Life history variation in pinnipeds

鳍足类生活史变异

• 批准号: RGPIN-2018-05403
• 负责人: Bowen, William
• 金额: $ 4.08万
• 依托单位: Dalhousie University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2022
• 资助国家: 加拿大
• 起止时间: 2022-01-01 至 2023-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=745621
• 关键词: Life; history; variation; pinnipeds

The long-term objective of my research is to understand the evolutionary and ecological factors that have shaped the foraging and reproductive strategies of seals. During the next five years, my students and I to plan build upon our long-term studies of life history and foraging ecology of grey seals (Halichoerus grypus). Variability in reproductive performance within and among individuals over their reproductive life has been documented for relatively few large long-lived vertebrates. Mean estimates of traits obscure potentially important variability in the response of individuals to environmental variability and trends. We plan to continue the collection of long-term data (>30 years in 2017) from >1700 individually marked, known-age females to investigate intrinsic and extrinsic sources of individual variability in reproductive performance and survival and to evaluate the consequences of this variability on offspring survival and size at weaning. These data will also be used to test for the nature of heterogeneity (fixed vs dynamic) in performance and the relationship between age at first birth and lifetime reproductive success. We will also use the sighting histories of permanently marked males (~600) and females (as above) to test hypotheses concerning sex-specific onset and rate of survival and reproductive senescence and how patterns of survival vary with changes in population abundance and environmental variability. Although offspring size is often used as a proxy for female and offspring fitness, this hypothesis has rarely been tested in large, long-lived (>20 yr) mammals. Size and other offspring traits were measured for about 2400 permanent-marked grey seals pups that were born from 1998 to 2002 and another 2100 pups from 2014 to 2016. We will measure size and age at recruitment of the survivors of those pups to test the relationship between offspring size, survival, and long-term reproductive performance. We will use fine-scale GPS tracks from grey seals fitted with two tri-axial accelerometers to develop algorithms to distinguish behaviours, including foraging, to validate behavioural states estimated from state-space movement models. Along with animal-borne cameras we seek to better understand the spatial and temporal pattern of foraging in an upper trophic-level marine predator.

我的研究的长期目标是了解塑造了印章的觅食和生殖策略的进化和生态因素。在接下来的五年中，我和我的学生计划基于我们对人生历史的长期研究和觅食灰密封的生态（Halichoerus Grypus）。个人内部和个人之间生殖寿命的生殖性能变异性已被记录在相对较少的大型长脊椎动物中。特征的平均估计值掩盖了个体对环境变异性和趋势的反应的潜在重要变异性。我们计划从> 1700个单独标记的已知年龄女性中继续收集长期数据（> 30年），以研究生殖性能和生存中个体可变性的固有和外在来源，并评估这种变异性对断奶时临界生存和尺寸的影响。这些数据还将用于测试性能的异质性（固定与动态）的性质以及第一出生和终生生殖成功的年龄之间的关系。我们还将使用永久标记的男性（〜600）和女性（如上所述）的目击历史来检验有关性别特定发作和生存和生殖衰老率的假设，以及生存模式与人口丰度和环境变异性的变化有所不同。尽管后代的大小通常被用作女性和后代健身的代理，但这种假设很少在大型，长寿（> 20年）的哺乳动物中进行检验。测量了从1998年到2002年出生的大约2400个永久性灰密封幼犬的大小和其他后代特征，并从2014年到2016年出生。我们将测量这些幼犬幸存者的大小和年龄，以测试这些幼犬的幸存者，以测试后代的大小，生存，生存，生存性生殖性能之间的关系。 我们将使用装有两个三轴加速度计的灰密封器的细尺度GPS轨道来开发算法来区分行为，包括觅食，以验证从状态空间运动模型中估计的行为状态。与动物传播相机一起，我们试图更好地理解上营养水平海洋捕食者中觅食的空间和时间模式。