Background information

Great Lakes Decadal Colonial Waterbird Census

Environment and Climate Change Canada’s Canadian Wildlife Service and the U.S. Fish and Wildlife Service conducted four decadal censuses (1976-1980, 1989-1990, 1997-2000, 2007-2009) of colonial waterbirds nesting across the North American Great Lakes and their associated waterways. Target species include ground-nesting birds (e.g., gulls, cormorants, pelicans, and terns) as well as tree-nesting birds (e.g., cormorants, herons, night-herons, and egrets).

Nest sites on the shoreline (and up to 1 km inland) and offshore islands (the main breeding sites) were surveyed from the Canada/U.S. border at the west end of Lake Superior near Pigeon Point, Minnesota to Cornwall, Ontario/Massena, and New York in the upper St. Lawrence River. Nest counts were completed in most years between mid-April and mid-June with the lower Great Lakes (Ontario and Erie), censused before the more northerly Great Lakes. Population trend data (based on nest counts) from all four censuses were calculated for all target species.

For additional information on individual waterbird species nesting on all the Great Lakes, please see Weseloh et al. (2002), Morris et al. (2003, 2010, 2011, 2012), Cotter et al. (2010) and Rush et al. (2015). For additional information on all colonial waterbird species nesting on individual Great Lakes, please see Weseloh et al. (2003), Hebert et al. (2008) and Morris et al. (2009).

References

  • Cotter, R.C., J-F. Rail, A.W. Boyne, G.J. Robertson, D.V. Weseloh, and K.G. Chaulk. 2010. Population status, distribution, and trends of gulls and kittiwakes breeding in eastern Canada, 1998-2007. Occasional Paper Number 120, Canadian Wildlife Service, Environment Canada. 96 pp.
  • Hebert, C.E., D.V. Weseloh, T. Havelka, C. Pekarik, J.L. Shutt, M. Shieldcastle, and F. Cuthbert. 2008. Lake Erie colonial waterbirds, 1974-2002: Trends in populations, contaminant levels, and stable isotope indicators of diet. pp 1-32 In: Checking the Pulse of Lake Erie. M. Munawar (Ed.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, Gopsons Papers Ltd., New Delhi.
  • Morris, R.D., D.V. Weseloh, and J.L. Shutt. 2003. Distribution and abundance of nesting pairs of Herring Gulls (Larus argentatus) on the North American Great Lakes, 1976 to 2000. Journal of Great Lakes Research 29:400-426.
  • Morris, R.D., D.V. Weseloh, and C. Pekarik. 2009. Colonial nesting waterbirds in the Canadian and U.S. waters of Lake Superior: patterns in colony distribution and breeding population numbers (1976-2000). pp. 583-624 In: State of Lake Superior. M. Munawar and R. Heath (Eds.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, Gopsons Papers Ltd., New Delhi.
  • Morris, R.D., D.V. Weseloh, F.J. Cuthbert, C. Pekarik, L.R. Wires, and L. Harper. 2010. Distribution and abundance of nesting Common and Caspian Terns on the North American Great Lakes, 1976 to 1999. Journal of Great Lakes Research 36:44-56.
  • Morris, R.D., D.V. Weseloh, L.R. Wires, C. Pekarik, F.J. Cuthbert, and D.J. Moore. 2011. Population trends of Ring-billed Gulls breeding on the North American Great Lakes, 1976 to 2009. Waterbirds 34:202-212.
  • Morris, R.D., C. Pekarik, and D.J. Moore. 2012. Current status and abundance trends of Common Terns breeding at known coastal and inland nesting regions in Canada. Waterbirds 35:194-207.
  • Rush, S.A., C. Pekarik, D.V. Weseloh, F. Cuthbert, D. Moore, and L. Wires. 2015. Changes in heron and egret populations on the Laurentian Great Lakes and connecting channels, 1977-2009. Avian Conservation and Ecology 10(1): 7. http://dx.doi.org/10.5751/ACE-00742-100107
  • Weseloh, D.V., C. Pekarik, T. Havelka, G. Barrett, and J. Reid. 2002. Population trends and colony locations of Double-crested Cormorants in the Canadian Great Lakes and immediately adjacent areas, 1990-2000: a manager’s guide. Journal of Great Lakes Research 28:125-144.
  • Weseloh, D.V., C. Pekarik, R. Joos, J.F. Farquhar, J.L. Shutt, T. Havelka, I. Mazzocchi, G. Barrett, R. McCollough, R.L. Miller, and A. Mathers. 2003. Monitoring Lake Ontario’s waterbirds: contaminants in Herring Gull eggs and population changes in the Lake’s nearly 1,0000,000 colonial waterbirds. pp. 597-631 In: State of Lake Ontario. M. Munawar (Ed.). Ecovision World Monograph Series, Aquatic Ecosystem Health and Management Society, Gopsons Papers Ltd., New Delhi.