Since the late 1960s, the Mid-Continent Population (MCP) of lesser snow geese has increased in size three-fold. This dramatic increase in numbers of lesser snow geese has been accompanied by significant habitat degradation as a result of grazing and grubbing by geese. Destruction of snow goose brood rearing habitat near La Pérouse Bay has likely resulted in brood movement along the Hudson Bay coastline into traditional Canada goose brood rearing habitats. Beginning in the early to mid-1980s, snow geese at the La Pérouse Bay colony have used coastal marsh habitats at the Cape Churchill study area for foraging and brood rearing; areas previously used primarily by Canada geese for brood rearing. The shift in snow goose brood rearing areas has resulted in a gradual shift in nesting areas of younger breeding birds, and an increasing proportion of snow geese using traditional Canada goose brood rearing areas. The consequences of high numbers of MCP lesser snow geese and concurrent habitat degradation for other species are not clear and information regarding impacts on other species is lacking. The level of interaction between snow geese and Canada geese on traditional Canada goose brood rearing areas is unknown.
Extensive data on both snow geese (La Pérouse Bay and the Hudson Bay Project) and Canada geese exist for the last 25 years, and the close proximity of study sites at La Pérouse Bay and Cape Churchill make it possible to more closely investigate the interaction between breeding snow geese and Canada geese at Cape Churchill than at any other site. To better understand the potential influence of snow geese on Canada geese during the breeding season we initiated a radio telemetry study in 1999. Our objectives were to:
- document current patterns of movements and habitat use of Canada goose broods
- relate current movements and habitat use patterns to historical information on Canada goose broods
- relate observed changes in movements and habitat use to changes in snow goose abundance and distribution.
Nack, R.R. 2003. Brood movements and distribution of Eastern Prairie Population (EPP) Canada geese (Branta canadensis interior) in northern Manitoba: Potential influence of increased snow goose (Chen caerulescens caerulescens) abundance. Thesis, University of Minnesota, St. Paul, Minnesota, USA. 66pp.
______ and D.E. Andersen. 2004. Distribution of Eastern Prairie Population Canada goose broods, 1977-2002: potential influence of snow geese. Pages 130-136 in T.J. Moser, R.D. Lien, K.C. VerCauteren, K.F. Abraham, D.E. Andersen, J.G. Bruggink, J.M. Colucey, D.A. Graber, J.O. Leafloor, D.R. Luukkonen, and R.R. Trost, editors. Proceedings of the 2003 International Canada Goose Symposium. Madison, WI, USA.
______ and D.E. Andersen. 2006. Brood movement of Eastern Prairie Population Canada geese: potential influence of light goose abundance. Journal of Wildlife Management 70:435-442.