Greeney Harold F, Meneses M Rocio, Hamilton Chris E, Lichter-Marck Eli, Mannan R William, Snyder Noel, Snyder Helen, Wethington Susan M, Dyer Lee A
Yanayacu Biological Station & Center for Creative Studies, Cosanga, Napo, Ecuador. ; Department of Biology, University of Nevada, Reno, NV 89557, USA. ; Department of Natural Resources, University of Arizona, Tucson, AZ 85721, USA.
Hummingbird Monitoring Network, P.O. Box 115, Patagonia, AZ 85624, USA.
Sci Adv. 2015 Sep 4;1(8):e1500310. doi: 10.1126/sciadv.1500310. eCollection 2015 Sep.
The indirect effects of predators on nonadjacent trophic levels, mediated through traits of intervening species, are collectively known as trait-mediated trophic cascades. Although birds are important predators in terrestrial ecosystems, clear examples of trait-mediated indirect effects involving bird predators have almost never been documented. Such indirect effects are important for structuring ecological communities and are likely to be negatively impacted by habitat fragmentation, climate change, and other factors that reduce abundance of top predators. We demonstrate that hummingbirds in Arizona realize increased breeding success when nesting in association with hawks. An enemy-free nesting space is created when jays, an important source of mortality for hummingbird nests, alter their foraging behavior in the presence of their hawk predators.
捕食者通过中间物种的特性对非相邻营养级产生的间接影响，统称为性状介导的营养级联效应。尽管鸟类是陆地生态系统中的重要捕食者，但涉及鸟类捕食者的性状介导间接影响的明确例子几乎从未被记录过。这种间接影响对于构建生态群落很重要，并且可能受到栖息地破碎化、气候变化和其他降低顶级捕食者数量的因素的负面影响。我们证明，亚利桑那州的蜂鸟与鹰一起筑巢时繁殖成功率会提高。当松鸦（蜂鸟巢死亡率的一个重要来源）在其鹰类捕食者面前改变其觅食行为时，就会创造出一个无天敌的筑巢空间。
