Life history and ecology of pinnipeds

我研究的长期目标是了解影响海豹觅食和繁殖策略的进化和生态因素。在接下来的五年里，我和我的学生们计划在我们对海豹生活史和觅食生态学的长期研究的基础上再接再厉。在相对较少的大型长寿脊椎动物中，记录了个体内和个体之间在其生殖生命过程中生殖性能的可变性。对性状的平均总体估计掩盖了个体对环境变化反应的潜在重要变异性。我们计划使用1450只单独标记的已知年龄雌性的长期数据来调查繁殖性能中个体变异的来源(例如，当地繁殖密度、栖息地、身体状况、年龄、出生日期、后代大小)。我们还将使用品牌男性和女性的重视数据来测试特定性别的假设，这些假设涉及招募时年龄的变化和特定年龄的生存，以及生存模式如何随着人口丰度和环境变异性的变化而变化。尽管后代的大小经常被用来代表雌性和后代的健康状况，但这一假设很少在大型哺乳动物身上得到验证。对1998年至2002年出生的大约1200只永久标记的雌性灰海豹幼崽的大小和其他后代特征进行了测量。我们测量了这些幼崽招募时的大小和年龄，以测试后代大小、存活率和招募时大小和年龄之间的关系。我们还将调查女性在哺乳期间在保护后代方面表现出个性的程度，以及个性差异对生殖成功的影响。最后，我们将使用一个大型数据库，其中包括灰海豹的卫星轨迹以及个体对食物和体重增长的估计，以更好地了解觅食行为和繁殖性能之间的关系。

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 seals. Variability in reproductive performance within and among individuals over their reproductive life has been documented for relatively few large long-lived vertebrates. Mean population estimates of traits obscure potentially important variability in the response of individuals to environmental variation. We plan to use long-term data from >1450 individually marked, known-age females to investigate sources of individual variability (e.g., local breeding density, habitat, body condition, age, birth date, offspring size at weaning) in reproductive performance. We will also use resighting data of branded males and females to test sex-specific hypotheses about variation in age at recruitment and age-specific survival 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 mammals. Size and other offspring traits were measured for about 1200 permanent-marked female grey seals pups that were born from 1998 to 2002. We have measured size and age at recruitment of the survivors of those pups to test the relationship between offspring size, survival and size and age at recruitment. We will also investigate the extent to which females exhibit personality with respect to the protection of their offspring during lactation and the consequences of differences in personality on reproductive success. Finally, we will use a large database of grey seals satellite tracks and individual estimates of diet and mass gain to better understand the relationship between foraging behaviour and reproductive performance.