The University of Michigan Biological Station (UMBS) was founded in 1909.
Population Trends of Ring-billed Gulls Breeding on the North American Great Lakes, 1976 to 2009
Title | Population Trends of Ring-billed Gulls Breeding on the North American Great Lakes, 1976 to 2009 |
Publication Type | Journal Article |
Year of Publication | 2011 |
Authors | Morris RD, Weseloh D.V, Wires LR, Pekarik C, Cuthbert FJean, Moore DJ |
Journal | Waterbirds |
Volume | 34 |
Pagination | 202 - 212 |
Date Published | 06/2011 |
Keywords | SURVEYS |
Abstract | {After near extirpation in the early 20th century, Ring-billed Gulls (Larus delawarensis) are currently (2009) the most abundant colonial waterbird nesting on the Great Lakes. Nest count data are reported from four decadal censuses (1976–2009) conducted by the Canadian Wildlife Service and the U.S. Fish and Wildlife Service. Numbers increased from 305,790 nests (1976–80) to a peak of 718,887 nests (1989–90), then decreased to 652,664 (1997–2000) and to 585,984 nests (2007–09). Changes varied spatially after the second census with greatest losses (-38.6%) at North Channel, Georgian Bay and northern Lake Huron colonies, and greatest gains (+324.2%) at Lake Michigan colonies. A total of 472 sites had nests in at least one census (Canada N = 319; U.S. N = 153). Eighteen (3.8%) colonies had >2,000 nests in all four censuses, and had 37.5–41.9% of all nests in each census. Site occupancy was fluid. A high proportion (56.8% |
DOI | 10.1675/063.034.0209 |