Date of this Version
Aborn, D.A. Possible competition between waterfowl and sandhill cranes at Hiwassee Wildlife Refuge, Tennessee. In: Hartup, Barry K., ed., Proceedings of the Eleventh North American Crane Workshop, Sep 23-27, 2008, Wisconsin Dells, Wisconsin (Baraboo, WI: North American Crane Working Group, 2010), pp. 15-21.
As a result of crop planting for waterfowl, numbers of eastern greater sandhill cranes (Grus canadensis tabida) staging and overwintering at the Hiwassee Wildlife Refuge in eastern Tennessee have sharply increased over the last 30-40 years. Peak numbers of wintering cranes have reached 14,000, and this large increase in crane numbers raises the possibility that they may be competing with waterfowl for food and space. I examined broad-scale changes in waterfowl numbers using Christmas Bird Count data, as well as small-scale changes using observations of waterfowl numbers and locations in relation to cranes on individual days. Preliminary results indicate that declines in Canada goose (Branta canadensis) numbers do not seem to be related to the increase in cranes, and while numbers of other waterfowl species have not shown changes, some species tend to remain farther from shore, and hence deeper water, when there are more cranes present. Waterfowl at Hiwassee may not be able be to deposit as much fat for inclement winter weather, spring migration, or breeding. Competition between cranes and waterfowl increases the need for wildlife managers to provide more food and habitat for both cranes and waterfowl.