Moult adaptation in relation to long-distance migration in petrels

Abstract

MEINERTZHAGEN1 has described in South Greenland seas (c. lat. 60°N.) flocks of wing-moulting, and often temporarily flightless, great shearwaters (Puffinus gravis) which migrate trans-equatorially northward from their Tristan da Cunha breeding grounds (lat. 37°6′ S.). He suggests that it "needs to be explained why the Great Shearwater moults in its winter quarters, whilst the Fulmar (Fulmarus glacialis) moults while the young are hatching". (The fulmar, of course, breeds locally.) © 1956 Nature Publishing Group.