Songbird nest predators in forest-pasture edge and forest interior in a fragmented landscape
Songbird nest predators in forest-pasture edge and forest interior in a fragmented landscape
复制标题
DOI：
10.2307/3060994
复制
发表时间：
2002-06-01
影响因子：
5
通讯作者：
Thompson, FR
中科院分区：
文献类型：
--
作者：
Chalfoun, AD;Ratnaswamy, MJ;Thompson, FR
许多研究比较了森林边缘和森林内部鸣禽的筑巢成功率；但很少有人指出潜在的因素，潜在的变化在巢捕食压力与边缘。研究了美国密苏里州中部一个破碎农业景观的森林边缘和内部的鸣鸟巢穴捕食者和褐头牛鹂（Molothrus ater）的相对丰度和物种丰富度。鸟类捕食者和牛鹂在森林边缘更为丰富。在边缘和内部，中小型哺乳动物捕食者的丰度没有差异。从边缘捕获的蛇几乎是从内部捕获的蛇的两倍。森林边缘的捕食者物种丰富度显著高于边缘。森林边缘和内部植被结构非常相似，表明捕食者丰度和物种丰富度的差异不是由生境结构的变化驱动的。因此，与栖息地边缘相关的巢捕食者分布可能取决于更大空间尺度的因素，如景观环境。我们认为，在农业破碎化地区，森林边缘的巢捕食者组合可能与森林内部的巢捕食者组合不同。边缘可能会吸引更多的捕食者物种，一些巢穴捕食者可能在森林斑块边缘附近更丰富，尽管这种趋势并不适用于所有的捕食者分类。因此，应谨慎地对巢捕食者和边缘进行概括，保护计划应考虑当地巢捕食者组合的组成，以预测对边缘栖息地筑巢鸟类的潜在影响。
Many studies have compared songbird nesting success between forest edge and interior; but few have addressed potential factors underlying variation in nest predation pressure in relation to edge. We examined the relative abundance and species richness of songbird nest predators and the abundance of Brown-headed Cowbirds (Molothrus ater) in forest edge and interior within a fragmented, agricultural landscape in central Missouri, USA. Avian predators and cowbirds were more abundant in forest edges. There were no differences in small- or medium-sized mammalian predator abundance between edge and interior. Almost twice as many snakes were captured in edge as in interior. Predator species richness was significantly higher in forest edge. Forest vegetation structure was very similar between edge and interior, suggesting that differences in predator abundance and species richness were not driven by variation in habitat structure. Nest predator distribution in relation to habitat edge may therefore depend on factors at larger spatial scales, such as landscape context. We suggest that in areas fragmented by agriculture, nest predator assemblages in forest edges may differ from those in forest interior. Edges may attract a greater number of predator species, and some nest predators may be more abundant near the edges of forest patches, although the trend does not apply across all predator taxa. Generalizations about nest predators and edges should thus be made with caution, and conservation plans should consider the composition of local nest predator assemblages in order to predict potential impacts on nesting birds in edge habitat.