PELAGIC BIRD FAUNAS OF THE INDO-PACIFIC OCEANS 467 



Greenland, Spitzbergen and northern Europe. The closely related 

 southern Fulmar, F. glacialoides, nests wholly within the Antarctic Con- 

 vergence, but migrates to beyond the Sub-tropical Convergence, par- 

 ticularly in the Atlantic Ocean and the eastern Pacific. 



Voous (1949) has shown that glacialoides resembles more the north 

 Pacific race (rodgersi) than the north Atlantic faces of the F. glacialis, 

 and explains the present distribution by glacialoides invading the north 

 Pacific in a period of glacial cooling. Entry to the north Atlantic was 

 made through the Bering water gap. This theory is accepted by Fisher 

 (1952, p. 17). 



Puffinus assimilis 



Puffinus assimilis is an almost circumpolar Sub-antarctic species 

 which has invaded the Sub-tropical region in Australia and New Zea- 

 land, where it has differentiated into a number of races (Fleming and 

 Serventy, 1943). In the eastern Atlantic it is one of three petrels which 

 has transgressed the tropics and established itself in the Azores, Madeira 

 and Canary Islands group. The race which survives here, haroli, is so 

 far different from the southern assimilis and with so many points of 

 resemblance to the tropical Iherminieri assemblage, that the situation 

 strongly suggests that Iherminieri is a warm-water derivative from a 

 northward transgressing assimilis stock which probably made the passage 

 in pre-Pleistocene times. 



The migratory dark Shearwaters of the genus Puffinus 



Three species of large all-dark Puffinus breed in the southern por- 

 tions of the Indo-Pacific and migrate across the equator to the northern 

 hemisphere. The widest ranging is Puffinus griseus, which breeds from 

 sub-antarctic to warm-temperate waters in the Australian and New 

 Zealand region and off South America. The closely related P. tenui- 

 rostris is a warm-temperate derivative in southeastern Australia. 



P. carneipes now breeds wholly in warm-temperate waters in south- 

 western Australia, the Tasman Sea and in New Zealand. 



Probable allies of this group are the more or less sedentary P. pacifi- 

 cus and P. nativitatis, now entirely of tropical and sub-tropical distri- 

 bution. 



Pterodroma mollis and its allies 



Pterodroma mollis is a breeding species of the southern Indian 

 and Atlantic Oceans, mainly occupying islands in the sub-antarctic 

 zone of surface water. It is of considerable interest in having nesting 

 colonies also in the North Atlantic, at Madeira and the Cape Verde 

 Islands— a distribution pattern paralleling in certain respects that of 

 Puffinus assimilis and Pelagodroma marina, and an example of a trans- 

 equatorial transgression along the eastern Atlantic route. 



