Habitat change at a multi-species goose breeding area on Southampton Island, Nunavut, Canada, 1979–2010

Abstract

Foraging by hyperabundant Arctic-nesting geese has significant impacts on vegetation of Arctic and subarctic coastal lowlands, but long-term data sets documenting these changes are rare. We undertook intensive surveys of plant communities at East Bay and South Bay, Southampton Island, Nunavut, Canada, in July 2010. Lesser Snow Geese, Ross’s Geese, Cackling Geese, and Brant nest and rear young at these sites; the first three have experienced up to 10-fold increases since the 1970s. At East Bay, we found significant declines in graminoids over the 31-year span, as well as significant declines in lichen and willow cover, and significant increases in rock cover. Transect data indicated graminoids were present at only 15%–36% of points at East Bay, whereas at South Bay, graminoids were present at 28%–90% of points. Moss was more prominent in transects at South Bay than at East Bay (40%–85% vs. 19%–42%), but quadrat data indicated much more of the moss cover at South Bay apparently was dead than at East Bay. Puccinellia phryganodes (Trin.) Scribn. & Merr. exceeded 1% in only two transects. Our data demonstrate a striking decline of preferred forage species and increases in non-forage cover, consistent with the hypothesis that changes resulted from persistent long-term foraging by the four species of breeding geese between spring arrival and late summer departure.