The gyrfalcon, Falco rusticolus, in the Yamal Peninsula: Dynamics of brood size and nest size over the years 1973–2008

Autor: V. N. Kalyakin, M. S. Romanov, S. A. Mechnikova, N. V. Kudryavtsev
Rok vydání: 2010
Předmět:
Zdroj: Russian Journal of Ecology. 41:256-263
ISSN: 1608-3334
1067-4136
DOI: 10.1134/s1067413610030100
Popis: The gyrfalcon in the Yamal Peninsula nests mostly on trees. The average brood size in this species decreased from 3.1 nestlings per active nest (n = 28) between 1973 and 1989 to 2.2 (n = 22) between 1998 and 2008. This decrease is probably explained by switching to the habit of using mostly smaller nests (built by the rough-legged buzzard, raven, or hooded crow) instead of large nests built by the white-tailed eagle. The survival rate of gyrfalcon nestlings in smaller nests is considerably lower: the average brood size is only 1.6 (n = 12), compared to 2.5 (n = 20) in medium-sized and 3.0 (n = 34) in large nests. The possible role of increase in snow cover density caused by climate warming in making large nests less accessible to the gyrfalcon is discussed.
Databáze: OpenAIRE
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