1. Department of Natural Resources Science; University of Rhode Island; 1 Greenhouse Road Kingston RI USA
2. Long Point Waterfowl; P.O. Box 160 Port Rowan ON N0E 1M0 Canada
3. Environment Canada; Canadian Wildlife Service; 123 Main Street, Suite 150 Winnipeg MB R3C 4W2 Canada
4. Department of Forest and Wildlife Ecology; 226 Russell Laboratories; University of Wisconsin-Madison; Madison WI 53706 USA