Novel questions about avian nesting ecology

关于鸟类筑巢生态学的新问题

• 批准号: RGPIN-2020-06532
• 负责人: Shutler, Dave
• 金额: $ 2.04万
• 依托单位: Acadia University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=741297
• 关键词: Novel; questions; about; avian; nesting

Predators put birds at extreme risk while at nests, whether as eggs, nestlings, or parents. For example, one major review reported that 23.1-87.0% of passerine nests produced fledglings, and that 20.2-85.3% of nest failures were due to predators. Thus, nest sites and behaviours that reduce predation risk can be of pivotal importance to a bird's reproductive strategy, particularly in species where many individuals do not survive beyond their first breeding season. Nest concealment is commonly assessed in studies of nest predation. However, concealment of nest odours has scarcely been considered. This is surprising given that the most common predators of passerine nests are reptiles and mammals that rely more on olfaction than vision to find nests. Similarly, little attention has been devoted to considering how predators use odours to find bird nests. These and many other overlooked questions complement my ongoing research program that is evaluating the importance of crypsis to reproductive success in tree swallows. To quantify their relative importance, I will collect data on visual, acoustic, and olfactory concealment of nests; I focus here on the latter. Odours produced by adults, nestlings, and nest materials have scarcely been quantified for any species. From nest-building through to post-fledging, I will quantify odours of tree swallow nest contents using state-of-the-art equipment: gas chromatography-mass spectrometry. A longer term goal is to collect data from numerous species to evaluate ecological (e.g., cavity- versus open-nesting, ground- vs. above-ground nesting) and phylogenetic (e.g., passerine versus non-passerine) signatures in nest odours. Once I identify single-molecule (odorant) contributors to nest odours, a next step will be to evaluate odorants to which predators respond. For example, candidate odorants will be piped into Y-tubes where model predators (e.g., deer mice) can choose to visit control versus known nest odorants. Subsequent work will evaluate combinations of odorants. Do different predator species (e.g., mice versus squirrels) prefer different odorants? At nests I monitor each year, are particular odorants associated with rates of nest predation? My research is highly collaborative; I work with swallow biologists (Golondrinas de las Americas) that have already published 8 papers investigating spatial variation in numerous aspects of swallow biology at an unprecedented spatial scale (i.e., from Tierra del Fuego to Alaska). My students and I will similarly be able to tap into this network to explore spatial variation in nest odours. I am excited about the diversity of questions within this novel research program, and the opportunities it presents to my students.

捕食者把鸟类置于极度危险的境地，而在巢中，无论是作为蛋，雏鸟，或父母。例如，一个主要的综述报告说，雀形目鸟类的巢中有23.1-87.0%产下雏鸟，而20.2-85.3%的巢失败是由于捕食者。因此，减少捕食风险的巢址和行为对鸟类的生殖策略至关重要，特别是在许多个体无法生存超过第一个繁殖季节的物种中。在巢捕食的研究中，通常会评估巢的隐蔽性。然而，隐藏的巢气味几乎没有被考虑。这是令人惊讶的，因为雀形目鸟类巢穴最常见的捕食者是爬行动物和哺乳动物，它们更依赖嗅觉而不是视觉来寻找巢穴。同样，很少有人关注捕食者如何利用气味来寻找鸟巢。这些和许多其他被忽视的问题补充了我正在进行的研究计划，该计划正在评估树燕繁殖成功的重要性。 为了量化它们的相对重要性，我将收集有关巢的视觉、听觉和嗅觉隐藏的数据;我在这里关注后者。气味产生的成年人，雏鸟，巢材料几乎没有量化的任何物种。从筑巢到羽翼丰满，我将使用最先进的设备：气相色谱-质谱仪量化树燕巢内容物的气味。一个长期目标是收集来自许多物种的数据，以评估生态（例如，腔巢与开放巢，地面巢与地上巢）和系统发育（例如，雀形目鸟类与非雀形目鸟类）在巢气味中的特征。一旦我确定了巢穴气味的单分子（气味）贡献者，下一步将是评估捕食者对气味的反应。例如，候选气味剂将被输送到Y形管中，在Y形管中模型捕食者（例如，鹿鼠）可以选择访问对照与已知的巢气味剂。随后的工作将评估气味剂的组合。不同的捕食者物种（例如，老鼠和松鼠）喜欢不同的气味？在我每年监测的巢穴中，特定的气味与巢穴捕食率有关吗？我的研究是高度合作的;我与燕子生物学家（Golondrinas de las Americas）合作，他们已经发表了8篇论文，以前所未有的空间尺度（即，从火地岛到阿拉斯加）。我和我的学生们同样能够利用这个网络来探索巢穴气味的空间变化。我对这个新颖的研究项目中的问题的多样性感到兴奋，以及它为我的学生提供的机会。