The Geography of the Gray Seal

Abstract

The gray seal, Halichoerus grypus (Fabricius), although it inhabits the coasts of the temperate North Atlantic within easy reach of large centers of human population, is still a relatively little-known species of mammal. In the British Isles it was initially confused with the bearded seal, Erignathus barbatus , and, as recently as 1935, Salmon pointed to further confusion with the harbor seal, Phoca vitulina. In eastern Canada, its true status was obscured for even longer. In the present review, I have attempted to survey the known distribution of the species, to explain some of the outstanding features of this distribution and to relate them to some characteristics of the biology of the gray seal which do not appear to have attracted the attention they deserve among zoologists. The literature cited represents only a fraction of that consulted and, in particular, the summaries of existing distribution and breeding seasons are based on many more authorities than those actually quoted. I am indebted to Professor H. N. Barber and Dr. H. D. Fisher for reading and commenting upon the manuscript. In addition, Dr. Fisher has allowed me access to unpublished material relating to Canadian gray seals. The known breeding range is shown in Fig. 1. There appear to be three distinct population groups, separated today by wide gaps in the total range of the species and by differences in the breeding season. Fig. 1 The breeding distribution of the gray seal. The known distribution is shown in black; in the hatched area, breeding is probable but not recorded. The first group has its headquarters in the Gulf of St. Lawrence. Fisher (1950) summarized its distribution as “north shore of Anticosti Island, around Mingan Islands, along the south shore of St. Lawrence estuary, Magdalen Islands, Northumberland Strait, Cape Breton Island on west and north, …