1. Alaska Department of Fish and Game; 1300 College Road Fairbanks AK 99701-1551 USA
2. Environment Canada; Beaverhill Bird Observatory; Box 33, Site 2, RR 2 Tofield AB T0B 4J0 Canada
3. Migration Research Foundation; P.O. Box 10005 Ste-Anne-de-Bellevue QC H9X0A6 Canada
4. Canadian Wildlife Service; Beaverhill Bird Observatory; Box 33, Site 2, RR 2 Tofield AB T0B 4J0 Canada
5. Hallkved; Glupen 299 755 97 Uppsala Sweden
6. Owl Research Institute; P.O. Box 39 Charlo MT 59824 USA
7. U.S. Fish and Wildlife Service; Migratory Bird Management; 1011 E. Tudor Road, MS 201 Anchorage AK 99503 USA
8. U.S. Fish and Wildlife Service; Migratory Bird Management; 3000 Vintage Boulevard, Suite 240 Juneau AK 99801 USA
9. Migration Research Foundation; PO Box 10005 Ste-Anne-de-Bellevue QC H9X0A6 Canada
10. 909 Birch Street; Baraboo WI 53913 USA