we recorded several videos of larvae foraging for each of 47 Drosophilid species. Then, using a supervised machine learning approach, we automatically annotated the video collection for the foraging sub-behaviors, including crawling, turning, head casting or burrowing. We also computed over 100 features to describe the posture and dynamics of each animal in each video frame. From these data, we fit models to the behavior of each species. The models each had the same parametric form, but differed in the exact parameters. By simulating larva behavior in virtual arenas we can infer which properties of the environments are better for each species. Comparisons between these inferred environments and the actual environments where these animals live will give us a deeper understanding about the evolution of foraging behavior in Drosophilid larvae.

  20. Optimal Lévy-flight foraging in a finite landscape.

    PubMed

    Zhao, Kun; Jurdak, Raja; Liu, Jiajun; Westcott, David; Kusy, Branislav; Parry, Hazel; Sommer, Philipp; McKeown, Adam

    2015-03-01

    We present a simple model to study Lévy-flight foraging with a power-law step-size distribution [P(l) ? l-?] in a finite landscape with countable targets. We find that different optimal foraging strategies characterized by a wide range of power-law exponent ?opt, from ballistic motion (?opt ? 1) to Lévy flight (1 < ?opt < 3) to Brownian motion (?opt ? 3), may arise in adaptation to the interplay between the termination of foraging, which is regulated by the number of foraging steps, and the environmental context of the landscape, namely the landscape size and number of targets. We further demonstrate that stochastic returning can be another significant factor that affects the foraging efficiency and optimality of foraging strategy. Our study provides a new perspective on Lévy-flight foraging, opens new avenues for investigating the interaction between foraging dynamics and the environment and offers a realistic framework for analysing animal movement patterns from empirical data. PMID:25631566

  1. A DIGITAL PHOTOGRAPHIC TECHNIQUE FOR ASSESSING FORAGE UTILIZATION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in forage utilization have been difficult to measure nondestructively without some level of subjectivity. This subjectivity, combined with a lack of reproducibility of visual estimates, has made forage utilization measurement techniques a topic of considerable discussion. The objective of ...

  2. Female degus ( Octodon degus ) monitor their environment while foraging socially

    Microsoft Academic Search

    Verónica Quirici; Rodrigo A. Castro; Javiera Oyarzún; Luis A. Ebensperger

    2008-01-01

    Vigilance or scanning involves interruptions in foraging behavior when individuals lift their heads and conduct visual monitoring\\u000a of the environment. Theoretical considerations assume that foraging with the “head down”, and scanning (“head up”) are mutually\\u000a exclusive activities, such that foraging precludes vigilance. We tested this generalization in a socially foraging, small\\u000a mammal model, the diurnal Chilean degu (Octodon degus). We

  3. Spatiotemporal chemotactic model for ant foraging

    NASA Astrophysics Data System (ADS)

    Ramakrishnan, Subramanian; Laurent, Thomas; Kumar, Manish; Bertozzi, Andrea L.

    2014-12-01

    In this paper, we present a generic theoretical chemotactic model that accounts for certain emergent behaviors observed in ant foraging. The model does not have many of the constraints and limitations of existing models for ants colony dynamics and takes into account the distinctly different behaviors exhibited in nature by ant foragers in search of food and food ferrying ants. Numerical simulations based on the model show trail formation in foraging ant colonies to be an emergent phenomenon and, in particular, replicate behavior observed in experiments involving the species P. megacephala. The results have broader implications for the study of randomness in chemotactic models. Potential applications include the developments of novel algorithms for stochastic search in engineered complex systems such as robotic swarms.

  4. Optimal Foraging and Predator-Prey Dynamics

    PubMed

    Krivan

    1996-06-01

    A system consisting of a population of predators and two types of prey is considered. The dynamics of the system is described by differential equations with controls. The controls model how predators forage on each of the two types of prey. The choice of these controls is based on the standard assumption in the theory of optimal foraging which requires that each predator maximizes the net rate of energy intake during foraging. Since this choice depends on the densities of populations involved, this allows us to link the optimal behavior of an individual with the dynamics of the whole system. Simple qualitative analysis and some simulations show the qualitative behavior of such a system. The effect of the optimal diet choice on the stability of the system is discussed. PMID:8813025

  5. Original article The foraging behaviour of honey bees

    E-print Network

    Paris-Sud XI, Université de

    Original article The foraging behaviour of honey bees (Apis mellifera L) and bumble bees (Bombus — The behaviour of honey bees and bumble bees while foraging on cultivated cranberry in southeastern Massachusetts was studied. Bumble bees were much more consistent foragers than are honey bees

  6. VARIABILITY IN RELATIONSHIPS AMONG FORAGE INTAKE, DIGESTIBILITY, NDF, AND ADF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Confusion exists about forage quality and in methods to measure or predict forage quality. The conventional wisdom is that there are close relationships between voluntary forage dry matter intake (DMI) and digestible dry matter (DDM) concentration, DMI and NDF, and DDM and ADF. Correlation coeffic...

  7. Intake and digestibility of four forages by Ilamas and sheep

    E-print Network

    Paris-Sud XI, Université de

    Intake and digestibility of four forages by Ilamas and sheep R Cordesse M Inesta, JL Gaubert ENSA of llamas to ingest and digest forages. We measured these capacities on 4 forages in comparison with sheep. The digestibility was measured by total col- lection of feces on the last 10 days of each period. Sheep had

  8. Long-term foraging optimization in northern shovelers

    Microsoft Academic Search

    Paul J. DuBowy

    1997-01-01

    In this paper I attempt to explain the seasonal foraging strategy employed by male northern shovelers (Anas clypeata). Through the use of dynamic-optimization modeling I demonstrate that male shovelers are optimizing total foraging time over the entire summer by foraging heavily when resources (cladocerans) are abundant and utilizing endogenous reserves during times when resources are in short supply. Additionally, I

  9. Overnight memory retention of foraging skills by bumblebees is imperfect

    Microsoft Academic Search

    TAMAR KEASAR; UZI MOTRO; YOAV SHUR; AVI SHMIDA

    1996-01-01

    Abstract. Newly emerged bees learn to forage more efficiently as they gain experience. To test the hypothesis that foraging efficiency would increase as bees gain experience during the day, but would decrease after a night, owing to loss of memory, naiveBombus terrestrisbumblebees were allowed to forage on two clusters of artificial flowers of unequal profitabilities during 3 consecutive days. Nectar

  10. Ant Foraging Revisited Liviu A. Panait and Sean Luke

    E-print Network

    George Mason University

    Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging models have to date re the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  11. Ant Foraging Revisited Liviu A. Panait and Sean Luke

    E-print Network

    Turk, Greg

    Ant Foraging Revisited Liviu A. Panait and Sean Luke George Mason University, Fairfax, VA 22030 lpanait@cs.gmu.edu, sean@cs.gmu.edu Abstract Most previous artificial ant foraging algorithms have to date the artificial ants with the knowledge of the nest direction. In contrast, the work presented solves ant foraging

  12. Perennial Grass Breeding Program for Forage and Biofuels - Tifton, GA

    Microsoft Academic Search

    Bill Anderson

    The perennial grass breeding program at Tifton, Georgia has a long history. Drs. Glenn Burton and Wayne Hanna, with collaborators, developed a significant number of forage and turf cultivars over the past 60-plus years. Work is continuing in areas of forage and turf improvements for the South. Forage improvement of bermudagrass and bahiagrass continues within the Crop Genetics and Breeding

  13. Perennial Forage Kochia for Increased Production of Winter Grazed Pastures

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grazing forage kochia (Kochia prostrata) during fall/winter has improved livestock health and reduced winter feeding costs. The objectives of this study were to compare forage production/quality and livestock performance of traditional winter pastures versus pastures with forage kochia. Two kochia...

  14. FORAGE FISH ABUNDANCE AND DISTRIBUTION AT FORRESTER ISLAND, ALASKA

    E-print Network

    composition of forage fishes near sea lion and seabird rookeries in Southeast Alaska, East Aleutians1 FORAGE FISH ABUNDANCE AND DISTRIBUTION AT FORRESTER ISLAND, ALASKA Brenda L. Norcross Principal National Oceanic and Atmospheric Administration Award No. NA66FX0455 #12;2 FORAGE FISH ABUNDANCE

  15. DO WINTERING HARLEQUIN DUCKS FORAGE NOCTURNALLY AT HIGH LATITUDES?

    Microsoft Academic Search

    Daniel J. Rizzolo; Daniel Esler; Daniel D. Roby; Robert L. Jarvis

    2005-01-01

    We monitored radio-tagged Harlequin Ducks (Histrionicus histrionicus) to determine whether nocturnal feeding was part of their foraging strategy during winter in south-central Alaska. Despite attri- butes of our study site (low ambient temperatures, harsh weather, short day length) and study species (small body size, high daytime foraging rates) that would be expected to favor nocturnal foraging, we found no evidence

  16. Density-dependent foraging effort of Deer Mice (Peromyscus maniculatus)

    Microsoft Academic Search

    D. L. Davidson; D. W. Morris

    2001-01-01

    Summary 1. Little is known about how population density affects the foraging behaviour of individuals. Simple models are developed to predict the net effect of density on the quitting-harvest rates of optimal foragers. The theory was tested with experiments that measured the foraging behaviour of free-ranging Deer Mice under control and reduced densities. 2. An increased density of conspecifics may

  17. Predator foraging behaviour drives food-web topological structure

    Microsoft Academic Search

    Xavier Lazzaro; Gérard Lacroix; Benoît Gauzens; Jacques Gignoux; Stéphane Legendre

    2009-01-01

    Summary 1. The structure and dynamics of prey populations are shaped by the foraging behaviours of their predators. Yet, there is still little documentation on how distinct predator foraging types control biodiversity, food-web architecture and ecosystem functioning. 2. We experimentally compared the effects of model fish species of two major foraging types of lake planktivores: a size-selective visual feeder (bluegill),

  18. From the Cover: Size, foraging, and food web structure

    Microsoft Academic Search

    Owen L. Petchey; Andrew P. Beckerman; Jens O. Riede; Philip H. Warren

    2008-01-01

    Understanding what structures ecological communities is vital to answering questions about extinctions, environmental change, trophic cascades, and ecosystem functioning. Optimal foraging theory was conceived to increase such understanding by providing a framework with which to predict species interactions and resulting community structure. Here, we use an optimal foraging model and allometries of foraging variables to predict the structure of real

  19. Harvester ants use interactions to regulate forager activation and availability

    E-print Network

    Gordon, Deborah

    behaviour complex system flexibility foraging interaction rate Pogonomyrmex barbatus regulation robustness examine how behavioural processes operating at two timescales regulate the foraging activity of colonies and predation. Previous work showed that the rate at which foragers return to the nest with food influences

  20. Extending the Particle Swarm Algorithm to Model Animal Foraging Behaviour

    E-print Network

    Poli, Riccardo

    Extending the Particle Swarm Algorithm to Model Animal Foraging Behaviour Cecilia Di Chio1] contains elements which map fairly strongly to the group-foraging problem in behavioural ecology: its here on simulating an abstraction of the group-foraging problem, where: (a) there are no predators

  1. Loggerhead Shrike (Lanius ludovicianus L) Foraging Patch and Perch Selection

    Microsoft Academic Search

    Miles Becker

    2006-01-01

    Loggerhead shrikes have disappeared across much of their former range, most likely due to habitat loss. I studied the habitat shrikes prefer for foraging. Shrikes forage from a perch on prey that they see in the surrounding vegetation. When I mowed the vegetation on one side of selected perches, shrikes strongly preferred to forage on the mowed side even though

  2. Piping Plover Foraging-Site Selection on the Missouri River

    Microsoft Academic Search

    D ANIELLE L E F ER; J AMES D. F RASER; ASEY D. K RUSE

    Selection of a foraging site entails costs and benefits which are reflected in survival and reproductive success. We studied Piping Plover ( Charadrius melodus ) foraging-site selection during the breeding season (2001- 2003) on the Missouri River and examined the relationship between site selection and invertebrate abundance in- dices within habitats. Foraging adult plovers selected protected shoreline (inter-sandbar channels, inlets,

  3. Oviduct Insertion of Radio Transmitters as a Means of Locating Northern Pike Spawning Habitat

    Microsoft Academic Search

    Rodney B. Pierce

    2004-01-01

    I inserted radio transmitters into the oviducts of northern pike Esox lucius in an attempt to find their spawning grounds. Oviduct insertion of miniature radio transmitters was quick and easy. I hoped that transmitters would be expelled with the eggs to aid in identifying critical habitat used for egg deposition. Ten transmitters were implanted in the egg masses of female

  4. Response of the residential piscivorous fish community to introduction of a new predator type in a mesotrophic lake

    Microsoft Academic Search

    Torsten Schulze; Ulrich Baade; Hendrik Dörner; Reiner Eckmann; Susanne S. Haertel-Borer; Franz Hölker; Thomas Mehner

    2006-01-01

    Although the effects of introduced predators on prey populations in aquatic ecosystems have been studied frequently, less is known about the interactions between predators. We performed a whole-lake experiment by stocking a non-native top predator (pikeperch (Sander lucioperca)) to two residential piscivores (Eurasian perch (Perca fluviatilis) and northern pike (Esox lucius)). By analyzing spatial distribution, diet composition, growth, and consump-

  5. Littoral Fish Community Response to Smallmouth Bass Removal from an Adirondack Lake

    E-print Network

    Kraft, Clifford E.

    littoral fish abundance, we removed 47,682 smallmouth bass Micropterus dolomieu from a 271-ha Adirondack 1999). Previous observational studies have shown that introductions of smallmouth bass Micropterus dolo- mieu, largemouth bass M. salmoides, and northern pike Esox lucius have been associated

  6. A BroadScale Approach to Management of Ontario's Recreational Fisheries

    Microsoft Academic Search

    Nigel P. Lester; Terry R. Marshall; Kim Armstrong; Warren I. Dunlop; Bev Ritchie

    2003-01-01

    Sustainable exploitation of Ontario's aquatic resources calls for a new management approach. This vast resource includes more than 250,000 lakes and offers angling opportunities for many popular species (e.g., walleye Sander vitreus (formerly Stizostedion vitreum), lake trout Salvelinus namaycush, brook trout S. fontinalis, northern pike Esox lucius, smallmouth bass Micropterus dolomieu, largemouth bass M. salmoides, and muskellunge E. masquinongy). In

  7. Interactions between Walleyes and Four Fish Species with Implications for Walleye Stocking

    Microsoft Academic Search

    Andrew H. Fayram; Michael J. Hansen; Timothy J. Ehlinger

    2005-01-01

    We used a number of different data sets and four criteria to evaluate evidence of competition and predation between walleye Sander vitreus and northern pike Esox lucius, muskellunge E. masquinongy, smallmouth bass Micropterus dolomieu, and largemouth bass M. salmoides in northern Wisconsin lakes. The four criteria were as follows: (1) indices of population abundance were inversely related, (2) two species

  8. Comparison of mercury and methylmercury in northern pike and Arctic grayling from western Alaska rivers

    Microsoft Academic Search

    Stephen C. Jewett; Xiaoming Zhang; A. Sathy Naidu; John J. Kelley; Doug Dasher; Lawrence K. Duffy

    2003-01-01

    In western Alaska, mercury (Hg) could be a potential health risk to people whose diet is primarily fish-based. In 2000, total Hg (THg) and methylmercury (MeHg) were examined in northern pike (Esox lucius) and Arctic grayling (Thymallus arcticus) from two watersheds in western Alaska, the Yukon and Kuskokwim rivers. Whitefish (Coregonus sp.) were also examined from the Kuskokwim River. Pike

  9. Construct Mechanical Pike and Tow Tank Chengcheng Feng

    E-print Network

    Mountziaris, T. J.

    Construct Mechanical Pike and Tow Tank Chengcheng Feng Faculty Mentor: Professor Yahya Modarres-Sadeghi, Mechanical and Industrial Engineering Biomimicry offers valuable solutions to engineering problems through observing nature. The aim of this project is to examine the mechanisms of a northern pike, esox lucius fast

  10. Using Bioenergetics Modeling to Estimate Consumption of Native Juvenile Salmonids by Nonnative Northern Pike in the Upper Flathead River System, Montana

    Microsoft Academic Search

    Clint C. Muhlfeld; David H. Bennett; R. Kirk Steinhorst; Brian Marotz; Matthew Boyer

    2008-01-01

    Introductions of nonnative northern pike Esox lucius have created recreational fisheries in many waters in the United States and Canada, yet many studies have shown that introduced northern pike may alter the composition and structure of fish communities through predation. We estimated the abundance of nonnative northern pike (2002–2003) and applied food habits data (1999–2003) to estimate their annual consumption

  11. Reactions of Gammarus lacustris to Chemical Stimuli from Natural Predators and Injured Conspecifics

    Microsoft Academic Search

    Karen Wudkevich; Brian D. Wisenden; Douglas P. Chivers; R. Jan F. Smith

    1997-01-01

    We exposed the freshwater amphipod Gammarus lacustris, to chemical stimuli from injured conspecifics and to chemical stimuli from two types of natural predators: dragonfly larvae (Aeshna eremita) and northern pike (Esox lucius). Exposure to all three stimuli caused G. lacustris to reduce significantly its level of activity relative to activity recorded in response to a distilled water control. The similarity

  12. Learned Recognition of Predation Risk by Enallagma Damselfly Larvae (Odonata, Zygoptera) on the Basis of Chemical Cues

    Microsoft Academic Search

    Brian D. Wisenden; Douglas P. Chivers; R. Jan. F. Smith

    1997-01-01

    We studied two populations of damselfly larvae (Enallagma boreale): one population cooccurred with a predatory fish (northern pike, Esox lucius); the other did not. Damselflies that cooccurred with pike adopted antipredator behavior (reduced activity) in response to chemical stimuli from injured conspecifics, and to chemical stimuli from pike, relative to a distilled water control. Damselflies from an area where pike

  13. Structural and functional impairment of the hypothalamo- pituitary-interrenal axis in fish exposed to bleached kraft mill effluent in the St Maurice River, Quebec

    Microsoft Academic Search

    ALICE Hontela; CLAUDE Daniel; JOSEPH B. Rasmussen

    1997-01-01

    The effects of bleached kraft mill effluent (BKME) on blood cortisol levels and the morphology of the pituitary-interrenal axis were investigated in two species of teleost fish, the northern pike, Esox lucius, and the yellow perch, Perca flavescens, sampled upstream and downstream from a pulp and paper mill on the St Maurice River, Quebec. Fish were acutely stressed by a

  14. Ontogenetic niche shifts and resource partitioning in a subarctic piscivore fish guild

    Microsoft Academic Search

    Per-Arne Amundsen; Thomas Bøhn; Olga A. Popova; Frode J. Staldvik; Yuri S. Reshetnikov; Nikolay A. Kashulin; Anatoly A. Lukin

    2003-01-01

    The feeding ecology of three piscivorous fish species (perch (Perca fluviatilis), pike (Esox lucius) and burbot (Lota lota)), was studied in the subarctic Pasvik watercourse (69 °?N), northern Norway and Russia. All three species primarily occupied the benthic habitats in the watercourse. Perch and burbot exhibited distinct ontogenetic niche shifts in food resource use, perch changing from a dominance of

  15. The role of olfaction in chemosensory-based predator recognition in the fathead minnow, Pimephales promelas

    Microsoft Academic Search

    Douglas P. Chivers; R. Jan F. Smith

    1993-01-01

    Solitary fathead minnows (Pimephales promelas) were rendered anosmic and exposed to chemical stimuli from a predatory northern pike (Esox lucius) to determine the role of olfaction in the minnow's ability to recognize predators on the basis of chemical stimuli. Anosmic fish did not respond to the pike stimuli with a typical fright reaction, while control fish, with intact olfactory receptors,

  16. Impaired cortisol stress response in fish from environments polluted by PAHs, PCBs, and mercury

    Microsoft Academic Search

    Alice Hontela; Joseph B. Rasmussen; Céline Audet; Gaston Chevalier

    1992-01-01

    The cortisol stress response to capture was investigated in two species of fish (Perca flavescens and Esox lucius) from sites polluted by high levels of polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), and mercury, and from reference sites in the St. Lawrence river system. Fish from the reference sites exhibited the normal elevation of serum cortisol in response to the

  17. Growth of Tiger Muskellunge Fed Different Amounts of Protein at Three Water Temperatures

    Microsoft Academic Search

    Carol A. Lemm; Donald V. Rottiers

    1986-01-01

    Growth rates of tiger muskellunge (muskellunge Esox masquinongy ? x northern pike E. lucius ?) fed diets containing 35, 45, or 55% crude protein for 5 weeks at 17, 20, or 23°C were compared. Fish fed diets containing 45 or 55% protein grew faster at all temperatures than those fed 35% protein. Growth of tiger muskellunge fed a diet containing

  18. Application of Liquid Oxytetracycline in Formulated Feeds to Mark and Treat Tiger Muskellunge (Northern Pike X Muskellunge)

    Microsoft Academic Search

    David H. Wahl; Roy A. Stein

    1987-01-01

    When added to pelleted diets, liquid oxytetracycline (500 mg\\/kg of fish per day) was effective in marking (after 12 d) and disease treatment (after 3 d) of tiger muskellunge (the hybrid of northern pike, Esox lucius, and muskellunge, E. masquinongy). Liquid oxytetracycline is more easily applied and costs less than traditional methods for these purposes.

  19. Largemouth Bass Predation on Stocked Tiger Muskellunge

    Microsoft Academic Search

    Roy A. Stein; Robert F. Carline; Robert S. Hayward

    1981-01-01

    To better understand why stocked esocids survive poorly, we estimated mortality rates of tiger muskellunge (F1 hybrid of female muskellunge Esox masquinongy x male northern pike E. lucius) that were placed into two Ohio reservoirs (mean fish total lengths, 171 and 179 mm; 62 fish per hectare). Because pond experiments showed that hybrids stocked at night experienced mortality rates as

  20. Predation by Pellet-Reared Tiger Muskellunge on Minnows and Bluegills in Experimental Systems

    Microsoft Academic Search

    Alan L. Gillen; Roy A. Stein; Robert F. Carline

    1981-01-01

    Studies in Wisconsin lakes have shown that stocked tiger muskellunge (F1 hybrids of female muskellunge, Esox masquinongy x male northern pike, E. lucius) reared on live food survive better than those reared entirely on dry pellet food. We evaluated the ability of pellet-reared hybrids to convert to a minnow (Notropis spp. and Pimephales promelas) or bluegill (Lepomis macrochirus) diet in

  1. Nutritional Requirements and Feeding of Selected Coolwater Fishes: A Review

    Microsoft Academic Search

    H. George Ketola

    1978-01-01

    A review was made of published and unpublished studies on nutritional requirements, diets, and feeding of selected coolwater species of fishes: yellow perch (Perca flavescens), European perch (P. fluviatilis), walleye (Stizostedion vitreum), smallmouth bass (Micropterus dolomieui), northern pike (Esox lucius), muskellunge (E. masquinongy), and the northern pike x muskellunge hybrid. The published information on nutritional requirements was meager, including only

  2. Damselfly larvae learn to recognize predators from chemical cues in the predator's diet

    Microsoft Academic Search

    DOUGLAS P. CHIVERS; BRIAN D. WISENDEN; R. JAN F. SMITH

    1996-01-01

    Chemosensory recognition of predators by naive prey may be facilitated if the predator's diet chemically ‘labels’ the predator. In a laboratory experiment, behaviour patterns were quantified in individual damselfly larvae,Enallagmaspp., that had never been exposed to pike,Esox lucius, before and after exposing the damselflies to one of three chemical stimuli: water from a tank that held pike fed a diet

  3. Mercury evolution (1978–1988) in fishes of the La Grande hydroelectric complex, Quebec, Canada

    Microsoft Academic Search

    R. Verdon; D. Brouard; C. Demers; R. Lalumiere; M. Laperle; R. Schetagne

    1991-01-01

    From 1978 to 1988, the evolution of the Hg content of fish has been monitored in the areas affected by the La Grande hydroelectric\\u000a complex. Four fish species were considered: two non piscivorous, lake whitefish (Coregonus clupeaformis) and longnose sucker (Catostomus catostomus), and two piscivorous, northern pike (Esox lucius) and walleye (Stizostedion vitreum). The evolution of Hg concentrations in time

  4. Development of a Riverine Index Netting Protocol: Comparisons of Net Orientation, Height, Panel Order, and Line Diameter

    Microsoft Academic Search

    Nicholas E. Jones; Geoffrey B. Yunker

    2011-01-01

    We developed a gillnetting protocol by sampling 17 nonwadeable rivers across northern Ontario over the course of four summers from 2005 to 2008. The rivers represented a range of habitats; however, all had a coolwater to warmwater fish community characterized by walleyes Sander vitreus, northern pike Esox lucius, white suckers Catostomus commersonii, yellow perch Perca flavescens, and smallmouth bass Micropterus

  5. Qualitative indices of edible and inedible products obtained from fish in the lower Yenisei River basin

    Microsoft Academic Search

    A. A. Gnedov; A. A. Kaizer

    2010-01-01

    The results of biochemical investigations of samples of products obtained from burbot (Lota lota L.), perch (Perca fluviatilis L.), and pike (Esox lucius L.) inhabiting the lower reaches of the Yenisei River basin are given. Biologically active substances—macro- and microelements,\\u000a fatty acids, amino acids, and vitamins—are analyzed.

  6. Relative cattle preference of 24 forage kochia (Kochia prostrata) entries and its relation to forage nutritive value and morphological characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage kochia [Kochia prostrata (L. Shrad.)] has been shown to have potential as a nutritious fall and winter forage on western rangelands; however, its utilization by livestock is not well understood. This study was conducted to determine differences in cattle utilization among 24 forage kochia en...

  7. Nitrates and Prussic Acid in Forages

    E-print Network

    Provin, Tony; Pitt, John L.

    2003-01-06

    When nitrates and prussic acid accumulate in forage, the feed may not be safe for livestock consumption. Learn the symptoms of nitrate and prussic acid poisoning and which plants are most likely to pose a risk to livestock. Also learn sampling...

  8. Forage and pasture management for laminitic horses

    Microsoft Academic Search

    Kathryn A. Watts

    2004-01-01

    In the past, many cases of laminitis have been of mysterious origin. Recent investigations in veterinary medicine, coupled with the availability of new techniques for analyzing hydrolyzable carbohydrates in forage may provide evidence to solve some of these mysteries. Fructan has been shown to be capable of inducing laminitis in clinical studies. Insulin resistance, a primary feature of Equine Metabolic

  9. SWITCHGRASS FOR BIOFUEL, FORAGE, AND MUSHROOMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Switchgrass (Panicum virgatum L.), a native perennial warm-season grass, is used as a forage and conservation plant in the eastern USA. During the last 15 years switchgrass has received much attention as a model energy crop. Attributes of switchgrass desirable for bioenergy cropping include its demo...

  10. BLUE WHALE-SIZED MOUTHFULS MAKE FORAGING

    E-print Network

    Martin, Paul R.

    Inside JEB i BLUE WHALE-SIZED MOUTHFULS MAKE FORAGING SUPER EFFICIENT When a blue whale dives from the University of British Columbia, Canada, explains that blue whales may be able to dive, measuring the energetics of blue whale lunges at depth seemed almost impossible until Shadwick and his

  11. The Dynamics of Infant Visual Foraging

    ERIC Educational Resources Information Center

    Robertson, Steven S.; Guckenheimer, John; Masnick, Amy M.; Bacher, Leigh F.

    2004-01-01

    Human infants actively forage for visual information from the moment of birth onward. Although we know a great deal about how stimulus characteristics influence looking behavior in the first few postnatal weeks, we know much less about the intrinsic dynamics of the behavior. Here we show that a simple stochastic dynamical system acts…

  12. DIEL FORAGING ACTIVITY OF AMERICAN EELS,

    E-print Network

    DIEL FORAGING ACTIVITY OF AMERICAN EELS, ANGUILLA ROSTRATA (LESUEUR), IN A RHODE ISLAND ESTUARY Although the American eel, Anguilla rostrata (LeSueur), is abundant and commercially exploited along Veen et aI. 1976; Westin and Nyman 1979), that American eel locomotor activity is noc- turnal

  13. Soil Carbon Fractionation under Perennial Forage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Crop management practices can improve soil quality. Forage type and N-sources might also affect soil organic matter, especially soil carbon fractionation. The objective of this study is to evaluate the impact of legume inter-planting and compost application on soil C pools under a perennial grass mi...

  14. Navigation: many senses make efficient foraging paths.

    PubMed

    Collett, Matthew; Cardé, Ring T

    2014-05-01

    Desert ants have a sequence of optimized behaviours that allow them to forage efficiently. Recent work shows that after using navigational memories to reach previously rewarding areas, ants follow long crosswind sweeps that appear adapted for encountering odour plumes. PMID:24801185

  15. Original article Worker piping associated with foraging

    E-print Network

    Paris-Sud XI, Université de

    Original article Worker piping associated with foraging in undisturbed queenright colonies of honey piping, previously reported only in association with colony disturbance or queen- lessness, was seen in undisturbed, queenright colonies. Workers piped by pressing the thorax to the comb, spreading the wings

  16. Virginia Small Grain Forage Variety Testing Report

    E-print Network

    Liskiewicz, Maciej

    Virginia Small Grain Forage Variety Testing Report: Long-Term Summary (1994-2004) www.ext.vt.edu Produced by Communications and Marketing, College of Agriculture and Life Sciences, Virginia Polytechnic Institute and State University, 2009 Virginia Cooperative Extension programs and employment are open to all

  17. Field and Forage Crop Pests. MEP 310.

    ERIC Educational Resources Information Center

    Morgan, Omar, D.; And Others

    As part of a cooperative extension service series by the University of Maryland, this publication introduces the identification and control of common agricultural pests that can be found in field and forage crops. The first of the five sections defines "pest" and "weed" and generally introduces different kinds of pests in the categories of…

  18. Memory dynamics and foraging strategies of honeybees

    Microsoft Academic Search

    Uwe Greggers; Randolf Menzel

    1993-01-01

    Summary The foraging behavior of a single bee in a patch of four electronic flower dummies (feeders) was studied with the aim of analyzing the informational components in the choice process. In different experimental combinations of reward rates, color marks, odors and distances of the feeders, the behavior of the test bee was monitored by a computer in real time

  19. Optimal Foraging The math and equations

    E-print Network

    Mitchell, Randall J.

    ://www.neiu.edu/~jkasmer/Biol380/Labs/optfor1.gif · Nice exercise on hummingbird foraging at http://bio150.chass ­ Matings.... Exercise · Harvest with tweezers · Remove shell if there is oneone ­ Sunflower seeds ­ Peanuts as though optimizing the rate of energy gain ­ Model balances costs against benefits · Search time dli i

  20. Foraging behaviour in fishes: perspectives on variance

    Microsoft Academic Search

    Brian M. Marcotte; Howard I. Browman

    1986-01-01

    Synopsis The positive relationship between size of prey and frequency of ingestion by predators has been a focal point of investigations in foraging ecology. Field studies compare the frequency distribution of prey sizes in the predator's gut with that in the environment. Laboratory and field (enclosure) studies are based upon comparison of the frequency distributions of prey sizes in controlled

  1. Nitrates and Prussic Acid in Forages 

    E-print Network

    Provin, Tony; Pitt, John L.

    2003-01-06

    When nitrates and prussic acid accumulate in forage, the feed may not be safe for livestock consumption. Learn the symptoms of nitrate and prussic acid poisoning and which plants are most likely to pose a risk to livestock. Also learn sampling...

  2. Lévy Processes, Saltatory Foraging, and Superdiffusion

    Microsoft Academic Search

    J. F. Burrow; P. D. Baxter; J. W. Pitchford

    2008-01-01

    It is well established that resource variability generated by spatial patchiness and turbu- lence is an important influence on the growth and recruitment of planktonic fish larvae. Em- pirical data show fractal-like prey distributions, and simulations indicate that scale-invariant foraging strategies may be optimal. Here we show how larval growth and recruitment in a turbulent environment can be formulated as

  3. Experiments with Honeybee Foraging Inspired Load Balancing

    Microsoft Academic Search

    Martin Randles; David Lamb; A. Taleb-Bendiab

    2009-01-01

    This paper investigates and analyses the dynamics engendered by the engineering of self-organisation in a global Service Oriented Architecture. The effects are assessed via a resource allocation algorithm for load balancing, based on the observed behaviour of foraging honeybees. It is implemented at the application layer of a simulated server farm type system and its impact is investigated across this

  4. Transformation of forage legumes using Agrobacterium tumefaciens

    Microsoft Academic Search

    K. J. Webb

    1986-01-01

    Galls were induced in six species of forage legumes following inoculation with wild-type strains of A. tumefaciens. The plant species was more influential than the bacterial strain in determining the type of tumour produced. Inoculation of Medicago sativa resulted in small, disorganised tumours. The three Trifolium species, T. repens, T. hybridum and T. pratense, formed galls which tended to produce

  5. Anterior Cingulate Engagement in a Foraging Context Reflects Choice Difficulty, Not Foraging Value

    PubMed Central

    Shenhav, Amitai; Straccia, Mark A.; Cohen, Jonathan D.; Botvinick, Matthew M.

    2014-01-01

    Previous theories predict that human dorsal anterior cingulate (dACC) should respond to decision difficulty. An alternative theory has been recently advanced which proposes that dACC evolved to represent the value of “non-default,” foraging behavior, calling into question its role in choice difficulty. However, this new theory does not take into account that choosing whether or not to pursue foraging-like behavior can also be more difficult than simply resorting to a “default.” The results of two neuroimaging experiments show that dACC is only associated with foraging value when foraging value is confounded with choice difficulty; when the two are dissociated, dACC engagement is only explained by choice difficulty, and not the value of foraging. In addition to refuting this new theory, our studies help to formalize a fundamental connection between choice difficulty and foraging-like decisions, while also prescribing a solution for a common pitfall in studies of reward-based decision making. PMID:25064851

  6. Summertime blues: August foraging leaves honey bees empty-handed.

    PubMed

    Couvillon, Margaret J; Fensome, Katherine A; Quah, Shaun Kl; Schürch, Roger

    2014-01-01

    A successful honey bee forager tells her nestmates the location of good nectar and pollen with the waggle dance, a symbolic language that communicates a distance and direction. Because bees are adept at scouting out profitable forage and are very sensitive to energetic reward, we can use the distance that bees communicate via waggle dances as a proxy for forage availability, where the further the bees fly, the less forage can be found locally. Previously we demonstrated that bees fly furthest in the summer compared with spring or autumn to bring back forage that is not necessarily of better quality. Here we show that August is also the month when significantly more foragers return with empty crops (P = 7.63e-06). This provides additional support that summer may represent a seasonal foraging challenge for honey bees. PMID:25346794

  7. Foraging strategy and predator avoidance behaviour: an intraspecific approach

    NASA Astrophysics Data System (ADS)

    Barbosa, Andrés

    1997-11-01

    Relationships between predator avoidance behaviour (scanning and flocking) and foraging were studied in Calidris alpina, to test predictions regarding the effect of foraging techniques on such behaviours. The scanning hypothesis predicts that individuals with a tactile hunting technique and individuals with a visual hunting technique (both continuous searchers) do not differ in any variable related to scanning behaviour. The flocking hypothesis predicts that visually hunting individuals witl tend to form smaller flocks than tactile-foraging individuals. The two continuous feeding strategies did not differ among individuals in vigilance rate, nor in vigilance time or mean scan duration. However, with respect to flocking behaviour, visual foragers differed from tactile foragers in foraging flock size. The relationships between flocking behaviour and foraging strategy are discussed. The pattern found at the intraspecific level are the same as those found at interspecific level.

  8. [Cytochemical characteristics of the labrocyte-like cells in the capsule of the plerocercoids of Triaenophorus nodulosus (Pallas, 1781) and Diphyllobothrium dendriticum (Nitzsch, 1824) cestodes].

