Scheibler D R
Departamento de Zoologia, Universidade Estadual Paulista, Rio Claro, SP, 13506-900, Brazil.
Braz J Biol. 2007 Feb;67(1):65-71. doi: 10.1590/s1519-69842007000100009.
I examined the diet of breeding White-tailed Kites (Elanus leucurus; Aves; Accipitridae) and Barn Owls (Tyto alba; Aves; Tytonidae) in an agrarian area of southern Brazil by analyzing regurgitated prey remains. The objective was to evaluate how these raptors, which differ markedly in their hunting activity periods (owls are nocturnal and kites diurnal), share their mammalian food component. 2,087 prey consumed by Barn Owls and 1,276 by White-tailed Kites were identified. They presented a high overlap of food-niches (Piankas index was 0.98). Based on the daily activity period of their main small mammal prey, a lower overlap would be expected. The crepuscular/nocturnal Mus musculus was the main prey for the diet of breeding Barn Owls (81%) and White-tailed Kites (63%). This small exotic rodent provided 63% of the small mammal biomass ingested by owls and 44% by kites. Larger native small mammals were also considered important for the diet of kites, mainly because of their biomass contribution. Although these raptors differ markedly in their hunting activity periods, Barn Owls and White-tailed Kites are very similar predators in southern Brazil, overlapping their diets.
我通过分析反刍出的猎物残骸，研究了巴西南部一个农业地区繁殖期白尾鸢（白尾鸢属；鸟纲；鹰科）和仓鸮（草鸮属；鸟纲；草鸮科）的饮食。目的是评估这些猛禽，它们在狩猎活动时间上有显著差异（仓鸮是夜行性的，白尾鸢是昼行性的），如何共享它们的哺乳动物食物组成部分。确定了仓鸮消耗的2087个猎物和白尾鸢消耗的1276个猎物。它们的食物生态位重叠度很高（ Pianka指数为0.98）。基于它们主要小型哺乳动物猎物的每日活动时间，预计重叠度会更低。晨昏性/夜行性的小家鼠是繁殖期仓鸮（81%）和白尾鸢（63%）饮食的主要猎物。这种小型外来啮齿动物提供了仓鸮摄入的小型哺乳动物生物量的63%，以及白尾鸢摄入的44%。较大的本地小型哺乳动物对白尾鸢的饮食也很重要，主要是因为它们的生物量贡献。尽管这些猛禽在狩猎活动时间上有显著差异，但在巴西南部，仓鸮和白尾鸢是非常相似的捕食者，它们的饮食有重叠。
