Growth, reproduction, age structure and feeding habits of white whales (Delphinapterus leucas) in West Greenland waters

Abstract

Reproductive organs, mandibular teeth, stomach contents and body measurements including total mass from white whales (Delphinapterus leucas) taken by Inuit hunters in West Greenland during 1985-1992 were analysed. Both sexes of white whales from West Greenland attain a greater length at physical maturity than do white whales from Alaska, Hudson Bay, northern Quebec, the White Sea and the Kara Sea. Male white whales attain sexual maturity at 6-7 years. Size of testes and presence of spermatozoa suggest that mating takes place in May or perhaps later.

Female white whales apparently become sexually mature at 4 to 7 years of age, but the negative bias of age estimates from whales whose teeth lack the neonatal line confounded our effort to estimate the age at sexual maturity. Gestation lasts at least 330 days, with implantation in May- June, and calves are likely to be born in April-May.