    PubMed

    Pronina, S V

    1977-07-01

    Out of six fish species examined (Esox lucius, Paracottus kessleri, Perca fluviatilis, Leuciscus leuciscus baicalensis, Coregonus autumnalis migratorius, Thymallus arcticus baicalensis) labrocyte-like cells were detected in Esox lucius, Leuciscus leuciscus baicalensis, Coregonus autumnalis migratotius. The cells contain large metachromatic granules. Histochemical methods revealed in them sulfated and carboxylic acid mucopolysacharides. The amount of labrocyte-like cells in the capsules around plerocercoids of Triaenophrus nodulosis from Esox lucits liver depends on the age of the capsule and that of the plerocercoid. It increases when the connective tissue papsule is forming and decreases again under aging and degeneration of the capsule containing plerocercoid. The amount of labrocyte-like cells in the cestodes capsules of Raillietina increases sharply when they locate in an accidental organ (liver). This demonstrates the acuteness of organ reactivity to a nonspecific helminth. PMID:143258

  9. Habitat-specific foraging of prothonotary warblers: Deducing habitat quality

    USGS Publications Warehouse

    Lyons, J.E.

    2005-01-01

    Foraging behavior often reflects food availability in predictable ways. For example, in habitats where food availability is high, predators should attack prey more often and move more slowly than in habitats where food availability is low. To assess relative food availability and habitat quality, I studied the foraging behavior of breeding Prothonotary Warblers (Protonotaria citrea) in two forest habitat types, cypress-gum swamp forest and coastal-plain levee forest. I quantified foraging behavior with focal animal sampling and continuous recording during foraging bouts. I measured two aspects of foraging behavior: 1) prey attack rate (attacks per minute), using four attack maneuvers (glean, sally, hover, strike), and 2) foraging speed (movements per minute), using three types of movement (hop, short flight [???1 m], long flight [>1 m]). Warblers attacked prey more often in cypress-gum swamp forest than in coastal-plain levee forest. Foraging speed, however, was not different between habitats. I also measured foraging effort (% time spent foraging) and relative frequency of attack maneuvers employed in each habitat; neither of these variables was influenced by forest type. I conclude that Prothonotary Warblers encounter more prey when foraging in cypress-gum swamps than in coastal-plain levee forest, and that greater food availability results in higher density and greater reproductive success for birds breeding in cypress-gum swamp.

  10. Foraging behaviour in Drosophila larvae: mushroom body ablation.

    PubMed

    Osborne, K A; de Belle, J S; Sokolowski, M B

    2001-02-01

    Drosophila larvae and adults exhibit a naturally occurring genetically based behavioural polymorphism in locomotor activity while foraging. Larvae of the rover morph exhibit longer foraging trails than sitters and forage between food patches, while sitters have shorter foraging trails and forage within patches. This behaviour is influenced by levels of cGMP-dependent protein kinase (PGK) encoded by the foraging (for) gene. Rover larvae have higher expression levels and higher PGK activities than do sitters. Here we discuss the importance of the for gene for studies of the mechanistic and evolutionary significance of individual differences in behaviour. We also show how structure-function analysis can be used to investigate a role for mushroom bodies in larval behaviour both in the presence and in the absence of food. Hydroxyurea fed to newly hatched larvae prevents the development of all post-embryonically derived mushroom body (MB) neuropil. This method was used to ablate MBs in rover and sitter genetic variants of foraging to test whether these structures mediate expression of the foraging behavioural polymorphism. We found that locomotor activity levels during foraging of both the rover and sitter larval morphs were not significantly influenced by MB ablation. Alternative hypotheses that may explain how variation in foraging behaviour is generated are discussed. PMID:11238255

  11. Utilisation of intensive foraging zones by female Australian fur seals.

    PubMed

    Hoskins, Andrew J; Costa, Daniel P; Arnould, John P Y

    2015-01-01

    Within a heterogeneous environment, animals must efficiently locate and utilise foraging patches. One way animals can achieve this is by increasing residency times in areas where foraging success is highest (area-restricted search). For air-breathing diving predators, increased patch residency times can be achieved by altering both surface movements and diving patterns. The current study aimed to spatially identify the areas where female Australian fur seals allocated the most foraging effort, while simultaneously determining the behavioural changes that occur when they increase their foraging intensity. To achieve this, foraging behaviour was successfully recorded with a FastLoc GPS logger and dive behaviour recorder from 29 individual females provisioning pups. Females travelled an average of 118 ± 50 km from their colony during foraging trips that lasted 7.3 ± 3.4 days. Comparison of two methods for calculating foraging intensity (first-passage time and first-passage time modified to include diving behaviour) determined that, due to extended surface intervals where individuals did not travel, inclusion of diving behaviour into foraging analyses was important for this species. Foraging intensity 'hot spots' were found to exist in a mosaic of patches within the Bass Basin, primarily to the south-west of the colony. However, the composition of benthic habitat being targeted remains unclear. When increasing their foraging intensity, individuals tended to perform dives around 148 s or greater, with descent/ascent rates of approximately 1.9 m•s-1 or greater and reduced postdive durations. This suggests individuals were maximising their time within the benthic foraging zone. Furthermore, individuals increased tortuosity and decreased travel speeds while at the surface to maximise their time within a foraging location. These results suggest Australian fur seals will modify both surface movements and diving behaviour to maximise their time within a foraging patch. PMID:25692978

  12. Evolution of larval foraging behaviour in Drosophila and its effects on growth and metabolic rates

    Microsoft Academic Search

    LAURENCE D. M UELLER; N G O C NGUYEN; P HUONG N GUYEN

    2005-01-01

    The evolution of foraging in Drosophila melanogaster (Meigen) is stud- ied using outbred populations that had been differentiated using laboratory selection. The foraging behaviour of Drosophila larvae is measured using the foraging path length of 72-h-old larvae. The foraging path length is the distance travelled by foraging larvae over 5 min. Populations of Drosophila selected for rapid development show significantly

  13. SEASONAL VARIATION IN THE FORAGING BEHAVIOR OF SOME MIGRATORY WESTERN WOOD WARBLERS

    Microsoft Academic Search

    RICHARD L. HUTTO

    I observed the foraging behavior of four warbler species (Dendroica petechia, Oporornis tolmiei, Geothlypis trichas, and Wilsonia pusilla) in the summer in Wyoming and in the winter in Nayarit, Mxico. Of six variables (absolute foraging height, relative foraging height, vegetation density, horizontal foraging position, feeding method, and foraging substrate) believed to be potentially important in distinguishing the warbler species ecologically,

  14. Pasture Production with Selected Forage Many species of grasses and legumes serve as forages. However, not all forage species are suited to New

    E-print Network

    New Hampshire, University of

    can be grouped into cool-season perennials, warm season grasses, and cool season annuals. None of three or four weeks between rotations. Forage #12;Perennial ryegrass and tall fescue are other grasses sometimes used in pastures. Perennial ryegrass offers better forage quality than any other grass species

  15. Forage-based feeding of hair sheep

    Microsoft Academic Search

    Stephan Wildeus

    Interest in hair sheep production in the U.S. has been increasing with a decline on return for wool, an increased acceptance of smaller carcasses in non-traditional markets, and a shift towards forage-based production (Notter, 2000). Hair sheep are generally smaller in size and have lower growth rates than more traditional wool sheep, but are reputed to be more tolerant to

  16. Forage Bermudagrass: Selection, Establishment and Management

    E-print Network

    Stichler, Charles; Bade, David H.

    2003-04-04

    hybrid between selec- tions from Georgia and South Africa), forage pro- duction with perennial grasses changed dramati- cally and permanently. Hybrid bermudagrass is sterile and will not produce viable seed, so it must be vegetatively propagated... and is usually planted by using ?sprigs.? Sprigs are made up of either root pieces or rooted stolons or runners. Immediately after its introduction, extensive research began in many states to evaluate the for- age potential of this hybrid grass under various...

  17. Foraging Swarms: From Biology to Engineering

    E-print Network

    ) Social foraging of honey bees: Optimal resource allocation model #12;16 OHIO STATE T . H . E UNIVERSITY food #12;12 OHIO STATE T . H . E UNIVERSITY Set of bacteria (positions): P(j, k, ) = i (j, k, )|i = 1 Optimization and Control" [5] #12;14 OHIO STATE T . H . E UNIVERSITY 0 10 20 30 0 5 10 15 20 25 30 Bacteria

  18. Decision ecology: foraging and the ecology of animal decision making.

    PubMed

    Stephens, David W

    2008-12-01

    In this article, I review the approach taken by behavioral ecologists to the study of animal foraging behavior and explore connections with general analyses of decision making. I use the example of patch exploitation decisions in this article in order to develop several key points about the properties of naturally occurring foraging decisions. First, I argue that experimental preparations based on binary, mutually exclusive choice are not good models of foraging decisions. Instead, foraging choices have a sequential foreground-background structure, in which one option is in the background of all other options. Second, behavioral ecologists view foraging as a hierarchy of decisions that range from habitat selection to food choice. Finally, data suggest that foraging animals are sensitive to several important trade-offs. These trade-offs include the effects of competitors and group mates, as well as the problem of predator avoidance. PMID:19033242

  19. Common attentional constraints in visual foraging.

    PubMed

    Kristjánsson, Árni; Jóhannesson, Ómar I; Thornton, Ian M

    2014-01-01

    Predators are known to select food of the same type in non-random sequences or "runs" that are longer than would be expected by chance. If prey are conspicuous, predators will switch between available sources, interleaving runs of different prey types. However, when prey are cryptic, predators tend to focus on one food type at a time, effectively ignoring equally available sources. This latter finding is regarded as a key indicator that animal foraging is strongly constrained by attention. It is unknown whether human foraging is equally constrained. Here, using a novel iPad task, we demonstrate for the first time that it is. Participants were required to locate and touch 40 targets from 2 different categories embedded within a dense field of distractors. When individual target items "popped-out" search was organized into multiple runs, with frequent switching between target categories. In contrast, as soon as focused attention was required to identify individual targets, participants typically exhausted one entire category before beginning to search for the other. This commonality in animal and human foraging is compelling given the additional cognitive tools available to humans, and suggests that attention constrains search behavior in a similar way across a broad range of species. PMID:24964082

  20. Common Attentional Constraints in Visual Foraging

    PubMed Central

    Kristjánsson, Árni; Jóhannesson, Ómar I.; Thornton, Ian M.

    2014-01-01

    Predators are known to select food of the same type in non-random sequences or “runs” that are longer than would be expected by chance. If prey are conspicuous, predators will switch between available sources, interleaving runs of different prey types. However, when prey are cryptic, predators tend to focus on one food type at a time, effectively ignoring equally available sources. This latter finding is regarded as a key indicator that animal foraging is strongly constrained by attention. It is unknown whether human foraging is equally constrained. Here, using a novel iPad task, we demonstrate for the first time that it is. Participants were required to locate and touch 40 targets from 2 different categories embedded within a dense field of distractors. When individual target items “popped-out” search was organized into multiple runs, with frequent switching between target categories. In contrast, as soon as focused attention was required to identify individual targets, participants typically exhausted one entire category before beginning to search for the other. This commonality in animal and human foraging is compelling given the additional cognitive tools available to humans, and suggests that attention constrains search behavior in a similar way across a broad range of species. PMID:24964082

  1. Visually Guided Decision Making in Foraging Honeybees

    PubMed Central

    Zhang, Shaowu; Si, Aung; Pahl, Mario

    2012-01-01

    Honeybees can easily be trained to perform different types of discrimination tasks under controlled laboratory conditions. This review describes a range of experiments carried out with free-flying forager honeybees under such conditions. The research done over the past 30 or so years suggests that cognitive abilities (learning and perception) in insects are more intricate and flexible than was originally imagined. It has become apparent that honeybees are capable of a variety of visually guided tasks, involving decision making under challenging situations: this includes simultaneously making use of different sensory modalities, such as vision and olfaction, and learning to use abstract concepts such as “sameness” and “difference.” Many studies have shown that decision making in foraging honeybees is highly flexible. The trained animals learn how to solve a task, and do so with a high accuracy, but when they are presented with a new variation of the task, they apply the learnt rules from the earlier setup to the new situation, and solve the new task as well. Honeybees therefore not only feature a rich behavioral repertoire to choose from, but also make decisions most apt to the current situation. The experiments in this review give an insight into the environmental cues and cognitive resources that are probably highly significant for a forager bee that must continually make decisions regarding patches of resources to be exploited. PMID:22719721

  2. Factors determining grazed forage intake of Coastal bermudagrass 

    E-print Network

    Davis, James Vollie

    1978-01-01

    'iember) August 1978 ABSTRACT Factors Determining Grazed Forage Intake of Coastal Bermudagrass. (A, q. st 1978) James Vollie Davis, B. S. , Texas ARM University Chairman of Advisory Committee; Dr. W. C. Ellis Esophageally fistulated Brahman X Jersey yearling... as adjustment to eliminate previous forage effects on the animal and the final three plots used for collection purposes. Esophageal samples, tillers of the available forage, and standing crop samples were collected. IVDOM was determined on leaf, stem...

  3. Assessing Habitat for Avian Species in Assessing Habitat for Avian Species in an Integrated Forage/Biofuels an Integrated Forage/Biofuels

    E-print Network

    Gray, Matthew

    in an Integrated Forage/Biofuels an Integrated Forage/Biofuels Management System Management System in the Midin NWSG mixes beneficial to forage, biofuels production, and wildlife habitatp , 3. identify wildlife habitat benefits associated with varying forage and biofuels management strategies 4. identify optimum

  4. Social foraging in honey bees: how nectar foragers assess their colony's nutritional status

    Microsoft Academic Search

    Thomas D. Seeley

    1989-01-01

    A honey bee colony operates as a tightly integrated unit of behavioral action. One manifestation of this in the context of foraging is a colony's ability to adjust its selectivity among nectar sources in relation to its nutritional status. When a colony's food situation is good, it exploits only highly profitable patches of flowers, but when its situation is poor,

  5. Downy woodpecker foraging behavior: foraging by expectation and energy intake rate

    Microsoft Academic Search

    Steven L. Lima

    1983-01-01

    I describe an artificial patch system that was used to study the foraging behavior of free-roaming downy woodpeckers (Picoides pubescens) in a woodlot in southeastern Michigan. The artificial “patches” used were thin logs into which were drilled small holes to hold food items (bits of sunflower seed kernels). Downy woodpeckers would systematically search the holes of a patch for food

  6. Eye size, foraging methods and the timing of foraging in shorebirds

    Microsoft Academic Search

    R. J. THOMAS; T. SZEKELY; R. F. POWELL; I. C. CUTHILL

    2006-01-01

    Summary 1. Birds with large eyes can achieve a greater pupil diameter and\\/or focal length, and hence, all other things being equal, greater visual sensitivity and resolution than birds with small eyes. Thus eye size is predicted to reflect adaptations to ecology. 2. We tested three predictions about the relationships between eye size, foraging method (from wholly visual to tactile

  7. Scale of heterogeneity of forage production and winter foraging by elk and bison

    Microsoft Academic Search

    L. L. Wallace; M. G. Turner; W. H. Romme; R. V. O'Neill; Yegang Wu

    1995-01-01

    The relationship between fine-scale spatial patterns of forage abundance and the feeding patterns of large ungulates is not well known. We compared these patterns for areas grazed in winter by elk and bison in a sagebrush-grassland landscape in northern Yellowstone National Park. At a fine scale, the spatial distribution of mapped feeding stations in 30 m × 30 m sites

  8. Elevation and forest clearing effects on foraging differ between surface--and subterranean--foraging army ants (Formicidae: Ecitoninae).

    PubMed

    Kumar, Anjali; O'Donnell, Sean

    2009-01-01

    1. Forest fragmentation often results in a matrix of open areas mixed with patches of forest. Both biotic and abiotic factors can affect consumer species' ability to utilize the altered habitat, especially for species that range over large areas searching for prey. 2. Army ants (Formicidae: Ecitoninae) are highly mobile top predators in terrestrial Neotropical ecosystems. Army ant foraging behaviour is influenced by forest clearing at lowland sites, and clearing can reduce army ant population persistence. 3. Because high temperatures are implicated in hindering above-ground army ant foraging, we predicted that forest clearing effects on army ant foraging would be reduced at higher (cooler) elevations in montane forest. We also predicted that subterranean foraging, employed by some army ant species, would buffer them from the negative effects of forest clearing. 4. We quantified the foraging rates of above-ground and underground foraging army ants at eight sites along an elevational gradient from 1090 to 1540 m a.s.l. We asked whether these two foraging strategies cause a difference in the ability of army ants to forage in open matrix areas relative to elevationally matched forested habitats, and whether elevation predicts open area vs. forest foraging rate differences. 5. As predicted, army ants that forage above-ground had lower foraging rates in open areas, but the open area vs. forest difference declined with elevation. In contrast, underground foragers were not affected by habitat type, and underground foraging rates increased with elevation. Ground surface temperatures were higher in open areas than forested areas. Temperatures declined with elevation, and temperature differences between open and forested areas decreased with elevation. 6. We conclude that army ants that forage above-ground may be restricted to forested areas due to a thermal tolerance threshold, but that they are released from this limitation at higher elevations. We further suggest that underground foraging permits some army ants to persist within modified landscapes. Our findings have implications for the effects of habitat modification and climate change on these top predators. PMID:19120597

  9. Complex scaling behavior in animal foraging patterns

    NASA Astrophysics Data System (ADS)

    Premachandra, Prabhavi Kaushalya

    This dissertation attempts to answer questions from two different areas of biology, ecology and neuroscience, using physics-based techniques. In Section 2, suitability of three competing random walk models is tested to describe the emergent movement patterns of two species of primates. The truncated power law (power law with exponential cut off) is the most suitable random walk model that characterizes the emergent movement patterns of these primates. In Section 3, an agent-based model is used to simulate search behavior in different environments (landscapes) to investigate the impact of the resource landscape on the optimal foraging movement patterns of deterministic foragers. It should be noted that this model goes beyond previous work in that it includes parameters such as spatial memory and satiation, which have received little consideration to date in the field of movement ecology. When the food availability is scarce in a tropical forest-like environment with feeding trees distributed in a clumped fashion and the size of those trees are distributed according to a lognormal distribution, the optimal foraging pattern of a generalist who can consume various and abundant food types indeed reaches the Levy range, and hence, show evidence for Levy-flight-like (power law distribution with exponent between 1 and 3) behavior. Section 4 of the dissertation presents an investigation of phase transition behavior in a network of locally coupled self-sustained oscillators as the system passes through various bursting states. The results suggest that a phase transition does not occur for this locally coupled neuronal network. The data analysis in the dissertation adopts a model selection approach and relies on methods based on information theory and maximum likelihood.

  10. Experience, corpulence and decision making in ant foraging.

    PubMed

    Robinson, Elva J H; Feinerman, Ofer; Franks, Nigel R

    2012-08-01

    Social groups are structured by the decisions of their members. Social insects typically divide labour: some decide to stay in the nest while others forage for the colony. Two sources of information individuals may use when deciding whether to forage are their own experience of recent task performance and their own physiology, e.g. fat reserves (corpulence). The former is primarily personal information; the latter may give an indication of the food reserves of the whole colony. These factors are hard to separate because typically leaner individuals are also more experienced foragers. We designed an experiment to determine whether foraging specialisation is physiological or experience based (or both). We invented a system of automatic doors controlled by radio-tag information to manipulate task access and decouple these two sources of information. Our results show that when information from corpulence and recent experience conflict, ants behave only in accordance with their corpulence. However, among ants physiologically inclined to forage (less corpulent ants), recent experience of success positively influenced their propensity to forage again. Hence, foraging is organised via long-term physiological differences among individuals resulting in a relatively stable response threshold distribution, with fine-tuning provided by short-term learning processes. Through these simple rules, colonies can organise their foraging effort both robustly and flexibly. PMID:22786642

  11. MACROMINERAL CONCENTRATIONS OF GRAZED FORAGE FERTILIZED WITH BROILER LITTER

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three farms in Northwest Arkansas and Northeast Oklahoma that utilized broiler litter for fertilizer were monitored for nutrient cycling from April 2000 to February 2001. Forage samples were taken monthly and analyzed for K, Ca, P, and Mg. Concentrations of these minerals in the forages were compa...

  12. ANIMAL RESPONSES TO CIRCADIAN RHYTHMS IN FORAGE QUALITY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Net photosynthesis and respiration in growing plants cause a circadian rhythm in forage quality. Soluble sugar concentrations increase in plants during the day causing a dilution in ADF and NDF. Herbivores show a strong preference for afternoon (PM) vs morning (AM) harvested forage. Cattle, sheep, g...

  13. Performance optimization for cyber foraging network via dynamic spectrum allocation

    Microsoft Academic Search

    Yang Cao; Shiyong Yang; Tao Jiang; Daiming Qu

    2011-01-01

    Recently, cyber foraging has been proposed to reduce the application response time and to save energy for the mobile hosts by offloading the resource-demanding tasks to the surrogates via wireless networks. However, communication overheads are further aggravated in the cyber foraging network (CFN), where multi-hosts share the same spectrum to offload tasks. Therefore, it is important for the CFN to

  14. FORAGING ECOLOGY OF NESTING BALD EAGLES IN ARIZONA

    Microsoft Academic Search

    W. GRAINGER HUNT; RONALD E. JACCV; DANIEL E. DRISCOLL; EDWARD W. BIANCHI

    2002-01-01

    We studied foraging ecology of nesting Bald Eagles (Haliaeetus leucocephalus) in Arizona during 1987-89, with emphasis on the influence of dams and river flow regulation. We examined diet, foraging modes, habitat selection, fish abundance, and factors associated with fish availability. Based on biomass, prey remains yielded 76% fish, 14% mammals, and 10% birds. On rivers, eagles primarily caught live fish

  15. Foraging decisions of American robins: somatic and reproductive tradeoffs

    Microsoft Academic Search

    Robert K. Swihart; Steven G. Johnson

    1986-01-01

    We examined the behavior of a central place forager, the American robin (Turdus migratorius), with emphasis on the self-feeding component of foraging bouts. Among individuals the mean percentage of all prey captured that was consumed by adults varied from 10% to 60% (x ; 31%). Size of prey appeared important in determing whether the prey was eaten; adults generally consumed

  16. Use of Active Acoustics to Study Fish and its Forage

    E-print Network

    Hawai'i at Manoa, University of

    Use of Active Acoustics to Study Fish and its Forage Pacific Islands Fisheries Science Center Acoustics · Fisheries Independent ­ Unbiased by fishing location gear type catchability · Predetermined · Schooling patterns and aggregative behavior · Simultaneous data on fish and its forage #12;Active Acoustics

  17. Sampling Hay Bales and Pastures for Forage Analysis

    E-print Network

    Provin, Tony; Pitt, John L.

    2002-05-03

    Forage analysis helps you know the nutritive value of forage and plan for any supplements that might be needed. To get an accurate analysis, hay and pastures must be sampled properly. In this publication you will learn how to sample both round...

  18. FLIGHT STRATEGIES OF MIGRATING OSPREY: FASTING VS. FORAGING

    Microsoft Academic Search

    GRADY L. CANDLERAND; PATRICIA L. KENNEDY

    We developed energetics models to predict migration times and fat consumption rates of osprey (Pandion haliaetus) migrating south from their breeding grounds in the Intermountain West of North America. In these models we simulated three migration strategies: fasting, foraging at several mid-migration stopovers (jump strategy) and frequent foraging at stopovers (hop strategy). Because these piscivores appear to migrate predominantly over

  19. Immigrant forage kochia: A closer look at this rangeland plant

    Technology Transfer Automated Retrieval System (TEKTRAN)

    ‘Immigrant’ forage kochia (Bassia prostrata, formerly Kochia prostrata) is a perennial semi-evergreen half shrub that averages 1 to 3 feet in height and has been widely used in revegetation efforts throughout the western United States. Forage kochia is native to the arid and semi-arid regions of Cen...

  20. Grazing management for fall-grown oat forages

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For the dairy (or beef) industry, the options for producing a late-summer emergency forage crop are limited, mostly because the growing season in Wisconsin is relatively short. Recent research has shown that oat, seeded in late-summer, can provide an excellent source of emergency forage before winte...

  1. Genetics of postweaning performance of beef cattle on forage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increases in the costs of feed grains have revived interest in increasing the use of forages and grazing in order to either market as forage-finished beef or to produce heavy calves that will finish on less grain. However, little is known about the interactions of animal genetics and grazing enviro...

  2. DIGESTIBILITY AND FIBER OF A FORAGE BERMUDAGRASS CORE COLLECTION

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bermudagrass is the most important warm-season grass forage for the South. Cultivars with good quality traits such as high dry matter digestibility have translated into higher daily gains for beef and improved milk production in dairy cattle. A forage bermudagrass core collection consisting of 168...

  3. Advances and Challenges in Breeding Forages with Improved Quality

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nearly 50 years have passed since the initial efforts to select and breed forage grasses with increased digestibility at the Welsh Plant Breeding Station, Aberystwyth, Wales and the USDA-ARS, Tifton, Georgia. Early efforts to improve forage quality were viewed with extreme skepticism by many breede...

  4. Livestock Responses to Complementary Forages in Shortgrass Steppe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage gaps for livestock producers exist in the spring and fall in shortgrass steppe because of dominance by the perennial warm-season grass blue grama (Bouteloua gracilis). Livestock gains of yearling Hereford heifers were evaluated during 1996-1999 on two complementary forage grasses [‘Bozoisky-S...

  5. Livestock responses to complementary forages in shortgrass steppe

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage gaps for livestock producers exist in the spring and fall in shortgrass steppe because of dominance by the perennial warm-season grass blue grama (Bouteloua gracilis). Livestock gains of yearling Hereford heifers were evaluated during 1996-1999 on two complementary forage grasses [‘Bozoisky-S...

  6. Comparative Sucrose Responsiveness in Apis mellifera and A. cerana Foragers

    PubMed Central

    Yang, Wenchao; Kuang, Haiou; Wang, Shanshan; Wang, Jie; Liu, Wei; Wu, Zhenhong; Tian, Yuanyuan; Huang, Zachary Y.; Miao, Xiaoqing

    2013-01-01

    In the European honey bee, Apis mellifera, pollen foragers have a higher sucrose responsiveness than nectar foragers when tested using a proboscis extension response (PER) assay. In addition, Africanized honey bees have a higher sucrose responsiveness than European honey bees. Based on the biology of the Eastern honey bee, A. cerana, we hypothesized that A. cerana should also have a higher responsiveness to sucrose than A. mellifera. To test this hypothesis, we compared the sucrose thresholds of pollen foragers and nectar foragers in both A. cerana and A. mellifera in Fujian Province, China. Pollen foragers were more responsive to sucrose than nectar foragers in both species, consistent with previous studies. However, contrary to our hypothesis, A. mellifera was more responsive than A. cerana. We also demonstrated that this higher sucrose responsiveness in A. mellifera was not due to differences in the colony environment by co-fostering two species of bees in the same mixed-species colonies. Because A. mellifera foragers were more responsive to sucrose, we predicted that their nectar foragers should bring in less concentrated nectar compared to that of A. cerana. However, we found no differences between the two species. We conclude that A. cerana shows a different pattern in sucrose responsiveness from that of Africanized bees. There may be other mechanisms that enable A. cerana to perform well in areas with sparse nectar resources. PMID:24194958

  7. FORAGING SUCCESS AND TREE SPECIES USE IN THE LEAST FLYCATCHER

    Microsoft Academic Search

    CHRISTOPHER M. ROGERS

    .,BSTRACT.--I examined the effect of tree species morphology on foraging behavior in a hover-gleaning bird species, the Least Flycatcher (Empidonax minimus). Birds in four breeding territories in northern Wisconsin displayed nonsignificant differences in an index of forag- ing success (S) among four tree species of divergent morphology. However, significant vari- ation in S occurred among the three tree species common

  8. Do bumblebees (Hymenoptera: Apidae) really forage close to their nests?

    Microsoft Academic Search

    W. E. Dramstad

    1996-01-01

    This paper questions whether bumblebees really forage as close to their nests as has commonly been assumed in the bumblebee literature. Three experiments are described that involved marking and reobservation bumblebees. None of these experiments showed any tendency for bumblebees to concentrate their foraging close to (e.g., within 50 m from) the nest. Rather, the results suggested that bumblebees may

  9. Positional Communication and Private Information in Honeybee Foraging Models

    E-print Network

    Napp, Nils

    Positional Communication and Private Information in Honeybee Foraging Models Peter Bailis1.werfel@wyss.harvard.edu Abstract. Honeybees coordinate foraging efforts across vast areas through a complex system of advertising-quality food sources and oversubscribing them. 1 Introduction Honeybee colonies are well

  10. Central place foraging in the Eastern chipmunk, Tamias striatus

    Microsoft Academic Search

    DONALD L. KRAMER; WILLIAM NOWELL

    1980-01-01

    Orians & Pearson (1979) considered the optimal foraging strategies of 'central place foragers', animals that repeatedly return with their food to a fixed location. We tested some of their predictions on eastern chipmunks, Tamias striatus. The rate of cheek pouch loading declines as the pouches fill; thus the optimal load size may vary, depending on the time required to travel

  11. Original article Lignin-carbohydrate complexes in forages

    E-print Network

    Boyer, Edmond

    Original article Lignin-carbohydrate complexes in forages: structure and consequences in the ruminal degradation of cell-wall carbohydrates A Cornu JM Besle P Mosoni, E Grenet INRA-Theix, Unité) Summary ― Lignin-carbohydrate complexes (LCCS) are recognised as key structures in forage

  12. Promoting Interactive Learning: A Classroom Exercise to Explore Foraging Strategies

    ERIC Educational Resources Information Center

    Beaumont, Ellen S.; Rowe, Graham; Mikhaylov, Natalie S.

    2012-01-01

    We describe a classroom exercise to allow students to explore foraging strategies in higher vertebrates. The exercise includes an initial interactive session in which students act as predators and are guided through foraging simulations, and a subsequent student-led session where classmates are employed as experimental subjects. Students rated the…

  13. Spatially explicit simulation of individual foraging behaviour across patchy resources

    Microsoft Academic Search

    James Barritt; Stephen Hartley; Marcus Frean; Marc Hasenbank

    2005-01-01

    This Masters project intends to explore by computer simulation the effects of individual foraging behaviour and resource aggregation on foraging patterns at multiple scales. An object-oriented approach will be taken to provide a flexible framework within which different simulation methods may be applied and compared. Examples of previously published methods include observational (Jones 1977) and correlated random walk (Cain 1985)

  14. ORIGINAL PAPER Time stress, predation risk and diurnalnocturnal foraging

    E-print Network

    Gotthard, Karl

    ORIGINAL PAPER Time stress, predation risk and diurnal­nocturnal foraging trade-offs in larval prey is likely to impose selection on larval anti-predator behaviour and since the risk of detection is likely time stress. Here we test if size-dependent risk and time constraints on feeding affect the foraging­predation

  15. Evapotranspiration of corn and forage sorghum for silage

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In the U.S. Southern High Plains, dairies have expanded and have increased the regional demand for forage and silage. The objectives were to measure water use and determine crop coefficients for corn (Zea mays L.) and forage sorghum (Sorghum bicolor (L.) Moench) produced for silage on the Southern ...

  16. Fall-grown oat forages: unique quality characteristics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    For the dairy industry, the options for producing a late-summer emergency forage crop are limited, mostly because the growing season is relatively short. Recent research has shown that oats, seeded in late-summer, can provide an excellent source of emergency forage before winter. Furthermore, fall-g...

  17. The Virginia Perennial Cool-Season Grass Forage Variety Report

    E-print Network

    Liskiewicz, Maciej

    The Virginia Perennial Cool-Season Grass Forage Variety Report: A 3-Year Summary (2002-2004) S performed with perennial cool-sea- son grasses at Virginia Tech Agricultural Research and Extension Centers, Virginia Tech D.R. Dixon, Senior Agriculture Manager, Northern Piedmont AREC Perennial cool-season forage

  18. SHORT COMMUNICATION White Storks, Ciconia ciconia, forage on rubbish dumps

    E-print Network

    Boyer, Edmond

    SHORT COMMUNICATION White Storks, Ciconia ciconia, forage on rubbish dumps in Poland--a novel on the foraging of White Storks on rubbish dumps, a novel behaviour in Central European populations, is presented one to 348 White Storks (median=2, N=116) were observed on rubbish dumps, and most of the records (86

  19. Negative impact of manganese on honeybee foraging.

    PubMed

    Søvik, Eirik; Perry, Clint J; LaMora, Angie; Barron, Andrew B; Ben-Shahar, Yehuda

    2015-03-01

    Anthropogenic accumulation of metals such as manganese is a well-established health risk factor for vertebrates. By contrast, the long-term impact of these contaminants on invertebrates is mostly unknown. Here, we demonstrate that manganese ingestion alters brain biogenic amine levels in honeybees and fruit flies. Furthermore, we show that manganese exposure negatively affects foraging behaviour in the honeybee, an economically important pollinator. Our findings indicate that in addition to its direct impact on human health, the common industrial contaminant manganese might also have indirect environmental and economical impacts via the modulation of neuronal and behavioural functions in economically important insects. PMID:25808001

  20. Forage polyphenol oxidase and ruminant livestock nutrition

    PubMed Central

    Lee, Michael R. F.

    2014-01-01

    Polyphenol oxidase (PPO) is predominately associated with the detrimental effect of browning fruit and vegetables, however, interest within PPO containing forage crops (crops to be fed to animals) has grown since the browning reaction was associated with reduced nitrogen (N) losses in silo and the rumen. The reduction in protein breakdown in silo of red clover (high PPO forage) increased the quality of protein, improving N-use efficiency [feed N into product N (e.g., Milk): NUE] when fed to ruminants. A further benefit of red clover silage feeding is a significant reduction in lipolysis (cleaving of glycerol-based lipid) in silo and an increase in the deposition of beneficial C18 polyunsaturated fatty acid (PUFA) in animal products, which has also been linked to PPO activity. PPOs protection of plant protein and glycerol based-PUFA in silo is related to the deactivation of plant proteases and lipases. This deactivation occurs through PPO catalyzing the conversion of diphenols to quinones which bind with cellular nucleophiles such as protein reforming a protein-bound phenol (PBP). If the protein is an enzyme (e.g., protease or lipase) the complexing denatures the enzyme. However, PPO is inactive in the anaerobic rumen and therefore any subsequent protection of plant protein and glycerol based-PUFA in the rumen must be as a result of events that occurred to the forage pre-ingestion. Reduced activity of plant proteases and lipases would have little effect on NUE and glycerol based-PUFA in the rumen due to the greater concentration of rumen microbial proteases and lipases. The mechanism for PPOs protection of plant protein in the rumen is a consequence of complexing plant protein, rather than protease deactivation per se. These complexed proteins reduce protein digestibility in the rumen and subsequently increase undegraded dietary protein flow to the small intestine. The mechanism for protecting glycerol-based PUFA has yet to be fully elucidated but may be associated with entrapment within PBP reducing access to microbial lipases or differences in rumen digestion kinetics of the forage and therefore not related to PPO activity. PMID:25538724

  1. Honeybees foraging response in genetically diversified opium poppy.

    PubMed

    Srivastava, H K; Singh, Dwijendra

    2006-09-01

    Studies were carried out on honeybees foraging on plant flowers. Results showed significantly higher foraging response of honeybees (Apis mellifera) in genetically divergent narcotic plant opium poppy (Papaver somniferum). Of the 18 mutants and two locally adapted cultivars of diverse genotypes screened, eight revealed significantly greater foraging response manifesting honeybee's preference towards specific plant morphotypes. The number of flower bloom did not correspond to number of foraging bees in both mutant and cultivar plant types of opium poppy. The genotype specific foraging response of honeybees could be attributed to physico-chemical properties of opium poppy flowers. This could have implications for the development of opium alkaloid fortified honeys for novel pharmaceuticals and isolation of natural spray compounds to attract honeybee pollinators for promoting crossing and sustainable hybridity in crops. PMID:16150594

  2. Mapping of wood stork foraging habitat with satellite data

    SciTech Connect

    Jensen, J.R.; Coulter, M.; Mackey, H.E. Jr.; Hodgson, M.E.

    1985-01-01

    Potential foraging sites for an endangered species, the wood stork, were identified using Landsat thematic mapper data for a section of north central Georgia and the Savannah River floodplain swamp in South Carolina. This was accomplished using innovative clustering techniques applied to known wood stork foraging sites around the Birdsville Colony in Georgia. The signatures for known sites were then geographically extended to a 1520-square-kilometer region surrounding the Birdsville Colony. Thematic maps were produced and foraging area acreages computed providing a regional assessment of existing and potential wood stork foraging sites. Approximately 1744 hectarea of potential shallow water and macrophyte foraging habitat were identified in the area surroundings the Birdsville Colony. 14 refs., 3 figs.

