The Experts below are selected from a list of 327 Experts worldwide ranked by ideXlab platform
John M Marzluff - One of the best experts on this subject based on the ideXlab platform.
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vancomycin resistant enterococcus spp from Crows and their environment in metropolitan washington state usa is there a correlation between vre positive Crows and the environment
Veterinary Microbiology, 2016Co-Authors: Marilyn C Roberts, John M Marzluff, Jack H Delap, Robert S TurnerAbstract:Vancomycin-resistant enterococci [VRE] have been isolated from municipal, hospital and agricultural wastewater, recreational beaches, wild animals, birds and food animals around the world. In this study, American Crows (Corvus brachyrhynchos) from sewage treatment plants (WWTP), dairy farms, and a large roost in a restored wetland with corresponding environmental samples were cultured for VRE. A total of 245 samples [156 Crows, 89 environmental] were collected and screened for acquired vanA, vanB and/or intrinsic vanC1 genes. Samples were enriched overnight in BHI supplemented with 20μg/mL aztreonam, 4μg/mL vancomycin and plated on m-Enterococcus agar media supplemented with 6μg/mL vancomycin. Selected colonies were grown on BHI media supplemented with 18μg/mL vancomycin. Of these, 24.5% of the crow and 55% the environmental/cow samples were VRE positive as defined by Enterococcus spp. able to grow on media supplemented with 18μg/mL vancomycin. A total of 122 VRE isolates, 43 crow and 79 environmental isolates were screened, identified to species level using 16S sequencing and further characterized. Four vanA E. faecium and multiple vanC1 E. gallinarum were identified from Crows isolated from three sites. E. faecium vanA and E. gallinarum vanC1 along with other Enterococcus spp. carrying vanA, vanB, vanC1 were isolated from three environments. All enterococci were multidrug resistant. Crows were more likely to carry vanA E. faecium than either the cow feces or wetland waters/soils. Comparing E. gallinarum vanC1 from Crows and their environment would be useful in determining whether Crows share VRE strains with their environment.
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wild american Crows gather around their dead to learn about danger
Animal Behaviour, 2015Co-Authors: Kaeli N. Swift, John M MarzluffAbstract:While a growing number of animals demonstrate avoidance of areas associated with conspecific death, the extent to which wild populations may use these experiences to learn about novel predators remains unclear. Here we demonstrate with experiments that wild American Crows, Corvus brachyrhynchos, respond to dead conspecifics by mobbing, increasing the time to approach food in areas associated with these events, and learning new predators based on their proximity to dead Crows and hawks. Avoidance of either dead conspecifics or areas associated with them is not shared by another urban bird, the rock pigeon, Columba livia. Crows mobbed and increased the time to approach food over the next 72 h after observing novel humans paired with a dead crow, a red-tailed hawk, Buteo jamaicensis, or a hawk with a dead crow. The sight of a dead pigeon did not elicit these responses. These findings suggest that, for Crows, dead conspecifics, but not dead heterospecifics, represent a salient danger akin to the observation of a predator. On the day the stimulus was presented, the number of trials that resulted in mobbing and avoidance of the food was strongest when Crows were presented a hawk with a dead crow. In addition, we demonstrate that Crows use the proximity of a human to predators, to dead conspecifics and to predators with dead conspecifics as cues to learn to recognize and subsequently scold the associated human after only one training event, and that this association can last 6 weeks. Together, our results support previous findings that Crows learn places associated with conspecific death, and further demonstrate that Crows can learn and remember people who appear complicit in these events.
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distinct neural circuits underlie assessment of a diversity of natural dangers by american Crows
Proceedings of The Royal Society B: Biological Sciences, 2013Co-Authors: Donna J Cross, John M Marzluff, Ila Palmquist, Satoshi Minoshima, Toru Shimizu, R S MiyaokaAbstract:Social animals encountering natural dangers face decisions such as whether to freeze, flee or harass the threat. The American crow, Corvus brachyrhynchos ,c onspicuously mobs dangers. We used positron emission tomography to test the hypothesis that distinct neuronal substrates underlie the crow’s consistent behavioural response to different dangers. We found that Crows activated brain regions associated with attention and arousal (nucleus isthmo-opticus/locus coeruleus), and with motor response (arcopallium), as they fixed their gaze on a threat. However, despite this consistent behavioural and neural response, the sight of a person who previously captured the crow, a person holding a dead crow and a taxidermy-mounted hawk activated distinct forebrain regions (amygdala, hippocampus and portion of the caudal nidopallium, respectively). We suggest that aspects of mobbing behaviour are guided by unique neural circuits that respond to differences in mental processing—learning, memoryformationandmultisensorydiscrimination—requiredtoappropriately nuance a risky behaviour to specific dangers.
