Destruction of wetland habitats by lesser snow geese: A keystone species on the west coast of Hudson Bay
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Authors: R. H. Kerbes, P. M. Kotanen, and R. L. Jefferies
Date: 1990
Journal: Journal of Applied Ecology
Volume: 27
Number: 1
Pages: 242-258
Summary of Methods: To estimate lesser snow geese populations and determine the effects of geese herbivory along the Hudson Bay in the Northwest Territories, nesting and population surveys were conducted along with plant species frequency and fecal counts. Aerial photographs were taken in June 1985 to count nesting birds, while population surveys were done from an airplane in 1977, 1980, 1981, and 1985. The geese population survey in 1978 was done with aerial photographs. Plant frequency and nest and fecal counts were conducted on seven non-degraded sites and five degraded sites in 1985.
Article Summary / Main Points: After a period of decline in 1980, geese numbers (218,000) and nesting area increased in 1985. In plots with low geese grazing, Carex aquatilis was most frequent and in areas of heavy goose herbivory, bare peat was often dominant. In 1985, large areas of bare peat were also evident in the aerial photographs of the areas with heavy goose herbivory. Fecal and nest counts were variable among the 12 sites measured; however, nest numbers were greater in degraded areas, while feces counts were larger in non-degraded areas. The high numbers of geese combined with reduced vegetation cover indicate geese were increasingly degrading the landscape and halting vegetation recovery.
Vegetation Types: Riparian and Wetlands
MLRA Ecoregions: Not Applicable
Agrovoc Control Words: Riparian zones Rangelands Wildlife
Article Review Type: Refereed
Article Type: Documented Case History
Keywords: lesser snow geese, chen caerulescens caerulescens, hudson bay, species composition, grubbing, fen
Annotation: Overgrazing by migratory birds is problematic when numbers increase beyond the carrying capacity of the land. This case study is applicable to other regions with similar vegetation and bird communities.
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