Feeding Ecology of Snowy Owls (Nyctea scandiaca) Wintering in
ABSTRACT. Food habits, habitat selection, and hunting behavior of snowy owls (Nyctea scandiaca) wintering nearcalgary, Alberta were investigated during the winters of 1976-77 and 1977-78. The owls preyed extensively upon rodents. Gray partridge (Perdixperdix) were an important prey only in one winte...
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| Language: | English |
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| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.547.6685 http://pubs.aina.ucalgary.ca/arctic/arctic35-2-282.pdf |
| Summary: | ABSTRACT. Food habits, habitat selection, and hunting behavior of snowy owls (Nyctea scandiaca) wintering nearcalgary, Alberta were investigated during the winters of 1976-77 and 1977-78. The owls preyed extensively upon rodents. Gray partridge (Perdixperdix) were an important prey only in one winter. Dietary differences between years seem to be related to differences in weather. Male snowy owls preyed almost exclusively upon mice, whereas females utilized a wider range of prey, including much larger species. The owls appeared to respond to variation in habitat quality by selecting those habitats with the highest availability of prey. Snowy owls were successful in 43 % of 51 attempts to capture prey. The success rate of attempts to capture birds,was lower than for small mammals. Juvenile females had lower success rates and longer prey-handling times than did adult females. Key words: snowy owl, Nyctea scandiaca, food habits, winter ecology, Alberta RÉSUMI?. Les habitudes alimentaires, le choix de l’habitat et le comportement de chasse des harfangs des neiges (Nycteu scundiuca) hivernant prbs de Calgary en Alberta, ont et6 etudiks durant les hivers 1976-77 et 1977-78. Les rongeurs furent le proie privilkgike des hiboux. La perdrix grise (Perdixperdix) fut une proie importante durant seulement un hiver. Les differences observees entre les annCes dans l’alimentation semblent &re reliees &des differences climatiques. Le harfang des neiges male chassait presqu’exclusivement la souris, alors que les femelles jetaient leur devolu sur une plus grande variete des proies incluant des espbces physiquement plus imposantes. Les harfangs semblent repondre aux variations de la qualit6 de l’habitat en choisissant les habitats offrant la plus grande varidte de proies. Sur un total observe de 51 tentatives de capture d’une proie, les harfangs des neiges rkussirent dans 43 % des cas. Ce taux de succes etait plus bas dans la cauture d’oiseaux aue des &its mammifbres. CornDarativement aux femelles adultes, les jeunes ... |
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