Ecology of polar bears in changing climate

北极熊赖以生存的海冰栖息地很容易受到预计的气候变化的影响。海冰面积、持续时间、厚度和积雪的减少不仅会对北极熊的繁殖成功、觅食、迁徙模式和生存产生重大影响，还会对它们的海洋哺乳动物猎物产生重大影响。这项研究的目的是确定影响种群动态(出生、死亡、迁入和迁出)的潜在生态过程，这些过程决定了北极熊数量的变化。它涉及对北极熊生活史组成部分的调查，以及对北极熊生活史与气候、海冰和猎物之间联系的定量描述。研究活动建立在3个种群(波弗特海、福克斯盆地和西哈德逊湾)。该项目涉及4个核心领域的重大创新：1)通过卫星跟踪结合卫星冰面图像，评估气候和海冰状况对北极熊活动的时空模式的影响。2)海冰状况的年际变化对表型指标、生活史特征和种群动态的影响。3)检查从北极熊采集的牙齿中牙骨质的沉积，并根据牙环宽度推断出生活史事件。4)使用诸如血清尿素/血肌酐水平、血瘦素和结合珠蛋白等生理参数来评估禁食/喂养动力学和健康状况。该项目将产生有关北极熊与其环境之间关系的量化数据，这些数据可用于预测未来对气候变化的生态反应。北极熊是一种对北方社区具有重要文化、社会和经济意义的物种。加拿大还致力于在签署《关于北极熊的国际协定》(1973年)的基础上对北极熊进行持续的研究。该项目收集的信息将直接影响加拿大北极地区北极熊和其他海洋哺乳动物的管理和保护工作。该项目与地区和联邦政府机构密切协调，并将结果提供给当地猎人和捕猎者组织及其综合机构。

The sea ice habitat upon which polar bears depend is vulnerable to projected climate change. Reduction in sea ice extent, duration, thickness, and snow cover can significantly impact reproductive success, foraging, migration patterns, and survivorship not only of polar bears, but also of their marine mammal prey. The objective of this research is to identify the underlying ecological processes that affect population dynamics (births, deaths, immigration and emigration) that determine shifts in polar bear abundance. It involves the investigation of life history components of polar bears and the development of quantitative descriptions of the linkages between their life history and climate, sea ice, and prey. Research activities are established in 3 populations (Beaufort Sea, Foxe Basin, and W. Hudson Bay). The project involves significant innovation in 4 core areas: 1) Assessing the effects of climate and sea ice conditions on spatial and temporal patterns of polar bears movements via satellite tracking in conjunction with satellite ice imagery. 2) The effects of interannual variability in sea ice conditions on the phenotypic metrics, life history traits, and population dynamics. 3) Examination of cementum deposition in teeth collected from polar bears with inferences on life history events derived from annuli widths. 4) Use of physiological parameters such as serum urea/ serum creatinine levels, blood leptin, and haptoglobin will be used to assess fasting/feeding dynamics and health. The project will yield quantitative data on the relationship between polar bears and their environment that can be used to predict future ecological responses to climate change. Polar bears are a species of great cultural, social, and economic importance for northern communities. Canada is also committed to ongoing research on polar bears based on signing of the International Agreement on Polar Bears (1973). Information collected in this project will directly influence management and conservation efforts for polar bears and other marine mammals in the Canadian Arctic. The project is closely coordinate with territorial and federal government agencies and results are provided to local hunter and trapper organizations and their integrating agencies.