  3. Foraging swarms as Nash equilibria of dynamic games.

    PubMed

    Özgüler, Arif Bülent; Yildiz, Aykut

    2014-06-01

    The question of whether foraging swarms can form as a result of a noncooperative game played by individuals is shown here to have an affirmative answer. A dynamic game played by N agents in 1-D motion is introduced and models, for instance, a foraging ant colony. Each agent controls its velocity to minimize its total work done in a finite time interval. The game is shown to have a unique Nash equilibrium under two different foraging location specifications, and both equilibria display many features of a foraging swarm behavior observed in biological swarms. Explicit expressions are derived for pairwise distances between individuals of the swarm, swarm size, and swarm center location during foraging. PMID:24122615

  4. Wood bison population recovery and forage availability in northwestern Canada.

    PubMed

    Strong, Wayne L; Gates, C Cormack

    2009-01-01

    Forage availability was assessed to determine sustainable stocking rates for eight broadly defined vegetation types (Treed Uplands, Treed Lowlands, Mixed Tall Shrub/Sedge, Closed-canopied Willow, and Open-canopied Willow, Meadow, Wetland Grass, Wetland Sedge) for use by wood bison (Bison bison athabascae), a threatened subspecies, in the Canadian boreal forest of northern Alberta. Clip plots (n=108) were used to sample peak availability of herbs and current annual growth of Salix spp. in late summer. Graminoid wetlands dominated by Carex atherodes, Carex aquatilis, Carex utriculata, Scolochloa festucacea, or Calamagrostis stricta produced 1975-4575 kg ha(-1) of fair to good quality forage, whereas treed stands produced < 250 kg ha(-1) of forb-dominated forage (>85% content), which was below a published 25% foraging efficiency threshold of 263 kg ha(-1) for bison. Upland forests that dominate the region produced < or = 1 animal unit day (AUD) of forage per hectare in summer. Most forest understory plants were of poor forage value, suggesting the potential sustainable stocking rate of such areas was actually < or = 0.3 AUD ha(-1), with even lower rates during winter due to snow cover. Herbaceous wetlands contained approximately 78 AUD ha(-1) of forage, but were considered largely unavailable in summer because of flooding and soft organic soils that make access difficult. Conversion of prime foraging habitat to agricultural land, forest expansion due to fire control, and a warmer and wetter climatic regime after the mid-1900s likely contributed to a regional reduction in carrying capacity. It is hypothesized that substantial recovery of the wood bison population toward historical levels will be constrained in northern Alberta by the availability of summer forage, and the limited extent of graminoid wetlands that provide winter foraging habitat. PMID:18191321

  5. Foraging in the giant forest ant, Camponotus gigas (Smith) (Hymenoptera: Formicidae): evidence for temporal and spatial specialization in foraging activity

    Microsoft Academic Search

    A. G. Orr; J. K. Charles

    1994-01-01

    The foraging behaviour of the giant ant Camponotus gigas, was studied in primary lowland rainforest in Brunei. Nests, found mainly in soil at the base of trees or in fallen timber, were present at a density of 14 per hectare. Foragers were active nearly 24 h per day but much higher levels of activity were recorded at night. By day

  6. EFFECTS OF FORAGE SPECIES ON FATTY ACID COMPOSITION OF BEEF LONGISSIMUS MUSCLE FROM FORAGE-FINISHED BEEF

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forty-seven Angus-crossbred steers were used to evaluate the effects of forage species grazed in the last 41 d of the finishing period on rib composition, color, and palatability in forage-finished beef and compared to traditional high concentrate finished. Steers grazed naturalized pastures (bluegr...

  7. Diet Composition, Forage Selection, and Potential for Forage Competition Among Elk, Deer, and Livestock on Aspen–Sagebrush Summer Range

    Microsoft Academic Search

    Jeffrey L. Beck; James M. Peek

    2005-01-01

    We evaluated elk (Cervus elaphus), mule deer (Odocoileus hemionus), cattle (Bos taurus), and domestic sheep (Ovis aries) diet composition, diet overlap, and forage selection on aspen (Populus tremuloides Michaux)-sagebrush (Artemisia spp. L.) summer range in northeastern Nevada to understand potential for forage competition to provide better information for managing these communities. Diets were determined through microhistological fecal analysis from 1998

  8. Tillage and Forage System Effects on Forage Yields and Nutrient Uptake under Broiler Litter–Amended Soils

    Microsoft Academic Search

    S. F. Whittington; C. W. Wood; B. H. Wood; R. L. Raper; D. W. Reeves; G. E. Brink

    2007-01-01

    Planting and harvesting high?yielding forage grasses may remove phosphorus (P), copper (Cu), and zinc (Zn) from surface soils with a long history of broiler litter application. A study was conducted in Alabama's Sand Mountain region from 1998 to 2000 to determine tillage and forage systems best suited for removing nutrients from such overloaded soils. Tillage treatments included no?till, moldboard plowing,

  9. Foraging behaviour of Nuthatches (Sitta europaea) in relation to the presence of mates and mixed flocks

    Microsoft Academic Search

    Erik Matthysen

    1999-01-01

    Summary Nuthatches (Sitta europaea) usually forage in pairs outside the breeding season. I investigated whether foraging site selection in winter (tree species, height, substrate size) differed between sexes and whether this difference was related to the presence of mixed-species flocks. Foraging sites of pair members foraging together were highly correlated. In the rare cases when each used different tree species,

  10. Foraging methods can affect patch choice: an experimental study in Mallard ( Anas platyrhynchos)

    Microsoft Academic Search

    Matthieu Guillemain; Hervé Fritz; Sandra Blais

    2000-01-01

    Animals can adapt to changes in feeding conditions by switching between foraging methods. Dabbling ducks use different foraging methods, including dabbling in deep water with the head and neck submerged, and grubbing in the mud (or shallow water) where the eyes are above the surface, so the bird can visually monitor its environment while foraging. Deep foraging is considered to

  11. The Effect of Conversion of Cropland to Forage Legumes on Soil Quality in a Semiarid Agroecosystem

    Microsoft Academic Search

    Zhao-Xia Zeng; Xiao-Li Liu; Yu Jia; Feng-Min Li

    2008-01-01

    This study explores the ecological restoration effects of the conversion of cropland to forage legumes on soil characteristics in the semi-arid Loess Plateau of China. Four types of treatments: fallow (F); alfalfa (Medicago sativa) forage legume (A); sweetclover (Melilotus officinalis) forage legume followed by fallow (SF) and erect milkvetch (Astragalus adsurgens) forage legume (E) were used to substitute for spring

  12. Exploring behavior of an unusual megaherbivore: a spatially explicit foraging model of the hippopotamus

    Microsoft Academic Search

    Rebecca L. Lewison; Jacoby Carter

    2004-01-01

    Herbivore foraging theories have been developed for and tested on herbivores across a range of sizes. Due to logistical constraints, however, little research has focused on foraging behavior of megaherbivores. Here we present a research approach that explores megaherbivore foraging behavior, and assesses the applicability of foraging theories developed on smaller herbivores to megafauna. With simulation models as reference points

  13. Both learning and heritability affect foraging behaviour of red-backed salamanders, Plethodon cinereus

    E-print Network

    Gibbons, Megan

    Both learning and heritability affect foraging behaviour of red-backed salamanders, Plethodon, and that at least some components of foraging behaviour must be heritable. Successful foraging behaviour, therefore and heritability estimates suggest that some aspects of foraging (e.g. prey recognition and latency to prey capture

  14. Can bees simultaneously engage in adaptive foraging behaviour and attend to cryptic predators?

    E-print Network

    Chittka, Lars

    Can bees simultaneously engage in adaptive foraging behaviour and attend to cryptic predators? Mu terrestris foraging predator avoidance predator crypsis visual search Bees foraging for nectar often have to difficult foraging tasks while simultaneously avoiding cryptic predators, but only do so when avoidance

  15. Both learning and heritability affect foraging behaviour of red-backed salamanders, Plethodon cinereus

    Microsoft Academic Search

    MEGAN E. GIBBONS; ARIANNE M. F ERGUSON; DANIELLE R. L EE

    2005-01-01

    Current theory suggests that most animal behaviours are the product of complex interactions between learning and inheritance. Optimal foraging theory predicts that animals should alter their foraging tactics depending on abundance and quality of available prey, and that at least some components of foraging behaviour must be heritable. Successful foraging behaviour, therefore, may require an individual to become an efficient

  16. Measurements of foraging success in a highly pelagic marine predator, the northern elephant seal

    E-print Network

    Costa, Daniel P.

    Measurements of foraging success in a highly pelagic marine predator, the northern elephant seal. Identification of foraging behaviour and the ability to assess foraging success is critical to understanding individual and between-species variation in habitat use and foraging ecology. For pelagic predators

  17. FOOD AND PREDATION RISK AS FACTORS RELATED TO FORAGING LOCATIONS OF NORTHERN FLICKERS

    Microsoft Academic Search

    CANDACE L. ELCHUK; KAREN L. WIEBE

    2002-01-01

    Foraging site selection by birds may be related to foraging efficiency, food availability and abundance, and predation risk. We identified selectively used foraging habitat within home ranges of 29 adult radio-tagged Northern Flickers (Colaptes auratus) in British Columbia during the nestling period. We compared habitat characteristics of flicker foraging locations to randomly selected locations in their home range using discriminant

  18. Differential root morphology response to no versus high phosphorus, in three hydroponically grown forage chicory cultivars

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage chicory is a productive forage resource for eastern North America; however, many soils in the region are acidic and deficient in P and might restrict the widespread use of forage chicory. There is no published information on response of forage chicory to P, or P acquisition strategies for mo...

  19. Personality, Foraging and Fitness Consequences in a Long Lived Seabird

    PubMed Central

    Patrick, Samantha C.; Weimerskirch, Henri

    2014-01-01

    While personality differences in animals are defined as consistent behavioural variation between individuals, the widely studied field of foraging specialisation in marine vertebrates has rarely been addressed within this framework. However there is much overlap between the two fields, both aiming to measure the causes and consequences of consistent individual behaviour. Here for the first time we use both a classic measure of personality, the response to a novel object, and an estimate of foraging strategy, derived from GPS data, to examine individual personality differences in black browed albatross and their consequences for fitness. First, we examine the repeatability of personality scores and link these to variation in foraging habitat. Bolder individuals forage nearer the colony, in shallower regions, whereas shyer birds travel further from the colony, and fed in deeper oceanic waters. Interestingly, neither personality score predicted a bird’s overlap with fisheries. Second, we show that both personality scores are correlated with fitness consequences, dependent on sex and year quality. Our data suggest that shyer males and bolder females have higher fitness, but the strength of this relationship depends on year quality. Females who forage further from the colony have higher breeding success in poor quality years, whereas males foraging close to the colony always have higher fitness. Together these results highlight the potential importance of personality variation in seabirds and that the fitness consequences of boldness and foraging strategy may be highly sex dependent. PMID:24504180

  20. Floral odor learning within the hive affects honeybees' foraging decisions

    NASA Astrophysics Data System (ADS)

    Arenas, Andrés; Fernández, Vanesa M.; Farina, Walter M.

    2007-03-01

    Honeybees learn odor cues quickly and efficiently when visiting rewarding flowers. Memorization of these cues facilitates the localization and recognition of food sources during foraging flights. Bees can also use information gained inside the hive during social interactions with successful foragers. An important information cue that can be learned during these interactions is food odor. However, little is known about how floral odors learned in the hive affect later decisions of foragers in the field. We studied the effect of food scent on foraging preferences when this learning is acquired directly inside the hive. By using in-hive feeders that were removed 24 h before the test, we showed that foragers use the odor information acquired during a 3-day stimulation period with a scented solution during a food-choice situation outside the nest. This bias in food preference is maintained even 24 h after the replacement of all the hive combs. Thus, without being previously collected outside by foragers, food odors learned within the hive can be used during short-range foraging flights. Moreover, correct landings at a dual-choice device after replacing the storing combs suggests that long-term memories formed within the colony can be retrieved while bees search for food in the field.

  1. Intake and performance of lactating cows grazing diverse forage mixtures.

    PubMed

    Soder, K J; Sanderson, M A; Stack, J L; Muller, L D

    2006-06-01

    Twenty multiparous Holstein cows in midlactation grazed pastures of 4 forage mixtures in a 12-wk study repeated during 2 grazing seasons to determine if forage mixture complexity affected intake and productivity of lactating dairy cows. The forage mixtures were 1) orchardgrass plus white clover [2 species (SP)]; 2) orchardgrass, white clover, and chicory (3SP); 3) orchardgrass, tall fescue, perennial ryegrass, red clover, birdsfoot trefoil, and chicory (6SP); and 4) 6SP mixture plus white clover, alfalfa, and Kentucky bluegrass (9SP). Total herbage intake was similar among forage mixtures, averaging 12.0 kg/d across all forage mixtures and years. Milk production and composition were not affected by forage mixture or year, and averaged 34.6 kg/d, 3.4%, and 2.8% for milk production, milk fat percentage, and milk protein percentage, respectively. The conjugated linoleic acid content of milk fat was higher for cows that grazed the 3SP, 6SP, and 9SP mixtures than from cows that grazed the 2SP mixture (1.02 vs. 0.87 g of conjugated linoleic acid/100 g of fatty acids, respectively). Blood glucose, blood urea nitrogen, and nonesterified fatty acids were not affected by forage mixture and averaged 69.2 mg/dL, 13.4 mg/dL, and 277.5 muEq/L, respectively. The results of this study indicate that altering the forage mixture in pastures did not affect dry matter intake, milk production, or blood metabolite profiles of lactating cows. The use of complex mixtures of forages in grazing systems should not affect dairy cow performance. PMID:16702282

  2. Increasing the costs of conspecific scanning in socially foraging starlings affects vigilance and foraging behaviour

    Microsoft Academic Search

    Esteban Fernández-Juricic; Rebecca Smith; Alex Kacelnik

    2005-01-01

    Social foragers receive and use information both about companions (social information) and about events external to the group, such as presence of potential predators. Scanning behaviour is often incorporated in theoretical models using simplifying assumptions in relation to the trade-off in information gathering between body postures (head-up versus head-down); however, some avian visual systems may allow individuals to scan in

  3. The Organization of Foraging in the Fire Ant, Solenopsis invicta

    PubMed Central

    Tschinkel, Walter R.

    2011-01-01

    Although natural selection in ants acts most strongly at the colony, or superorganismal level, foraging patterns have rarely been studied at that level, focusing instead on the behavior of individual foragers or groups of foragers. The experiments and observations in this paper reveal in broad strokes how colonies of the fire ant, Solenopsis invicta Buren (Hymenoptera: Formicidae), allocate their available labor to foraging, how they disperse that force within their territory, and how this force changes with colony size, season and worker age. Territory area is positively related to colony size and the number of foragers, more so during the spring than fall. Changes of colony size and territory area are driven by seasonal variation of sexual and worker production, which in turn drive seasonal variation of worker age-distribution. During spring sexual production, colonies shrink because worker production falls below replacement. This loss is proportional to colony size, causing forager density in the spring to be negatively related to colony and territory size. In the fall, colonies emphasize worker production, bringing colony size back up. However, because smaller colonies curtailed spring worker production less than larger ones, their fall forager populations are proportionally greater, causing them to gain territory at the expense of large colonies. Much variation of territory area remains unexplained and can probably be attributed to pressure from neighboring colonies. Boundaries between territories are characterized by “no ants' zones” mostly devoid of fire ants. The forager population can be divided into a younger group of recruitable workers that wait for scouts to activate them to help retrieve large food finds. About one-third of the recruits wait near openings in the foraging tunnels that underlie the entire territory, while two-thirds wait in the nest. Recruitment to food is initially very rapid and local from the foraging tunnels, while sustained recruitment gradually involves the recruits waiting in the nest. As recruits age, they become scouts searching for food on the surface, and die about two weeks later. Foraging tunnels decrease in cross-sectional area with distance from the nest, in keeping with the gradual bleeding off of workers to the surface with distance. Foragers lack route-faithfulness, and having been marked and released at one point within the territory, they can be recaptured at any other point a day later. The size of the territory actually occupied may be limited during dry weather, resulting in very large no-ants' zones. PMID:21529150

  4. Transformation of forage legumes using Agrobacterium tumefaciens.

    PubMed

    Webb, K J

    1986-04-01

    Galls were induced in six species of forage legumes following inoculation with wild-type strains of A. tumefaciens. The plant species was more influential than the bacterial strain in determining the type of tumour produced. Inoculation of Medicago sativa resulted in small, disorganised tumours. The three Trifolium species, T. repens, T. hybridum and T. pratense, formed galls which tended to produce roots and both Onobrychis viciifolia and Lotus corniculatus produced teratomatous galls. The shoots elongated in the latter species only. In L. corniculatus, tissues that were infected by five bacterial strains were capable of shoot regeneration when cultured on a hormone-free medium. The transformed nature of these shoots was confirmed by their failure to root, the production of callus from leaves cultured on hormone-free medium and the presence of opines. PMID:24247771

  5. Adélie penguin foraging location predicted by tidal regime switching.

    PubMed

    Oliver, Matthew J; Irwin, Andrew; Moline, Mark A; Fraser, William; Patterson, Donna; Schofield, Oscar; Kohut, Josh

    2013-01-01

    Penguin foraging and breeding success depend on broad-scale environmental and local-scale hydrographic features of their habitat. We investigated the effect of local tidal currents on a population of Adélie penguins on Humble Is., Antarctica. We used satellite-tagged penguins, an autonomous underwater vehicle, and historical tidal records to model of penguin foraging locations over ten seasons. The bearing of tidal currents did not oscillate daily, but rather between diurnal and semidiurnal tidal regimes. Adélie penguins foraging locations changed in response to tidal regime switching, and not to daily tidal patterns. The hydrography and foraging patterns of Adélie penguins during these switching tidal regimes suggest that they are responding to changing prey availability, as they are concentrated and dispersed in nearby Palmer Deep by variable tidal forcing on weekly timescales, providing a link between local currents and the ecology of this predator. PMID:23383091

  6. DYNAPHORE, INC., FORAGER SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    The Forager Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. he technology treats contaminated groundwater, surface voters and porous waters by absorbing d...

  7. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Even generalist pollinators are typically taxonomic specialists during individual foraging bouts. Such floral constancy restricts pollen flow, and thereby gene flow, between otherwise inter-fertile flowering species, thus serving as an ethological mating barrier. Among incipient species, however, ...

  8. Specialist Osmia Bees Forage Indiscriminately Among Hybridizing Balsamorhiza Floral Hosts

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Even generalist pollinators are typically taxonomic specialists during individual foraging bouts. Such floral constancy restricts pollen flow, and thereby gene flow, between otherwise inter-fertile flowering species, thus serving as an ethological mating barrier. Among incipient species, however, ...

  9. Pasture, Rangeland and Forage Risk Management Insurance Pilot Program Continues

    E-print Network

    Pena, Jose G.; Bevers, Stan; Thompson, Bill

    2007-10-29

    A new insurance program is available from USDA to protect producers from the loss of forage produced for grazing or harvested for hay. Insurance polices may be purchased through local crop insurance agents until November 30, 2007. This publication...

  10. Managing Insect and Mite Pests of Texas Forage Crops

    E-print Network

    Muegge, Mark A.; Robinson, James V.

    2002-10-09

    This publication describes and illustrates common pests of forage crops in Texas. It discusses treatment options and pesticide application techniques as well as specific insecticides labeled to treat specific pests....

  11. Foraging Behavior of Coptotermes formosanus and Reticulitermes flavipes (Isoptera: Rhinotermitidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The foraging behavior of two serious structural pests, the Formosan subterranean termite, Coptotermes formosanus Shiraki and the eastern subterranean termite, Reticulitermes flavipes (Kollar) was examined. Comparative laboratory studies of the trail following, feeding, tunneling behavior, and intera...

  12. ORIGINAL PAPER Polymodal foraging in adult female loggerheads (Caretta caretta)

    E-print Network

    Florida, University of

    exhibit polymorphic foraging strategies, we evaluated skin sam- ples for stable isotopes of carbon (d13 C- grate our results with results from other stable isotope studies, satellite telemetry, and flipper tags

  13. SITE TECHNOLOGY CAPSULE: DYNAPHORE, INC., FORAGER¿ SPONGE TECHNOLOGY

    EPA Science Inventory

    The Forager¿ Sponge is a volume reduction technology in which heavy metal contaminants from an aqueous medium are selectively concentrated into a smaller volume for facilitated disposal. The technology treats contaminated groundwater, surface waters, and process waters by absorbi...

  14. Pasture, Rangeland and Forage Risk Management Insurance Pilot Program Continues 

    E-print Network

    Pena, Jose G.; Bevers, Stan; Thompson, Bill

    2007-10-29

    A new insurance program is available from USDA to protect producers from the loss of forage produced for grazing or harvested for hay. Insurance polices may be purchased through local crop insurance agents until November 30, 2007. This publication...

  15. Red Knots Forage for Horseshoe Crab Eggs at Delaware Bay

    USGS Multimedia Gallery

    Red knots forage for horseshoe crab eggs and other invertebrates on the beaches of Delaware Bay. The bird in the center has an orange leg flag indicating it was captured and flagged in the past in Argentina....

  16. FINISHING BEEF CATTLE FOR SLAUGHTER ON ALL-FORAGE DIETS

    Microsoft Academic Search

    P. R. Utley; R. E. Hellwig

    Summary Thirty-two crossbred calves (223 kg)and 36 crossbred yearlings (306 kg) were finished for slaughter with either a conventional high-energy diet or an all-forage diet to study the feedlot performance, carcass characteristics and eco- nomic feasibility of each system. Steers fed the high-energy diet gained 2.97 lb (1.35 kg) daily (P< .05) and steers fed the all-forage diet gained 2.33

  17. Bacterial Foraging Optimization Algorithm: Theoretical Foundations, Analysis, and Applications

    Microsoft Academic Search

    Swagatam Das; Arijit Biswas; Sambarta Dasgupta; Ajith Abraham

    2009-01-01

    Bacterial foraging optimization algorithm (BFOA) has been widely accepted as a global optimization algorithm of current interest\\u000a for distributed optimization and control. BFOA is inspired by the social foraging behavior of Escherichia coli. BFOA has already drawn the attention of researchers because of its efficiency in solving real-world optimization problems\\u000a arising in several application domains. The underlying biology behind the

  18. Foragers of the harvester ant, Pogonomyrmex owyheei : a disposable caste?

    Microsoft Academic Search

    Sanford D. Porter; Clive D. Jorgensen

    1981-01-01

    1.Exterior workers of the harvester ant, Pogonomyrmex owyheei, were subdivided into forager, defender and refuse worker behavior roles (Fig. 2). Exterior workers comprised approximately 16% of the total colony population with interior workers comprising the remainder.2.An average of less than 10% of the total worker population foraged (Table 1). Studies of role changes comfirmed a general one-way progression from interior

  19. Potential digestibilities and digestion kinetics of forage cell wall components

    E-print Network

    Tauskey, William Henry

    1973-01-01

    , 12, 18, 24, 48 and 72 hrs. with common source innocula. Forage and in sitz'o residue composition was analyzed for neutral detergent fiber (NDF); easily hydrolyzable hemicellulose (EHH); difficultly hydrolyzable hemicellulose (DHH); cellulose (C...); and lignin (L) . Between species comparison of forage composition indicated a higher percent neutral detergent extract (cell solubles) and cellulose for Sorghums. The coefficients of digestibility for all fractions were higher for the Sorghums...

  20. Nutritional factors limiting forage yields in Houston black clay 

    E-print Network

    Gentzsch, Enrique Pedro

    1968-01-01

    NUTRITIONAL FACTORS LIMITING FORAGE YIELDS IN HOUSTON BLACK CLAY A Thesis By ENRIQUE PEDRO GENTZSCH Submitted to the Graduate College of the TEXAS AQ4 UNIVERSITY in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE... May 1968 Major Subject: Soil Fertility NUTRITIONAL FACTORS LIMITING FORAGE YIELDS IN HOUSTON BLACK CLAY A Thesis By ENRIQUE PEDRO GENTZSCH Approved as to style and content by; (C axrman of Committee) (Head o Department (Memb r May 1968...

  1. The Forager Oral Tradition and the Evolution of Prolonged Juvenility

    PubMed Central

    Scalise Sugiyama, Michelle

    2011-01-01

    The foraging niche is characterized by the exploitation of nutrient-rich resources using complex extraction techniques that take a long time to acquire. This costly period of development is supported by intensive parental investment. Although human life history theory tends to characterize this investment in terms of food and care, ethnographic research on foraging skill transmission suggests that the flow of resources from old-to-young also includes knowledge. Given the adaptive value of information, parents may have been under selection pressure to invest knowledge – e.g., warnings, advice – in children: proactive provisioning of reliable information would have increased offspring survival rates and, hence, parental fitness. One way that foragers acquire subsistence knowledge is through symbolic communication, including narrative. Tellingly, oral traditions are characterized by an old-to-young transmission pattern, which suggests that, in forager groups, storytelling might be an important means by which adults transfer knowledge to juveniles. In particular, by providing juveniles with vicarious experience, storytelling may expand episodic memory, which is believed to be integral to the generation of possible future scenarios (i.e., planning). In support of this hypothesis, this essay reviews evidence that: mastery of foraging knowledge and skill sets takes a long time to acquire; foraging knowledge is transmitted from parent to child; the human mind contains adaptations specific to social learning; full assembly of learning mechanisms is not complete in early childhood; and forager oral traditions contain a wide range of information integral to occupation of the foraging niche. It concludes with suggestions for tests of the proposed hypothesis. PMID:21897825

  2. Associative influence on the foraging behavior of pigeons (Columba livia).

    PubMed

    Rashotte, M E; O'Connell, J M; Beidler, D L

    1982-04-01

    In a laboratory simulation of foraging conditions, pigeons maintained ad lib weight by treadle pressing for lengthy periods of access to grain in a 24-hr live-in environment. Localized visual signals produced by treadle pressing evoked approach and pecking behavior if they signaled impending food presentation (Pavlovian first-order conditioning) or the presentation of an established signal for food (Pavlovian second-order conditioning). These findings imply a role for associative mechanisms in the control of foraging. PMID:7069376

  3. Auto-Clustering Using Particle Swarm Optimization and Bacterial Foraging

    Microsoft Academic Search

    Jakob R. Olesen; Jorge Cordero Hernandez; Yifeng Zeng

    2009-01-01

    This paper presents a hybrid approach for clustering based on particle swarm optimization (PSO) and bacteria foraging algorithms\\u000a (BFA). The new method AutoCPB (Auto-Clustering based on particle bacterial foraging) makes use of autonomous agents whose primary objective is to cluster\\u000a chunks of data by using simplistic collaboration. Inspired by the advances in clustering using particle swarm optimization,\\u000a we suggest further

  4. Waggle Dance Distances as Integrative Indicators of Seasonal Foraging Challenges

    PubMed Central

    Couvillon, Margaret J.; Schürch, Roger; Ratnieks, Francis L. W.

    2014-01-01

    Even as demand for their services increases, honey bees (Apis mellifera) and other pollinating insects continue to decline in Europe and North America. Honey bees face many challenges, including an issue generally affecting wildlife: landscape changes have reduced flower-rich areas. One way to help is therefore to supplement with flowers, but when would this be most beneficial? We use the waggle dance, a unique behaviour in which a successful forager communicates to nestmates the location of visited flowers, to make a 2-year survey of food availability. We “eavesdropped” on 5097 dances to track seasonal changes in foraging, as indicated by the distance to which the bees as economic foragers will recruit, over a representative rural-urban landscape. In year 3, we determined nectar sugar concentration. We found that mean foraging distance/area significantly increase from springs (493 m, 0.8 km2) to summers (2156 m, 15.2 km2), even though nectar is not better quality, before decreasing in autumns (1275 m, 5.1 km2). As bees will not forage at long distances unnecessarily, this suggests summer is the most challenging season, with bees utilizing an area 22 and 6 times greater than spring or autumn. Our study demonstrates that dancing bees as indicators can provide information relevant to helping them, and, in particular, can show the months when additional forage would be most valuable. PMID:24695678

  5. Waggle dance distances as integrative indicators of seasonal foraging challenges.

    PubMed

    Couvillon, Margaret J; Schürch, Roger; Ratnieks, Francis L W

    2014-01-01

    Even as demand for their services increases, honey bees (Apis mellifera) and other pollinating insects continue to decline in Europe and North America. Honey bees face many challenges, including an issue generally affecting wildlife: landscape changes have reduced flower-rich areas. One way to help is therefore to supplement with flowers, but when would this be most beneficial? We use the waggle dance, a unique behaviour in which a successful forager communicates to nestmates the location of visited flowers, to make a 2-year survey of food availability. We "eavesdropped" on 5097 dances to track seasonal changes in foraging, as indicated by the distance to which the bees as economic foragers will recruit, over a representative rural-urban landscape. In year 3, we determined nectar sugar concentration. We found that mean foraging distance/area significantly increase from springs (493 m, 0.8 km2) to summers (2156 m, 15.2 km2), even though nectar is not better quality, before decreasing in autumns (1275 m, 5.1 km2). As bees will not forage at long distances unnecessarily, this suggests summer is the most challenging season, with bees utilizing an area 22 and 6 times greater than spring or autumn. Our study demonstrates that dancing bees as indicators can provide information relevant to helping them, and, in particular, can show the months when additional forage would be most valuable. PMID:24695678

  6. Social calls predict foraging success in big brown bats.

    PubMed

    Wright, Genevieve Spanjer; Chiu, Chen; Xian, Wei; Wilkinson, Gerald S; Moss, Cynthia F

    2014-04-14

    Animals foraging in the dark are engaged simultaneously in prey pursuit, collision avoidance, and interactions with conspecifics, making efficient nonvisual communication essential. A variety of birds and mammals emit food-associated calls that inform, attract, or repel conspecifics (e.g.,). Big brown bats (Eptesicus fuscus) are insectivorous aerial hawkers that may forage near conspecifics and are known to emit social calls (e.g.,). Calls recorded in a foraging setting might attract (e.g.,) or repel conspecifics and could denote territoriality or food claiming. Here, we provide evidence that the "frequency-modulated bout" (FMB), a social call emitted only by male bats (exclusively in a foraging context), is used to claim food and is individually distinct. Bats were studied individually and in pairs in a flight room equipped with synchronized high-speed stereo video and audio recording equipment while sex and experience with a foraging task were experimentally manipulated. Male bats emitting the FMB showed greater success in capturing prey. Following FMB emission, interbat distance, diverging flight, and the other bat's distance to the prey each increased. These findings highlight the importance and utility of vocal communication for a nocturnal animal mediating interactions with conspecifics in a fast-paced foraging setting. PMID:24684936

  7. Social Calls Predict Foraging Success in Big Brown Bats

    PubMed Central

    Wright, Genevieve Spanjer; Chiu, Chen; Xian, Wei; Wilkinson, Gerald S.; Moss, Cynthia F.

    2014-01-01

    Animals foraging in the dark are simultaneously engaged in prey pursuit, collision avoidance and interactions with conspecifics, making efficient, non-visual communication essential. A variety of birds and mammals emit food-associated calls that inform, attract, or repel conspecifics [e.g., 1]. Big brown bats (Eptesicus fuscus) are insectivorous aerial hawkers that may forage near conspecifics and are known to emit social calls [e.g., 2, 3, 4, 5]. Calls recorded in a foraging setting might attract [e.g., 6] or repel conspecifics [7] and could denote territoriality or food-claiming. Here, we provide evidence that a social call emitted only by male bats, exclusively in a foraging context [5], the “frequency-modulated bout” (FMB), is used to claim food and is individually distinct. Bats were studied individually and in pairs in a flight room equipped with synchronized high-speed stereo video and audio recording equipment, while sex and experience with a foraging task were experimentally manipulated. Male bats emitting the FMB showed greater success in capturing prey. Following FMB emission, inter-bat distance, diverging flight, and the other bat’s distance to the prey each increased. These findings highlight the importance and utility of vocal communication for a nocturnal animal mediating interactions with conspecifics in a fast-paced foraging setting. PMID:24684936

  8. Foraging proficiency during the nonbreeding season of a specialized forager: are juvenile American Oystercatchers "bumble-beaks" compared to adults?

    USGS Publications Warehouse

    Hand, Christine E.; Sanders, Felicia J.; Jodice, Patrick G.

    2010-01-01

    In many species, immature individuals are less proficient at foraging than are adults, and this difference may be especially critical during winter when survival can be at its minimum. We investigated the foraging proficiency of adult and immature American Oystercatchers (Haematopus palliatus) during the nonbreeding season. Oystercatchers forage on prey that must be handled with specialized skills, so age-related differences in foraging behavior may be expected. We found that adults spent more time searching than did immatures, a trend toward immatures taking longer to handle prey than did adults, and immatures more often handling prey unsuccessfully than did adults. Feeding rates and diet composition did not differ by age class. We posit that the immature birds traded off longer handling times with shorter searching times and that ultimately the abundant prey in the region may contribute to the ability of immature birds to feed at rates similar to those of adults.

  9. Harvester Ant Colony Variation in Foraging Activity and Response to Humidity

    PubMed Central

    Gordon, Deborah M.; Dektar, Katherine N.; Pinter-Wollman, Noa

    2013-01-01

    Collective behavior is produced by interactions among individuals. Differences among groups in individual response to interactions can lead to ecologically important variation among groups in collective behavior. Here we examine variation among colonies in the foraging behavior of the harvester ant, Pogonomyrmex barbatus. Previous work shows how colonies regulate foraging in response to food availability and desiccation costs: the rate at which outgoing foragers leave the nest depends on the rate at which foragers return with food. To examine how colonies vary in response to humidity and in foraging rate, we performed field experiments that manipulated forager return rate in 94 trials with 17 colonies over 3 years. We found that the effect of returning foragers on the rate of outgoing foragers increases with humidity. There are consistent differences among colonies in foraging activity that persist from year to year. PMID:23717415

  10. Performance and economic analyses of year-round forage systems for forage-fed beef production in the Gulf Coast.

    PubMed

    Scaglia, G; Rodriguez, J; Gillespie, J; Bhandari, B; Wang, J J; McMillin, K W

    2014-12-01

    On a global scale, most beef is produced from grazing pastures or rangelands. Certain limitations exist, however, such as not having adequate animal rates of gain for marbling and availability of adequate forage nutritional value and quantity for constant animal weight gains. In the last 20 yr, there has been an increased interest in forage-fed beef for multiple reasons (health related, environmental concerns, and welfare issues). Starting on June 5, 13, 14, and 8 in 4 consecutive yr, 54 steers (initial BW=259±5.6 kg; average of 9 mo of age) were randomly allotted to 3 yr-round forage systems. Each system occupied 6 ha/replicate and had the same stocking rate. System 1 had annual ryegrass (Lolium multiflorum) for winter grazing and bermudagrass (Cynodon dactylon) for summer grazing; while Systems 2 and 3 added rye and a clover mix to the ryegrass and diversified the use of pastures in the fall (dallisgrass [Paspalum dilatatum] and clovers [Trifolium spp.]). System 3 added the use of annual summer forages. During their respective growing season for each forage or forage mix, mass and height did not limit animal performance; however, there was a sampling date effect (P<0.05) for nutritive value variables since it decreased as forages became mature. The ADG observed (0.44 kg) for all systems (P=0.78) during summer was lower than expected and might have been limited by the observed temperature as well as forage nutritive value. Systems 1 and 2 had more grazing days (P=0.03) during summer (155 and 146 d, respectively) compared to System 3 (132 d) due to the greater pasture area of bermudagrass in those systems. Steers in System 3 were fed more hay for a longer period of time (P<0.05) than on the other 2 systems. System 1 and 2 produced more hay per hectare than System 3 (P<0.05). No differences (P>0.05) were detected between systems in ADG year round, during the winter season, or carcass characteristics. Return over total direct costs and total specified expenses were greater for Systems 1 and 2, while System 3 was the lowest. Hay making and bale sales played a major role in explaining the economic results of this study. Where possible, year-round forage systems are a viable alternative for forage-fed beef production; however, the low gains during summer and forage availability during the transition period when hay is necessary deserve further research to find alternatives to improve productivity during those times of the year. PMID:25367513

  11. Persistence of forage fish ‘hot spots’ and its association with foraging Steller sea lions (Eumetopias jubatus) in southeast Alaska

    NASA Astrophysics Data System (ADS)

    Gende, Scott M.; Sigler, Michael F.

