PREDATION DANGER IN THE ECOLOGY OF MIGRATION

迁徙生态中的捕食危险

• 批准号: RGPIN-2015-04001
• 负责人: Ydenberg, Ronald
• 金额: $ 2.33万
• 依托单位: Simon Fraser University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=684388
• 关键词: PREDATION; DANGER; ECOLOGY; MIGRATION

PREDATION DANGER IN THE ECOLOGY OF MIGRATION******Top predators exert powerful effects on prey populations. As exemplified by the changes induced in the Yellowstone ecosystem by the reintroduction of wolves, these effects can ripple throughout entire communities, transmitted via the anti-predator behavior of prey animals. The strong recovery of raptor populations since 1973 (when DDT was banned) is a continental scale version of the Yellowstone wolf reintroduction, and suggests that analogous impacts are to be expected. In recent NSERC DGs, I found that top predators (falcons of the genus Falco) strongly impact the ecology and evolution of migration in sandpipers of the genus Calidris. The projects I propose here continue this line of inquiry, asking whether anti-predator behavior plays a role in other aspects of their biology linked to migration. ******Like many other avian migrants, the western sandpiper (Calidris mauri) shows strong nonbreeding sexual segregation. Does predation risk affect dispersion over non-breeding areas? I propose to test the `predation risk' hypothesis, originally put forward for ungulates. The hypothesis predicts that members of the more vulnerable sex pay a cost (greater distance) to migrate to safer nonbreeding sites. ******The aspect ratio (width/length) of wings greatly affects flight performance, with long wings better for energetic efficiency, and wide wings better for rapid take-off and agility, traits important in eluding predators. Data show that the wing length of semipalmated sandpipers (Calidris pusilla) has shortened dramatically since 1980. I propose to test the hypothesis that natural selection for more defensive flight morphology, created as falcon populations recovered, is responsible for this morphological shift.******The study of population dynamics has of course considered predation, but the role of anti-predator behavior has received little attention. I have found that the population dynamics of nonbreeding dunlins (Calidris alpina) has not been affected by falcons over the past 36 years, even though falcon numbers have increased 3-7 fold. I propose to test the hypothesis that a shift by dunlins toward more defensive non-breeding behavior (analogous to the wing length shift above) has mediated the effects of predators and starvation in a compensatory fashion.******Finally, I propose to continue my work on sockeye salmon Oncoryhnchus nerka. The role of predation danger in the ecology and evolution of salmon migration has rarely been considered. In British Columbia, sockeye populations differ greatly in the timing of their up-river spawning migrations, a pattern classically explained by the effects of temperature on adult and incubation metabolism. I propose to test the hypothesis that river-entry timing is selected for to avoid exposure to predators such as bears. **

迁徙生态学中的捕食危险 * 顶级捕食者对猎物种群产生强大的影响。正如黄石公园生态系统因狼的重新引入而引起的变化所证明的那样，这些影响可以通过猎物的反捕食行为涟漪到整个社区。 自1973年（滴滴涕被禁止）以来，猛禽种群的强劲复苏是黄石狼重新引入的大陆规模版本，并表明类似的影响是可以预期的。在最近的NSERC DG中，我发现顶级捕食者（Falco属的猎鹰）强烈地影响了Calidris属鹬的生态和迁移进化。我在这里提出的项目继续这条调查路线，询问反捕食者行为是否在与迁移有关的生物学的其他方面发挥作用。** 像许多其他鸟类迁徙者一样，西矶鹬（Calidris mauri）表现出强烈的非繁殖性隔离。捕食风险是否影响非繁殖区的扩散？我建议测试“捕食风险”的假设，最初提出的有蹄类动物。 该假说预测，更脆弱的性别成员支付成本（更长的距离）迁移到更安全的非繁殖地点。 ** 翅膀的长宽比（宽/长）对飞行性能有很大影响，长翅膀更有利于能量效率，宽翅膀更有利于快速起飞和敏捷，这些特征在躲避捕食者方面很重要。 数据显示，自1980年以来，半掌状滨鹬（Calidris pusilla）的翅长急剧缩短。 我建议检验这样一个假设，即随着猎鹰种群的恢复，自然选择产生了更具防御性的飞行形态，这是造成这种形态转变的原因。种群动力学的研究当然考虑了捕食，但反捕食行为的作用却很少受到关注。我发现，在过去的36年里，尽管猎鹰的数量增加了3-7倍，但非繁殖的杜林鱼（Calidris alpina）的种群动态并没有受到猎鹰的影响。 我建议检验这样一个假设，即邓林斯向更具防御性的非繁殖行为的转变（类似于上面的翼长转变）以补偿的方式介导了捕食者和饥饿的影响。最后，我建议继续我对红鲑鱼Oncoryhnchus nerka的研究。 捕食危险在鲑鱼洄游的生态学和进化中的作用很少被考虑。在不列颠哥伦比亚省，红红眼种群在上游产卵迁移的时间上差异很大，这种模式经典地解释了温度对成年和孵化代谢的影响。 我建议测试的假设，河流入口的时间选择，以避免暴露于食肉动物，如熊。 **