1. Marine Mammal Research Program, Texas A&M University at Galveston, 4700 Avenue U, Building 303, Galveston, Texas 77551‐5923, U.S.A.
2. Whale Conservation Institute, 191 Weston Road, Lincoln, Massachusetts 01773, U.S.A.
3. Biology Department, Earlham College, Richmond,‘Indiana 47374, U.S.A.