    2006-02-01

    Whereas primary and secondary productivity at oceanic 'hotspots' may be a function of upwelling and temperature fronts, the aggregation of higher-order vertebrates is a function of their ability to search for and locate these areas. Thus, understanding how predators aggregate at these productive foraging areas is germane to the study of oceanic hot spots. We examined the spatial distribution of forage fish in southeast Alaska for three years to better understand Steller sea lion ( Eumetopias jubatus) aggregations and foraging behavior. Energy densities (millions KJ/km 2) of forage fish were orders of magnitude greater during the winter months (November-February), due to the presence of schools of overwintering Pacific herring ( Clupea pallasi). Within the winter months, herring consistently aggregated at a few areas, and these areas persisted throughout the season and among years. Thus, our study area was characterized by seasonally variable, highly abundant but highly patchily distributed forage fish hot spots. More importantly, the persistence of these forage fish hot spots was an important characteristic in determining whether foraging sea lions utilized them. Over 40% of the variation in the distribution of sea lions on our surveys was explained by the persistence of forage fish hot spots. Using a simple spatial model, we demonstrate that when the density of these hot spots is low, effort necessary to locate these spots is minimized when those spots persist through time. In contrast, under similar prey densities but lower persistence, effort increases dramatically. Thus an important characteristic of pelagic hot spots is their persistence, allowing predators to predict their locations and concentrate search efforts accordingly.

  12. A bioenergetics modeling evaluation of top-down control of ruffe in the St. Louis River, western Lake Superior

    USGS Publications Warehouse

    Mayo, Kathleen R.; Selgeby, James H.; McDonald, Michael E.

    1998-01-01

    Ruffe (Gymnocephalus cernuus), were accidentally introduced into the St. Louis River estuary, western Lake Superior, in the mid 1980s and it was feared that they might affect native fish through predation on eggs and competition for forage and habitat. In an effort to control the abundance of ruffe and limit dispersal, a top-down control strategy using predators was implemented in 1989. We used bioenergetics modeling to examine the efficacy of top-down control in the St. Louis River from 1991 to 1994. Five predators--northern pike (Esox lucius), walleye (Stizostedion vitreum vitreum), smallmouth bass (Micropterus dolomieui), brown bullhead (Ictalurus nebulosus), and yellow perch (Perca flavescens)--were modeled to determine their consumption of ruffe and four other native prey species-spottail shiner (Notropis hudsonius), emerald shiner (Notropis atherinoides), yellow perch (Perca flavescens), and black crappie (Pomoxis nigromaculatus). Although predators ate as much as 47% of the ruffe biomass in 1 year, they were not able to halt the increase in ruffe abundance. The St. Louis River is an open system that allows predators to move freely out of the system, and the biomass of managed predators did not increase. A selectivity index showed all five predators selected the native prey and avoided ruffe. The St. Louis River has several predator and prey species creating many complex predator-prey interactions; and top-down control of ruffe by the predators examined in this study did not occur.

  13. Forage choice in pasturelands: Influence on cattle foraging behavior and performance.

    PubMed

    Villalba, J J; Cabassu, R; Gunter, S A

    2015-04-01

    We determined if combinations of adjacent pastures of 3 forage species led to complementary relationships that influenced animal behavior and performance over monocultures. Grazing bouts, behavioral levels of activity, blood urea N (BUN), chemical composition of feces, BW, and herbage biomass before and after grazing were monitored when beef calves strip-grazed 3 replications of 4 treatments from June 14 through August 23, 2013 (9 animals/treatment). Animals grazed monocultures of: 1) tall fescue (TF), 2) alfalfa (ALF), 3) sainfoin (SAN), or 4) a choice of strips of forages TF, ALF, and SAN (CHOICE). The lowest and greatest incidence of foraging bouts occurred for cattle in CHOICE and SAN, respectively ( < 0.01). Animals in CHOICE grazed SAN > ALF > TF ( < 0.01). Animals on TF and CHOICE took greater number of steps than animals grazing a monocultures of either legume ( = 0.01). Calves in TF had lower BUN ( < 0.01) and fecal CP concentration ( < 0.01) than calves grazing the remaining treatments, whereas animals in SAN showed the greatest concentrations of fecal CP ( < 0.01). Fecal NDF concentration was the greatest for animals grazing TF and the lowest for animals grazing SAN ( 0.01), whereas fecal ADF concentration was greater for animals grazing TF and SAN than for animals grazing CHOICE and ALF ( = 0.02). Calcium, Mg, and Zn concentrations were the lowest in feces from calves grazing TF and the greatest for calves grazing a monoculture of either legume ( 0.05). When averaging both periods, animals grazing SAN, ALF, or CHOICE gained more BW than animals grazing TF ( < 0.01). Thus, calves in CHOICE incorporated tall fescue into their diets, were more active, and displayed a lower number of grazing bouts than calves grazing monoculture of either legume. Herbage diversity may lead to levels of ADG comparable to legume monocultures with the potential benefit of maintaining plant species diversity in pasturelands. PMID:26020195

  14. Managing manure nutrients through multi-crop forage production.

    PubMed

    Newton, G L; Bernard, J K; Hubbard, R K; Allison, J R; Lowrance, R R; Gascho, G J; Gates, R N; Vellidis, G

    2003-06-01

    Concentrated sources of dairy manure represent significant water pollution potential. The southern United States may be more vulnerable to water quality problems than some other regions because of climate, typical farm size, and cropping practices. Dairy manure can be an effective source of plant nutrients and large quantities of nutrients can be recycled through forage production, especially when multi-cropping systems are utilized. Linking forage production with manure utilization is an environmentally sound approach for addressing both of these problems. Review of two triple-crop systems revealed greater N and P recoveries for a corn silage-bermudagrass hay-rye haylage system, whereas forage yields and quality were greater for a corn silage-corn silage-rye haylage system, when manure was applied at rates to supply N. Nutrient uptake was lower than application during the autumn-winter period, and bermudagrass utilized more of the remaining excess than a second crop of corn silage. Economic comparison of these systems suggests that the added value of the two corn silage crop system was not enough to off-set its increased production cost. Therefore, the system that included bermudagrass demonstrated both environmental and economic advantages. Review of the N and P uptake and calculated crop value of various single, double, and triple crop forage systems indicated that the per hectare economic value as well as the N and P uptakes tended to follow DM yields, and grasses tended to out-perform broadleaf forages. Taken across all systems, systems that included bermudagrass tended to have some of the highest economic values and uptakes of N and P. Manure applied at rates to supply N results in application of excess P, and production will not supply adequate quantities of forage to meet the herd's needs. Systems that lower manure application and supply supplemental N to produce all necessary forage under manure application will likely be less economically attractive due to additional costs of moving manure further and, applying it to greater land areas, but will be environmentally necessary in most cases. Intensive forage systems can produce acceptable to high quality forage, protect the environment, and be economically attractive. The optimal manure-forage system will depend on the farm characteristics and specific local conditions. Buffers and nutrient sinks can protect streams and water bodies from migrating nutrients and should be included as a part of crop production systems. PMID:12836962

  15. Simultaneous brightness contrast of foraging Papilio butterflies.

    PubMed

    Kinoshita, Michiyo; Takahashi, Yuki; Arikawa, Kentaro

    2012-05-22

    This study focuses on the sense of brightness in the foraging Japanese yellow swallowtail butterfly, Papilio xuthus. We presented two red discs of different intensity on a grey background to butterflies, and trained them to select one of the discs. They were successfully trained to select either a high intensity or a low intensity disc. The trained butterflies were tested on their ability to perceive brightness in two different protocols: (i) two orange discs of different intensity presented on the same intensity grey background and (ii) two orange discs of the same intensity separately presented on a grey background that was either higher or lower in intensity than the training background. The butterflies trained to high intensity red selected the orange disc of high intensity in protocol 1, and the disc on the background of low intensity grey in protocol 2. We obtained similar results in another set of experiments with purple discs instead of orange discs. The choices of the butterflies trained to low intensity red were opposite to those just described. Taken together, we conclude that Papilio has the ability to learn brightness and darkness of targets independent of colour, and that they have the so-called simultaneous brightness contrast. PMID:22179808

  16. Color and polarization vision in foraging Papilio.

    PubMed

    Kinoshita, Michiyo; Arikawa, Kentaro

    2014-06-01

    This paper gives an overview of behavioral studies on the color and polarization vision of the Japanese yellow swallowtail butterfly, Papilio xuthus. We focus on indoor experiments on foraging individuals. Butterflies trained to visit a disk of certain color correctly select that color among various other colors and/or shades of gray. Correct selection persists under colored illumination, but is systematically shifted by background colors, indicating color constancy and simultaneous color contrast. While their eyes contain six classes of spectral receptors, their wavelength discrimination performance indicates that their color vision is tetrachromatic. P. xuthus innately prefers brighter targets, but can be trained to select dimmer ones under certain conditions. Butterflies trained to a dark red stimulus select an orange disk presented on a bright gray background over one on dark gray. The former probably appears darker to them, indicating brightness contrast. P. xuthus has a strong innate preference for vertically polarized light, but the selection of polarized light changes depending on the intensity of simultaneously presented unpolarized light. Discrimination of polarization also depends on background intensity. Similarities between brightness and polarization vision suggest that P. xuthus perceive polarization angle as brightness, such that vertical polarization appears brighter than horizontal polarization. PMID:24722674

  17. Mixed encounters, limited perception and optimal foraging.

    PubMed

    Berec, L

    2000-09-01

    This article demonstrates how perceptual constraints of predators and the possibility that predators encounter prey both sequentially (one prey type at a time) and simultaneously (two or more prey types at a time) may influence the predator attack decisions, diet composition and functional response of a behavioural predator-prey system. Individuals of a predator species are assumed to forage optimally on two prey types and to have exact knowledge of prey population numbers (or densities) only in a neighbourhood of their actual spatial location. The system characteristics are inspected by means of a discrete-time, discrete-space, individual-based model of the one-predator-two-prey interaction. Model predictions are compared with ones that have been obtained by assuming only sequential encounters of predators with prey and/or omniscient predators aware of prey population densities in the whole environment. It is shown that the zero-one prey choice rule, optimal for sequential encounters and omniscient predators, shifts to abruptly changing partial preferences for both prey types in the case of omniscient predators faced with both types of prey encounters. The latter, in turn, become gradually changing partial preferences when predator omniscience is considered only local. PMID:11016087

  18. Eye structure and amphibious foraging in albatrosses

    PubMed Central

    Martin, G. R.

    1998-01-01

    Anterior eye structure and retinal visual fields were determined in grey-headed and black-browed albatrosses, Diomedea melanophris and D. chrysostoma (Procellariiformes, Diomedeidae), using keratometry and an ophthalmoscopic reflex technique. Results for the two species were very similar and indicate that the eyes are of an amphibious optical design suggesting that albatross vision is well suited to the visual pursuit of active prey both on and below the ocean surface. The corneas are relatively flat (radius ca. 14.5 mm) and hence of low absolute refractive power (ca. 23 dioptres). In air the binocular fields are relatively long (vertical extent ca. 70 degrees) and narrow (maximum width in the plane of the optic axes 26–32 degrees), a topography found in a range of bird species that employ visual guidance of bill position when foraging. The cyclopean fields measure approximately 270 degrees in the horizontal plane, but there is a 60 degrees blind sector above the head owing to the positioning of the eyes below the protruding supraorbital ridges. Upon immersion the monocular fields decrease in width such that the binocular fields are abolished. Anterior eye structure, and visual field topography in both air and water, show marked similarity with those of the Humboldt penguin.

  19. Ocean acidification impairs crab foraging behaviour.

    PubMed

    Dodd, Luke F; Grabowski, Jonathan H; Piehler, Michael F; Westfield, Isaac; Ries, Justin B

    2015-07-01

    Anthropogenic elevation of atmospheric CO2 is driving global-scale ocean acidification, which consequently influences calcification rates of many marine invertebrates and potentially alters their susceptibility to predation. Ocean acidification may also impair an organism's ability to process environmental and biological cues. These counteracting impacts make it challenging to predict how acidification will alter species interactions and community structure. To examine effects of acidification on consumptive and behavioural interactions between mud crabs (Panopeus herbstii) and oysters (Crassostrea virginica), oysters were reared with and without caged crabs for 71 days at three pCO2 levels. During subsequent predation trials, acidification reduced prey consumption, handling time and duration of unsuccessful predation attempt. These negative effects of ocean acidification on crab foraging behaviour more than offset any benefit to crabs resulting from a reduction in the net rate of oyster calcification. These findings reveal that efforts to evaluate how acidification will alter marine food webs should include quantifying impacts on both calcification rates and animal behaviour. PMID:26108629

  20. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts.

    PubMed

    Cane, James H

    2011-09-01

    Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar floral traits can yield mixed reproductive outcomes among pollinator-dependent species. In these cases, floral constancy by polyleges sometimes serves as an ethological mating barrier. More often, their foraging infidelities instead facilitate host introgression and hybridization. Many other bee species are oligolectic (taxonomic specialists for pollen). Oligoleges could be more discriminating connoisseurs than polyleges when foraging among their limited set of related floral hosts. If true, greater foraging constancy might ensue, contributing to positive assortative mating and disruptive selection, thereby facilitating speciation among their interfertile floral hosts. To test this Connoisseur Hypothesis, nesting females of two species of oligolectic Osmia bees were presented with randomized mixed arrays of flowers of two sympatric species of their pollen host, Balsamorhiza, a genus known for hybridization. In a closely spaced grid, the females of both species preferred the larger flowered B. macrophylla, evidence for discrimination. However, both species' females showed no floral constancy whatsoever during their individual foraging bouts, switching randomly between species proportional to their floral preference. In a wider spaced array in which the bouquets reflected natural plant spacing, foraging oligolectic bees often transferred pollen surrogates (fluorescent powders) both between conspecific flowers (geitonogamy and xenogamy) and between the two Balsamorhiza species. The Connoisseur Hypothesis was therefore rejected. Foraging infidelity by these oligolectic Osmia bees will contribute to introgression and hybridization where interfertile species of Balsamorhiza meet and flower together. A literature review reveals that other plant genera whose species hybridize also attract numerous oligolectic bees, providing independent opportunities to test the generality of this conclusion. PMID:21468665

  1. Modelling foraging movements of diving predators: a theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency.

    PubMed

    Chimienti, Marianna; Barto?, Kamil A; Scott, Beth E; Travis, Justin M J

    2014-01-01

    Foraging in the marine environment presents particular challenges for air-breathing predators. Information about prey capture rates, the strategies that diving predators use to maximise prey encounter rates and foraging success are still largely unknown and difficult to observe. As well, with the growing awareness of potential climate change impacts and the increasing interest in the development of renewable sources it is unknown how the foraging activity of diving predators such as seabirds will respond to both the presence of underwater structures and the potential corresponding changes in prey distributions. Motivated by this issue we developed a theoretical model to gain general understanding of how the foraging efficiency of diving predators may vary according to landscape structure and foraging strategy. Our theoretical model highlights that animal movements, intervals between prey capture and foraging efficiency are likely to critically depend on the distribution of the prey resource and the size and distribution of introduced underwater structures. For multiple prey loaders, changes in prey distribution affected the searching time necessary to catch a set amount of prey which in turn affected the foraging efficiency. The spatial aggregation of prey around small devices (? 9 × 9 m) created a valuable habitat for a successful foraging activity resulting in shorter intervals between prey captures and higher foraging efficiency. The presence of large devices (? 24 × 24 m) however represented an obstacle for predator movement, thus increasing the intervals between prey captures. In contrast, for single prey loaders the introduction of spatial aggregation of the resources did not represent an advantage suggesting that their foraging efficiency is more strongly affected by other factors such as the timing to find the first prey item which was found to occur faster in the presence of large devices. The development of this theoretical model represents a useful starting point to understand the energetic reasons for a range of potential predator responses to spatial heterogeneity and environmental uncertainties in terms of search behaviour and predator-prey interactions. We highlight future directions that integrated empirical and modelling studies should take to improve our ability to predict how diving predators will be impacted by the deployment of manmade structures in the marine environment. PMID:25250211

  2. Modelling foraging movements of diving predators: a theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency

    PubMed Central

    Barto?, Kamil A.; Scott, Beth E.; Travis, Justin M.J.

    2014-01-01

    Foraging in the marine environment presents particular challenges for air-breathing predators. Information about prey capture rates, the strategies that diving predators use to maximise prey encounter rates and foraging success are still largely unknown and difficult to observe. As well, with the growing awareness of potential climate change impacts and the increasing interest in the development of renewable sources it is unknown how the foraging activity of diving predators such as seabirds will respond to both the presence of underwater structures and the potential corresponding changes in prey distributions. Motivated by this issue we developed a theoretical model to gain general understanding of how the foraging efficiency of diving predators may vary according to landscape structure and foraging strategy. Our theoretical model highlights that animal movements, intervals between prey capture and foraging efficiency are likely to critically depend on the distribution of the prey resource and the size and distribution of introduced underwater structures. For multiple prey loaders, changes in prey distribution affected the searching time necessary to catch a set amount of prey which in turn affected the foraging efficiency. The spatial aggregation of prey around small devices (? 9 × 9 m) created a valuable habitat for a successful foraging activity resulting in shorter intervals between prey captures and higher foraging efficiency. The presence of large devices (? 24 × 24 m) however represented an obstacle for predator movement, thus increasing the intervals between prey captures. In contrast, for single prey loaders the introduction of spatial aggregation of the resources did not represent an advantage suggesting that their foraging efficiency is more strongly affected by other factors such as the timing to find the first prey item which was found to occur faster in the presence of large devices. The development of this theoretical model represents a useful starting point to understand the energetic reasons for a range of potential predator responses to spatial heterogeneity and environmental uncertainties in terms of search behaviour and predator–prey interactions. We highlight future directions that integrated empirical and modelling studies should take to improve our ability to predict how diving predators will be impacted by the deployment of manmade structures in the marine environment. PMID:25250211

  3. Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico

    PubMed Central

    Shaver, Donna J; Hart, Kristen M; Fujisaki, Ikuko; Rubio, Cynthia; Sartain, Autumn R; Peña, Jaime; Burchfield, Patrick M; Gamez, Daniel Gomez; Ortiz, Jaime

    2013-01-01

    For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their “final” foraging sites. We identified new foraging “hotspots” where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species. PMID:23919146

  4. Foraging area fidelity for Kemp's ridleys in the Gulf of Mexico

    USGS Publications Warehouse

    Shaver, Donna J.; Hart, Kristen M.; Fujisaki, Ikuko; Rubio, Cynthia; Sartain, Autumn R.; Peña, Jaime; Burchfield, Patrick M.; Gamez, Daniel Gomez; Ortiz, Jaime

    2013-01-01

    For many marine species, locations of key foraging areas are not well defined. We used satellite telemetry and switching state-space modeling (SSM) to identify distinct foraging areas used by Kemp's ridley turtles (Lepidochelys kempii) tagged after nesting during 1998–2011 at Padre Island National Seashore, Texas, USA (PAIS; N = 22), and Rancho Nuevo, Tamaulipas, Mexico (RN; N = 9). Overall, turtles traveled a mean distance of 793.1 km (±347.8 SD) to foraging sites, where 24 of 31 turtles showed foraging area fidelity (FAF) over time (N = 22 in USA, N = 2 in Mexico). Multiple turtles foraged along their migratory route, prior to arrival at their "final" foraging sites. We identified new foraging "hotspots" where adult female Kemp's ridley turtles spent 44% of their time during tracking (i.e., 2641/6009 tracking days in foraging mode). Nearshore Gulf of Mexico waters served as foraging habitat for all turtles tracked in this study; final foraging sites were located in water <68 m deep and a mean distance of 33.2 km (±25.3 SD) from the nearest mainland coast. Distance to release site, distance to mainland shore, annual mean sea surface temperature, bathymetry, and net primary production were significant predictors of sites where turtles spent large numbers of days in foraging mode. Spatial similarity of particular foraging sites selected by different turtles over the 13-year tracking period indicates that these areas represent critical foraging habitat, particularly in waters off Louisiana. Furthermore, the wide distribution of foraging sites indicates that a foraging corridor exists for Kemp's ridleys in the Gulf. Our results highlight the need for further study of environmental and bathymetric components of foraging sites and prey resources contained therein, as well as international cooperation to protect essential at-sea foraging habitats for this imperiled species.

  5. Foraging depths of sea otters and implications to coastal marine communities

    USGS Publications Warehouse

    Bodkin, J.L.; Esslinger, G.G.; Monson, D.H.

    2004-01-01

    We visually observed 1,251 dives, of 14 sea otters instrumented with TDRs in southeast Alaska, and used attribute values from observed dives to classify 180,848 recorded dives as foraging (0.64), or traveling (0.36). Foraging dives were significantly deeper, with longer durations, bottom times, and postdive surface intervals, and greater descent and ascent rates, compared to traveling dives. Most foraging occurred in depths between 2 and 30 m (0.84), although 0.16 of all foraging was between 30 and 100 m. Nine animals, including all five males, demonstrated bimodal patterns in foraging depths, with peaks between 5 and 15 m and 30 and 60 m, whereas five of nine females foraged at an average depth of 10 m. Mean shallow foraging depth was 8 m, and mean deep foraging depth was 44 m. Maximum foraging depths averaged 61 m (54 and 82 for females and males, respectively) and ranged from 35 to 100 m. Female sea otters dove to depths 20 m on 0.85 of their foraging dives while male sea otters dove to depths 45 m on 0.50 of their foraging dives. Less than 0.02 of all foraging dives were >55 m, suggesting that effects of sea otter foraging on nearshore marine communities should diminish at greater depths. However, recolonization of vacant habitat by high densities of adult male sea otters may result in initial reductions of some prey species at depths >55 m.

  6. Subjective costs drive overly patient foraging strategies in rats on an intertemporal foraging task

    PubMed Central

    Wikenheiser, Andrew M.; Stephens, David W.; Redish, A. David

    2013-01-01

    Laboratory studies of decision making often take the form of two-alternative, forced-choice paradigms. In natural settings, however, many decision problems arise as stay/go choices. We designed a foraging task to test intertemporal decision making in rats via stay/go decisions. Subjects did not follow the rate-maximizing strategy of choosing only food items associated with short delays. Instead, rats were often willing to wait for surprisingly long periods, and consequently earned a lower rate of food intake than they might have by ignoring long-delay options. We tested whether foraging theory or delay discounting models predicted the behavior we observed but found that these models could not account for the strategies subjects selected. Subjects’ behavior was well accounted for by a model that incorporated a cost for rejecting potential food items. Interestingly, subjects’ cost sensitivity was proportional to environmental richness. These findings are at odds with traditional normative accounts of decision making but are consistent with retrospective considerations having a deleterious influence on decisions (as in the “sunk-cost” effect). More broadly, these findings highlight the utility of complementing existing assays of decision making with tasks that mimic more natural decision topologies. PMID:23630289

  7. Predator interference alters foraging behavior of a generalist predatory arthropod.

    PubMed

    Schmidt, Jason M; Crist, Thomas O; Wrinn, Kerri; Rypstra, Ann L

    2014-06-01

    Interactions between predators foraging in the same patch may strongly influence patch use and functional response. In particular, there is continued interest in how the magnitude of mutual interference shapes predator-prey interactions. Studies commonly focus on either patch use or the functional response without attempting to link these important components of the foraging puzzle. Predictions from both theoretical frameworks suggest that predators should modify foraging efforts in response to changes in feeding rate, but this prediction has received little empirical attention. We study the linkage between patch departure rates and food consumption by the hunting spider, Pardosa milvina, using field enclosures in which prey and predator densities were manipulated. Additionally, the most appropriate functional response model was identified by fitting alternative functional response models to laboratory foraging data. Our results show that although prey availability was the most important determinant of patch departure rates, a greater proportion of predators left enclosures containing elevated predator abundance. Functional response parameter estimation revealed significant levels of interference among predators leading to lower feeding rates even when the area allocated for each predator was kept constant. These results suggest that feeding rates determine patch movement dynamics, where interference induces predators to search for foraging sites that balance the frequency of agonistic interactions with prey encounter rates. PMID:24648022

  8. Journal of Natural History, 2002, 36, 22112227 Foraging ecology of the giant Amazonian ant Dinoponera gigantea

    E-print Network

    Oliveira, Paulo S.

    Dinoponera gigantea (Hymenoptera, Formicidae, Ponerinae): activity schedule, diet and spatial foraging rhythms, ants, Dinoponera, Formicidae, Ponerinae, spatial foraging patterns, territorial contests. Fourcassie´ and P. S. Oliveira2212 Formicidae is extremely diverse (Carroll and Janzen, 1973; Ho

  9. Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences for prey consumption

    E-print Network

    Evidence of hypoxic foraging forays by yellow perch (Perca flavescens) and potential consequences and foraging patterns. For example, Lake Erie yellow perch (Perca flavescens) continue to consume benthic prey

  10. 7 CFR 407.13 - Area risk protection insurance for forage.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Protection Insurance Forage Crop Insurance Provisions 1. Definitions Forage. Planted perennial alfalfa, perennial red clover, perennial grasses, or a mixture thereof, or other species as shown in the actuarial documents....

  11. Acoustics as a tool for the assessment of Great Lakes forage fishes

    USGS Publications Warehouse

    Argyle, Ray L.

    1992-01-01

    Sharp reductions in forage fish populations in Lake Michigan have raised concerns about the continued ability of the forage stocks to support large populations of lake trout and other salmonid predators. There was a need for a more comprehensive and accurate estimate of forage fish abundance and distribution to evaluate these concerns. In response, cooperative diel surveys of the Lake Michigan forage species were conducted in late summer 1987 and spring 1989 with acoustics, midwater and bottom trawls.

  12. The relationship between skull morphology, biting performance and foraging mode in Kalahari lacertid lizards

    Microsoft Academic Search

    LANCE D. MCBRAYER

    2004-01-01

    Lizards are a diverse clade in which one radiation consists entirely of sit-and-wait foragers and another consists of wide foragers. Lizards utilizing these two foraging modes are known to differ in diet, but little is known about how feeding morphology relates to diet and\\/or foraging mode. This study tested the hypothesis that skull morphology and biting performance are related to

  13. Spatio-temporal ranging behaviour and its relevance to foraging strategies in wide-ranging wolverines

    Microsoft Academic Search

    Roel May; Jiska van Dijk; Arild Landa; Roy Andersen; Reidar Andersen

    2010-01-01

    Conservation of carnivores in an increasingly changing environment is greatly helped by understanding the decision-making processes underlying habitat patch choice. Foraging theory may give us insight into spatio-temporal search patterns and consequent foraging decisions that carnivores make in heterogeneous and fluctuating environments. Constraints placed on central-place foragers in particular are likely to influence both foraging decisions and related spatio-temporal movement

  14. The Müller-Lyer Illusion in Ant Foraging

    PubMed Central

    Sakiyama, Tomoko; Gunji, Yukio-Pegio

    2013-01-01

    The Müller-Lyer illusion is a classical geometric illusion in which the apparent (perceived) length of a line depends on whether the line terminates in an arrow tail or arrowhead. This effect may be caused by economic compensation for the gap between the physical stimulus and visual fields. Here, we show that the Müller-Lyer illusion can also be produced by the foraging patterns of garden ants (Lasius niger) and that the pattern obtained can be explained by a simple, asynchronously updated foraging ant model. Our results suggest that the geometric illusion may be a byproduct of the foraging process, in which local interactions underlying efficient exploitation can also give rise to global exploration, and that visual information processing in human could implement similar modulation between local efficient processing and widespread computation. PMID:24349117

  15. Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl.

    PubMed

    Schneider, Eve R; Mastrotto, Marco; Laursen, Willem J; Schulz, Vincent P; Goodman, Jena B; Funk, Owen H; Gallagher, Patrick G; Gracheva, Elena O; Bagriantsev, Sviatoslav N

    2014-10-14

    Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents. PMID:25246547

  16. Neuronal mechanism for acute mechanosensitivity in tactile-foraging waterfowl

    PubMed Central

    Schneider, Eve R.; Mastrotto, Marco; Laursen, Willem J.; Schulz, Vincent P.; Goodman, Jena B.; Funk, Owen H.; Gallagher, Patrick G.; Gracheva, Elena O.; Bagriantsev, Sviatoslav N.

    2014-01-01

    Relying almost exclusively on their acute sense of touch, tactile-foraging birds can feed in murky water, but the cellular mechanism is unknown. Mechanical stimuli activate specialized cutaneous end organs in the bill, innervated by trigeminal afferents. We report that trigeminal ganglia (TG) of domestic and wild tactile-foraging ducks exhibit numerical expansion of large-diameter mechanoreceptive neurons expressing the mechano-gated ion channel Piezo2. These features are not found in visually foraging birds. Moreover, in the duck, the expansion of mechanoreceptors occurs at the expense of thermosensors. Direct mechanical stimulation of duck TG neurons evokes high-amplitude depolarizing current with a low threshold of activation, high signal amplification gain, and slow kinetics of inactivation. Together, these factors contribute to efficient conversion of light mechanical stimuli into neuronal excitation. Our results reveal an evolutionary strategy to hone tactile perception in vertebrates at the level of primary afferents. PMID:25246547

  17. Optimal foraging for specific nutrients in predatory beetles.

    PubMed

    Jensen, Kim; Mayntz, David; Toft, Søren; Clissold, Fiona J; Hunt, John; Raubenheimer, David; Simpson, Stephen J

    2012-06-01

    Evolutionary theory predicts that animals should forage to maximize their fitness, which in predators is traditionally assumed equivalent to maximizing energy intake rather than balancing the intake of specific nutrients. We restricted female predatory ground beetles (Anchomenus dorsalis) to one of a range of diets varying in lipid and protein content, and showed that total egg production peaked at a target intake of both nutrients. Other beetles given a choice to feed from two diets differing only in protein and lipid composition selectively ingested nutrient combinations at this target intake. When restricted to nutritionally imbalanced diets, beetles balanced the over- and under-ingestion of lipid and protein around a nutrient composition that maximized egg production under those constrained circumstances. Selective foraging for specific nutrients in this predator thus maximizes its reproductive performance. Our findings have implications for predator foraging behaviour and in the structuring of ecological communities. PMID:22237910

  18. Nodulation study of natural forage legume in semiarid region, Turkey.

    PubMed

    Küçük, Ci?dem; Cevheri, Cenap

    2014-04-01

    In this study, we investigated the natural nodulation of legume forage crops were widely grown in the natural pastures in Sanliurfa, Turkey. This legume forage crops are Vicia sativa L. subsp. sativa L., Vicia narbonensis L. var. narbonensis L., Vicia palaestina Boiss., Vicia hybrida L., Vicia lutea L. var. lutea Boiss. ET Ball., Pisum sativum L. subsp. sativum L. var. sativum L, Cicer echinospermum P.H. Davis, Trifolium tomentosum L., Trifolium retusum L., Trifolium campestre SCHREB., Medicago truncatula GAERTN. var. truncatula Schultz Bip., Trigonella mesopotamica Hub.-Mor., Lens culinaris Medik., Onobrychis crista-galli, Lathyrus cassius Boiss., Melilotus officinalis (L.) DESR., Coronilla scorpioides (L.) W.D.J. Koch. Nodulation, nodule colors and shapes were examined at the blooming period of forage legumes. In this study, the colour of the interior of nodules are pink-red colour and may be related to high rates of nitrogen fixation in legume crops. PMID:25911842

  19. Comparative baseline levels of mercury, Hsp 70 and Hsp 60 in subsistence fish from the Yukon-Kuskokwim delta region of Alaska

    Microsoft Academic Search

    Lawrence K Duffy; Erica Scofield; Tauni Rodgers; Molly Patton; R. Terry Bowyer

    1999-01-01

    In subsistence fish; northern pike (Esox lucius), burbot (Lota lota), whitefish (Coregonus nelsoni), grayling (Thymallus arcticus) and sheefish (Stenodus lencichthys), we determined the Hsp 60 and Hsp 70 levels in 31 samples from adult fish gills. A dot-blot analysis using antibodies to either Hsp 70 or Hsp 60 showed the average Hsp 70 concentration was 9.1 ?g\\/mg protein, while the

  20. High levels of mercury in biota of a new Prairie irrigation reservoir with a simplified food web in Southern Alberta, Canada

    Microsoft Academic Search

    Lars BrinkmannJoseph; Joseph B. Rasmussen

    2010-01-01

    This study examined mercury levels in northern pike (Esox lucius) from the Twin Valley Reservoir in southern Alberta, 2 years after construction in 2003. The hypothesis was tested that mercury\\u000a concentrations in pike from the reservoir are significantly higher than in pike from the nearby Oldman River. Mercury concentrations\\u000a in muscle tissue (0.37–1.54 ppm) generally exceeded the consumption guideline of 0.5 ppm total

  1. Clearing lakes. An ecosystem approach to the restoration and management of shallow lakes in the Netherlands

    Microsoft Academic Search

    H. Hosper

    1997-01-01

    In the 1950 s and 1960 s, most shallow lakes in the Netherlands shifted from macrophyte-dominated clear water lakes, towards algae-dominated turbid water lakes. Eutrophication, i.e. increased nutrient loading, is the main cause of the deterioration of the lake ecosystems. Other perturbations, such as the loss of lake-marginal wetlands (nutrient filters, habitat for pike, Esox lucius) and chemical pollution toxic

  2. Density and Biomass of Native Northern Pike Populations in Relation to Basin-Scale Characteristics of North-Central Minnesota Lakes

    Microsoft Academic Search

    Rodney B. Pierce; Cynthia M. Tomcko

    2005-01-01

    Habitat and ecological constraints that influence populations of northern pike Esox lucius at the scale of the lake basin were determined for 16 north-central Minnesota lakes that varied in size, depth, and chemical productivity. The density and biomass of northern pike greater than 350 mm total length were highly variable among lakes (3.2–59.0 fish\\/ha, 3.6–33.6 kg\\/ha). Densities of large northern

  3. Experimental Intensive Culture of Tiger Muskellunge in a Water Reuse System

    Microsoft Academic Search

    Charles H. Pecor

    1979-01-01

    Tiger muskellunge (female muskellunge, Esox masquinongy, x male northern pike, E. lucius) 14.5 cm long were reared for 45 days in a three-pass (pass I, II, and III) water reuse system. Cumulative growth rates for the fish were 0.143 cm\\/day in the first use of the water (pass I), 0.125 in the second use (pass II), and 0.108 in the

  4. Cultural transmission of predator recognition in fishes: intraspecific and interspecific learning

    Microsoft Academic Search

    ALICIA MATHIS; DOUGLAS P. CHIVERS; R. JAN F. SMITH

    1996-01-01

    Individuals that live in groups may have the opportunity to learn to recognize unfamiliar predators by observing the fright responses of experienced individuals in the group. In intraspecific trials, naive fathead minnows,Pimephales promelas, gave fright responses to chemical stimuli from predatory northern pike,Esox lucius, when paired with pike-experienced conspecifics but not when paired with pike-naive conspecifics. These pike-conditioned minnows retained

  5. Foraging rate versus sociality in the starling Sturnus vulgaris.

    PubMed Central

    Vásquez, R A; Kacelnik, A

    2000-01-01

    It is well established that social conditions often modify foraging behaviour, but the theoretical interpretation of the changes produced is not straightforward. Changes may be due to alterations of the foraging currency (the mathematical expression that behaviour maximizes) and/or of the available resources. An example of the latter is when both solitary and social foragers maximize rates of gain over time, but competition alters the behaviour required to achieve this, as assumed by ideal free distribution models. Here we examine this problem using captive starlings Sturnus vulgaris. Subjects had access to two depleting patches that replenished whenever the alternative patch was visited. The theoretical rate-maximizing policy was the same across all treatments, and consisted of alternating between patches following a pattern that could be predicted using the marginal value theorem (MVT). There were three treatments that differed in the contents of an aviary adjacent to one of the two patches (called the 'social' patch). In the control treatment, the aviary was empty, in the social condition it contained a group of starlings, and in a non-specific stimulus control it contained a group of zebra finches. In the control condition both patches were used equally and behaviour was well predicted by the MVT. In the social condition, starlings foraged more slowly in the social than in the solitary patch. Further, foraging in the solitary patch was faster and in the social patch slower in the social condition than in the control condition. Although these changes are incompatible with overall rate maximization (gain rate decreased by about 24% by self-imposed changes), if the self-generated gain functions were used the MVT was a good predictor of patch exploitation under all conditions. We discuss the complexities of nesting optimal foraging models in more comprehensive theoretical accounts of behaviour integrating functional and mechanistic perspectives. PMID:10687821

  6. Context dependence in foraging behaviour of Achillea millefolium.

    PubMed

    Karst, Justine D; Belter, Pamela R; Bennett, Jonathan A; Cahill, James F

    2012-12-01

    Context-dependent foraging behaviour is acknowledged and well documented for a diversity of animals and conditions. The contextual determinants of plant foraging behaviour, however, are poorly understood. Plant roots encounter patchy distributions of nutrients and soil fungi. Both of these features affect root form and function, but how they interact to affect foraging behaviour is unknown. We extend the use of the marginal value theorem to make predictions about the foraging behaviour of roots, and test our predictions by manipulating soil resource distribution and inoculation by soil fungi. We measured plant movement as both distance roots travelled and time taken to grow through nutrient patches of varied quality. To do this, we grew Achillea millefolium in the centers of modified pots with a high-nutrient patch and a low-nutrient patch on either side of the plant (heterogeneous) or patch-free conditions (homogeneous). Fungal inoculation, but not resource distribution, altered the time it took roots to reach nutrient patches. When in nutrient patches, root growth decreased relative to homogeneous soils. However, this change in foraging behaviour was not contingent upon patch quality or fungal inoculation. Root system breadth was larger in homogeneous than in heterogeneous soils, until measures were influenced by pot edges. Overall, we find that root foraging behaviour is modified by resource heterogeneity but not fungal inoculation. We find support for predictions of the marginal value theorem that organisms travel faster through low-quality than through high-quality environments, with the caveat that roots respond to nutrient patches per se rather than the quality of those patches. PMID:22622873

  7. Foraging habitat use by wood storks nesting in the coastal zone of Georgia, USA

    Microsoft Academic Search

    Karen F. Gaines; Bryan A. Lawrence Jr; Philip M. Dixon; Michael J. Harris

    1998-01-01

    We studied foraging habitat use of Wood Storks (Mycteria americana) from three coastal colonies us- ing United States Fish and Wildlife Service National Wetlands Inventory data within a geographic information sys- tem (GIS). Observers followed storks from breeding colonies to foraging sites in a fixed-winged aircraft. The main objectives of the study were to estimate the foraging range of each

  8. Hydrocarbons emitted by waggle-dancing honey bees stimulate colony foraging activity by causing experienced

    E-print Network

    Hydrocarbons emitted by waggle-dancing honey bees stimulate colony foraging activity by causing. INTRODUCTION The waggle dance is a pattern of movement performed by successful honey bee foragers within the nest to recruit colony mates to forage on a profitable food source. This honey bee "dance language

  9. Colony state and regulation of pollen foraging in the honey bee, Apis mellifera L

    Microsoft Academic Search

    Jennifer H. Fewell; Mark L. Winston

    1992-01-01

    To place social insect foraging behavior within an evolutionary context, it is necessary to establish relationships between individual foraging decisions and parameters influencing colony fitness. To address this problem, we examined interactions between individual foraging behavior and pollen storage levels in the honey bee, Apis mellifera L. Colonies responded to low pollen storage conditions by increasing pollen intake rates 54%

  10. Nonconsumptive effects in a multiple predator system reduce the foraging efficiency of a keystone predator

    E-print Network

    Chalcraft, David R.

    of experiments with larval dragonflies, adult newts (a known keystone predator), and their tadpole prey. We tadpoles to hide under leaf litter (a NCE), where newts spend less time foraging, which reduced the forag- ing success (CE) of newts. Newts altered tadpole behavior but not in a way that altered the foraging

  11. The influence of social interactions on the foraging path of Bewick's Swans Cygnus columbianus bewickii

    Microsoft Academic Search

    R. H. G. Klaassen; B. A. Nolet; D. Bankert

    2006-01-01

    The efficiency in which high-density food patches are found is determined by the way foragers move between patches. In this study we explore the effect of social interactions on the foraging path, in particular the distance moved between patches. We studied Bewick¿s Swans Cygnus columbianus bewickii that foraged on belowground tubers of Fennel Pondweed Potamogeton pectinatus. We accurately mapped the

  12. FORAGING BEHAVIOR AND MONETARY IMPACT OF WADING BIRDS AT ARKANSAS BAITFISH FARMS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We conducted foraging observations, food habits studies, and producer surveys to determine the foraging behavior and monetary impact of great blue herons Ardea herodias, great egrets A. alba, and little blue herons Egretta caerulea foraging at Arkansas baitfish farms. Although great egrets captured...

