H^MATOPUS. 
The New World “ Sooty ” Oystercatchers are easily differentiated from 
those of the Old World by the coloration and bill-characters. 
Round the New Zealand coasts, aU Australia, and at South Africa occurs 
a “ Sooty ” Oystercatcher, of which more later. In the two former places a 
form of H. ostralegus hves alongside, but at South Africa only the “ Sooty ” 
form is found. Whether this form occurs up West Africa is not known, but the 
Canary Islands harbour a close relative. It should be remembered that in 
this family the female is always larger than the male though generally 
somewhat duller in coloration. This superiority in size of the female is most 
marked in the length of the bill, and though recorded in the Catalogue of the 
Birds in the British Museum in the case of the British Oystercatcher, in most 
other species the disparity in size is not noted. This may be due to lack of * 
data on the specimens or to ignorance of the plumage-changes undergone 
by exotic species. In the case of the Austrahan Pied Oystercatcher the 
immature would seem to take on the adult-plumage at the end of the first 
season when it is not fuUy grown, and in all its measurements is much smaller 
than an old bird. If a female in this plumage were compared with an old 
male, the differences in size might not be noticed. 
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