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Crows and Crow Feeders: Observations on Interspecific Semiotics
Biocommunication of Animals, 2013Co-Authors: John M Marzluff, Marc L. MillerAbstract:Biosemiotic studies include those which focus on systems of signs linking humans and animals. We review the general roots of interspecific communication with emphasis on biosemiotic studies. Beyond domestic animal—human communication, humans are known to communicate closely with a few wild animals with which they have mutualistic foraging relationships (dolphins, honeyguides). We reveal another such relationship in a pilot field study of American Crows (Corvus brachyrhynchos) and human crow feeders. Our study illustrates an interdisciplinary consideration of interspecific communication goals, tactics, rewards and signals. Always alert to threats in searches for food, Crows responded to a repertoire of messages and behaviors of crow feeders they recognized. Crow feeders—motivated to attract, feed, and spend time with particular Crows—fall into two categories. Crow friends talk and behave with Crows as they might with people. Crow observers are more detached, wanting unobtrusive interaction without emphasis on personal identities or feelings. We propose that the crow feeding events can be usefully studied with a strategic engagement model. We encourage future biosemiotic projects to (1) employ an interdisciplinary approach, (2) examine genetic in addition to biological and cultural processes, (3) explore variation across biosemiotic systems, and (4) consider real-world implications of findings.
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Lasting recognition of threatening people by wild American Crows
Animal Behaviour, 2010Co-Authors: John M Marzluff, Jeff Walls, Heather N. Cornell, John C. Withey, David P. CraigAbstract:While many domestic and laboratory animals recognize familiar humans, such ability in wild animals is only anecdotally known. Here we demonstrate experimentally that a cognitively advanced, social bird, the American crow, Corvus brachyrhynchos, quickly and accurately learns to recognize the face of a dangerous person and continues to do so for at least 2.7 years. We exposed wild Crows to a novel ‘dangerous face’ by wearing a unique face mask as we trapped, banded and released 7–15 birds at five sites near Seattle, WA, U.S.A. After trapping, Crows consistently used harsh vocalizations to scold and mob people of different sizes, ages, genders and walking gaits who wore the dangerous mask, even when they were in crowds. In contrast, prior to trapping, few Crows scolded people who wore the dangerous mask. Furthermore, after trapping, few Crows scolded trappers who wore no mask or who wore a mask that had not been worn during trapping. In a fully crossed, balanced experiment in which each site had a unique trapping (dangerous) mask and five neutral masks, Crows scolded and mobbed a mask more when it was the dangerous mask at that site than when it was a neutral mask at another site. When simultaneously presented with a person in the dangerous mask and a person in the neutral mask, Crows typically ignored the neutral mask and followed and scolded the person wearing the dangerous mask. Risky, aggressive scolding by Crows was sensitive to variable costs across study sites; aggression was less where people persecuted Crows most. We suggest that conditioned and observational learning of specific threats may allow local bird behaviours to include aversions to individual people.
Gad Baneth - One of the best experts on this subject based on the ideXlab platform.
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Neospora caninum in Crows from Israel.
Veterinary parasitology, 2015Co-Authors: Harold Salant, Abed Nasereddin, E Blinder, Monica L Mazuz, I. Savitsky, Gad BanethAbstract:A cross-sectional Neospora caninum seroprevalence study was performed on free ranging Crows (Corvus cornix, Corvus monedula and Corvus splendens) from Israel in order to assess their exposure to this pathogen and evaluate their role as potential hosts or as sentinels of infection. Using the modified agglutination test (MAT) with a cutoff titer of 1:100, 30 out of 183 Crows (16.4%) were found to be N. caninum seropositive. Positive results were validated and confirmed by the indirect fluorescent antibody test (IFAT). There was 100% agreement between tests when cut-off titers of 1:50 and 1:100 were applied for the IFAT and MAT, respectively. PCR analysis of brain extracts from all Crows resulted in the detection of N. caninum DNA for the first time in Crows belonging to two species, C. cornix and C. monedula. The high N. caninum seroprevalence in Crows suggests that widespread exposure to infection with N. caninum exists especially in central and northern Israel and that Crows may act as suitable markers for disease prevalence in the areas in which they are found.
Robert S Turner - One of the best experts on this subject based on the ideXlab platform.
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vancomycin resistant enterococcus spp from Crows and their environment in metropolitan washington state usa is there a correlation between vre positive Crows and the environment
Veterinary Microbiology, 2016Co-Authors: Marilyn C Roberts, John M Marzluff, Jack H Delap, Robert S TurnerAbstract:Vancomycin-resistant enterococci [VRE] have been isolated from municipal, hospital and agricultural wastewater, recreational beaches, wild animals, birds and food animals around the world. In this study, American Crows (Corvus brachyrhynchos) from sewage treatment plants (WWTP), dairy farms, and a large roost in a restored wetland with corresponding environmental samples were cultured for VRE. A total of 245 samples [156 Crows, 89 environmental] were collected and screened for acquired vanA, vanB and/or intrinsic vanC1 genes. Samples were enriched overnight in BHI supplemented with 20μg/mL aztreonam, 4μg/mL vancomycin and plated on m-Enterococcus agar media supplemented with 6μg/mL vancomycin. Selected colonies were grown on BHI media supplemented with 18μg/mL vancomycin. Of these, 24.5% of the crow and 55% the environmental/cow samples were VRE positive as defined by Enterococcus spp. able to grow on media supplemented with 18μg/mL vancomycin. A total of 122 VRE isolates, 43 crow and 79 environmental isolates were screened, identified to species level using 16S sequencing and further characterized. Four vanA E. faecium and multiple vanC1 E. gallinarum were identified from Crows isolated from three sites. E. faecium vanA and E. gallinarum vanC1 along with other Enterococcus spp. carrying vanA, vanB, vanC1 were isolated from three environments. All enterococci were multidrug resistant. Crows were more likely to carry vanA E. faecium than either the cow feces or wetland waters/soils. Comparing E. gallinarum vanC1 from Crows and their environment would be useful in determining whether Crows share VRE strains with their environment.