  13. Author's personal copy Digestive utilization of ozone-exposed forage by rabbits (Oryctolagus cuniculus)

    E-print Network

    Ditchkoff, Steve

    Author's personal copy Digestive utilization of ozone-exposed forage by rabbits (Oryctolagus Digestibility Forage quality Herbivore nutrition Phenolics Rabbits Southern Piedmont a b s t r a c t A mixture) in a digestibility experiment. Forages and feed refusals were analyzed for concentrations of total cell wall

  14. Selective differences between naive and experienced cattle foraging among eight grasses

    Microsoft Academic Search

    David Ganskopp; Ruben Cruz

    1999-01-01

    Cattle are often required to adapt to new forages when they are moved to new pasture. The objectives of this research were: (1) to determine how rapidly naive cattle express clearly defined preferences when they encounter a new array of forages, and (2) to compare their evolving forage preferences and grazing behavior with those of experienced cattle. Three naive and

  15. Bumble bee pollen foraging regulation: role of pollen quality, storage levels, and odor

    E-print Network

    Nieh, James

    ERRATUM Bumble bee pollen foraging regulation: role of pollen quality, storage levels, and odor T was made to the article title. The correct title should read: Bumble bee pollen foraging regulation: role for Behavioral Ecology and Sociobiology Bumble bee pollen foraging regulation: role of pollen quality, storage

  16. POLLEN MAKES BEES HOT Forager bees like nothing more than a

    E-print Network

    Nieh, James

    Inside JEB iii POLLEN MAKES BEES HOT Forager bees like nothing more than a sweet supply of nectar. But bees do not live by nectar alone. One of their main sources of protein is pollen. Knowing that bees% pollen protein samples and offered them to a bee colony in an isolated foraging arena. Measuring foraging

  17. Case Study: Nutrient values for spring and summer annual forages in a single cut harvest

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Annual forages were grown in the Central High Plains of the USA in both irrigated and dryland trials and the harvested forage was analyzed for forage composition and energy concentration. Three spring cereal crops (oats, barley, and triticale), three legumes (peas, soybeans, and vetch) and five sum...

  18. Optimal Resource Allocation to Survival and Reproduction in Parasitic Wasps Foraging in

    E-print Network

    Paris-Sud XI, Université de

    Optimal Resource Allocation to Survival and Reproduction in Parasitic Wasps Foraging in Fragmented and environmental variability affect the optimal reproductive strategies of parasitic wasps foraging for hosts in Parasitic Wasps Foraging in Fragmented Habitats. PLoS ONE 7(6): e38227. doi:10.1371/journal.pone.0038227

  19. Resource diversity and landscape-level homogeneity drive native bee foraging

    E-print Network

    and human-altered landscapes can be managed for increased native bee nesting and extended foraging, dually colony growth (6), the mechanism behind how human-altered landscapes impact native pollinator foraging understanding of native pollinator population and foraging biology. Using a population genetics approach, we

  20. The foraging benefits of information and the penalty of ignorance Ola Olsson and Joel S. Brown

    E-print Network

    Brown, Joel S.

    , variability allows the forager to bias its searching efforts towards rich patches and away from poor patches are not constant across patches but increase with search time in the patch. That is, correct Bayesian foraging, a forager may gain knowledge on the whereabouts of rich and poor patches from visual, auditory or chemical

  1. Foraging games between gerbils and their predators: temporal dynamics of resource depletion and apprehension in gerbils

    Microsoft Academic Search

    Burt P. Kotler; Joel S. Brown; Sasha R. X. Dall; Shaan Gresser; David Ganey; Amos Bouskila

    2002-01-01

    Predator-prey interactions constitute a foraging game when prey individuals manage risk from predators and predator individuals manage fear in their prey. As tools for managing risk, clever prey can use time allocation and apprehension (redirecting attention from foraging to predator detection). One such foraging game occurs between gerbils and their predators on the sand dunes of the Negev Desert. Here,

  2. Foraging modes of stream benthic fishes in relation to their predation effects on local prey density

    Microsoft Academic Search

    Mikio Inoue; Masanobu Miyayoshi; Shin Sone

    2005-01-01

    Habitat use and foraging behavior of two benthic insectivorous gobies, Rhinogobius sp. CO (cobalt type) and Rhinogobius sp. DA (dark type), were examined in relation to their predation effects on local prey density in a small coastal stream in southwestern Shikoku, Japan. Correlations among the foraging range, frequency of foraging attempts and current velocity indicated that individuals using fast-current habitats

  3. Characterization of in situ dry matter and protein degradation of green and ensiled oats forages

    E-print Network

    Boyer, Edmond

    Characterization of in situ dry matter and protein degradation of green and ensiled oats forages de Santar6m, Portugal Oat (Avena sativa L.) is one of the forages produced in the Azores for use as green forage or as silage. Oats were cut at three stages of growth, namely : fifth leaf stage (F), bolt

  4. Foraging behaviour and echolocation in the rufous horseshoe bat ( Rhinolophus rouxi ) of Sri Lanka

    Microsoft Academic Search

    G. Neuweiler; W. Metzner; U. Heilmann; R. Riibsamen; M. Eckrich; H. H. Costa

    1987-01-01

    In October 1984 foraging areas and foraging behaviour of the rufous horseshoe bat, Rhinolophus rouxi, were studied around a nursery colony on the hill slopes of Sri Lanka. The bats only foraged in dense forest and were not found in open woodlands (Fig. 1). This strongly supports the hypothesis that detection of fluttering prey is by pure tone echolocation within

  5. Foraging and spatiotemporal territories in the honey ant Myrmecocystus mimicus wheeler (Hymenoptera: Formicidae)

    Microsoft Academic Search

    Bert Hölldobler

    1981-01-01

    The honey ant Myrmecocystus mimicus is a scavenger, forages extensively on termites, collects floral nectar, and tends homoptera. Individual foragers of M. mimicus usually disperse in all directions when leaving the nest, but there are also groups of foragers that tend to swarm out of the nest primarily in one direction. Such massive departues are usually at irregular intervals, which

  6. Spatial arrangement, population density and legume species effect of yield of forage sorghum-legume intercropping

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Sorghum (Sorghum bicolor) is a stress tolerant forage crop grown extensively in the Southern High Plains. However, sorghum forage quality is lower than that of corn. Intercropping sorghum with legumes can improve quality and productivity of forage. However, tall statured sorghum limits the resources...

  7. New Insights into the Physiology of Natural Foraging* Jennifer M. Burns1

    E-print Network

    Burns, Jennifer M.

    242 New Insights into the Physiology of Natural Foraging* Jennifer M. Burns1 Terrie M. Williams2 The purpose of this symposium was to examine how foraging physiology is studied in the field across- versity, two core themes emerged: that foraging strategies and behaviors are limited by physiology

  8. A MULTI-SCALE TEST OF THE FORAGE MATURATION HYPOTHESIS IN A PARTIALLY MIGRATORY UNGULATE POPULATION

    Microsoft Academic Search

    Mark Hebblewhite; Evelyn Merrill; Greg McDermid

    2008-01-01

    The forage maturation hypothesis (FMH) proposes that ungulate migration is driven by selection for high forage quality. Because quality declines with plant maturation, but intake declines at low biomass, ungulates are predicted to select for intermediate forage biomass to maximize energy intake by following phenological gradients during the growing season. We tested the FMH in the Canadian Rocky Mountains by

  9. RESEARCH PAPER Effects of Structural Refuge and Density on Foraging Behaviour

    E-print Network

    RESEARCH PAPER Effects of Structural Refuge and Density on Foraging Behaviour and Mortality-offs between prey foraging opportunity vs. predation risk (McPeek 2004; Steiner & Van Buskirk 2009). Previous), with food-limited individuals exhibiting risk-prone foraging and accepting attendant increase in predation

  10. Anim. Behao., 1989,31,455464 Sunfish foraging among patches: the patch-departure decision

    E-print Network

    Chesson, Peter L.

    43210, U.S.A Abstract. Patch-use behaviour of small bluegill sunfish, Lepomis macrochirus, foraging animals that forage for patchily distributed prey in the absence of predators decide how to exploitAnim. Behao., 1989,31,455464 Sunfish foraging among patches: the patch-departure decision DENNIS R

  11. ASSESSING EFFECTS OF PREDATION RISK ON FORAGING BEHAVIOR OF MULE DEER

    Microsoft Academic Search

    Kelly B. Altendorf; John W. Laundré; Carlos A. López González; Joel S. Brown

    2001-01-01

    We applied optimal foraging theory to test effects of habitat and predation risk on foraging behavior of mule deer (Odocoileus hemionus) subject to predation by mountain lions (Puma concolor). We predicted that deer would spend less time foraging, have higher giving-up densities of food (GUDs), and have higher vigilance behavior when occupying patch edges than when in open and forest

  12. Specialization and development of beach hunting, a rare foraging behavior, by wild bottlenose dolphins ( Tursiops sp.)

    Microsoft Academic Search

    B. L. Sargeant; J. Mann; P. Berggren; M. Krützen

    2005-01-01

    Foraging behaviors of bottlenose dolphins vary within and among populations, but few studies attempt to ad- dress the causes of individual variation in foraging behavior. We examined how ecological, social, and developmental factors relate to the use of a rare foraging tactic by wild bottlenose dolphins (Tursiops sp. Gervais, 1855) in Shark Bay, Western Australia. Beach hunting involves partial and

  13. Breeding Better Forages to Help Feed Man and Preserve and Enhance the Environment

    ERIC Educational Resources Information Center

    Burton, Glenn W.

    1973-01-01

    Discusses the importance of forages in agriculture, and expresses the need for the same high level of technology that is used in the production of corn, wheat, and rice to be applied to forage production. Describes promising forage species, breeding objectives, and breeding procedures used in research. (JR)

  14. Foraging reactivation in the honeybee Apis mellifera L.: factors affecting the return to known nectar sources

    Microsoft Academic Search

    Mariana Gil; Walter Marcelo Farina

    2002-01-01

    This paper addresses, what determines that experienced forager honeybees return to places where they have previously exploited nectar. Although there was already some evidence that dance and trophallaxis can cause bees to return to feed, the fraction of unemployed foragers that follow dance or receive food from employed foragers before revisiting the feeder was unknown. We found that 27% of

  15. The Cost of Capturing Prey: Measuring Largemouth Bass Foraging Activity using Glycolytic Enzymes (Lactate Dehydrogenase)

    E-print Network

    The Cost of Capturing Prey: Measuring Largemouth Bass Foraging Activity using Glycolytic Enzymes THE COST OF CAPTURING PREY: MEASURING LARGEMOUTH BASS FORAGING ACTIVITY USING GLYCOLYTIC ENZYMES (LACTATE #12;11 The Cost of Capturing Prey: Measuring Largemouth Bass Foraging Activity using Glycolytic

  16. PIGEON PEA: A POTENTIAL FORAGE AND GRAIN FOR THE SOUTHERN GREAT PLAINS IN U.S.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A basic goal of livestock grazing programs is to provide high-quality forage year-around to reduce costs of storing and purchasing forage or concentrated feeds. Forage-based livestock production is a significant component of the agricultural economy throughout the Southern Great Plains of the U.S. ...

  17. Filling the forage gaps with novel endophyte-infected tall fescue

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Arkansas beef producers rely on both warm season (bermudagrass) as well as cool season (usually endophyte-infected tall fescue) perennial forages to achieve as close to a 12-month grazing season as possible. Even with this combined warm-cool season forage system, “forage gaps” still exist at certai...

  18. HOW DOES PLANT POPULATION AFFECT THE YIELD, QUALITY, AND CANOPY OF NATIVE BLUESTEM (ANDROPOGON SPP.) FORAGE?

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The density at which a crop is grown is known to affect its growth and quality. Little, however, is known about how plant density affects the growth of perennial forage grasses. The objectives of this study were to investigate the effects of plant population density on the forage yield, forage qua...

  19. Foraging habitat selection by breeding Common Kestrels Falco tinnunculus on lowland farmland in England

    Microsoft Academic Search

    Claudia M. Garratt; Martin Hughes; Giselle Eagle; Tanya Fowler; Philip V. Grice; Mark J. Whittingham

    2011-01-01

    Capsule Breeding Common Kestrels prefer to forage over recently cut grass than all other habitat types on farmland.Aims To identify foraging habitat and prey of Common Kestrels during the breeding season.Methods We observed seven pairs of Common Kestrels during the breeding season over three years, using fixed vantage point observations. We recorded foraging attempts, and habitat and prey data for

  20. The impact of giant panda foraging on bamboo dynamics in an isolated environment

    E-print Network

    The impact of giant panda foraging on bamboo dynamics in an isolated environment Vanessa Hull to characterize the impact of panda foraging on the sustainability of its food resource, bamboo, in an enclosed cover as a result of panda foraging, particularly in younger bamboo age classes. We constructed

  1. Interactions with Combined Chemical Cues Inform Harvester Ant Foragers' Decisions to Leave the Nest in Search of Food

    PubMed Central

    Greene, Michael J.; Pinter-Wollman, Noa; Gordon, Deborah M.

    2013-01-01

    Social insect colonies operate without central control or any global assessment of what needs to be done by workers. Colony organization arises from the responses of individuals to local cues. Red harvester ants (Pogonomyrmex barbatus) regulate foraging using interactions between returning and outgoing foragers. The rate at which foragers return with seeds, a measure of food availability, sets the rate at which outgoing foragers leave the nest on foraging trips. We used mimics to test whether outgoing foragers inside the nest respond to the odor of food, oleic acid, the odor of the forager itself, cuticular hydrocarbons, or a combination of both with increased foraging activity. We compared foraging activity, the rate at which foragers passed a line on a trail, before and after the addition of mimics. The combination of both odors, those of food and of foragers, is required to stimulate foraging. The addition of blank mimics, mimics coated with food odor alone, or mimics coated with forager odor alone did not increase foraging activity. We compared the rates at which foragers inside the nest interacted with other ants, blank mimics, and mimics coated with a combination of food and forager odor. Foragers inside the nest interacted more with mimics coated with combined forager/seed odors than with blank mimics, and these interactions had the same effect as those with other foragers. Outgoing foragers inside the nest entrance are stimulated to leave the nest in search of food by interacting with foragers returning with seeds. By using the combined odors of forager cuticular hydrocarbons and of seeds, the colony captures precise information, on the timescale of seconds, about the current availability of food. PMID:23308106

  2. Optimum forage-beef systems for East Texas 

    E-print Network

    Poenisch, Kenneth Ray

    1975-01-01

    depress the growth of the perennial forages in the early spring and may limit hay produced. Tables 23 through 24 give the grazing patterns for cows, stockers and grass fat cattle. Budgeting Techniques Livestock and forage budgets reflect the costs... as an industry and has increased greatly by the development of pastures planted to improved grasses [5, p. 112]. Statistics show that there were 1, 716, 000 head of cattle on the approximately 16, 668, 654 acres that made up East Texas on January 1, 1973...

  3. Foraging by bats in cleared, thinned and unharvested boreal forest

    Microsoft Academic Search

    Krista J. Patriquin; Robert M. R. Barclay

    2003-01-01

    Summary 1. Modern silvicultural methods employ various styles of selective harvesting in addi- tion to traditional clear-cutting. This can create a mosaic of patches with different tree densities that may influence habitat use by foraging bats. Use of forest patches may also vary among bat species due to variation in their manoeuvrability. Apart from studies investigating use of clear-cuts, few

  4. Yield and quality of forages grown on mine spoil

    Microsoft Academic Search

    W. F. Kuenstler; D. S. Henry

    1980-01-01

    Pasture or hayland is a potential use for much of the reclaimed mined land in Kentucky. To determine the usefulness of several species for forage production, two study areas were established, one in the eastern coal fields, the second in the western coal fields. Eight species were seeded in eight different mixtures at each location. Each plot was harvested twice

  5. Behavioral Genomics of Honey Bee foraging and nest defense

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We superimposed confidence intervals (CIs) with genomic sequence for seven confirmed honey bee quantitative trait loci (QTLs) influencing foraging division of labor (pollen or nectar collecting) and nest defense (stinging and guarding). The high recombination rate of the bee allowed us to narrow th...

  6. Fall Growth Potential of Cereal Grain Forages in Northern Arkansas

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Arkansas, producers utilizing cereal grains as fall forage for weaned calves usually do not harvest a grain crop the following summer. This contrasts sharply from practices observed commonly in neighboring Oklahoma, and allows for much wider latitude with respect to management strategies, especia...

  7. Methodological Problems in Evolutionary Biology. XI. Optimal Foraging Theory Revisited

    Microsoft Academic Search

    Wim J. van der Steen

    1998-01-01

    Optimality theory, particularly optimal foraging theory (OFT), has spurned controversy over decades. I argue that the controversy results from conceptual pitfalls. The focus in this article is on pitfalls underlying the concept of constraint. Constraints in OFT models are a means to distinguish between possible and impossible behaviours. I argue that the seemingly innocuous notion of (im)possibility is tricky. It

  8. Potential energetic effects of mountain climbers on foraging grizzly bears

    USGS Publications Warehouse

    White, D., Jr.; Kendall, K.C.; Picton, H.D.

    1999-01-01

    Most studies of the effects of human disturbance on grizzly bears (Ursus arctos horribilis) have not quantified the energetic effects of such interactions. In this study, we characterized activity budgets of adult grizzly bears as they foraged on aggregations of adult army cutworm moths (Euxoa auxiliaris) in the alpine of Glacier National Park, Montana, during 1992, 1994, and 1995. We compared the activity budgets of climber-disturbed bears to those of undisturbed bears to estimate the energetic impact of climber disturbance. When bears detected climbers, they subsequently spent 53% less time foraging on moths, 52% more time moving within the foraging area, and 23% more time behaving aggressively, compared to when they were not disturbed. We estimated that grizzly bears could consume approximately 40,000 moths/day or 1,700 moths/hour. At 0.44 kcal/moth, disruption of moth feeding cost bears approximately 12 kcal/minute in addition to the energy expended in evasive maneuvers and defensive behaviors. To reduce both climber interruption of bear foraging and the potential for aggressive bear-human encounters, we recommend routing climbers around moth sites used by bears or limiting access to these sites during bear-use periods.

  9. Sociality in river otters: cooperative foraging or reproductive strategies?

    Microsoft Academic Search

    Gail M. Blundell; Merav Ben-David

    2002-01-01

    We evaluated factors influencing social organization in coastal river otters (Lontra canadensis) to test two hypotheses: group formation is an antipredation strategy, or, alternatively, group information is related to cooperative foraging. Data on group size, group composition, and sociality were obtained through radiotracking 55 otters in Prince William Sound, Alaska, USA, from 1996 through 1998. For males, larger groups occurred

  10. People's Study Time Allocation and its Relation to Animal Foraging

    PubMed Central

    Metcalfe, Janet; Jacobs, W. Jake

    2010-01-01

    In this article we suggest a relation between people's metacognitively guided study time allocation strategies and animal foraging. These two domains are similar insofar as people use specific metacognitive cues to assist their study time allocation just as other species use cues, such as scent marking. People decline to study items that they know they already know, just as other species use a win-shift strategy – avoiding already visited and depleted patches – in foraging. People selectively study the easiest as-yet-unlearned items first, before turning to more difficult items just as other species take the ‘just right’ size and challenge of prey--the so-called Goldilocks principle. People use a stop rule by which they give up on one item and turn to another when the returns diminish just as others species use a stop rule that guides shifting from one patch to another. The value that each item is assigned on the criterion test, if known during study, influenced which items people choose to study and how long they study them just as knowledge of the nutritional or energy value of the food influences choices and perseverance in foraging. Finally, study time allocation strategies can differ in their effectiveness depending upon the expertise of the student just as some species forage close to optimally while others do not. PMID:20026197

  11. Allocating Great Lakes forage bases in response to multiple demand

    USGS Publications Warehouse

    Brown, Edward H., Jr.; Busiahn, Thomas R.; Jones, Michael L.; Argyle, Ray L.

    1999-01-01

    Forage base allocation, which has become an important issue because of major changes in the fish communities and fisheries of the Great Lakes since the 1950s is examined and documented in this chapter. Management initiatives that were used to address the issue, and supporting research and development that provided new or improved methods of field sampling and analysis are also highlighted.

  12. Thermal and digestive constraints to foraging behaviour in marine mammals

    E-print Network

    Thermal and digestive constraints to foraging behaviour in marine mammals David A. S. Rosen1 digestive limitations to food intake and thermoregulation. The ability of an animal to consume sufficient by maximum digestion capacity and the time devoted to digestion). Failure to consume sufficient prey

  13. In Vitro Digestion Rate of Forage Cell Wall Components

    Microsoft Academic Search

    L. W. Smith; H. K. Goering; D. R. Waldo; C. H. Gordon

    1971-01-01

    Linearity of the semilog plots of remain- ing digestible fiber on time and their corre- lations (r = .98 approximately) indicated first order digestion kinetics for each of the six forages even though composition and observed rates of fiber digestion were markedly different. Immature rye cell walls digested fastest (27.03 ± .81%\\/ hour, r 2 -- .999) and mature timothy

  14. Novel forages for growth and health in farmed deer

    Microsoft Academic Search

    TN Barry; SO Hoskin; PR Wilson

    2002-01-01

    AIMS: This paper reviews recent research on the use of new forages in deer farming that may be useful for increasing growth in weaner deer for venison production, increasing the trace element status of deer, and for developing systems less reliant on chemical inputs, notably of anthelmintics used to control internal parasites.GROWTH: Grazing on pure swards of red clover (Trifolium

  15. Leucaena forage analysis using near infrared reflectance spectroscopy

    Microsoft Academic Search

    Robert A. Wheeler; William R. Chaney; Keith D. Johnson; Larry G. Butler

    1996-01-01

    Leucaena is a fast growing, multipurpose tree planted in tropical regions for many uses including forage. Leaf and leaf + stem material were collected from Leucaena species, varieties, and hybrids grown at two sites in Hawaii and in Australia. Neutral detergent fiber, acid detergent fiber, crude protein, in-vitro dry matter digestibility, and relative condensed tannin were determined by both laboratory

  16. Development of Techniques for Evaluating Grazed Forage1

    Microsoft Academic Search

    A. L. Lesperance; V. R. Bohman; D. W. Marble

    1960-01-01

    SUMMARY Techniques were developed to sample grazed forage with steers, using both esophageal and rumen fistulas. Comparisons between feeds of known composition and samples col- lected from these same feeds through fistulas indicated that some changes in composition occurred. These changes in composition of certain constituents were influenced by the type of feed and type of fistula. Regression equations for

  17. ORIGINAL ARTICLE Collective decisions in ants when foraging

    E-print Network

    Nicolis, Stamatios C.

    ORIGINAL ARTICLE Collective decisions in ants when foraging under crowded conditions Audrey-recruiting ant Lasius niger. In our experiment, ants had to go from their nest to a food source by crossing underlying the choice of route in ants. A mathematical model was developed to evaluate the impor- tance

  18. Foraging Ecology of Pileated Woodpeckers in Coastal Forests of Washington

    Microsoft Academic Search

    CATHERINE M. RALEY; KEITH B. AUBRY

    2006-01-01

    In the Pacific Northwest, providing adequate habitat forpileated woodpeckers (Dryocopus pileatus) has been a key component Of federal forest management strategies for over 20 years. Although their nesting and roosting ecology has been well studied, information on their foraging ecology is limited. From 1990 to 1995, we studied food habits of pileated woodpeckers in coastal forests (with scat analysis); estimated

  19. FORAGE SUBSURFACE DRIP IRRIGATION USING TREATED SWINE EFFLUENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experimental subsurface drip irrigation (SDI) system was initiated to evaluate the use of treated swine effluent on a bermuda grass forage crop. The SDI system was installed in Duplin County, North Carolina, at the location of an innovative swine wastewater treatment system. The effluent from the...

  20. Forage subsurface drip irrigation using treated swine effluent

    Technology Transfer Automated Retrieval System (TEKTRAN)

    An experimental subsurface drip irrigation (SDI) system was initiated to evaluate the use of treated swine effluent on a bermuda grass forage crop. The SDI system was installed in Duplin County, North Carolina, at the location of an innovative swine wastewater treatment system. The effluent from the...

  1. At-Sea Associations in Foraging Little Penguins

    PubMed Central

    Berlincourt, Maud; Arnould, John P. Y.

    2014-01-01

    Prey distribution, patch size, and the presence of conspecifics are important factors influencing a predator’s feeding tactics, including the decision to feed individually or socially. Little is known about group behaviour in seabirds as they spend most of their lives in the marine environment where it is difficult to observe their foraging activities. In this study, we report on at-sea foraging associations of little penguins (Eudyptula minor) during the breeding season. Individuals could be categorised as (1) not associating; (2) associating when departing from and/or returning to the colony; or (3) at sea when travelling, diving or performing synchronised dives. Out of 84 separate foraging tracks, 58 (69.0%) involved associations with conspecifics. Furthermore, in a total of 39 (46.4%), individuals were found to dive during association and in 32 (38.1%), individuals were found to exhibit synchronous diving. These behaviours suggest little penguins forage in groups, could synchronise their underwater movements and potentially cooperate to concentrate their small schooling prey. PMID:25119718

  2. INTRODUCTION Ants can learn long and individually stereotyped foraging routes

    E-print Network

    Sussex, University of

    2739 INTRODUCTION Ants can learn long and individually stereotyped foraging routes guided in part that may result from linking visual features encountered sequentially along a route, such that seeing one sequentially presented visual stimuli, we used a simplified version of Zhang et al's (Zhang et al., 1999

  3. Forage Kochia (Kochia Prostrata) for Fall and Winter Grazing

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage kochia (Kochia prostrata (L.) Scrad), also known as prostrate kochia, or prostrate summer cypress is a long-lived, perennial, semi-evergreen, half-shrub well adapted to the temperate, semiarid and arid regions of central Asia and the western U.S. In these areas, it has proven to be a valuabl...

  4. HABITAT USE BY FORAGING NORTHERN HARRIERS ON NANTUCKET ISLAND, MASSACHUSETTS

    E-print Network

    McGarigal, Kevin

    ,2 CURTICE R. GRIFFIN,1 AND KEVIN MCGARIGAL1 ABSTRACT.--The Northern Harrier (Circus cyaneus) is of major reduces foraging habitat. Received 26 January 2009. Accepted 9 July 2009. Northern Harriers (Circus cyaneus) have been identified as a species of national concern by the U.S. Fish and Wildlife Service (USDI

  5. Use of Urban Marine Habitats by Foraging Wading Birds

    EPA Science Inventory

    Wading birds that utilize coastal habitats may be at risk from increasing urbanization near their foraging and stopover sites. However, the relative importance of human disturbance in the context of other landscape and biological factors that may be influencing their distributio...

  6. Estimating Shrub Forage Yield and Utilization Using a Photographic Technique

    Microsoft Academic Search

    Daalkhaijav Damiran; Timothy DelCurto; Douglas E. Johnson; Scott L. Findholt; Bruce K. Johnson

    2006-01-01

    We assessed a photographic technique to estimate shrub yield and utilization of common snowberry (Symphoricarpos albus (L.) Blake), snowbrush (Ceanothus velutinus Douglas ex Hook.), and firmleaf willow ( Salix rigida Muhl.) found in mixed-conifer rangelands. We determined the correlation between green leaf area size (LA) and forage yield (Y) and compared plant utilization estimated by photographic technique (ULA) to actual

  7. RESEARCH ARTICLE Shorter-lived workers start foraging earlier

    E-print Network

    Tofilski , Adam

    ¨user Verlag, Basel/Switzerland 2009 Abstract In social insects it is often observed that young workers perform their death is less costly to the colony than the death of young workers. The expected longevity of workersRESEARCH ARTICLE Shorter-lived workers start foraging earlier A. Tofilski Received: 11 February

  8. FORAGE YIELD AND PERSISTENCE OF CHICORY AND ENGLISH PLANTAIN

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Graziers in the northeast often face forage shortages in midsummer. Chicory (Cichorium intybus L.) and English plantain (Plantago lanceolata L.) have been introduced in the USA as perennial herbs for pastures and have been touted as drought tolerant. We conducted two field-plot experiments at Rock S...

  9. PREDICTING FORAGE QUALITY IN THE NORTHERN MIXED-GRASS PRAIRIE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Quality and quantity of forage produced are important factors affecting livestock production from grazinglands. 'Greenness' has been proposed as an indicator of herbage quality particularly N content. In this study, standing crop samples were collected during the period April through October over 3 ...

  10. Cervid forage utilization in noncommercially thinned ponderosa pine forests

    USGS Publications Warehouse

    Gibbs, M.C.; Jenks, J.A.; Deperno, C.S.; Sowell, B.F.; Jenkins, Kurt J.

    2004-01-01

    To evaluate effects of noncommercial thinning, utilization of forages consumed by elk (Cervus elaphus L.), mule deer (Odocoileus hemionus Raf.), and white-tailed deer (Odocoileus virginianus Raf.) was measured in ponderosa pine (Pinus ponderosa P. & C. Lawson) stands in Custer State Park, S. D. Treatments consisted of unthinned (control; 22 to 32 m2/ha basal area), moderately thinned (12 to 22 m2/ha basal area), and heavily thinned (3 to 13 m2/ha basal area) stands of ponderosa pine. During June, July, and August, 1991 and 1992, about 7,000 individual plants were marked along permanent transects and percent-weight-removed by grazing was ocularly estimated. Sample plots were established along transects and plants within plots were clipped to estimate standing biomass. Pellet groups were counted throughout the study area to determine summer habitat use of elk and deer. Diet composition was evaluated using microhistological analysis of fecal samples. Average percent-weight-removed from all marked plants and percent-plants-grazed were used to evaluate forage utilization. Standing biomass of graminoids, shrubs, and forbs increased (P 0.05) across treatments. Forb use averaged less than 5% within sampling periods when measured as percent-weight-removed and percent-of-plants grazed and did not differ among treatments. Results of pellet group surveys indicated that cervids were primarily using meadow habitats. When averaged over the 2 years, forbs were the major forage class in deer diets, whereas graminoids were the major forage class in diets of elk.

  11. ORIGINAL PAPER Foraging habitats of Myotis emarginatus in Central Europe

    E-print Network

    Paris-Sud XI, Université de

    % of the total forest area, but only 10% of the foraging areas were located in this forest type. Deciduous, the availability of native deciduous forest and of fly-infested stables within a radius of 6 km around the colony . Deciduous forests . Spruce monoculture . Behaviour. Cow shed Introduction Myotis emarginatus is regarded

  12. Rearing and foraging affects bumblebee (Bombus terrestris) gut microbiota.

    PubMed

    Newbold, Lindsay K; Oliver, Anna E; Cuthbertson, Leah; Walkington, Sarah E; Gweon, Hyun S; Heard, Matthew S; van der Gast, Christopher J

    2015-08-01

    Bumblebees are ecologically and economically important as pollinators of crop and wild plants, especially in temperate systems. Species, such as the buff-tailed bumblebee (Bombus terrestris), are reared commercially to pollinate high-value crops. Their highly specific gut microbiota, characterized by low diversity, may affect nutrition and immunity and are likely to be important for fitness and colony health. However, little is known about how environmental factors affect bacterial community structure. We analysed the gut microbiota from three groups of worker bumblebees (B.?terrestris) from distinct colonies that varied in rearing and foraging characteristics: commercially reared with restricted foraging (RR); commercially reared with outside foraging (RF); and wild-caught workers (W). Contrary to previous studies, which indicate that bacterial communities are highly conserved across workers, we found that RF individuals had an intermediate community structure compared with RR and W types. Further, this was shaped by differences in the abundances of common operational taxonomic units (OTUs) and the diversity of rare OTUs present, which we propose results from an increase in the variety of carbohydrates obtained through foraging. PMID:25994560

  13. Green Crab (Carcinus maenas) Foraging Efficiency Reduced by Fast Flows

    PubMed Central

    Robinson, Elizabeth M.; Smee, Delbert L.; Trussell, Geoffrey C.

