Evidence of a North Atlantic right whale Eubalaena glacialis mating ground

Abstract

The location of mating grounds used by Endangered North Atlantic right whales Eubalaena glacialis has eluded discovery despite centuries of whaling and decades of marine mammal surveys. If this species’ gestation duration is similar to the closely related southern right whale E. australis, then conception for the North Atlantic right whale occurs in the boreal winter. Between 2002 and 2008, aerial surveys identified half the North Atlantic population in the central Gulf of Maine between November and January. Generalized linear models indicated that significantly higher proportions of both known fathers and conceptive females were present in this region compared to most other areas seasonally inhabited by right whales. Their presence in the central Gulf of Maine during the estimated conception period strongly suggests that this region is a mating ground for the species. Roseway Basin, on the southwestern Scotian Shelf, also had high proportions of reproductive whales and may be the site of some conceptions if right whale gestation extends to 14 mo.