Monitoring of Greater Snow Goose reproduction on Bylot Island, Nunavut, Canada

Nest searches are carried out on foot from our main field station since 1989 and from a secondary field camp inside the main goose colony since 1992. Nests are found during laying or incubation period by searches conducted over various areas in both sectors. At the main goose colony, systematic nest searches are conducted using two methods: (1) over an intensively-studied core area (ca 50 ha) located in the centre of the colony every year, and (2) since 1999, within a variable number of 1 and 2-ha plots randomly located throughout the colony. We also attempt to find the nests of as many neck-collared females as possible through intensive searches throughout the nesting colony. Nests are positioned with a GPS receiver and revisited twice or more to determine laying date, clutch size, hatching date and nesting success.自1989年起，研究团队便从主野外站步行开展巢址搜寻工作；自1992年起，新增了位于主要雁群栖息地内的二级野外营地作为补充作业据点。研究人员会在产卵期或孵化期，对两个作业区域内的各类生境开展搜寻以定位巢址。在核心雁群栖息地中，我们采用两种系统性巢址搜寻方案：其一为每年对栖息地中心约50公顷的长期密集研究核心区域开展搜寻；其二为自1999年起，在全栖息地范围内随机布设的可变数量1公顷与2公顷样地内开展搜寻。此外，我们还会在整个筑巢栖息地内开展密集搜寻，尽可能定位佩戴颈圈的雌性个体的巢址。研究人员使用GPS接收机对巢址进行定位，并至少重访两次，以确定产卵日期、窝卵数、孵化日期及筑巢成功率。