    2011-01-01

    Predators can strongly influence prey populations and the structure and function of ecosystems, but these effects can be modified by environmental stress. For example, fluid velocity and turbulence can alter the impact of predators by limiting their environmental range and altering their foraging ability. We investigated how hydrodynamics affected the foraging behavior of the green crab (Carcinus maenas), which is invading marine habitats throughout the world. High flow velocities are known to reduce green crab predation rates and our study sought to identify the mechanisms by which flow affects green crabs. We performed a series of experiments with green crabs to determine: 1) if their ability to find prey was altered by flow in the field, 2) how flow velocity influenced their foraging efficiency, and 3) how flow velocity affected their handling time of prey. In a field study, we caught significantly fewer crabs in baited traps at sites with fast versus slow flows even though crabs were more abundant in high flow areas. This finding suggests that higher velocity flows impair the ability of green crabs to locate prey. In laboratory flume assays, green crabs foraged less efficiently when flow velocity was increased. Moreover, green crabs required significantly more time to consume prey in high velocity flows. Our data indicate that flow can impose significant chemosensory and physical constraints on green crabs. Hence, hydrodynamics may strongly influence the role that green crabs and other predators play in rocky intertidal communities. PMID:21687742

  14. ORGANOCHLORINE CONTAMINANTS OF WINTERING DUCKS FORAGING ON DETROIT RIVER SEDIMENTS

    EPA Science Inventory

    Organochlorine analysis was performed on carcasses of 13 diving ducks from a 1981 wintering population that foraged on contaminated sediments in the lower Detroit River. Mean total PCB concentrations were 10 mg/kg for seven lesser scaups (Aythya affinis), 11 mg/kg for three great...

  15. Forage Systems for Minimizing Hay and Concentrate Needs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cattlemen typically simplify their pasture management by relying on one or two forages that are well adapted and persist under their targeted levels of management and production. The 5.5 million acres of Kentucky-31 tall fescue in Kentucky is a strong indication how producers in the state rely on t...

  16. Climatic determinants of diet and foraging behaviour in baboons

    Microsoft Academic Search

    R. A. Hill; R. I. M. Dunbar

    2002-01-01

    Baboons (Papio spp.) are characterised by a large degree of variation in foraging behaviour and dietary composition. Previous analyses have suggested that much of this can be traced to differences in ecological conditions between sites. The proximate mechanism underlying these relationships is assumed to be mediated via the impact of climatic conditions on food availability, and ultimately the impact that

  17. PERENNIAL GRASS BREEDING PROGRAM FOR FORAGE AND BIOFUELS - TIFTON, GA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage improvement of bermudagrass and bahiagrass continues within the Crop Genetics and Breeding Research Unit of USDA/ARS. Recently, a new effort has begun within the unit toward developing perennial grass crops as feedstocks for bio-energy in the Southeast. An emphasis beginning three years ago...

  18. FORAGING ECOLOGY OF BALD EAGLES ON A REGULATED RIVER

    Microsoft Academic Search

    W. GRAINGER HUNT; MARK JENKINS; RONALD E. JACKMAN; CARL G. THELANDER; ARNOLD T. GERSTELL

    1992-01-01

    ABSTRCT.--We studied the habitat, foraging behavior, and prey of eight pairs of Bald Eagles (Haliaeetus leucocephalus) nesting along northern California's Pit River where flows and reservoir elevations were regulated by five hydroelectric facilities. Prey remains (N = 1166) and photographic data (N- 117) indicated that eagles fed on a variety of fishes (88%), birds (9%), and mammals (4%), but one

  19. Managing Manure Nutrients Through Multi-crop Forage Production

    Microsoft Academic Search

    G. L. Newton; J. K. Bernard; R. K. Hubbard; J. R. Allison; R. R. Lowrance; G. J. Gascho; R. N. Gates; G. Vellidis

    2003-01-01

    Concentrated sources of dairy manure represent sig- nificant water pollution potential. The southern USA may be more vulnerable to water quality problems than someotherregionsbecauseofclimate,typicalfarmsize, and cropping practices. Dairy manure can be an effec- tive source of plant nutrients and large quantities of nutrients can be recycled through forage production, especially when multi-cropping systems are utilized. Linkingforageproductionwithmanureutilizationisan environmentally sound approach for

  20. GROWTH OF THREE FORAGE SPECIES IN SALINE CONDITIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potential forage crops were evaluated under simulated saline conditions found in southeast Colorado. Due to elevated salinity levels in both the soils and in the irrigation waters of this region identifying salt tolerant crops for sustained productivity is important. The objective of the greenhous...

  1. Sampling requirements for forage quality characterization of rectangular hay bales

    SciTech Connect

    Sheaffer, C.C.; Martin, N.P.; Jewett, J.G.; Halgerson, J.; Moon, R.D.; Cuomo, G.R.

    2000-02-01

    Commercial lots of alfalfa (Medicago sativa L.) hay are often bought and sold on the basis of forage quality. Proper sampling is essential to obtain accurate forage quality results for pricing of alfalfa hay, but information about sampling is limited to small, 20- to 40-kg rectangular bales. Their objectives were to determine the within-bale variation in 400-kg rectangular bales and to determine the number and distribution of core samples required to represent the crude protein (CP), acid detergent fiber (ADF), neutral detergent fiber (NDF), and dry matter (DM) concentration in commercial lots of alfalfa hay. Four bales were selected from each of three hay lots and core sampled nine times per side for a total of 54 cores per bale. There was no consistent pattern of forage quality variation within bales. Averaged across lots, any portion of a bale was highly correlated with bale grand means for CP, ADF, NDF, and DM. Three lots of hay were probed six times per bale, one core per bale side from 55, 14, and 14 bales per lot. For determination of CP, ADF, NDF, and DM concentration, total core numbers required to achieve an acceptable standard error (SE) were minimized by sampling once per bale. Bootstrap analysis of data from the most variable hay lot suggested that forage quality of any lot of 400-kg alfalfa hay bales should be adequately represented by 12 bales sampled once per bale.

  2. Quest for Nutritional and Medicinal Forages for Meat Goats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Appalachian meat goat producers are encountering animal nutritional and health problems for which research-based solutions are limited. Goats prefer to eat weeds and browse, selecting the highest quality herbage available. Foraging on traditional pastures not only limits the variety of plant speci...

  3. Effects of humic acid on forage digestibility in ruminants 

    E-print Network

    Faulkenbery, James Marcus

    1995-01-01

    Three experiments were conducted to determine the effects of purified humic acid (HA) on rate and extent of microbial digestion of various forages in ruminants. In Exp. 1 the in vitro dry matter disappearance (DMD) of Coastal Bermuda grass hay (CBH...

  4. Foraging Ecology of Rainbow Skinks (Mabuya margaritifer) in Southern Africa

    Microsoft Academic Search

    Monica N. Wymann; Martin J. Whiting; C. Guyer

    2002-01-01

    We determined group composition and foraging mode in a wild population of rupicolous rainbow skinks (Mabuya margaritifer) on rocky outcrops in a humid sa- vannah of South Africa and examined diet, sexual dimorphism, and life-history traits in museum material. We also field-tested lizards for prey chemical discrimination. Males were larger than females in both body and head size. Both sexes

  5. IMPLICATIONS OF FORAGE MANAGEMENT ON FARM PROFITABILITY AND THE ENVIRONMENT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The management of forage-based farms for dairy production is complex. Software tools can aid decision making by helping integrate the large amount of information that must be considered. Whole-farm simulation is particularly useful for predicting the long term effects of management changes on farm p...

  6. DYNAPHORE, INC. FORAGER¿ SPONGE TECHNOLOGY - INNOVATIVE TECHNOLOGY EVALUATION REPORT

    EPA Science Inventory

    The Forager¿ Sponge is an open-celled cellulose sponge incorporating an amine-containing chelating polymer that selectively absorbs dissolved heavy metals from aqueous waste streams. The Developer states that the technology can be utilized to remove and concentrate heavy metals f...

  7. Rational Analyses of Information Foraging on the Web

    ERIC Educational Resources Information Center

    Pirolli, Peter

    2005-01-01

    This article describes rational analyses and cognitive models of Web users developed within information foraging theory. This is done by following the rational analysis methodology of (a) characterizing the problems posed by the environment, (b) developing rational analyses of behavioral solutions to those problems, and (c) developing cognitive…

  8. Estimating Forage Quality of Grazing Ruminants (Part 2)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Meeting the nutritional needs of a mother cow through the different physiological stages of reproduction, lactation and recovery from parturition is very important to sustained productivity. Having a calf and nursing it to weaning every year is quite a task. Consuming sufficient high quality forag...

  9. Small Grains Forage Management and Evaluation in Central Texas

    E-print Network

    Franks, Aaron Michael

    2013-04-25

    Hard Red Winter (HRW) and Soft Red Winter (HRW) wheat classes (Triticum aestivum L.) and oat (Avena sativa L.) are commonly established as a source of winter and spring forage for cattle grazing in many regions of Texas and the U.S. Southern Great...

  10. Optimal management of MicroGrid using Bacterial Foraging Algorithm

    Microsoft Academic Search

    R. Noroozian; H. Vahedi

    2010-01-01

    This paper focused on optimal operating strategy and cost optimization scheme for a MicroGrid by using Bacterial Foraging Algorithm. Prior to the optimization of the microgrid itself, the system model components from some real manufactural data are constructed. The proposed cost function takes into consideration the costs of the emissions NOx, SO2, and CO2 as well as the operation and

  11. ON SOME PROPERTIES OF ARTIFICIAL FORAGING ANT COMMUNITIES

    E-print Network

    de Lara, Juan

    and simulation of artificial foraging ant communities. Each virtual ant (vant) taking part in the simulation, exchange of information can occur between colliding vants. We have used simulation and mathematical: Artificial Societies, Agent-Based Simulation, Random Walks, Emergence. 1. INTRODUCTION Computer modellization

  12. Adaptive foraging and flexible food web topology Vlastimil Krivan

    E-print Network

    Krivan, Vlastimil

    modelling shows that single systems of predators, adaptive herbivores and resources can display food chain, adaptive omnivory causes the exploitative competition, linear food chain and multi-trophic level omnivory be confounded by topological shifts in the system itself. Keywords: adaptive foraging, food chain, food web

  13. Feasibility study of wood stork foraging habitat mapping using landsat multispectral data

    SciTech Connect

    Jensen, J.R.; Hodgson, M.E.; Coulter, M.; Mackey, H.E. Jr.

    1986-01-01

    The wood stork is a large wading bird which forages in shallow wetlands up to 70 kilometers from the colony. Landsat data were evaluated to determine if remote sensing data were suitable for locating and estimating the extent of potential foraging habitat for this species over such a large range. Thematic Mapper data of north-central Georgia and the Savannah River floodplain in South Carolina were obtained May 5, 1984. Spectral signatures from known foraging sites near a colony in Georgia were identified. Computer clustering techniques were used to identify and map shallow water and marsh wetland foraging habitats. Foraging acreages were computed, and maps of the locations of candidate foraging sites were produced for a 1520-square-kilometer area. Remote sensing appears to provide a feasible method of evaluating the regional wetland foraging habitat available to this wide-ranging species.

  14. Good foragers can also be good at detecting predators.

    PubMed Central

    Cresswell, W; Quinn, J L; Whittingham, M J; Butler, S

    2003-01-01

    The degree to which foraging and vigilance are mutually exclusive is crucial to understanding the management of the predation and starvation risk trade-off in animals. We tested whether wild-caught captive chaffinches that feed at a higher rate do so at the expense of their speed in responding to a model sparrowhawk flying nearby, and whether consistently good foragers will therefore tend to respond more slowly on average. First, we confirmed that the time taken to respond to the approaching predator depended on the rate of scanning: as head-up rate increased so chaffinches responded more quickly. However, against predictions, as peck rate increased so head-up rate increased and mean length of head-up and head-down periods decreased. Head-up rate was probably dependent on peck rate because almost every time a seed was found, a bird raised its head to handle it. Therefore chaffinches with higher peck rates responded more quickly. Individual chaffinches showed consistent durations of both their head-down and head-up periods and, therefore, individuals that were good foragers were also good detectors of predators. In relation to the broad range of species that have a similar foraging mode to chaffinches, our results have two major implications for predation/starvation risk trade-offs: (i) feeding rate can determine vigilance scanning patterns; and (ii) the best foragers can also be the best at detecting predators. We discuss how our results can be explained in mechanistic terms relating to fundamental differences in how the probabilities of detecting food rather than a predator are affected by time. In addition, our results offer a plausible explanation for the widely observed effect that vigilance continues to decline with group size even when there is no further benefit to reducing vigilance. PMID:12803897

  15. The dilemma of foraging herbivores: dealing with food and fear.

    PubMed

    McArthur, Clare; Banks, Peter B; Boonstra, Rudy; Forbey, Jennifer Sorensen

    2014-11-01

    For foraging herbivores, both food quality and predation risk vary across the landscape. Animals should avoid low-quality food patches in favour of high-quality ones, and seek safe patches while avoiding risky ones. Herbivores often face the foraging dilemma, however, of choosing between high-quality food in risky places or low-quality food in safe places. Here, we explore how and why the interaction between food quality and predation risk affects foraging decisions of mammalian herbivores, focusing on browsers confronting plant toxins in a landscape of fear. We draw together themes of plant-herbivore and predator-prey interactions, and the roles of animal ecophysiology, behaviour and personality. The response of herbivores to the dual costs of food and fear depends on the interplay of physiology and behaviour. We discuss detoxification physiology in dealing with plant toxins, and stress physiology associated with perceived predation risk. We argue that behaviour is the interface enabling herbivores to stay or quit food patches in response to their physiological tolerance to these risks. We hypothesise that generalist and specialist herbivores perceive the relative costs of plant defence and predation risk differently and intra-specifically, individuals with different personalities and physiologies should do so too, creating individualised landscapes of food and fear. We explore the ecological significance and emergent impacts of these individual-based foraging outcomes on populations and communities, and offer predictions that can be clearly tested. In doing so, we provide an integrated platform advancing herbivore foraging theory with food quality and predation risk at its core. PMID:25270335

  16. Elevation and forest clearing effects on foraging differ between surface - and subterranean - foraging army ants (Formicidae: Ecitoninae)

    Microsoft Academic Search

    Anjali Kumar; Sean O'Donnell

    2009-01-01

    Summary 1. Forest fragmentation often results in a matrix of open areas mixed with patches of forest. Both biotic and abiotic factors can affect consumer species' ability to utilize the altered habitat, especially for species that range over large areas searching for prey. 2. Army ants (Formicidae: Ecitoninae) are highly mobile top predators in terrestrial Neotropical ecosystems. Army ant foraging

  17. Persistence of forage fish `hot spots' and its association with foraging Steller sea lions (Eumetopias jubatus) in southeast Alaska

    Microsoft Academic Search

    Scott M. Gende; Michael F. Sigler

    2006-01-01

    Whereas primary and secondary productivity at oceanic `hotspots' may be a function of upwelling and temperature fronts, the aggregation of higher-order vertebrates is a function of their ability to search for and locate these areas. Thus, understanding how predators aggregate at these productive foraging areas is germane to the study of oceanic hot spots. We examined the spatial distribution of

  18. Persistence of forage fish ‘hot spots’ and its association with foraging Steller sea lions ( Eumetopias jubatus) in southeast Alaska

    Microsoft Academic Search

    Scott M. Gende; Michael F. Sigler

    2006-01-01

    Whereas primary and secondary productivity at oceanic ‘hotspots’ may be a function of upwelling and temperature fronts, the aggregation of higher-order vertebrates is a function of their ability to search for and locate these areas. Thus, understanding how predators aggregate at these productive foraging areas is germane to the study of oceanic hot spots. We examined the spatial distribution of

  19. Effects of Forage Particle Size, Forage Source, and Grain Fermentability on Performance and Ruminal pH in Midlactation Cows

    Microsoft Academic Search

    K. M. Krause; D. K. Combs

    2003-01-01

    Ourstudyinvestigatedtheeffectsof,andinteractions between, forage particle size, level of dietary ruminally fermentable carbohydrate (RFC), and level of dietary starch on performance, chewing activity, and ruminal pH for dairy cows fed one level of dietary NDF. Twelve cows (48 DIM) were assigned to six treatments in a replicated 6 × 6 Latin square. Treatments were ar- ranged in an incomplete 2 × 2

  20. Foraging honeybees can learn many things (Menzel and Giurfa, 2001) and thus have many memories. In foraging, they

    E-print Network

    Cheng, Ken

    1019 Foraging honeybees can learn many things (Menzel and Giurfa, 2001) and thus have many memories (honeybees: Collett and Kelber, 1988; Collett et al., 1997) and indoors (honeybees: Collett and Baron, 1995 interference is found (Fauria et al., 2002). In recent work, we created situations in which honeybees exhibited

  1. Foraging Fidelity as a Recipe for a Long Life: Foraging Strategy and Longevity in Male Southern Elephant Seals

    PubMed Central

    Authier, Matthieu; Bentaleb, Ilham; Ponchon, Aurore; Martin, Céline; Guinet, Christophe

    2012-01-01

    Identifying individual factors affecting life-span has long been of interest for biologists and demographers: how do some individuals manage to dodge the forces of mortality when the vast majority does not? Answering this question is not straightforward, partly because of the arduous task of accurately estimating longevity in wild animals, and of the statistical difficulties in correlating time-varying ecological covariables with a single number (time-to-event). Here we investigated the relationship between foraging strategy and life-span in an elusive and large marine predator: the Southern Elephant Seal (Mirounga leonina). Using teeth recovered from dead males on îles Kerguelen, Southern Ocean, we first aged specimens. Then we used stable isotopic measurements of carbon () in dentin to study the effect of foraging location on individual life-span. Using a joint change-point/survival modelling approach which enabled us to describe the ontogenetic trajectory of foraging, we unveiled how a stable foraging strategy developed early in life positively covaried with longevity in male Southern Elephant Seals. Coupled with an appropriate statistical analysis, stable isotopes have the potential to tackle ecological questions of long standing interest but whose answer has been hampered by logistic constraints. PMID:22505993

  2. Forage yield of grass-alfalfa and grass-forage kochia mixtues on semi-arid rangelands

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Increased productivity of semiarid western U.S.A. grazing lands is possible with the appropriate plant material combinations. The objective of this study was to compare late summer forage yield of 'Vavilov' Siberian wheatgrass (Agropyron fragile) and 'Mustang' altai wildrye (Leymus angustus) in bin...

  3. Fearful foragers: honey bees tune colony and individual foraging to multi-predator presence and food quality.

    PubMed

    Tan, Ken; Hu, Zongwen; Chen, Weiwen; Wang, Zhengwei; Wang, Yuchong; Nieh, James C

    2013-01-01

    Fear can have strong ecosystem effects by giving predators a role disproportionate to their actual kill rates. In bees, fear is shown through foragers avoiding dangerous food sites, thereby reducing the fitness of pollinated plants. However, it remains unclear how fear affects pollinators in a complex natural scenario involving multiple predator species and different patch qualities. We studied hornets, Vespa velutina (smaller) and V. tropica (bigger) preying upon the Asian honey bee, Apis cerana in China. Hornets hunted bees on flowers and were attacked by bee colonies. Bees treated the bigger hornet species (which is 4 fold more massive) as more dangerous. It received 4.5 fold more attackers than the smaller hornet species. We tested bee responses to a three-feeder array with different hornet species and varying resource qualities. When all feeders offered 30% sucrose solution (w/w), colony foraging allocation, individual visits, and individual patch residence times were reduced according to the degree of danger. Predator presence reduced foraging visits by 55-79% and residence times by 17-33%. When feeders offered different reward levels (15%, 30%, or 45% sucrose), colony and individual foraging favored higher sugar concentrations. However, when balancing food quality against multiple threats (sweeter food corresponding to higher danger), colonies exhibited greater fear than individuals. Colonies decreased foraging at low and high danger patches. Individuals exhibited less fear and only decreased visits to the high danger patch. Contrasting individual with emergent colony-level effects of fear can thus illuminate how predators shape pollination by social bees. PMID:24098734

  4. GPS tracking devices reveal foraging strategies of black-legged kittiwakes

    USGS Publications Warehouse

    Kotzerka, Jana; Garthe, Stefan; Hatch, Scott A.

    2010-01-01

    The Black-legged Kittiwake Rissa tridactyla is the most abundant gull species in the world, but some populations have declined in recent years, apparently due to food shortage. Kittiwakes are surface feeders and thus can compensate for low food availability only by increasing their foraging range and/or devoting more time to foraging. The species is widely studied in many respects, but long-distance foraging and the limitations of conventional radio telemetry have kept its foraging behavior largely out of view. The development of Global Positioning System (GPS) loggers is advancing rapidly. With devices as small as 8 g now available, it is possible to use this technology for tracking relatively small species of oceanic birds like kittiwakes. Here we present the first results of GPS telemetry applied to Black-legged Kittiwakes in 2007 in the North Pacific. All but one individual foraged in the neritic zone north of the island. Three birds performed foraging trips only close to the colony (within 13 km), while six birds had foraging ranges averaging about 40 km. The maximum foraging range was 59 km, and the maximum distance traveled was 165 km. Maximum trip duration was 17 h (mean 8 h). An apparently bimodal distribution of foraging ranges affords new insight on the variable foraging behaviour of Black-legged Kittiwakes. Our successful deployment of GPS loggers on kittiwakes holds much promise for telemetry studies on many other bird species of similar size and provides an incentive for applying this new approach in future studies.

  5. Honey loading for pollen collection: regulation of crop content in honeybee pollen foragers on leaving hive.

    PubMed

    Harano, Ken-ichi; Mitsuhata-Asai, Akiko; Sasaki, Masami

    2014-07-01

    Before foraging honeybees leave the hive, each bee loads its crop with some amount of honey "fuel" depending on the distance to the food source and foraging experience. For pollen collection, there is evidence that foragers carry additional honey as "glue" to build pollen loads. This study examines whether pollen foragers of the European honeybee Apis mellifera regulate the size of the crop load according to food-source distances upon leaving the hive and how foraging experience affects load regulation. The crop contents of bees foraging on crape myrtle Lagerstroemia indica, which has no nectary, were larger than those foraging on nectar from other sources, confirming a previous finding that pollen foragers carry glue in addition to fuel honey from the hive. Crop contents of both waggle dancers and dance followers showed a significant positive correlation with waggle-run durations. These results suggest that bees carry a distance-dependent amount of fuel honey in addition to a fixed amount of glue honey. Crop contents on leaving the hive were statistically larger in dancers than followers. Based on these results, we suggest that pollen foragers use information obtained through foraging experience to adjust crop contents on leaving the hive. PMID:24925356

  6. Exploring behavior of an unusual megaherbivore: A spatially explicit foraging model of the hippopotamus

    USGS Publications Warehouse

    Lewison, R.L.; Carter, J.

    2004-01-01

    Herbivore foraging theories have been developed for and tested on herbivores across a range of sizes. Due to logistical constraints, however, little research has focused on foraging behavior of megaherbivores. Here we present a research approach that explores megaherbivore foraging behavior, and assesses the applicability of foraging theories developed on smaller herbivores to megafauna. With simulation models as reference points for the analysis of empirical data, we investigate foraging strategies of the common hippopotamus (Hippopotamus amphibius). Using a spatially explicit individual based foraging model, we apply traditional herbivore foraging strategies to a model hippopotamus, compare model output, and then relate these results to field data from wild hippopotami. Hippopotami appear to employ foraging strategies that respond to vegetation characteristics, such as vegetation quality, as well as spatial reference information, namely distance to a water source. Model predictions, field observations, and comparisons of the two support that hippopotami generally conform to the central place foraging construct. These analyses point to the applicability of general herbivore foraging concepts to megaherbivores, but also point to important differences between hippopotami and other herbivores. Our synergistic approach of models as reference points for empirical data highlights a useful method of behavioral analysis for hard-to-study megafauna. ?? 2003 Elsevier B.V. All rights reserved.

  7. Effects of predator chemical cues and behavioral biorhythms on foraging activity of terrestrial salamanders.

    PubMed

    Maerz, J C; Panebianco, N L; Madison, D M

    2001-07-01

    Red-backed salamanders, Plethodon cinereus, show a variety of alarm responses to chemical cues from eastern garter snakes, Thamnophis sirtalis. We measured the foraging activity of red-backed salamanders exposed to water soiled by a garter snake (fed P. cinereus) or to unsoiled water. Salamanders exposed to snake-soiled water showed less foraging activity than salamanders exposed to unsoiled water; therefore, predators could have nonlethal effects on salamander populations. Our results also show additional factors influenced salamander foraging activity. Salamander foraging activity and responsiveness to chemical cues do not appear to have been affected by sex or food deprivation. Salamander foraging activity does appear to have been influenced by activity biorhythms. Foraging activity of animals in both treatments showed a bimodal periodicity that is consistent with natural activity patterns controlled by internal biorhythms. Exposure to snake-soiled water significantly reduced foraging activity during periods of peak foraging activity, but had a subtler effect on foraging activity during natural lulls in activity. We suggest that both activity biorhythms and exposure to chemical cues are important factors affecting salamander foraging behavior. PMID:11504031

  8. Foraging decisions and behavioural flexibility in trap-building predators: a review.

    PubMed

    Scharf, Inon; Lubin, Yael; Ovadia, Ofer

    2011-08-01

    Foraging theory was first developed to predict the behaviour of widely-foraging animals that actively search for prey. Although the behaviour of sit-and-wait predators often follows predictions derived from foraging theory, the similarity between these two distinct groups of predators is not always obvious. In this review, we compare foraging activities of trap-building predators (mainly pit-building antlions and web-building spiders), a specific group of sit-and-wait predators that construct traps as a foraging device, with those of widely-foraging predators. We refer to modifications of the trap characteristics as analogous to changes in foraging intensity. Our review illustrates that the responses of trap-building and widely-foraging predators to different internal and external factors, such as hunger level, conspecific density and predation threat are quite similar, calling for additional studies of foraging theory using trap-building predators. In each chapter of this review, we summarize the response of trap-building predators to a different factor, while contrasting it with the equivalent response characterizing widely-foraging predators. We provide here evidence that the behaviour of trap-building predators is not stereotypic or fixed as was once commonly accepted, rather it can vary greatly, depending on the individual's internal state and its interactions with external environmental factors. PMID:21062400

  9. Organization of foraging behavior in larvae of cosmopolitan, widespread, and endemic Drosophila species.

    PubMed

    Godoy-Herrera, Raúl; Connolly, Kevin

    2007-07-01

    To explore the evolution of higher order behavioral traits we investigated the organization of foraging patterns in first instar larvae of natural populations of Drosophila. We examined Drosophila simulans (cosmopolitan); D. mauritania (widespread); D. pavani, and D. gaucha (endemic). Larvae of these four species share the same behavior components that comprise foraging (locomotion, feeding, bending, and turning). D. simulans and D. mauritania larvae show uncoupled foraging patterns organized into partially independent behavioral elements. Larvae of D. pavani and D. gaucha exhibit coupled foraging behaviors based on a dependency between behavioral components. Hybrid larvae obtained from crosses of natural populations of D. simulans and D. mauritania show an organization of foraging patterns similar to that of the parental lines. In contrast, hybridization disrupts the organization of foraging patterns in D. pavani and D. gaucha intra- and inter-specific hybrid larvae. This suggests genetic co-adaptation for linkage between the behavioral components that comprise foraging. The organization of larval foraging patterns of the endemic species D. pavani seems readily affected by hybridization. The absence of linkage between behavioral components, as in the case of larval foraging patterns of D. simulans and D. mauritania could lead to an increase in the variability of organization of this higher order behavior. The possibility that larvae may use a variable and flexible behavioral integration of foraging patterns could contribute to their development and feeding in a diversity of substrates and climates. PMID:17394057

  10. SYMPOSIUM: FORAGE UTILIZATION BY THE LACTATING COW Role of Particle Size and Forage Quality in Digestion and Passage by Cattle and Sheep 1,2

    Microsoft Academic Search

    F. A. MARTZ; R. L. BELYEA

    Diminution of forage particles includes mastication, chewing, and digestion. In rumen of cattle and sheep fed all forage diets, particle size can range from 200 to over 1200 \\/am. Particle size reduction to about <1200 gtm must occur before passage. Dietary particle size may in- fluence rumen particle size, but mastica- tion and rumination minimizes differ- ences among diets. Rumnants

  11. Small is profitable: No support for the optimal foraging theory in sea stars Asterias rubens foraging on the blue edible mussel Mytilus edulis

    NASA Astrophysics Data System (ADS)

    Hummel, Christiaan; Honkoop, Pieter; van der Meer, Jaap

    2011-07-01

    Doubt has been shed recently on the most popular optimal foraging theory stating that predators should maximize prey profitability, i.e., select that prey item that contains the highest energy content per handling time. We hypothesized that sea stars do not forage on blue mussels according to the classical optimal foraging theory but are actively avoiding damage that may be caused by e.g. capture of foraging on too-strong mussel shells, hence the sea stars will have a stronger preference for mussels that are smaller than the most profitable ones. Here we present experimental evidence of the sea star Asterias rubens as a predator that indeed chooses much smaller blue mussels Mytilus edulis to forage on than the most profitable ones. Hence this study does not support the optimal foraging theory. There may be other constraints involved in foraging than just optimizing energy intake, for example predators may also be concerned with preventing potential loss or damage of their foraging instruments.

  12. Effects of short-term variation in forage quality and forage to concentrate ratio on lactating dairy cows.

    PubMed

    Yoder, P S; St-Pierre, N R; Daniels, K M; O'Diam, K M; Weiss, W P

    2013-10-01

    Within-farm variation in forage composition can be substantial and potentially costly, and it presents challenges for sampling the forage accurately. We hypothesized that day-to-day variation in forage neutral detergent fiber (FNDF) concentrations and diet variation caused by sampling error would have negative effects on production measures in lactating dairy cows. Twenty-four Holstein cows (73 d in milk) were used in 8 replicated 3 × 3 Latin squares with 21-d periods. Treatments were (1) control (CON), (2) variable (VAR), and (3) overreacting (ORR). On average, over the 21-d period, all 3 treatments were the same [24.7% FNDF and 48.2% forage dry matter (DM) composed of 67% alfalfa silage and 33% grass silage]. The CON treatment was essentially consistent day-to-day in total forage and FNDF concentrations and proportion of alfalfa and grass silages. The VAR treatment changed daily (in a random pattern) in proportion of alfalfa and grass silages fed, which resulted in day-to-day changes in FNDF (range was 21.5 to 28%). The ORR treatment varied in a 5-d cyclic pattern in total forage and FNDF concentrations (26, 24, 28, and 21.5% FNDF). Over the 21 d, ORR (25.1 kg/d) had higher DM intake compared with CON (24.5 kg/d) and VAR (24.3 kg/d). Milk production (42.8 kg/d), milk fat (3.5%), and milk protein (2.8%) were not affected by treatment; however, a treatment × day interaction was observed for milk production. Lower daily milk yields for VAR and ORR compared with CON were rare; they only followed sustained 4- and 5-d periods of feeding higher FNDF diets compared with CON. In contrast, increased daily milk yields for VAR and ORR versus CON were more frequent and followed sustained diet changes of only 2 or 3d. Lipolytic and lipogenic-related enzyme mRNA abundances in subcutaneous adipose tissue were not affected by treatment. Treatment × day interactions were observed for milk fatty acid markers of cellulolytic bacteria (iso-14:0, iso-15:0, iso-16:0) and lipolysis (18:0) and generally followed the expected response to changes in daily rations. Overall, extreme daily fluctuations in FNDF had no cumulative negative effect on production measures over a 21-d period, and daily responses to transient increases in FNDF were less than expected. PMID:23958009

  13. Responses of late-lactation cows to forage substitutes in low-forage diets supplemented with by-products.

    PubMed

    Hall, M B; Chase, L E

    2014-05-01

    In response to drought-induced forage shortages along with increased corn and soy prices, this study was conducted to evaluate lactation responses of dairy cows to lower-forage diets supplemented with forage substitutes. By-product feeds were used to completely replace corn grain and soybean feeds. Forty-eight late-lactation cows were assigned to 1 of 4 diets using a randomized complete block design with a 2-wk covariate period followed by a 4-wk experimental period. The covariate diet contained corn grain, soybean meal, and 61% forage. Experimental diets contained chopped wheat straw (WS)/sugar beet pulp at 0/12, 3/9, 6/6, or 9/3 percentages of diet dry matter (DM). Corn silage (20%), alfalfa silage (20%), pelleted corn gluten feed (25.5%), distillers grains (8%), whole cottonseed (5%), cane molasses/whey blend (7%), and vitamin and mineral mix with monensin (2.5%) comprised the rest of diet DM. The WS/sugar beet pulp diets averaged 16.5% crude protein, 35% neutral detergent fiber, and 11% starch (DM basis). Cows consuming the experimental diets maintained a 3.5% fat- and protein-corrected milk production (35.2 kg; standard deviation=5.6 kg) that was numerically similar to that measured in the covariate period (35.3 kg; standard deviation=5.0 kg). Intakes of DM and crude protein declined linearly as WS increased, whereas neutral detergent fiber intake increased linearly. Linear increases in time spent ruminating (from 409 to 502 min/d) and eating (from 156 to 223 min/d) were noted as WS inclusion increased. Yields of milk fat and 3.5% fat-and protein-corrected milk did not change as WS increased, but those of protein and lactose declined linearly. Phosphorous intakes were in excess of recommended levels and decreased linearly with increasing WS inclusion. Nutritional model predictions for multiparous cows were closest to actual performance for the National Research Council 2001 model when a metabolizable protein basis was used; primiparous cow performance was better predicted by energy-based predictions made with the National Research Council or Cornell Net Carbohydrate and Protein System models. Model predictions of performance showed a quadratic diet effect with increasing WS. Lactating dairy cows maintained production on low-forage diets that included forage substitutes, and in which by-product feeds fully replaced corn grain and soybean. However, longer-term studies are needed to evaluate animal performance and to improve model predictions of performance on these nontraditional diets. PMID:24612800

  14. Diffusion dynamics of socially learned foraging techniques in squirrel monkeys.

    PubMed

    Claidière, Nicolas; Messer, Emily J E; Hoppitt, William; Whiten, Andrew

    2013-07-01

    Social network analyses and experimental studies of social learning have each become important domains of animal behavior research in recent years yet have remained largely separate. Here we bring them together, providing the first demonstration of how social networks may shape the diffusion of socially learned foraging techniques. One technique for opening an artificial fruit was seeded in the dominant male of a group of squirrel monkeys and an alternative technique in the dominant male of a second group. We show that the two techniques spread preferentially in the groups in which they were initially seeded and that this process was influenced by monkeys' association patterns. Eigenvector centrality predicted both the speed with which an individual would first succeed in opening the artificial fruit and the probability that they would acquire the cultural variant seeded in their group. These findings demonstrate a positive role of social networks in determining how a new foraging technique diffuses through a population. PMID:23810529

  15. Chemical compounds of the foraging recruitment pheromone in bumblebees

    NASA Astrophysics Data System (ADS)

    Granero, Angeles Mena; Sanz, José M. Guerra; Gonzalez, Francisco J. Egea; Vidal, José L. Martinez; Dornhaus, Anna; Ghani, Junaid; Serrano, Ana Roldán; Chittka, Lars

    2005-08-01

    When the frenzied and irregular food-recruitment dances of bumblebees were first discovered, it was thought that they might represent an evolutionary prototype to the honeybee waggle dance. It later emerged that the primary function of the bumblebee dance was the distribution of an alerting pheromone. Here, we identify the chemical compounds of the bumblebee recruitment pheromone and their behaviour effects. The presence of two monoterpenes and one sesquiterpene (eucalyptol, ocimene and farnesol) in the nest airspace and in the tergal glands increases strongly during foraging. Of these, eucalyptol has the strongest recruitment effect when a bee nest is experimentally exposed to it. Since honeybees use terpenes for marking food sources rather than recruiting foragers inside the nest, this suggests independent evolutionary roots of food recruitment in these two groups of bees.

  16. Ultraviolet vision and foraging in dip and plunge diving birds

    PubMed Central

    Håstad, Olle; Ernstdotter, Emma; Ödeen, Anders

    2005-01-01

    Many fishes are sensitive to ultraviolet (UV) light and display UV markings during courtship. As UV scatters more than longer wavelengths of light, these signals are only effective at short distances, reducing the risk of detection by swimming predators. Such underwater scattering will be insignificant for dip and plunge diving birds, which prey on fishes just below the water surface. One could therefore expect to find adaptations in the eyes of dip and plunge diving birds that tune colour reception to UV signals. We used a molecular method to survey the colour vision tuning of five families of dip or plunge divers and compared the results with those from sister taxa of other foraging methods. We found evidence of extended UV vision only in gulls (Laridae). Based on available evidence, it is more probable that this trait is associated with their terrestrial foraging habits rather than piscivory. PMID:17148194

  17. Identifying robustness in the regulation of collective foraging of ant colonies using an interaction-based model with backward bifurcation.

