Linking demography, life-history theory and conservation of birds

生态学家对影响野生动物存活率和繁殖率的因素很感兴趣，因为这些比率反映了野生动物的总体健康状况，并对种群规模和持久性产生巨大影响。在加拿大，许多迁徙野生动物物种受到当地发展以及世界其他地区影响所导致的环境变化的威胁。为了实现长期目标，我和我的学生将继续测试生态理论，以加强我们对影响候鸟分布、数量、繁殖和存活率的自然和人类相关过程的理解。然后，我们将利用我们关于这些过程的新知识来推荐管理计划或保护计划，并提高这些行动的成本效益。我们的主要项目侧重于候鸟，以及景观特征（特别是农业土地利用强度）和筑巢地点如何影响鸟类的个体质量及其生存和繁殖率。我们将在不同的农业集约化（和农药使用）地点测量树燕（一种空中食虫动物，严重依赖飞虫为食的物种）筑巢季节的食物丰度，以评估父母的觅食和传播行为、生理和生存如何被不同的食物供应所改变。在更广泛的范围内，我们还将研究两种草原筑巢鸭（绿头鸭和斑尾鸭雌性）的生殖生态与个体质量和景观特征的关系。

Ecologists are interested in factors affecting survival and reproductive rates of wild animals because these rates reflect the general health of wildlife and have an enormous impact on population size and persistence. In Canada, many migratory wildlife species are threatened by environmental changes resulting from local developments as well as impacts in other parts of the world. To achieve long-term objectives, my students and I will continue to test ecological theories to strengthen our understanding about the natural and human-related processes that affect distribution, abundance, and reproductive and survival rates of migratory birds. We will then use our new knowledge about these processes to recommend management programs or conservation initiatives and to improve the cost-effectiveness of these actions. Our main projects focus on migratory birds, and how characteristics of landscapes - particularly the intensity of agricultural land use – and nest sites influence individual quality of birds, and their survival and reproductive rates. We will measure food abundance during the nesting season of tree swallows (an aerial insectivore, a species that relies heavily on flying insects for food) on sites of varying agricultural intensification (and pesticide use) to evaluate how parental foraging and dispersal behaviours, physiology and survival may be modified by variable food supplies. For broader scope, we will also investigate reproductive ecology of two species of prairie-nesting ducks (mallard and pintail females) in relation to measurements of individual quality and landscape characteristics. Presumably, habitat preferences in animals are related to benefits such as higher reproductive success or survival, yet most studies of animals fail to link habitat selection to these key demographic rates. Using several unique data sets from well-replicated local and landscape-scale experiments, we will validate new indices of individual quality and test for positive correlations between demographic rates and habitat selection in tree swallows, pintails and mallards. Specifically, by incorporating a variety of innovative techniques, we will further validate the use of feather corticosterone (the “stress” hormone) as an integrated index of individual quality in diverse species; link survival and reproductive success to an individual’s characteristics such as age and quality, nest site use and climatic conditions; and evaluate demographic consequences of nest site choices using powerful cross-fostering experiments. Importantly, these new Discovery Grant studies will: (i) clarify basic processes affecting survival rates and breeding success, (ii) apply this knowledge to identify management alternatives or to enhance the cost-effectiveness of conservation programs, and (iii) provide a stimulating, productive place for training emerging ecologists - individuals who will have to address increasingly complex environmental challenges, now and in the future.