Nicholas Komar - One of the best experts on this subject based on the ideXlab platform.
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Differential virulence of West Nile strains for American Crows.
Emerging infectious diseases, 2004Co-Authors: Aaron C. Brault, Stanley A. Langevin, Richard A. Bowen, Nicholas A. Panella, Brad J. Biggerstaff, Barry R. Miller, Nicholas KomarAbstract:Crow deaths were observed after West Nile virus (WNV) was introduced into North America, and this phenomenon has subsequently been used to monitor the spread of the virus. To investigate potential differences in the crow virulence of different WNV strains, American Crows were inoculated with Old World strains of WNV from Kenya and Australia (Kunjin) and a North American (NY99) WNV genotype. Infection of Crows with NY99 genotype resulted in high serum viremia levels and death; the Kenyan and Kunjin genotypes elicited low viremia levels and minimal deaths but resulted in the generation of neutralizing antibodies capable of providing 100% protection from infection with the NY99 strain. These results suggest that genetic alterations in NY99 WNV are responsible for the crow-virulent phenotype and that increased replication of this strain in Crows could spread WNV in North America.
Kaeli N. Swift - One of the best experts on this subject based on the ideXlab platform.
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wild american Crows gather around their dead to learn about danger
Animal Behaviour, 2015Co-Authors: Kaeli N. Swift, John M MarzluffAbstract:While a growing number of animals demonstrate avoidance of areas associated with conspecific death, the extent to which wild populations may use these experiences to learn about novel predators remains unclear. Here we demonstrate with experiments that wild American Crows, Corvus brachyrhynchos, respond to dead conspecifics by mobbing, increasing the time to approach food in areas associated with these events, and learning new predators based on their proximity to dead Crows and hawks. Avoidance of either dead conspecifics or areas associated with them is not shared by another urban bird, the rock pigeon, Columba livia. Crows mobbed and increased the time to approach food over the next 72 h after observing novel humans paired with a dead crow, a red-tailed hawk, Buteo jamaicensis, or a hawk with a dead crow. The sight of a dead pigeon did not elicit these responses. These findings suggest that, for Crows, dead conspecifics, but not dead heterospecifics, represent a salient danger akin to the observation of a predator. On the day the stimulus was presented, the number of trials that resulted in mobbing and avoidance of the food was strongest when Crows were presented a hawk with a dead crow. In addition, we demonstrate that Crows use the proximity of a human to predators, to dead conspecifics and to predators with dead conspecifics as cues to learn to recognize and subsequently scold the associated human after only one training event, and that this association can last 6 weeks. Together, our results support previous findings that Crows learn places associated with conspecific death, and further demonstrate that Crows can learn and remember people who appear complicit in these events.
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Wild American Crows use funerals to learn about danger
2015Co-Authors: Kaeli N. SwiftAbstract:Wild American Crows use funerals to learn about danger Kaeli Swift Chair of Supervisory Committee: Dr. John Marzluff School of Environmental and Forest Sciences While a growing number of animals demonstrate seemingly ritualistic behaviors around the death or body of a conspecific, the evolutionary basis for this behavior remains unclear. Here we demonstrate that wild American Crows (Corvus brachyrhynchos) are using funeral gatherings as an opportunity to engage in social learning, inform future resource use, infer novel predators, and that this behavior is not shared by another urban bird: the rock pigeon (Columba livia). Novel humans paired with a dead crow, a redtailed hawk (Buteo jamaicensis), and a hawk with a dead crow all evoked mobbing and decreased foraging by Crows, while pairing with a dead pigeon did not. These findings suggest that dead conspecifics, but not heterospecifics, represent a salient danger akin to observation of a predator. Mobbing and decreased foraging immediately after stimulus removal were strongest when Crows were presented a hawk with a dead crow. Over the next 3 d we found that Crows avoided food in areas associated with these dangerous events. However, site avoidance was uniform across stimuli suggesting that crow sensitivity to the identity of the threat dissipates after 24 h. In addition, we demonstrated that Crows use proximity to predators, dead conspecifics and predators with conspecific