Donald G. Calkins
Alaska Department of Fish and Game
31 Papers
515 Citations
Donald G. Calkins is an academic researcher from Alaska Department of Fish and Game. The author has contributed to research in topics: Eumetopias jubatus & Population. The author has an hindex of 20, co-authored 31 publications. Previous affiliations of Donald G. Calkins include Alaska SeaLife Center.
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Papers
Reproductive performance of female Steller sea lions: an energetics-based reproductive strategy?
TL;DR: The reproductive performance of female Steller sea lions was examined in order to evaluate the hypothesis that low pup production was associated with nutritional stress and to assess the response of males to nutritional stress.
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Dispersal, rookery fidelity, and metapopulation structure of steller sea lions (eumetopias jubatus) in an increasing and a decreasing population in alaska
Kimberly L. Raum-Suryan,Kenneth W. Pitcher,Donald G. Calkins,John L. Sease,Thomas R. Loughlin +4 more
TL;DR: In this paper, the authors examined the extent of dispersal of Steller sea lions away from their natal rookeries, movements between stocks, and degree of natal fidelity.
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Steller sea lion status and trend in southeast alaska: 1979–1997
TL;DR: In this paper, the authors analyzed trends in numbers of pup and non-pup Steller sea lions counted in Southeast Alaska between 1979 and 1997 and estimated the Southeast Alaska breeding population of Steller Sea lions at about 19,000 animals of all ages in 1997, a level that is probably near the highest in recorded history.
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Anthropogenic causes of the western Steller sea lion Eumetopias jubatus population decline and their threat to recovery
TL;DR: The western Steller sea lion Eumetopias jubatus population has experienced a chronic decline since the 1960s and the causes are likely multifactorial and a combination of anthropogenic and natural factors.
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Spatial and temporal variation in the timing of births of steller sea lions
Kenneth W. Pitcher,Vladimir N. Burkanov,Donald G. Calkins,Donald G. Calkins,Burney J. Le Boeuf,Evgeny G. Mamaev,Richard L. Merrick,Grey W. Pendleton +7 more
TL;DR: There are significant differences in timing of births between rookeries with the earliest mean date of birth at Forrester Island, Alaska, and the latest at Año Nuevo Island, California, with the most likely explanation for temporal variability being variable nutritional status of reproductive females.
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