Long-term effects of habitat quality on juvenile fitness along contrasting environmental gradients

栖息地质量对不同环境梯度下青少年健康的长期影响

• 批准号: RGPIN-2016-05344
• 负责人: Stutchbury, Bridget
• 金额: $ 2.7万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=708506
• 关键词: Long; term; effects; habitat; quality

The long term objective of my research program is to understand how anthropogenic stressors contribute to population declines of migratory songbirds. Dozens of North American species have been in steep decline for decades and many are now designated as Species at Risk in Canada. One of the biggest challenges in migratory songbird conservation has been determining the link between well-studied breeding populations and threats elsewhere in their life cycle. In 2009, my lab published a ground-breaking study in Science that used miniaturized tracking devices to map the start-to-finish migration of songbirds for the first time, and this triggered a revolution in our understanding of songbird migration ecology and conservation. However, a critical gap in knowledge remains because juvenile survival is poorly understood in migratory songbirds yet is expected to have a large impact on population dynamics. Offspring disperse away from their parent's territory a month or so after hatching, become increasingly mobile and difficult to track, and after migration few return close enough to their natal site to be detected by researchers. Environmental stressors are expected to have a big impact on independent juveniles because their foraging efficiency is initially low yet they must build fat reserves to prepare for their inaugural fall migration that is thousands of kilometers across unfamiliar terrain. My research program is novel because I will track juveniles by deploying new long-lasting (>1 year) coded radio-transmitters within a new array of automated telemetry receivers that blankets southwestern Ontario. By combining manual and automated tracking, my students will test how habitat quality affects juvenile condition, survival, dispersal and onset of fall migration and we will re-locate recruits that return the next spring within the ~100,000 square kilometer array. This novel technology will allow us to test a series of hypotheses for how and why habitat quality impacts short-and long-term juvenile fitness in migratory songbirds. Poor habitat quality is expected to reduce nestling body condition and carry over to have long-lasting and negative effects on juvenile fitness. We will evaluate the nature and duration of these development effects along two contrasting environmental gradients (forest fragmentation, agricultural intensification) that differ in their underlying ecological stressors. Our results will directly inform habitat management decisions through population modelling scenarios that clearly identify the consequences of habitat loss and fragmentation on migratory songbirds.

我的研究项目的长期目标是了解人为压力如何导致迁徙鸣禽的数量下降。几十年来，数十种北美物种数量急剧下降，许多物种现在被加拿大指定为濒危物种。迁徙鸣禽保护的最大挑战之一是确定经过充分研究的繁殖种群与其生命周期中其他地方的威胁之间的联系。2009年，我的实验室在《科学》杂志上发表了一项突破性的研究，首次使用微型跟踪设备绘制了鸣禽迁徙的全程地图，这引发了我们对鸣禽迁徙生态学和保护的理解的革命。然而，一个关键的知识差距仍然存在，因为青少年的生存在迁徙鸣禽知之甚少，但预计将有很大的影响，人口动态。后代在孵化后一个月左右就离开父母的领地，变得越来越移动的，难以追踪，迁移后很少有人回到离纳塔尔地足够近的地方，以至于被研究人员发现。环境压力预计会对独立的青少年产生重大影响，因为他们的觅食效率最初很低，但他们必须建立脂肪储备，为他们的首次秋季迁徙做准备，这是数千公里的陌生地形。 我的研究计划是新颖的，因为我将通过在安大略西南部的自动遥测接收器阵列中部署新的持久（>1年）编码无线电发射器来跟踪青少年。通过结合手动和自动跟踪，我的学生将测试栖息地质量如何影响少年状况，生存，分散和秋季迁徙的开始，我们将重新定位在10万平方公里阵列内的第二个春天返回的新兵。这项新技术将使我们能够测试一系列关于栖息地质量如何以及为什么影响迁徙鸣禽短期和长期青少年健康的假设。栖息地质量差，预计将减少雏鸟的身体状况和结转有长期的和负面的影响，对少年健身。我们将评估这些发展效应的性质和持续时间沿着两个对比的环境梯度（森林破碎化，农业集约化），不同的潜在生态压力。我们的结果将通过种群建模情景直接为栖息地管理决策提供信息，这些情景可以清楚地识别栖息地丧失和破碎对候鸟的后果。