Summary
- Large numbers of lesser snow geese breed in colonies in coastal
brackish and freshwater marshes in the lowlands along the west coast of
Hudson Bay. Where colonies are present, the geese determine the
structure and species composition of the coastal plant communities.
- During recent decades, substantial increases in the number of birds
have occurred, resulting in the outward spread of the colonies into new
areas which are used for nesting, feeding and moulting.
- Patterns of foraging vary in space and time. In spring at the
nesting sites, before the onset of above ground growth of vegetation,
adult geese grub for roots and rhizomes of graminoid plants in
relatively dry areas, and in wet habitats they eat the swollen bases of
shoots of sedges, particularly Carex aquatilis. In summer, adults
and goslings graze intensively on leaves of grasses and sedges over wide
areas. Swards dominated by Carex subspathacea are produced in
brackish marshes, but the leaves of graminoids of the freshwater sedge
meadows are also clipped extensively.
- Grubbing of vegetation by geese each spring creates bare areas (1-5
m2) of peat and sediment. The increased numbers of birds
have increased the scale of disturbance, with large areas now stripped
of vegetation, particularly by the McConnell River. At some sites,
erosion of peat has exposed the underlying glacial gravels. There is
little likelihood that the vegetation which re establishes will closely
resemble the original. Further expansion of goose colonies in this
region may be limited by available food resources.
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