COLLABORATIVE: Geographic Structure of Adelie Penguin Colonies - Demography of Population Change

本项目是对南极洲罗斯岛和博弗特岛上阿德利企鹅的地理结构、新殖民地的建立和种群变化的国际合作调查。这些栖息地发生的长期变化代表了整个罗斯海的变化，30%的阿德利企鹅生活在罗斯海，在某种程度上与气候变化有关。最近，罗斯岛和波弗特岛的两座巨大冰山搁浅，海冰范围的变化也随之增加，这提供了一个无与伦比的自然实验，影响了种群生产力、觅食努力、哲学和招募方面的野生年际波动。这项自然实验的结果可以为该物种的人口统计学和地理种群结构提供见解，对了解其未来对气候变化的反应以及解释其令人惊讶的全新世历史具有重要意义。这项正在进行的研究将继续考虑限制或促进群体生长的资源的相对重要性（筑巢栖息地，获得食物）；自然历史中受邻近殖民地间剥削性竞争或干扰性竞争影响的方面（繁殖成功、觅食努力）；影响后者的气候因素，特别是海冰型态；以及影响群体增长的行为机制，作为初始大小和位置的函数（移民，移民）。更多的努力将集中在了解影响越冬生存的因素上。假设是，克罗泽角的年龄结构在过去的30年里发生了变化，不再反映附近较小的殖民地。根据最近的分析，罗斯岛企鹅似乎在南极圈以北（日光持续存在的地方）和南极环极流南边界以南（食物丰富的地方）的狭窄海冰地带过冬。更大范围的冬季冰层将企鹅带到边界以北，在那里它们的死亡率更高。因此，企鹅在哪里过冬可能取决于其繁殖后离开的时间（在不同的种群中是不同的），这影响了它第一次遇到海冰的地方，在哪里蜕皮，以及它将被日益增长的冰原运送到哪里。觅食努力和对食物的干扰竞争被认为是驱动殖民地地理结构的因素。这项研究包括对已知年龄的企鹅进行普查，研究觅食的努力和种群之间的重叠；确定换羽和越冬区域的位置。资料将与卫星图像量化的海冰状况有关。将使用人口统计学和觅食努力模型来综合结果。冰山自然实验是一个无与伦比的机会来调查极地海鸟的人口特征及其对气候变化的反应。这种明显的、年际间的变化，以及收集到的关于其原因的具体数据，是脊椎动物研究中很少遇到的情况。更广泛的影响包括与新西兰和意大利的研究人员合作，让高中教师和学生参与实地考察，并继续建立一个网站，向科学家和公众突出结果。

This project is an international collaborative investigation of geographic structuring, founding of new colonies, and population change of Adelie penguins (Pygoscelis adelia) nesting on Ross and Beaufort islands, Antarctica. The long-term changes occurring at these colonies are representative of changes throughout the Ross Sea, where 30% of all Adelie penguins reside, and are in some way related to changing climate. The recent grounding of two very large icebergs against Ross and Beaufort islands, with associated increased variability in sea-ice extent, has provided an unparalleled natural experiment affecting wild, interannual swings in colony productivity, foraging effort, philopatry and recruitment. Results of this natural experiment can provide insights into the demography and geographic population structuring of this species, having relevance Antarctic-wide in understanding its future responses to climate change as well as interpreting its amazingly well known Holocene history. This ongoing study will continue to consider the relative importance of resources that constrain or enhance colony growth (nesting habitat, access to food); the aspects of natural history that are affected by exploitative or interference competition among neighboring colonies (breeding success, foraging effort); climatic factors that influence the latter, especially sea ice patterns; and behavioral mechanisms that influence colony growth as a function of initial size and location (emigration, immigration). An increased effort will focus on understanding factors that affect over-winter survival. The hypothesis is that the age structure of Cape Crozier has changed over the past thirty years and no longer reflects the smaller colonies nearby. Based on recent analyses, it appears that the Ross Island penguins winter in a narrow band of sea ice north of the Antarctic Circle (where daylight persists) and south of the southern boundary of the Antarctic Circumpolar Current (where food abounds). More extensive winter ice takes the penguins north of that boundary where they incur higher mortality. Thus, where a penguin winters may be due to the timing of its post-breeding departure (which differs among colonies), which affects where it first encounters sea ice on which to molt and where it will be transported by the growing ice field. Foraging effort and interference competition for food suggested as factors driving the geographic structuring of colonies. The research includes a census of known-age penguins, studies of foraging effort and overlap among colonies; and identification of the location of molting and wintering areas. Information will be related to sea-ice conditions as quantified by satellite images. Demographic and foraging-effort models will be used to synthesize results. The iceberg natural experiment is an unparalleled opportunity to investigate the demographics of a polar seabird and its response to climate change. The marked, interannual variability in apparent philopatry, with concrete data being collected on its causes, is a condition rarely encountered among studies of vertebrates. Broader impacts include collaborating with New Zealand and Italian researchers, involving high school teachers and students in the fieldwork and continuing a website to highlight results to both scientists and the general public.