Canada goose populations and goose damage complaints are widespread in North American urban environments and growing. With a potential for impacting millions of human residents, and the ongoing conflicts over management approaches, urban geese present a major wildlife challenge. There is a critical need to evaluate promising techniques and integrate them into effective, comprehensive management programs. The control of goose damage by habitat modification, while potentially ecologically beneficial in urban settings, is biologically complex, expensive, and may be difficult to implement.
Because the species uses islands, muskrat lodges, man-made structures, and other elevated sites in semi-permanent and permanent wetlands for nesting, habitat modification options during the nesting period are limited to the simple, elimination of man-made nest structures, and the highly undesirable, filling or draining of the water bodies, and the elimination of islands.
Most (94%) goose damage complaints occur during the late spring and summer brood-rearing period when the birds are flightless, thus, habitat modification during this interval presents the greatest opportunity for limiting damage. Short-term applications where the objective is to reduce or eliminate goose use of specific property have the most promise. Proposed methods include: not fertilizing and mowing grasses, replanting lawns with rough grasses, ivy, shrubs, trees, etc., planting shoreline barrier strips of vegetation, and the erection of fences. However, there is a paucity of research on the efficacy, acceptability, and cost of these techniques.
The Canada goose appears adaptive and will use unmanicured grasses if alternatives are lacking; the bird also readily traverses dense vegetation in island environments with low mammalian predator densities, and observations indicate that the bird may behave this way in urban settings. Research on human landscape preferences strongly suggests a predisposition, like that of the Canada goose, for savannas with water bodies. Studies of the relationships between urban crime and vegetation shows a clear correlation between visual depth and risk, that is, dense visibility obscuring plantings are associated with higher crime rates. Because crime is a crucial urban issue, public acceptance of widespread removal of turf is unclear. In light of these concerns, habitat modification recommendations in recent publications (Gosser et al. 1997, Grandy and Hadidian 1997), while stated as uncomplicated solutions, ignore critical application constraints, do not address long-term population management needs, fail to consider the potential for inhumane flightless goose starvation, overlook potential impacts on other urban wildlife, and do not address economic constraints.
Clearly, if habitat modification that limits Canada geese damage in urban environments can be accomplished humanely, without compromising human safety or landscape quality or the management of other wildlife species, and within fiscal constraints, then such as program would indeed be beneficial. However, significantly more research is needed before currently proposed methods can be deemed effective and environmentally sound.
ACKNOWLEDGMENTS
Minnesota Extension Service, the cities of Minneapolis, Brooklyn Center, Golden Valley, Plymouth, and others, General Mills Inc., the Federal Aviation Administration, and Metropolitan Airports Commission, and the Minnesota Department of Natural Resources. I thank the Minnesota Department of Natural Resources, the U. S. Fish and Wildlife Service, and the U. S. Department of Agriculture for coordinating permits and assistance with capture, relocation, and band recovery data. Al Eiden, Ted Dick, and Erik Thorson, University of Minnesota, and Tom Landwehr, Kathy DonCarlos, Blair Joselyn, Roger Johnson, and Tom Keefe, Minnesota Department of Natural Resources provided helpful critiques of the concepts presented in the paper.