    PubMed

    Udiani, Oyita; Pinter-Wollman, Noa; Kang, Yun

    2015-02-21

    Collective behaviors in social insect societies often emerge from simple local rules. However, little is known about how these behaviors are dynamically regulated in response to environmental changes. Here, we use a compartmental modeling approach to identify factors that allow harvester ant colonies to regulate collective foraging activity in response to their environment. We propose a set of differential equations describing the dynamics of: (1) available foragers inside the nest, (2) active foragers outside the nest, and (3) successful returning foragers, to understand how colony-specific parameters, such as baseline number of foragers, interactions among foragers, food discovery rates, successful forager return rates, and foraging duration might influence collective foraging dynamics, while maintaining functional robustness to perturbations. Our analysis indicates that the model can undergo a forward (transcritical) bifurcation or a backward bifurcation depending on colony-specific parameters. In the former case, foraging activity persists when the average number of recruits per successful returning forager is larger than one. In the latter case, the backward bifurcation creates a region of bistability in which the size and fate of foraging activity depends on the distribution of the foraging workforce among the model's compartments. We validate the model with experimental data from harvester ants (Pogonomyrmex barbatus) and perform sensitivity analysis. Our model provides insights on how simple, local interactions can achieve an emergent and robust regulatory system of collective foraging activity in ant colonies. PMID:25484006

  18. Woolly Locoweed and Forage Response to Herbicides in West Texas.

    E-print Network

    Freeman, M.R.; Ueckert, D.N.; Nelson, J.T.

    1982-01-01

    firms in the Big Bend region of the Texas Trans Pecos have suffered serious livestock losses for decades as the result of poisoning by poisonous plants including woolly locoweed (Astragalus mollissirnus Torr. var. ear- lei [Rydb.] Tidestr.), also...). Livestock consume woolly locoweed primarily during fall, winter, and spring. Animals usually will not con- sume lethal quantities of woolly locoweed or other toxic species of Astragalus if high quality forage is available (James and Johnson, 1976...

  19. Woolly Locoweed and Forage Response to Herbicides in West Texas.

    E-print Network

    Freeman, M. R.; Ueckert, D. N.; Nelson, J. T.

    1982-01-01

    livestock losses for decades as the result of poisoning by poisonous plants including woolly locoweed (Astragalus mollissimus Torr. var. ear lei [Rydb.] Tidestr. ), also referred to as Earle loco, purple loco, and Texas loco. Woolly locoweed, a robust... or other toxic species of Astragalus if high quality forage is available (James and Johnson, 1976; Krueger and Sharp, 1978; Sperry et al., 1964). Sperry et al. (1964) indicated that proper supplemental feeding reduced the amount of woolly locoweed...

  20. Activity Time Budget during Foraging Trips of Emperor Penguins

    PubMed Central

    Watanabe, Shinichi; Sato, Katsufumi; Ponganis, Paul J.

    2012-01-01

    We developed an automated method using depth and one axis of body acceleration data recorded by animal-borne data loggers to identify activities of penguins over long-term deployments. Using this technique, we evaluated the activity time budget of emperor penguins (n?=?10) both in water and on sea ice during foraging trips in chick-rearing season. During the foraging trips, emperor penguins alternated dive bouts (4.8±4.5 h) and rest periods on sea ice (2.5±2.3 h). After recorder deployment and release near the colony, the birds spent 17.9±8.4% of their time traveling until they reached the ice edge. Once at the ice edge, they stayed there more than 4 hours before the first dive. After the first dive, the mean proportions of time spent on the ice and in water were 30.8±7.4% and 69.2±7.4%, respectively. When in the water, they spent 67.9±3.1% of time making dives deeper than 5 m. Dive activity had no typical diurnal pattern for individual birds. While in the water between dives, the birds had short resting periods (1.2±1.7 min) and periods of swimming at depths shallower than 5 m (0.25±0.38 min). When the birds were on the ice, they primarily used time for resting (90.3±4.1% of time) and spent only 9.7±4.1% of time traveling. Thus, it appears that, during foraging trips at sea, emperor penguins traveled during dives >5 m depth, and that sea ice was primarily used for resting. Sea ice probably provides refuge from natural predators such as leopard seals. We also suggest that 24 hours of sunlight and the cycling of dive bouts with short rest periods on sea ice allow emperor penguins to dive continuously throughout the day during foraging trips to sea. PMID:23185608

  1. Woolly Locoweed and Forage Response to Herbicides in West Texas. 

    E-print Network

    Freeman, M.R.; Ueckert, D.N.; Nelson, J.T.

    1982-01-01

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Mentioned in Text back cover KEYWORDS: Poisonous plantslrange managementlwoolly locoweed/Earle loco/purple loco/Texas loco/ 2,4-D/dicamba/3,6-dichloropicolinic a id~picloram/tebuthiuron/trichlopyr/pelleted herbicides. Woolly Locoweed and Forage Response... of foliar sprays containing picloram, whereas control usually was not manifested for almost a year following application of picloram pellets. Woolly locoweed was effectively controlled in the fall with foliar sprays of picloram + triclopyr ester (1:l...

  2. FORAGE AND ANIMAL MANAGEMENT IMPLICATIONS OF SPRING AND FALL CALVING

    Microsoft Academic Search

    R. J. Kartchner; L. R. Rittenhouse; R. J. Raleigh

    2010-01-01

    SUMMARY Forage dry matter intake (FDMI), body weight changes and milk production were determined for six fall-calving and six spring- calving cow-calf pairs grazing in common on crested wheatgrass pasture over a 125-day period from April 29 to August 31. For fall- and spring-born calves, respective daily FDMI averaged 4.25 kg and .94 kg (P<.01); and respective daily gains averaged

  3. Sexy birds are superior at solving a foraging problem.

    PubMed

    Mateos-Gonzalez, Fernando; Quesada, Javier; Senar, Juan Carlos

    2011-10-23

    Yellow, red or orange carotenoid-based colorations in male birds are often a signal to prospecting females about body condition, health status and ability to find food. However, this general 'ability to find food' has never been defined. Here we show that more brightly ornamented individuals may also be more efficient when foraging in novel situations. The results highlight the fact that evolution may have provided females tools to evaluate cognitive abilities of the males. PMID:21450725

  4. Collective construction of numerical potential fields for the foraging problem

    Microsoft Academic Search

    Olivier Simonin; Francois Charpillet; Eric Thierry

    2007-01-01

    Abstract: We consider the problem of deploying a team of agents (robots) for the foraging problem. In this problem agents have to collect disseminated resources in an unknown,environment. They must therefore be endowed,with explo- ration and path-planning abilities. This paper presents a reactive multiagent system that is able to simultaneously perform the two desired activities - exploration and path-planning -

  5. Bee foraging in uncertain environments using predictive hebbian learning

    Microsoft Academic Search

    P. Read Montague; Peter Dayan; Christophe Person; Terrence J. Sejnowski

    1995-01-01

    RECENT work has identified a neuron with widespread projections to odour processing regions of the honeybee brain whose activity represents the reward value of gustatory stimuli1,2. We have constructed a model of bee foraging in uncertain environments based on this type of neuron and a predictive form of hebbian synaptic plasticity. The model uses visual input from a simulated three-dimensional

  6. FORAGE INTAKE OF ALPACAS GRAZING ANDEAN RANGELAND IN PERU 1

    Microsoft Academic Search

    R. J. Reiner; F. C. Bryant; R. D. Farfan; B. F. Craddock

    This study estimated forage intake of free-ranging alpacas grazing an Andean Festuca\\/Muhlen- bergia pasture during the dry and wet seasons. The ratio of fecal output to diet indigestibility was used to estimate intake. Total fecal output from six adult castrated male alpacas was collected for 5 d during each season. Average body weight was 62.0 kg during the wet season

  7. Spatial and temporal patterns of resource heterogeneity and foraging behavior 

    E-print Network

    Baum, Kristen Anne

    1999-01-01

    nectar was evenly distributed. Other studies have shown nectar-feeding species respond to variations in resource quality and quantity by changing their territorial behavior and foraging strategy (Gill and Wolf 1975, Lyon et aL 1977, Carpenter 1987... temporary, local depressions in nectar availability (Zimmerman 1981, Wolf and Hainsworth 1983, Armstrong et al. 1987). Pleasants and Zimmerman (1983) suggested the shape of the standing crop frequency distribution reflects nectarivore abundance, with a...

  8. Optimal web investment in sub-optimal foraging conditions

    NASA Astrophysics Data System (ADS)

    Harmer, Aaron M. T.; Kokko, Hanna; Herberstein, Marie E.; Madin, Joshua S.

    2012-01-01

    Orb web spiders sit at the centre of their approximately circular webs when waiting for prey and so face many of the same challenges as central-place foragers. Prey value decreases with distance from the hub as a function of prey escape time. The further from the hub that prey are intercepted, the longer it takes a spider to reach them and the greater chance they have of escaping. Several species of orb web spiders build vertically elongated ladder-like orb webs against tree trunks, rather than circular orb webs in the open. As ladder web spiders invest disproportionately more web area further from the hub, it is expected they will experience reduced prey gain per unit area of web investment compared to spiders that build circular webs. We developed a model to investigate how building webs in the space-limited microhabitat on tree trunks influences the optimal size, shape and net prey gain of arboricolous ladder webs. The model suggests that as horizontal space becomes more limited, optimal web shape becomes more elongated, and optimal web area decreases. This change in web geometry results in decreased net prey gain compared to webs built without space constraints. However, when space is limited, spiders can achieve higher net prey gain compared to building typical circular webs in the same limited space. Our model shows how spiders optimise web investment in sub-optimal conditions and can be used to understand foraging investment trade-offs in other central-place foragers faced with constrained foraging arenas.

  9. Fine-scale variability in harbor seal foraging behavior.

    PubMed

    Wilson, Kenady; Lance, Monique; Jeffries, Steven; Acevedo-Gutiérrez, Alejandro

    2014-01-01

    Understanding the variability of foraging behavior within a population of predators is important for determining their role in the ecosystem and how they may respond to future ecosystem changes. However, such variability has seldom been studied in harbor seals on a fine spatial scale (<30 km). We used a combination of standard and Bayesian generalized linear mixed models to explore how environmental variables influenced the dive behavior of harbor seals. Time-depth recorders were deployed on harbor seals from two haul-out sites in the Salish Sea in 2007 (n?=?18) and 2008 (n?=?11). Three behavioral bout types were classified from six dive types within each bout; however, one of these bout types was related to haul-out activity and was excluded from analyses. Deep foraging bouts (Type I) were the predominant type used throughout the study; however, variation in the use of bout types was observed relative to haul-out site, season, sex, and light (day/night). The proportional use of Type I and Type II (shallow foraging/traveling) bouts differed dramatically between haul-out sites, seasons, sexes, and whether it was day or night; individual variability between seals also contributed to the observed differences. We hypothesize that this variation in dive behavior was related to habitat or prey specialization by seals from different haul-out sites, or individual variability between seals in the study area. The results highlight the potential influence of habitat and specialization on the foraging behavior of harbor seals, and may help explain the variability in diet that is observed between different haul-out site groups in this population. PMID:24717815

  10. Specialist Osmia bees forage indiscriminately among hybridizing Balsamorhiza floral hosts

    Microsoft Academic Search

    James H. Cane

    Pollinators, even floral generalists (=polyleges), typically specialize during individual foraging bouts, infrequently switching\\u000a between floral hosts. Such transient floral constancy restricts pollen flow, and thereby gene flow, to conspecific flowers\\u000a in mixed plant communities. Where incipient flowering species meet, however, weak cross-fertility and often similar floral\\u000a traits can yield mixed reproductive outcomes among pollinator-dependent species. In these cases, floral constancy

  11. Optimal foraging: food patch depletion by ruddy ducks

    Microsoft Academic Search

    Michael W. Tome

    1988-01-01

    I studied the foraging behavior of ruddy ducks (Oxyura jamaicensis) feeding on patchily distributed prey in a large (5-m long, 2-m wide, and up to 2-m deep) aquarium. The substrate consisted of a 4x4 array of wooden trays (1.0-m long, 0.5-m wide, and 0.1-m deep) which contained 6 cm of sand. Any tray could be removed from the aquarium and

  12. Food for Thought: Honeybee Foraging, Memory, and Acetylcholine

    NSDL National Science Digital Library

    Norman M. Weinberger (Irvine; University of California REV)

    2006-05-23

    Recent research implicates acetylcholine signaling through muscarinic receptors in structural changes that take place in the honeybee brain in response to foraging. These new findings are consistent with research from earlier studies implicating cholinergic signaling in associative learning as well as in the response to an enriched environment in mammals, which suggests that cholinergic signaling may play a critical role in learning and memory mechanisms across phyla.

  13. Wood bison population recovery and forage availability in northwestern Canada

    Microsoft Academic Search

    Wayne L. Strong; C. Cormack Gates

    2009-01-01

    Forage availability was assessed to determine sustainable stocking rates for eight broadly defined vegetation types (Treed Uplands, Treed Lowlands, Mixed Tall Shrub\\/Sedge, Closed-canopied Willow, and Open-canopied Willow, Meadow, Wetland Grass, Wetland Sedge) for use by wood bison (Bison bison athabascae), a threatened subspecies, in the Canadian boreal forest of northern Alberta. Clip plots (n=108) were used to sample peak availability

  14. Motivation and memory in zebra finch ( Taeniopygia guttata ) foraging behavior

    Microsoft Academic Search

    Kirsten Sanford; Nicola S. Clayton

    2008-01-01

    Remembering combinations of information such as what resources have been seen in which locations could play an important role\\u000a in enhancing individual survival through increased foraging success. To date, there have been relatively few investigations\\u000a of avian memory involving more than one category of information. This study explored zebra finches’ (Taeniopygia guttata) capacity to recall two categories in combination, namely

  15. Effect of protein deficiency on forage intake and digestibility 

    E-print Network

    Loza, Hector Javier

    1979-01-01

    rman of Advisory Committee: Dr. W. C . Ellis Grazing and pen studies were conducted with rumen-esophageal fis- tulated animals, which were fed diets containing different crude protein levels to determine the effects of dietary CP level upon DM intake... Organic Matter Digestibility. 10 12 Fecal Output and Forage Intake Determinations . 13 IV RESULTS Rates of Passage. Statistical Analysis. 14 14 15 Trial l. Standing Crop Yields. Characterization of Standing Crop and Esophageal Extrusa...

  16. Food foraging of honey bees in a microwave field (2. 45 GHz CW)

    SciTech Connect

    Gary, N.E.; Westerdahl, B.B.

    1982-02-15

    Honey bees were trained to fly 400 m from their colony to an indoor laboratory foraging arena exposed to 2.45 GHz continuous wave microwaves at 5 power densities (0, 5, 10, 20, and 40 mW/cm/sup 2/). Foraging behavior did not differ from controls foraging within an unexposed sham arena in (1) number of round trips completed during a 3-h exposure session, (2) round trip time between the colony and the foraging arena, and (3) the length of time required to navigate the illuminated foraging arena. This study indicates that honey bees would not be adversely affected by foraging within a similar microwave field that would exist in future receiving antennae for the proposed solar power satellite energy transmission system in which power levels are expected to range from 23 mW/cm/sup 2/ at the antenna center to 1 mW/cm/sup 2/ at the edge.

  17. Nocturnal activity and foraging of prairie raccoons (Procyon lotor) in North Dakota

    USGS Publications Warehouse

    Greenwood, R.J.

    1982-01-01

    Nocturnal activity and foraging of 39 radio-equipped raccoons (Procyon lotor) in eastern North Dakota were studied from April-July in 1974-1976. Sixteen of the raccoons were collected after foraging bouts for stomach content analysis. Raccoon activity consisted of running (13%), walking (49%) and local movement in confined areas (38%). Local movement was foraging on large or locally abundant food items. Adult males traveled farther in a night, ran twice as often, and moved locally only half as often as adult females and yearlings. Differences in activity patterns between adult females and yearlings were not detected. There was no difference among age-sex groups in use of foraging habitats. All raccoons foraged extensively in farmyards and wetlands. Stomach content analysis substantiated foraging determinations obtained by radiotelemetry. Principal foods were grain, aquatic animals, rodents, birds and bird eggs.

  18. Communal roosting and foraging behavior of staging sandhill cranes

    USGS Publications Warehouse

    Sparling, D.W.; Krapu, G.L.

    1994-01-01

    Each spring more than 300,000 Sandhill Cranes (Grus canadensis) roost communally at night in river channels in the Platte River Valley of Nebraska and disperse at dawn to forage in agricultural fields. Cranes with central roosts had activity ranges double the size of those with peripheral roosts; 42% of the birds changed activity ranges prior to the onset of migration. Minimum daily flight distance generally increased during the staging period. Cranes used native grassland and planted hayland more often than expected, relative to their percentage of occurrence, and fed longest there; cornfields were underutilized. These differences probably reflect, in part, (1) limited distribution of grasslands and haylands resulting in a greater energy expenditure to acquire protein in the form of macroinvertebrates and (2) wider distribution of cornfields with adequate energyrich foods but limited protein. Cranes probably forage more efficiently and conserve energy by following conspecifics from communal roosts to local feeding grounds, by settling in fields where foraging flocks are already present, and by establishing diurnal activity centers. Alert behavior varied with flock size but not as predicted from group size, presumably because predation of staging adult cranes is inconsequential.

  19. Piping Plover brood foraging ecology on New York barrier islands

    USGS Publications Warehouse

    Elias, S.P.; Fraser, J.D.; Buckley, P.A.

    2000-01-01

    Effective management of piping plover (Charadrius melodus) populations requires knowledge of the habitats that foster successful reproduction. We studied piping plover chick foraging ecology and survival on the central barrier islands of Long Island, New York, 1992 and 1993. Within the 90-km study area, all 1-km beach segments with ephemeral pools or bay tidal flats were used for nesting and brood rearing, whereas <50% of beach segments without these habitats were used. On beach segments with ephemeral pools, broods preferred ephemeral pools to ocean intertidal zone, wrack, backshore, open vegetation, and interdune habitat. Indices of terrestrial arthropod abundance and foraging rates were greater in ephemeral pools than in other habitats. In 1992, chick survival was higher on beach segments with ephemeral pools than on segments without ephemeral pools. On beach segments with bay tidal flats, broods preferred bay tidal flats and wrack to ocean intertidal zone, backshore, and open vegetation habitats. Foraging rates in bay tidal flats were similar to those in ephemeral pools and greater than in open vegetation, wrack, and backshore habitats. On beach segments without ephemeral pools and bay tidal flats, broods preferred wrack to all other habitats, and open vegetation was second most preferred. To assist in the recovery of the piping plover, land-use planners should avoid beach management practices (e.g., beach filling, dune building, renourishment) that typically inhibit natural renewal of ephemeral pools, bay tidal flats, and open vegetation habitats.

  20. Alleles underlying larval foraging behaviour influence adult dispersal in nature.

    PubMed

    Edelsparre, Allan H; Vesterberg, Anders; Lim, Jang H; Anwari, Milad; Fitzpatrick, Mark J

    2014-03-01

    The dispersal and migration of organisms have resulted in the colonisation of nearly every possible habitat and ultimately the extraordinary diversity of life. Animal dispersal tendencies are commonly heterogeneous (e.g. long vs. short) and non-random suggesting that phenotypic and genotypic variability between individuals can contribute to population-level heterogeneity in dispersal. Using laboratory and field experiments, we demonstrate that natural allelic variation in a gene underlying a foraging polymorphism in larval fruit flies (for), also influences their dispersal tendencies as adults. Rover flies (for(R) ; higher foraging activity) have consistently greater dispersal tendencies and are more likely to disperse longer distances than sitter flies (for(s) ; lower foraging activity). Increasing for expression in the brain and nervous system increases dispersal in sitter flies. Our study supports the notion that variation in dispersal can be driven by intrinsic variation in food-dependent search behaviours and confirms that single gene pleiotropic effects can contribute to population-level heterogeneity in dispersal. PMID:24386971

  1. Exotic invaders gain foraging benefits by shoaling with native fish

    PubMed Central

    Camacho-Cervantes, Morelia; Garcia, Constantino Macías; Ojanguren, Alfredo F.; Magurran, Anne E.

    2014-01-01

    Freshwater habitats are under increasing threat due to invasions of exotic fish. These invasions typically begin with the introduction of small numbers of individuals unfamiliar with the new habitat. One way in which the invaders might overcome this disadvantage is by associating with native taxa occupying a similar ecological niche. Here we used guppies (Poecilia reticulata) from a feral population in Mexico to test the prediction that exotic shoaling fish can associate with heterospecifics, and that they improve their foraging efficiency by doing so. Guppies have invaded the Mexican High Plateau and are implicated in the declines of many native topminnow (Goodeinae) species. We show that heterospecific associations between guppies and topminnows can deliver the same foraging benefits as conspecific shoals, and that variation in foraging gains is linked to differences in association tendency. These results uncover a mechanism enabling founding individuals to survive during the most vulnerable phase of an invasion and help explain why guppies have established viable populations in many parts of Mexico as well in every continent except Antarctica.

  2. Geometry for a selfish foraging group: a genetic algorithm approach

    PubMed Central

    Barta, Z.; Flynn, R.; Giraldeau, L.-A.

    1997-01-01

    The advantages of group living are not shared equally among all group members and these advantages may depend on the spatial position occupied by a forager within the group. For instance, it is thought that socially dominant individuals prefer the predator-safe central position of groups forcing subordinates to the periphery. Uneven spread of benefits among group members can occur when some animals (the scroungers) parasitically exploit the food findings of other foragers (the producers). Here we focus on how playing producer or scrounger affects an individual's spatial position within a group. We model the movement of foraging animals playing scrounger or producer using a spatially explicit simulation and use a genetic algorithm to establish movement rules. We find that groups containing producers and scroungers are more compact compared to an equivalent group of producers only. Furthermore, the position occupied by strategies varies: scroungers are mainly found in central positions, while producers in the periphery, suggesting that the best position for strategies differs. Dominants, therefore, should prefer movement rules which lead to central positions because of the positional benefits provided to the scrounger strategy they use. Moreover, position within a group will introduce an asymmetry among otherwise phenotypically symmetric individuals.

  3. Imidacloprid Alters Foraging and Decreases Bee Avoidance of Predators

    PubMed Central

    Tan, Ken; Chen, Weiwen; Dong, Shihao; Liu, Xiwen; Wang, Yuchong; Nieh, James C.

    2014-01-01

    Concern is growing over the effects of neonicotinoid pesticides, which can impair honey bee cognition. We provide the first demonstration that sublethal concentrations of imidacloprid can harm honey bee decision-making about danger by significantly increasing the probability of a bee visiting a dangerous food source. Apis cerana is a native bee that is an important pollinator of agricultural crops and native plants in Asia. When foraging on nectar containing 40 µg/L (34 ppb) imidacloprid, honey bees (Apis cerana) showed no aversion to a feeder with a hornet predator, and 1.8 fold more bees chose the dangerous feeder as compared to control bees. Control bees exhibited significant predator avoidance. We also give the first evidence that foraging by A. cerana workers can be inhibited by sublethal concentrations of the pesticide, imidacloprid, which is widely used in Asia. Compared to bees collecting uncontaminated nectar, 23% fewer foragers returned to collect the nectar with 40 µg/L imidacloprid. Bees that did return respectively collected 46% and 63% less nectar containing 20 µg/L and 40 µg/L imidacloprid. These results suggest that the effects of neonicotinoids on honey bee decision-making and other advanced cognitive functions should be explored. Moreover, research should extend beyond the classic model, the European honey bee (A. mellifera), to other important bee species. PMID:25025334

  4. Imidacloprid alters foraging and decreases bee avoidance of predators.

    PubMed

    Tan, Ken; Chen, Weiwen; Dong, Shihao; Liu, Xiwen; Wang, Yuchong; Nieh, James C

    2014-01-01

    Concern is growing over the effects of neonicotinoid pesticides, which can impair honey bee cognition. We provide the first demonstration that sublethal concentrations of imidacloprid can harm honey bee decision-making about danger by significantly increasing the probability of a bee visiting a dangerous food source. Apis cerana is a native bee that is an important pollinator of agricultural crops and native plants in Asia. When foraging on nectar containing 40 µg/L (34 ppb) imidacloprid, honey bees (Apis cerana) showed no aversion to a feeder with a hornet predator, and 1.8 fold more bees chose the dangerous feeder as compared to control bees. Control bees exhibited significant predator avoidance. We also give the first evidence that foraging by A. cerana workers can be inhibited by sublethal concentrations of the pesticide, imidacloprid, which is widely used in Asia. Compared to bees collecting uncontaminated nectar, 23% fewer foragers returned to collect the nectar with 40 µg/L imidacloprid. Bees that did return respectively collected 46% and 63% less nectar containing 20 µg/L and 40 µg/L imidacloprid. These results suggest that the effects of neonicotinoids on honey bee decision-making and other advanced cognitive functions should be explored. Moreover, research should extend beyond the classic model, the European honey bee (A. mellifera), to other important bee species. PMID:25025334

  5. Wild chacma baboons (Papio ursinus) remember single foraging episodes.

    PubMed

    Noser, Rahel; Byrne, Richard W

    2015-07-01

    Understanding animal episodic-like memory is important for tracing the evolution of the human mind. However, our knowledge about the existence and nature of episodic-like memory in non-human primates is minimal. We observed the behaviour of a wild male chacma baboon faced with a trade-off between protecting his stationary group from aggressive extra-group males and foraging among five out-of-sight platforms. These contained high-priority food at a time of natural food shortage. In 10 morning and eight evening trials, the male spontaneously visited the platforms in five and four different sequences, respectively. In addition, he interrupted foraging sequences at virtually any point on eight occasions, returning to the group for up to 2 h. He then visited some or all of the remaining platforms and prevented revisits to already depleted ones, apparently based on his memory for the previous foraging episode about food value, location, and time. Efficient use of memory allowed him to keep minimal time absent from his group while keeping food intake high. These findings support the idea that episodic-like memory offers an all-purpose solution to a wide variety of problems that require flexible, quick, yet precise decisions in situations arising from competition for food and mates in wild primates. PMID:25833223

  6. Olfactory eavesdropping by a competitively foraging stingless bee, Trigona spinipes.

    PubMed Central

    Nieh, James C.; Barreto, Lillian S.; Contrera, Felipe A. L.; Imperatriz-Fonseca, Vera L.

    2004-01-01

    Signals that are perceived over long distances or leave extended spatial traces are subject to eavesdropping. Eavesdropping has therefore acted as a selective pressure in the evolution of diverse animal communication systems, perhaps even in the evolution of functionally referential communication. Early work suggested that some species of stingless bees (Hymenoptera, Apidae, Meliponini) may use interceptive olfactory eavesdropping to discover food sources being exploited by competitors, but it is not clear if any stingless bee can be attracted to the odour marks deposited by an interspecific competitor. We show that foragers of the aggressive meliponine bee, Trigona spinipes, can detect and orient towards odour marks deposited by a competitor, Melipona rufiventris, and then rapidly take over the food source, driving away or killing their competitors. When searching for food sources at new locations that they are not already exploiting, T. spinipes foragers strongly prefer M. rufiventris odour marks to odour marks deposited by their own nest-mates, whereas they prefer nest-mate odour marks over M. rufiventris odour marks at a location already occupied by T. spinipes nest-mates. Melipona rufiventris foragers flee from T. spinipes odour marks. This olfactory eavesdropping may have played a role in the evolution of potentially cryptic communication mechanisms such as shortened odour trails, point-source only odour marking and functionally referential communication concealed at the nest. PMID:15306311

  7. Foraging and farming as niche construction: stable and unstable adaptations

    PubMed Central

    Rowley-Conwy, Peter; Layton, Robert

    2011-01-01

    All forager (or hunter–gatherer) societies construct niches, many of them actively by the concentration of wild plants into useful stands, small-scale cultivation, burning of natural vegetation to encourage useful species, and various forms of hunting, collectively termed ‘low-level food production’. Many such niches are stable and can continue indefinitely, because forager populations are usually stable. Some are unstable, but these usually transform into other foraging niches, not geographically expansive farming niches. The Epipalaeolithic (final hunter–gatherer) niche in the Near East was complex but stable, with a relatively high population density, until destabilized by an abrupt climatic change. The niche was unintentionally transformed into an agricultural one, due to chance genetic and behavioural attributes of some wild plant and animal species. The agricultural niche could be exported with modifications over much of the Old World. This was driven by massive population increase and had huge impacts on local people, animals and plants wherever the farming niche was carried. Farming niches in some areas may temporarily come close to stability, but the history of the last 11 000 years does not suggest that agriculture is an effective strategy for achieving demographic and political stability in the world's farming populations. PMID:21320899

  8. Evidence for acoustic communication among bottom foraging humpback whales

    PubMed Central

    Parks, Susan E.; Cusano, Dana A.; Stimpert, Alison K.; Weinrich, Mason T.; Friedlaender, Ari S.; Wiley, David N.

    2014-01-01

    Humpback whales (Megaptera novaeangliae), a mysticete with a cosmopolitan distribution, demonstrate marked behavioural plasticity. Recent studies show evidence of social learning in the transmission of specific population level traits ranging from complex singing to stereotyped prey capturing behaviour. Humpback whales have been observed to employ group foraging techniques, however details on how individuals coordinate behaviour in these groups is challenging to obtain. This study investigates the role of a novel broadband patterned pulsed sound produced by humpback whales engaged in bottom-feeding behaviours, referred to here as a ‘paired burst' sound. Data collected from 56 archival acoustic tag deployments were investigated to determine the functional significance of these signals. Paired burst sound production was associated exclusively with bottom feeding under low-light conditions, predominantly with evidence of associated conspecifics nearby suggesting that the sound likely serves either as a communicative signal to conspecifics, a signal to affect prey behaviour, or possibly both. This study provides additional evidence for individual variation and phenotypic plasticity of foraging behaviours in humpback whales and provides important evidence for the use of acoustic signals among foraging individuals in this species. PMID:25512188

  9. Benefits to satellite members in mixed-species foraging groups: an experimental analysis

    Microsoft Academic Search

    ANDREW S DOLBY; THOMAS C GRUBB JR

    1998-01-01

    Hypotheses proposed to explain the formation of mixed-species foraging groups have focused on both foraging and antipredation benefits. Mixed-species flocks of bark-foraging birds form during the winter in the eastern deciduous forests of North America. These flocks are composed of two parid nuclear species, tufted titmice,Baeolophus bicolor, and either Carolina or black-capped chickadees,Poecile carolinensisorP.atricapillus, and several satellite species including downy

  10. Quality-related characteristics of forages as influenced by plant environment and agronomic factors

    Microsoft Academic Search

    Dwayne R. Buxton

    1996-01-01

    The most important factor influencing forage quality is herbage maturity. For example, a 1-week delay in harvesting of alfalfa (Medicago sativa L.) will decrease digestibility and crude protein concentration by about 20 g kg?1 and increase cell-wall concentration by approximately 30 g kg?1. Forage quality also is influenced by the environment in which forages are grown and by soil fertility

  11. Food habits and foraging behaviour of benthivorous cichlid fishes in Lake Tanganyika

    Microsoft Academic Search

    Masahide Yuma

    1994-01-01

    A study was made of the food habits and foraging behaviour of coexisting benthivorous cichlid fishes along the rocky northwestern coast of Lake Tanganyika. The five group-foraging species regularly found in the study area,Gnathochromis pfefferi, Lamprologus callipterus, Altolamprologus compressiceps, Lepidiolamprologus elongatus andLobochilotes labiatus, have different foraging techniques, although all eat shrimps (family Atyidae). Individuals of each species allow potential food-competitors

  12. Investigating foraging utilization distribution of female New Zealand sea lions, Auckland Islands

    Microsoft Academic Search

    B. Louise Chilvers; Jacinda M. Amey; Luis A. Huckstadt; Dan P. Costa

    2011-01-01

    Detrimental interactions between marine mammals and fisheries are increasing worldwide. The ability to manage these interactions\\u000a requires the knowledge of where and how interactions occur and the effects they have on species. Many pinnipeds are central\\u000a place foraging colonial breeders who are restricted in foraging range during breeding. Here, we use a utilization distribution\\u000a approach to examine the foraging habitats

  13. The foraging behavior of granivorous rodents and short-term apparent competition among seeds

    Microsoft Academic Search

    Joseph A. Veech

    2001-01-01

    The foraging behavior of a predator species is thought to be the cause of short-term apparent competition among those prey species that share the predator. Short-term apparent competition is the negative indirect effect that one prey species has on another prey species via its effects on predator foraging behavior. In theory, the density-dependent foraging behavior of gra- nivorous rodents and

  14. Loggerhead Turtles (Caretta caretta) Use Vision to Forage on Gelatinous Prey in Mid-Water

    PubMed Central

    Narazaki, Tomoko; Sato, Katsufumi; Abernathy, Kyler J.; Marshall, Greg J.; Miyazaki, Nobuyuki

    2013-01-01

    Identifying characteristics of foraging activity is fundamental to understanding an animals’ lifestyle and foraging ecology. Despite its importance, monitoring the foraging activities of marine animals is difficult because direct observation is rarely possible. In this study, we use an animal-borne imaging system and three-dimensional data logger simultaneously to observe the foraging behaviour of large juvenile and adult sized loggerhead turtles (Caretta caretta) in their natural environment. Video recordings showed that the turtles foraged on gelatinous prey while swimming in mid-water (i.e., defined as epipelagic water column deeper than 1 m in this study). By linking video and 3D data, we found that mid-water foraging events share the common feature of a marked deceleration phase associated with the capture and handling of the sluggish prey. Analysis of high-resolution 3D movements during mid-water foraging events, including presumptive events extracted from 3D data using deceleration in swim speed as a proxy for foraging (detection rate?=?0.67), showed that turtles swam straight toward prey in 171 events (i.e., turning point absent) but made a single turn toward the prey an average of 5.7±6.0 m before reaching the prey in 229 events (i.e., turning point present). Foraging events with a turning point tended to occur during the daytime, suggesting that turtles primarily used visual cues to locate prey. In addition, an incident of a turtle encountering a plastic bag while swimming in mid-water was recorded. The fact that the turtle’s movements while approaching the plastic bag were analogous to those of a true foraging event, having a turning point and deceleration phase, also support the use of vision in mid-water foraging. Our study shows that integrated video and high-resolution 3D data analysis provides unique opportunities to understand foraging behaviours in the context of the sensory ecology involved in prey location. PMID:23776603

  15. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals.

    PubMed

    Peterson, Sarah H; Ackerman, Joshua T; Costa, Daniel P

    2015-07-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200-1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and ?(13)C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation. PMID:26085591

  16. Pollen foraging: learning a complex motor skill by bumblebees (Bombus terrestris).

    PubMed

    Raine, Nigel E; Chittka, Lars

    2007-06-01

    To investigate how bumblebees (Bombus terrestris) learn the complex motor skills involved in pollen foraging, we observed naïve workers foraging on arrays of nectarless poppy flowers (Papaver rhoeas) in a greenhouse. Foraging skills were quantified by measuring the pollen load collected during each foraging bout and relating this to the number of flowers visited and bout duration on two consecutive days. The pollen standing crop (PSC) in each flower decreased drastically from 0530 to 0900 hours. Therefore, we related foraging performance to the changing levels of pollen available (per flower) and found that collection rate increased over the course of four consecutive foraging bouts (comprising between 277 and 354 individual flower visits), suggesting that learning to forage for pollen represents a substantial time investment for individual foragers. The pollen collection rate and size of pollen loads collected at the start of day 2 were markedly lower than at the end of day 1, suggesting that components of pollen foraging behaviour could be subject to imperfect overnight retention. Our results suggest that learning the necessary motor skills to collect pollen effectively from morphologically simple flowers takes three times as many visits as learning how to handle the most morphologically complex flowers to extract nectar, potentially explaining why bees are more specialised in their choice of pollen flowers. PMID:17149583

  17. Marine foraging ecology influences mercury bioaccumulation in deep-diving northern elephant seals

    USGS Publications Warehouse

    Peterson, Sarah H.; Ackerman, Joshua T.; Costa, Daniel P.

