1. Southeastern Cooperative Wildlife Disease Study, College of Veterinary Medicine, The University of Georgia, Athens, Georgia 30602, USA
2. Present address: Tieraerztliche Hochschule Hannover, Bischof-sholer Damm 15, 3000 Hannover 1, Federal Republic of Germany
3. Tall Timbers Research, Inc., Route 1, Box 678, Tallahassee, Florida 32312, USA