Chamberlain C P, Waldbauer J R, Fox-Dobbs K, Newsome S D, Koch P L, Smith D R, Church M E, Chamberlain S D, Sorenson K J, Risebrough R
Department of Geological and Environmental Science, Stanford University, Stanford, CA 94305-2115, USA.
Proc Natl Acad Sci U S A. 2005 Nov 15;102(46):16707-11. doi: 10.1073/pnas.0508529102. Epub 2005 Nov 7.
We used carbon and nitrogen isotopes to investigate changes in the diet of California condors from the Pleistocene to the recent. During the Pleistocene, condors from California fed on both terrestrial megafauna and marine mammals. Early accounts reported condors feeding on the carcasses of marine mammals, but by the late 1700s, condor diets had shifted predominantly to terrestrial animals, following the commercial harvesting of marine mammals and the development of cattle ranching on land. At present, dairy calves provided by humans significantly augment condor diet, constituting an artificial support of the current population. Reestablishing a marine mammal component in the condor diet may be an effective strategy for fostering viable condor populations independent of direct human subsidies.
我们利用碳和氮同位素来研究更新世到近代加利福尼亚神鹰饮食的变化。在更新世，加利福尼亚的神鹰以陆地巨型动物和海洋哺乳动物为食。早期记载报道神鹰以海洋哺乳动物的尸体为食，但到18世纪后期，随着海洋哺乳动物的商业捕捞以及陆上养牛业的发展，神鹰的饮食已主要转向陆地动物。目前，人类提供的奶牛犊显著增加了神鹰的食物，构成了对当前种群的一种人为支持。在神鹰的饮食中重新引入海洋哺乳动物成分可能是培育独立于直接人类补贴的、能够存活的神鹰种群的有效策略。
