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，我们从主研究站徒步进行巢穴搜索，自1992年起，在主雁群内部的次级野外营地亦开展此项工作。通过在两个区域的不同区域进行的搜索，在产卵或孵化期间发现巢穴。在主雁群，采用两种系统性的巢穴搜索方法：一是每年在雁群中心约50公顷的密集研究区域进行搜索；二是自1999年以来，在雁群中随机分布的若干1至2公顷的区块内进行搜索。我们亦通过在巢穴群落中进行的密集搜索，尽可能寻找尽可能多的颈圈雌雁的巢穴。使用GPS接收器定位巢穴，并对之进行两次或更多次的回访，以确定产卵日期、蛋群大小、孵化日期以及巢穴的成功率。