    2015-01-01

    Mercury contamination of oceans is prevalent worldwide and methylmercury concentrations in the mesopelagic zone (200–1000 m) are increasing more rapidly than in surface waters. Yet mercury bioaccumulation in mesopelagic predators has been understudied. Northern elephant seals (Mirounga angustirostris) biannually travel thousands of kilometres to forage within coastal and open-ocean regions of the northeast Pacific Ocean. We coupled satellite telemetry, diving behaviour and stable isotopes (carbon and nitrogen) from 77 adult females, and showed that variability among individuals in foraging location, diving depth and ?13C values were correlated with mercury concentrations in blood and muscle. We identified three clusters of foraging strategies, and these resulted in substantially different mercury concentrations: (i) deeper-diving and offshore-foraging seals had the greatest mercury concentrations, (ii) shallower-diving and offshore-foraging seals had intermediate levels, and (iii) coastal and more northerly foraging seals had the lowest mercury concentrations. Additionally, mercury concentrations were lower at the end of the seven-month-long foraging trip (n = 31) than after the two-month- long post-breeding trip (n = 46). Our results indicate that foraging behaviour influences mercury exposure and mesopelagic predators foraging in the northeast Pacific Ocean may be at high risk for mercury bioaccumulation.

  18. Forage selection by Royle's pika (Ochotona roylei) in the western Himalaya, India.

    PubMed

    Bhattacharyya, Sabuj; Adhikari, Bhupendra S; Rawat, Gopal S

    2013-10-01

    Forage selection decisions of herbivores are often complex and dynamic; they are modulated by multiple cues, such as quality, accessibility and abundance of forage plants. To advance the understanding of plant-herbivore interactions, we explored foraging behavior of the alpine lagomorph Royle's pika (Ochotona roylei) in Kedarnath Wildlife Sanctuary, India. Pika bite counts on food plants were recorded through focal sampling in three permanently marked plots. Food plant abundance was recorded by traditional quadrat procedures; forage selection was estimated with Jacob's selection index. Multiple food-choice experiments were conducted to determine whether forage selection criteria would change with variation in food plant composition. We also analyzed leaf morphology and nutrient content in both major food plants and abundantly available non-food plants. Linear regression models were used to test competing hypotheses in order to identify factors governing forage selection. Royle's pika fed primarily on 17 plant species and each forage selection decision was positively modulated by leaf area and negatively modulated by contents of avoided substances (neutral detergent fiber, acid detergent fiber, acid detergent lignin and tannin) in food plants. Furthermore, significance of the interaction term "leaf size × avoided substance" indicates that plants with large leaves were selected only when they had low avoided substance content. The forage selection criteria did not differ between field and laboratory experiments. The parameter estimates of best fit models indicate that the influence of leaf size or amount of avoided substance on pika forage selection was modulated by the magnitude of predation risk. PMID:23932023

  19. The Social Cognition of Social Foraging: Partner Selection by Underlying Valuation

    PubMed Central

    DELTON, ANDREW W.; ROBERTSON, THERESA E.

    2012-01-01

    Humans and other animals have a variety of psychological abilities tailored to the demands of asocial foraging, that is, foraging without coordination or competition with other conspecifics. Human foraging, however, also includes a unique element, the creation of resource pooling systems. In this type of social foraging, individuals contribute when they have excess resources and receive provisioning when in need. Is this behavior produced by the same psychology as asocial foraging? If so, foraging partners should be judged by the same criteria used to judge asocial patches of resources: the net energetic benefits they provide. The logic of resource pooling speaks against this. Maintaining such a system requires the ability to judge others not on their short-term returns, but on the psychological variables that guide their behavior over the long-term. We test this idea in a series of five studies using an implicit measure of categorization. Results showed that (1) others are judged by the costs they incur (a variable not relevant to asocial foraging) whereas (2) others are not judged by the benefits they provide when benefits provided are unrevealing of underlying psychological variables (despite this variable being relevant to asocial foraging). These results are suggestive of a complex psychology designed for both social and asocial foraging. PMID:23162372

  20. Foraging mode and evolution of strike-induced chemosensory searching in lizards.

    PubMed

    Cooper, William E

    2003-04-01

    Strike-induced chemosensory searching (SICS) in lizards and snakes is a means of relocating prey by scent-trailing. The two main components of SICS are an elevated tongue-flick rate for vomerolfactory sampling after biting prey (PETF) and searching movements. In combination, these behaviors permit scent-trailing. Prey chemical discrimination, which is a prerequisite for SICS, is present in active foragers, but not in ambush foragers. Using comparative data. I show that searching movements and SICS have undergone correlated evolution with foraging mode and with prey chemical discrimination in lizards. This suggests that active foraging selects for prey chemical discrimination, which is then employed to search for escaped prey using the typical movements and tongue-flicking behaviors of active foragers. SICS in lizards is simply heightened active foraging after biting prey. In nonvenomous snakes, SICS is similar to that in lizards but is not restricted to active foragers. Only highly venomous snakes voluntarily release dangerous prey upon envenomation, pause to let the venom incapacitate the prey, and then relocate the prey by scent-trailing. PETF was observed in two ambush foragers and is not evolutionarily correlated with foraging mode or searching movements. Because it occurs in species lacking prey chemical discrimination, such PETF may be a response to gustatory cues or to internal chemicals not encountered on surfaces or trails of uninjured prey. PMID:12775158

  1. Remote sensing of endangered species foraging habitats: a wood stork example

    SciTech Connect

    Jensen, J.R.; Hodgson, M.E.; Mackey, H.E. Jr.; Coulter, M.

    1986-03-01

    Potential foraging sites for an endangered species, the wood stork, were identified using thematic mapper data for May 1984, for a section of north-central Georgia. This was accomplished using innovative clustering techniques applied to known wood stork foraging sites around the Birdsville Colony in Georgia. The signatures for known sites were then geographically extended to a 1,520-square-kilometer region surrounding the Birdsville Colony. Thematic maps were produced, and foraging area acreages computed providing a regional assessment of existing and potential wood stork foraging sits. 16 refs., 6 figs.

  2. Characterizing Variation of Isotopic Markers in Northern Alaskan Caribou Forages

    NASA Astrophysics Data System (ADS)

    VanSomeren, L.; Barboza, P. S.; Gustine, D. D.; Parrett, L. S.; Stricker, C. A.

    2013-12-01

    Isotopic markers in feces and tissues are a potential tool for monitoring the importance of feeding areas for migratory herbivores such as caribou (Rangifer tarandus). Many of these techniques are currently limited by gaps in our knowledge of how these isotopic signatures vary over the landscape. We collected seven species of preferred caribou forages along a latitudinal gradient in the summer ranges of the Central Arctic (9 sites) and Teshekpuk Lake (4 sites) caribou herds during 2011 and 2012. We analyzed forages at peak protein content and at the end of the season to characterize temporal, species-specific, and spatial variation in isotopic markers. The availability of C and N was measured by digestion in vitro. Isotopic signatures of digested samples were used to calculate fractionation that would bias the isotopic signature of feces. The range of values for isotopes (all values ‰) of nitrogen (?15N -9.5 - +4.3), and sulfur (?34S -3.6 - +15.5) were greater than those for carbon (?13C -30.5 - -24.9). Small declines in forage ?13C with latitude (Carex aquatilis, Eriophorum vaginatum, Salix pulchra, and S. richardsonii [all P < 0.01]), season (all species except C. bigelowii [all P ? 0.01]), and season x year (S. richardsonii; P = 0.01) were probably associated with changes in water availability. Fractionation of ?13C in early season forages was 0.1 × 1.0 and positively related to C availability (58% × 15%; P < 0.01) with the greatest fractionation for the highly digestible forb Pedicularis langsdorfii (1.43 × 0.44; P < 0.01). Sedges (Carex and Eriophorum) were significantly higher in ?15N than Salix spp. and other dicots (2.0 × 1.1 vs. -2.9 × 2.2; P < 0.01). For Salix spp., ?15N was consistent over the season and between years. Fractionation of ?15N in early season forages was 0.2 × 1.8 and not related to N availability (60% × 17%). For S. pulchra, ?34S may indicate usage of coastal habitats over foothills because ?34S was higher on the coastal plain than in the foothills (11.1 × 3.3 and 3.1 × 2.6; P < 0.01). Isotopic ratios in N and S show the greatest promise for tracking diet and location of migratory caribou whereas the narrow range in ?13C is affected by species, season and location.

  3. When Michaelis and Menten met Holling: towards a mechanistic theory of plant nutrient foraging behaviour.

    PubMed

    McNickle, Gordon G; Brown, Joel S

    2014-01-01

    Plants are adept at assessing and responding to nutrients in soil, and generally proliferate roots into nutrient-rich patches. An analogy between this growth response and animal foraging movement is often drawn, but because of differences between plants and animals it has not always been clear how to directly apply existing foraging theory to plants. Here we suggest one way to unite pre-existing ideas in plant nutrient uptake with foraging theory. First, we show that the Michaelis-Menten equation used by botanists and the Holling disc equation used by zoologists are actually just rearrangements of the same functional response. This mathematical unity permits the translation of existing knowledge about the nutrient uptake physiology of plants into the language of foraging behaviour, and as a result gives botanists direct access to foraging theory. Second, we developed a model of root foraging precision based on the Holling disc equation and the marginal value theorem, and parameterize it from the literature. The model predicts (i) generally plants should invest in higher quality patches compared to lower quality patches, and as patch background-contrast increases; (ii) low encounter rates between roots and nutrients result in high root foraging precision; and (iii) low handling times for nutrients should result in high root foraging precision. The available data qualitatively support these predictions. Third, to parameterize the model above we undertook a review of the literature. From that review we obtained parameter estimates for nitrate and/or ammonium uptake for 45 plant species from 38 studies. We observe that the parameters ranged over six orders of magnitude, there was no trade-off in foraging ability for nitrate versus ammonium: plants that were efficient foragers for one form of nitrogen were efficient foragers for the other, and there was also no phylogenetic signal in the parameter estimates. PMID:25341427

  4. When Michaelis and Menten met Holling: towards a mechanistic theory of plant nutrient foraging behaviour

    PubMed Central

    McNickle, Gordon G.; Brown, Joel S.

    2014-01-01

    Plants are adept at assessing and responding to nutrients in soil, and generally proliferate roots into nutrient-rich patches. An analogy between this growth response and animal foraging movement is often drawn, but because of differences between plants and animals it has not always been clear how to directly apply existing foraging theory to plants. Here we suggest one way to unite pre-existing ideas in plant nutrient uptake with foraging theory. First, we show that the Michaelis–Menten equation used by botanists and the Holling disc equation used by zoologists are actually just rearrangements of the same functional response. This mathematical unity permits the translation of existing knowledge about the nutrient uptake physiology of plants into the language of foraging behaviour, and as a result gives botanists direct access to foraging theory. Second, we developed a model of root foraging precision based on the Holling disc equation and the marginal value theorem, and parameterize it from the literature. The model predicts (i) generally plants should invest in higher quality patches compared to lower quality patches, and as patch background–contrast increases; (ii) low encounter rates between roots and nutrients result in high root foraging precision; and (iii) low handling times for nutrients should result in high root foraging precision. The available data qualitatively support these predictions. Third, to parameterize the model above we undertook a review of the literature. From that review we obtained parameter estimates for nitrate and/or ammonium uptake for 45 plant species from 38 studies. We observe that the parameters ranged over six orders of magnitude, there was no trade-off in foraging ability for nitrate versus ammonium: plants that were efficient foragers for one form of nitrogen were efficient foragers for the other, and there was also no phylogenetic signal in the parameter estimates. PMID:25341427

  5. Systematic review of the influence of foraging habitat on red-cockaded woodpecker reproductive success.

    SciTech Connect

    Garabedian, James E. [North Carolina State University

    2014-04-01

    Relationships between foraging habitat and reproductive success provide compelling evidence of the contribution of specific vegetative features to foraging habitat quality, a potentially limiting factor for many animal populations. For example, foraging habitat quality likely will gain importance in the recovery of the threatened red-cockaded woodpecker Picoides borealis (RCW) in the USA as immediate nesting constraints are mitigated. Several researchers have characterized resource selection by foraging RCWs, but emerging research linking reproductive success (e.g. clutch size, nestling and fledgling production, and group size) and foraging habitat features has yet to be synthesized. Therefore, we reviewed peer-refereed scientific literature and technical resources (e.g. books, symposia proceedings, and technical reports) that examined RCW foraging ecology, foraging habitat, or demography to evaluate evidence for effects of the key foraging habitat features described in the species’ recovery plan on group reproductive success. Fitness-based habitat models suggest foraging habitat with low to intermediate pine Pinus spp. densities, presence of large and old pines, minimal midstory development, and herbaceous groundcover support more productive RCW groups. However, the relationships between some foraging habitat features and RCW reproductive success are not well supported by empirical data. In addition, few regression models account for > 30% of variation in reproductive success, and unstandardized multiple and simple linear regression coefficient estimates typically range from -0.100 to 0.100, suggesting ancillary variables and perhaps indirect mechanisms influence reproductive success. These findings suggest additional research is needed to address uncertainty in relationships between foraging habitat features and RCW reproductive success and in the mechanisms underlying those relationships.

  6. Foraging Ecology of Green Turtles (Chelonia mydas) on the Texas Coast, as Determined by Stable Isotope Analysis 

    E-print Network

    Gorga, Catherine Concetta Theresa

    2011-10-21

    they forage as omnivores, to coastal neritic habitat, where they become primarily herbivores, foraging on algae and seagrass. Anecdotal evidence and gut-content analyses suggest that juvenile green turtles in south Texas bays, such as the lower Laguna Madre...

  7. High Energy Forages for Grass-Finishing Beef Kim Cassida, Jason Rowntree, Matt Raven, Janice Harte, Jeannine Schweihofer, and Sarah

    E-print Network

    and oats (`Forage Plus' oats, 50 lb/acre) to provide effective fiber. The complex mix contains Winfred turnip (3 lb/acre) and Forage Plus oat (20 lb/acre), plus `Barsica' rape (3 lb/acre), `Jumbo' annual

  8. Echolocation-based foraging by harbor porpoises and sperm whales, including effects of noise and acoustic propagation

    E-print Network

    DeRuiter, Stacy L

    2008-01-01

    In this thesis, I provide quantitative descriptions of toothed whale echolocation and foraging behavior, including assessment of the effects of noise on foraging behavior and the potential influence of ocean acoustic ...

  9. Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment

    Microsoft Academic Search

    Jennifer J. Templeton; Luc-Alain Giraldeau

    1996-01-01

    Group foragers may be able to assess patch quality more efficiently by paying attention to the sampling activities of conspecifics\\u000a foraging in the same patch. In a previous field experiment, we showed that starlings foraging on patches of hidden food could\\u000a use the successful foraging activities of others to help them assess patch quality. In order to determine whether a

  10. Resource heterogeneity and foraging behaviour of cattle across spatial scales

    PubMed Central

    Utsumi, Santiago A; Cangiano, Carlos A; Galli, Julio R; McEachern, Mary B; Demment, Montague W; Laca, Emilio A

    2009-01-01

    Background Understanding the mechanisms that influence grazing selectivity in patchy environments is vital to promote sustainable production and conservation of cultivated and natural grasslands. To better understand how patch size and spatial dynamics influence selectivity in cattle, we examined grazing selectivity under 9 different treatments by offering alfalfa and fescue in patches of 3 sizes spaced with 1, 4, and 8 m between patches along an alley. We hypothesized that (1) selectivity is driven by preference for the forage species that maximizes forage intake over feeding scales ranging from single bites to patches along grazing paths, (2) that increasing patch size enhances selectivity for the preferred species, and that (3) increasing distances between patches restricts selectivity because of the aggregation of scale-specific behaviours across foraging scales. Results Cows preferred and selected alfalfa, the species that yielded greater short-term intake rates (P < 0.0001) and greater daily intake potential. Selectivity was not affected by patch arrangement, but it was scale dependent. Selectivity tended to emerge at the scale of feeding stations and became strongly significant at the bite scale, because of differences in bite mass between plant species. Greater distance between patches resulted in longer patch residence time and faster speed of travel but lower overall intake rate, consistent with maximization of intake rate. Larger patches resulted in greater residence time and higher intake rate. Conclusion We conclude that patch size and spacing affect components of intake rate and, to a lesser extent, the selectivity of livestock at lower hierarchies of the grazing process, particularly by enticing livestock to make more even use of the available species as patches are spaced further apart. Thus, modifications in the spatial pattern of plant patches along with reductions in the temporal and spatial allocation of grazing may offer opportunities to improve uniformity of grazing by livestock and help sustain biodiversity and stability of plant communities. PMID:19393094

  11. Behavioral genomics of honeybee foraging and nest defense

    PubMed Central

    Amdam, Gro V.; Schlipalius, David; Emore, Christine; Sardesai, Nagesh; Williams, Christie E.; Rueppell, Olav; Guzmán-Novoa, Ernesto; Arechavaleta-Velasco, Miguel; Chandra, Sathees; Fondrk, M. Kim; Beye, Martin; Page, Robert E.

    2006-01-01

    The honeybee has been the most important insect species for study of social behavior. The recently released draft genomic sequence for the bee will accelerate honeybee behavioral genetics. Although we lack sufficient tools to manipulate this genome easily, quantitative trait loci (QTLs) that influence natural variation in behavior have been identified and tested for their effects on correlated behavioral traits. We review what is known about the genetics and physiology of two behavioral traits in honeybees, foraging specialization (pollen versus nectar), and defensive behavior, and present evidence that map-based cloning of genes is more feasible in the bee than in other metazoans. We also present bioinformatic analyses of candidate genes within QTL confidence intervals (CIs). The high recombination rate of the bee made it possible to narrow the search to regions containing only 17–61 predicted peptides for each QTL, although CIs covered large genetic distances. Knowledge of correlated behavioral traits, comparative bioinformatics, and expression assays facilitated evaluation of candidate genes. An overrepresentation of genes involved in ovarian development and insulin-like signaling components within pollen foraging QTL regions suggests that an ancestral reproductive gene network was co-opted during the evolution of foraging specialization. The major QTL influencing defensive/aggressive behavior contains orthologs of genes involved in central nervous system activity and neurogenesis. Candidates at the other two defensive-behavior QTLs include modulators of sensory signaling (Am5HT7 serotonin receptor, AmArr4 arrestin, and GABA-B-R1 receptor). These studies are the first step in linking natural variation in honeybee social behavior to the identification of underlying genes. PMID:17171388

  12. The bacterial communities associated with honey bee (Apis mellifera) foragers.

    PubMed

    Corby-Harris, Vanessa; Maes, Patrick; Anderson, Kirk E

    2014-01-01

    The honey bee is a key pollinator species in decline worldwide. As part of a commercial operation, bee colonies are exposed to a variety of agricultural ecosystems throughout the year and a multitude of environmental variables that may affect the microbial balance of individuals and the hive. While many recent studies support the idea of a core microbiota in guts of younger in-hive bees, it is unknown whether this core is present in forager bees or the pollen they carry back to the hive. Additionally, several studies hypothesize that the foregut (crop), a key interface between the pollination environment and hive food stores, contains a set of 13 lactic acid bacteria (LAB) that inoculate collected pollen and act in synergy to preserve pollen stores. Here, we used a combination of 454 based 16S rRNA gene sequencing of the microbial communities of forager guts, crops, and corbicular pollen and crop plate counts to show that (1) despite a very different diet, forager guts contain a core microbiota similar to that found in younger bees, (2) corbicular pollen contains a diverse community dominated by hive-specific, environmental or phyllosphere bacteria that are not prevalent in the gut or crop, and (3) the 13 LAB found in culture-based studies are not specific to the crop but are a small subset of midgut or hindgut specific bacteria identified in many recent 454 amplicon-based studies. The crop is dominated by Lactobacillus kunkeei, and Alpha 2.2 (Acetobacteraceae), highly osmotolerant and acid resistant bacteria found in stored pollen and honey. Crop taxa at low abundance include core hindgut bacteria in transit to their primary niche, and potential pathogens or food spoilage organisms seemingly vectored from the pollination environment. We conclude that the crop microbial environment is influenced by worker task, and may function in both decontamination and inoculation. PMID:24740297

  13. Harvest management of switchgrass for biomass feedstock and forage production

    SciTech Connect

    Sanderson, M.A.; Read, J.C.; Reed, R.L.

    1999-02-01

    Switchgrass (Panicum virgatum L.), a warm-season perennial grass native to North America, has potential as a biomass energy crop. Their objective was to develop harvest management recommendations for biomass feedstock and forage production. Alamo switchgrass was established in 1992 at Stephenville and Dallas, TX. Four harvest frequencies (one to four cuts per year) and three final autumn harvests (Sept., Oct., or Nov.) were imposed from 1993 to 1996. Tiller densities were counted each spring. Neutral detergent fiber (NDF) and crude protein (CP) concentrations were measured in 1993 and 1994. Concentrations of NDF were lowest and of CP were highest in May-harvested biomass. Forage quality of regrowth decreased with age, reaching NDF concentrations of 790 g kg{sup {minus}1} and CP of < 20 g kg{sup {minus}1}. Total seasonal yields decreased as harvest frequency increased; however, a severe drought reversed this trend at Dallas in 1996. The highest yields occurred with a single harvest in mid-September. Delaying the final harvest until November reduced yields. Harvest date and frequency did not affect tiller density, although tiller density decreased from 900 to 650 and 630 to 310 m{sup {minus}2} at Dallas and Stephenville, respectively, during 1994 to 1997. Thus, a single mid-September harvest should maximize biomass yields in the south-central USA. A two-cut (spring-autumn) system may allow a farmer to use initial growth as forage and the regrowth for biomass, but total yields would be reduced. More frequent harvests would reduce yields further.

  14. Transport Infrastructure Shapes Foraging Habitat in a Raptor Community

    PubMed Central

    Planillo, Aimara; Kramer-Schadt, Stephanie; Malo, Juan E.

    2015-01-01

    Transport infrastructure elements are widespread and increasing in size and length in many countries, with the subsequent alteration of landscapes and wildlife communities. Nonetheless, their effects on habitat selection by raptors are still poorly understood. In this paper, we analyzed raptors’ foraging habitat selection in response to conventional roads and high capacity motorways at the landscape scale, and compared their effects with those of other variables, such as habitat structure, food availability, and presence of potential interspecific competitors. We also analyzed whether the raptors’ response towards infrastructure depends on the spatial scale of observation, comparing the attraction or avoidance behavior of the species at the landscape scale with the response of individuals observed in the proximity of the infrastructure. Based on ecological hypotheses for foraging habitat selection, we built generalized linear mixed models, selected the best models according to Akaike Information Criterion and assessed variable importance by Akaike weights. At the community level, the traffic volume was the most relevant variable in the landscape for foraging habitat selection. Abundance, richness, and diversity values reached their maximum at medium traffic volumes and decreased at highest traffic volumes. Individual species showed different degrees of tolerance toward traffic, from higher abundance in areas with high traffic values to avoidance of it. Medium-sized opportunistic raptors increased their abundance near the traffic infrastructures, large scavenger raptors avoided areas with higher traffic values, and other species showed no direct response to traffic but to the presence of prey. Finally, our cross-scale analysis revealed that the effect of transport infrastructures on the behavior of some species might be detectable only at a broad scale. Also, food availability may attract raptor species to risky areas such as motorways. PMID:25786218

  15. The Effects of Drought on Foraging Habitat Selection of Breeding Wood Storks in Coastal Georgia

    Microsoft Academic Search

    Karen F. Gaines; Bryan A. Lawrence Jr; Philip M. Dixon

    2000-01-01

    Foraging habitat use by Wood Storks (Mycteria americana) during the breeding season was studied for three coastal colonies during a drought year and compared to habitat use during normal rainfall years. Information on the distribution of wetland habitat types was derived using U.S. Fish and Wildlife Service National Wetland In- ventory (NWI) data within a Geographic Information System (GIS). Foraging

  16. Differences in foraging and broodnest temperature in the honey bees Apis cerana and A. mellifera

    E-print Network

    Differences in foraging and broodnest temperature in the honey bees Apis cerana and A. mellifera The ecological success of honey bees depends in part on their ability to thermoregulate and to thereby forage at lower temperatures than com- peting bee species (Goulson 2003). The internal temperature of a honey bee

  17. Green Frogs Show Reduced Foraging Success in Habitats Invaded by Japanese knotweed

    Microsoft Academic Search

    John C. Maerz; Bernd Blossey; Victoria Nuzzo

    2005-01-01

    Habitat loss is causing amphibian population declines worldwide, so there is increased attention to forces that degrade remaining habitats. Terrestrial habitats surrounding wetlands are critical foraging areas for temperate anurans. We investigated plant community changes in two old fields invaded by Japanese knotweed (Fallopia japonica) and the foraging success of Green frogs (Rana clamitans) in invaded and non-invaded portions of

  18. Social influences on foraging in vertebrates: causal mechanisms and adaptive functions

    Microsoft Academic Search

    Bennett G. Galef; Luc-Alain Giraldeau

    2001-01-01

    We summarize 20 years of empirical and theoretical research on causes and functions of social influences on foraging by animals. We consider separately studies of social influence on when, where, what and how to eat. Implicit in discussion of the majority of studies is our assumption that social influences on foraging reflect a biasing of individual learning processes by social

  19. The Evolution of Foraging Rate across Local and Geographic Gradients in Predation Risk and Competition.

    PubMed

    Urban, Mark C; Richardson, Jonathan L

    2015-07-01

    Multiple theories predict the evolution of foraging rates in response to environmental variation in predation risk, intraspecific competition, time constraints, and temperature. We tested six hypotheses for the evolution of foraging rate in 24 spotted salamander (Ambystoma maculatum) populations from three latitudinally divergent sites using structural equation models derived from theory and applied to our system. We raised salamander larvae in a common-garden experiment and then assayed foraging rate under controlled conditions. Gape-limited predation risk from marbled salamanders solely explained foraging rate variation among populations at the southern site, which was dominated by this form of selection. However, at the middle and northern sites, populations evolved different foraging rates depending on their unique responses to local intraspecific density. The coupling of gape-limited predation risk from marbled salamanders and high intraspecific density at the middle site jointly contributed to selection for rapid foraging rate. At the northernmost site, intraspecific density alone explained 97% of the interpopulation variation in foraging rate. These results suggest that foraging rate has evolved multiple times in response to varying contributions from predation risk and intraspecific competition. Predation risk often varies along environmental gradients, and, thus, organisms might often shift evolutionary responses from minimizing predation risk to maximizing intraspecific competitive performance. PMID:26098352

  20. Is Altering Grazing Selectivity of Invasive Forage Species With Patch Burning More Effective Than Herbicide Treatments?

    Microsoft Academic Search

    D. Chad Cummings; Samuel D. Fuhlendorf; David M. Engle

    2007-01-01

    Invasion of rangeland by exotic forage species threatens ecosystem structure and function and can cause catastrophic economic losses. Herbicide treatments often are the focus of management efforts to control invasions. Management with the fire-grazing interaction (or patch burning) might suppress an invasive forage species that has grazing persistence mechanisms developed apart from the fire-grazing interaction. We studied tallgrass prairies invaded

  1. Assessing herbivore foraging behavior with GPS collars in a semiarid grassland

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Advances in global positioning system (GPS) technology have dramatically enhanced the ability to track and study distributions of free-ranging livestock. However, understanding factors controlling livestock foraging distribution requires the ability to assess when and where they are foraging. We col...

  2. Nutritive value of fall-grown cereal-grain forages over time.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in nutritive value of fall-grown cereal-grain forages can affect cattle performance. The objective of this study was to evaluate the nutritive value of various fall-grown cereal-grain forages over time. One variety each of hard red (HR) and soft red (SR) winter wheat (Triticum aestivum L.), ...

  3. Nutritive Value of Fall-Grown Cereal-Grain Forages Over Time

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Changes in nutritive value of fall-grown cereal-grain forages over time can affect cattle performance. The objective of this study was to evaluate nutritive values of various fall-grown cereal-grain forages over time. One variety each of hard red (HR) and soft red (SR) winter wheat (Triticum aesti...

  4. Plant root distributions and nitrogen uptake predicted by a hypothesis of optimal root foraging

    E-print Network

    Plant root distributions and nitrogen uptake predicted by a hypothesis of optimal root foraging-uptake fraction, nitrogen-uptake model, nitrogen-use efficiency, optimal foraging by roots, optimal rooting depth, root distributions, root strategies. Correspondence Ross E. McMurtrie, School of Biological, Earth

  5. MOAB: a spatially explicit, individual-based expert system for creating animal foraging models

    Microsoft Academic Search

    Jacoby Carter; John T Finn

    1999-01-01

    We describe the development, structure, and corroboration process of a simulation model of animal behavior (MOAB). MOAB can create spatially explicit, individual-based animal foraging models. Users can create or replicate heterogeneous landscape patterns, and place resources and individual animals of a given species on that landscape to simultaneously simulate the foraging behavior of multiple species. The heuristic rules for animal

  6. Effects of multiple competitors for pollination on bumblebee foraging patterns and Mimulus ringens reproductive success

    E-print Network

    Mitchell, Randall J.

    siphilitica, and quantified reproductive success for a third species, Mimulus ringens. Patterns of pollinator to a similar 40% reduction in Mimulus ringens seed set. However, the patterns of pollinator foraging we200 Effects of multiple competitors for pollination on bumblebee foraging patterns and Mimulus

  7. Filling the Niche: Looking at Alternative Uses and Species of Forage Crops

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The forage breeding program at Tifton, Georgia has a long, notable history that began with the release of ‘Coastal’ Bermudagrass (Cynodon spp.) in 1943, which is now planted on 10 million acres, nation wide. Forage releases have continued with ‘Tifton 85’ bermudagrass, ‘Tifton 9’ bahiagrass (Paspa...

  8. New modes of use and opportunities for research in forage plants

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forages play an important role in the production of meat and dairy throughout the world. Forages are not only an integral part of human protein production, but they can also improve row crop production management systems, play a role in reducing the dependence on fossil fuels and mitigate environme...

  9. Does Human Proximity Affect Antibody Prevalence in Marine-Foraging River Otters (Lontra canadensis)?

    Microsoft Academic Search

    Joseph K. Gaydos; Patricia A. Conrad; Kirsten V. K. Gilardi; Gail M. Blundell; Merav Ben-David

    2007-01-01

    The investigation of diseases of free-ranging river otters (Lontra canadensis )i s a primary conservation priority for this species; however, very little is known about diseases of river otters that forage in marine environments. To identify and better understand pathogens that could be important to marine-foraging river otters, other wildlife species, domestic animals, and humans and to determine if proximity

  10. Intraspecific competition in foraging Griffon Vultures Gyps fulvus: 2. The influence of supplementary feeding management

    Microsoft Academic Search

    Olivier Duriez; Sophie Herman; François Sarrazin

    2012-01-01

    Capsule Young vultures have better access to food resources at supplementary feeding sites where carcasses are fewer and less predictable, and placed further from colonies.Aims To investigate the impact of the management of supplementary feeding sites on foraging and feeding behaviour in Griffon Vultures Gyps fulvus.Methods With focal and scan sampling we studied whether group size, group composition and foraging

  11. An integrated approch to the foraging ecology of marine birds and mammals

    Microsoft Academic Search

    Donald A. Croll; Bernie R. Tershy; Roger P. Hewitt; David A. Demer; Paul C. Fiedler; Susan E. Smith; Wesley Armstrong; Jacqueline M. Popp; Thomas Kiekhefer; Vanesa R. Lopez; Jorge Urban; Diane Gendron

    1998-01-01

    Birds and mammals are important components of pelagic marine ecosystems, but our knowledge of their foraging ecology is limited. We distinguish six distinct types of data that can be used in various combinations to understand their foraging behavior and ecology. We describe methods that combine concurrent dive recorder deployment, oceanographic sampling, and hydroacoustic surveys to generate hypotheses about interactions between

  12. A Foraging Cost of Migration for a Partially Migratory Cyprinid Fish

    E-print Network

    their stomach fullness and diet composition, we tested if migrating roach pay a cost of reduced foraging whenA Foraging Cost of Migration for a Partially Migratory Cyprinid Fish Ben B. Chapman1 *, Anders of Denmark (DTU), Silkeborg, Denmark, 3 Department of Fish Ecology and Evolution, EAWAG Swiss Federal

  13. Intake and digestibility of different forages in Hamas compared to sheep

    E-print Network

    Paris-Sud XI, Université de

    Note Intake and digestibility of different forages in Hamas compared to sheep Jean-Pierre Dulphy 1997) Abstract - Results of four trials, in which intake and digestibility of nine roughages had been ingest more straw and a lower quantity of high-graded forages than sheep. Overall mean digestibility

  14. Forage radish winter cover crop suppresses winter annual weeds in fall and before corn planting

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Forage radish (Raphanus sativus L. var. longipinnatus) is a new winter cover crop in the Mid-Atlantic region. The objective of this project was to characterize the repeatability, amount, and duration of weed suppression during and after a fall-planted forage radish cover crop and to quantify the sub...

  15. Morphology, echolocation and foraging behaviour in two sympatric sibling species of bat (Tylonycteris pachypus and

    E-print Network

    Auckland, University of

    Morphology, echolocation and foraging behaviour in two sympatric sibling species of bat University, Shanghai, China Keywords echolocation calls; flight speed; foraging behaviour; resource June 2006 doi:10.1111/j.1469-7998.2006.00210.x Abstract We studied the wing morphology, echolocation

  16. Nutrient composition of tall fescue pasture forage free of or infested with Acremonium coenophialum

    E-print Network

    Paris-Sud XI, Université de

    Nutrient composition of tall fescue pasture forage free of or infested with Acremonium coenophialum with the endophytic fungus A. coenophialum is associated with substantial economic reduction in grazing livestock is related to nutrient composition of the forage. Two treatments were established near Knoxville (35°49'N, 83

  17. Effects of Intraspecific Competition and Host-Parasitoid Developmental Timing on Foraging Behaviour

    E-print Network

    van Nouhuys, Saskya

    Effects of Intraspecific Competition and Host-Parasitoid Developmental Timing on Foraging Behaviour of a Parasitoid Wasp Christelle Couchoux & Saskya van Nouhuys Revised: 21 September 2013 /Accepted: 23 September parasitoids foraging for hosts might experience intraspecific competition. We investigated the effects of host

  18. Effects of Intraspecific Competition and Host-Parasitoid Developmental Timing on Foraging Behaviour

    E-print Network

    van Nouhuys, Saskya

    Effects of Intraspecific Competition and Host-Parasitoid Developmental Timing on Foraging Behaviour of a Parasitoid Wasp Christelle Couchoux & Saskya van Nouhuys Revised: 21 September 2013 /Accepted: 23 September to parasitism for a limited time, female parasitoids foraging for hosts might experience intraspecific

  19. Late Season Forage Plantings Dr. Heather Darby and Dr. Sid Bosworth, UVM Extension Agronomists

    E-print Network

    Hayden, Nancy J.

    Late Season Forage Plantings Dr. Heather Darby and Dr. Sid Bosworth, UVM Extension Agronomists June for the winter months. Below is an outline of options for late season forage production. HOW LATE CAN I PLANT or heat units are calculated for each day starting the day after planting. The "length of growing season

  20. Annual variation in foraging ecology of prothonotary warblers during the breeding season

    USGS Publications Warehouse

    Petit, L.J.; Petit, D.R.; Petit, K.E.; Fleming, W.J.

    1990-01-01

    We studied foraging ecology of Prothonotary Warblers (Protonotaria citrea) along the Tennessee River in west-central Tennessee during the breeding seasons of 1984-1987. We analyzed seven foraging variables to determine if this population exhibited annual variation in foraging behavior. Based on nearly 3,000 foraging maneuvers, most variables showed significant interyear variation during the four prenestling and three nestling periods we studied. This interyear variation probably was due -to proximate, environmental cues--such as distribution and abundance of arthropods--which, in turn, were influenced by local weather conditions. Researchers should consider the consequences of combining foraging behavior data collected in different years, because resolution of ecological trends may be sacrificed by considering only general patterns of foraging ecology and not the dynamics of those activities. In addition, because of annual variability, foraging data collected in only one year, regardless of the number of observations gathered, may not provide an accurate concept of the foraging ecology in insectivorous birds.