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Animal Sciences Commons

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Articles 1 - 3 of 3

Full-Text Articles in Animal Sciences

Fluctuating Survival Selection Explains Variation In Avian Group Size, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche, Valerie A. O'Brien, Catherine E. Page May 2016

Fluctuating Survival Selection Explains Variation In Avian Group Size, Charles R. Brown, Mary Bomberger Brown, Erin A. Roche, Valerie A. O'Brien, Catherine E. Page

School of Natural Resources: Faculty Publications

Most animal groups vary extensively in size. Because individuals in certain sizes of groups often have higher apparent fitness than those in other groups, why wide group size variation persists in most populations remains unexplained. We used a 30-y mark– recapture study of colonially breeding cliff swallows (Petrochelidon pyrrhonota) to show that the survival advantages of different colony sizes fluctuated among years. Colony size was under both stabilizing and directional selection in different years, and reversals in the sign of directional selection regularly occurred. Directional selection was predicted in part by drought conditions: birds in larger colonies tended …


Differential Wolf-Pack-Size Persistence And The Role Of Risk When Hunting Dangerous Prey, Shannon M. Barber-Meyer, L. David Mech, Wesley E. Newton, Bridget L. Borg Jan 2016

Differential Wolf-Pack-Size Persistence And The Role Of Risk When Hunting Dangerous Prey, Shannon M. Barber-Meyer, L. David Mech, Wesley E. Newton, Bridget L. Borg

United States Geological Survey, Northern Prairie Wildlife Research Center: Publications

Risk to predators hunting dangerous prey is an emerging area of research and could account for possible persistent differences in gray wolf (Canis lupus) pack sizes. We documented significant differences in long-term wolf-pack-size averages and variation in the Superior National Forest (SNF), Denali National Park and Preserve, Yellowstone National Park, and Yukon, Canada (p < 0.01). The SNF differences could be related to the wolves’ risk when hunting primary prey, for those packs (N = 3) hunting moose (Alces americanus) were significantly larger than those (N = 10) hunting white-tailed deer (Odocoileus virginianus) (F1,8 = 16.50, p = 0.004). Our data support the hypothesis that differential pack-size persistence may be perpetuated by differences in primary prey riskiness to …


Social Organization And Determinants Of Spatial Distribution Of Khur (Equus Hemionus Khur), Nita Shah, Qamar Qureshi Jan 2007

Social Organization And Determinants Of Spatial Distribution Of Khur (Equus Hemionus Khur), Nita Shah, Qamar Qureshi

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

Khur (Equus hemionus khur) is an endangered species for the most part restricted in little Rann of Kutch (India) and surrounding areas. We investigated factors influencing spatial distribution and social organization of khur. The spatial distribution is largely influenced by distribution of food patches and water in this ecosystem. The inter group distances were smaller in resource rich areas in comparison to resource poor areas (p = 0.017). The group sizes are larger in areas having higher productivity (r = 0.85) and rainfall (r = 0.88). Four social units are observed in khur (a) Family …