Size and condition of lesser snow geese.
For sites where the habitat is heavily degraded, the size and survival of lesser snow geese have declined over the last 10 years (e.g. La Pérouse Bay). In contrast, the size and success of fledglings hatched at La Pérouse Bay but reared in less degraded areas is higher. These studies will be continued and parallel studies will be conducted at a) Akimiski Island, where the north shore is badly degraded and where habitat is shared with Canada geese, b) the estuaries of the Knife and Seal rivers (north of Churchill) where the habitat is partially degraded and c) West Pen Islands where habitat is excellent. Prefledging birds will be collected at regular spatial intervals from these sites and a series of morphometric data will be collected in order to assess their size. Since preliminary studies have indicated that the level of asymmetry in bilateral morphological characters increases in degraded habitats, we will collect bilateral measurements. The birds will also be necropsied since preliminary studies have demonstrated a relation between the type of forage being used (salt marsh versus inland fresh-water habitat) and both salt glands and digestive system (gizzard and caeca).
Historical size information from James and Hudson Bay goose camps and check stations and from collections housed at several US and Canadian museums will be analyzed. These data will be compared to morphometric measurements of newly sampled birds to determine whether locally observed size declines in adults and fledged first-fall young are widespread.
- revised 10/11/97 -