61 



Distinctions. Smaller size, slightly darker coloration, square instead of forked tail, 

 and the yellow foot webs will separate this Petrel from Leach's. The Storm Petrel 

 also is said to occur off the Atlantic coast, but is too rare to be considered here. Unim- 

 peachable evidence of its occurrence is desirable. It is recognizable by having the white 

 rump feathers tipped with black. 



Field Marks. Square instead of slightly forked tail is probably the most reliable 

 guide to the specific identity of this Petrel in life, but accurate observation is necessary 

 to make the distinction. 



Nesting. In ground burrows or rock crevices. 



Distribution. From the, Antarctic to Labrador and to the British Isles across the 

 Atlantic. 



Wilson's Petrel is notable as being one of the very few North American 

 species that are known to nest at the southern end of their migratory 

 range. Hence individuals seen here in the summer are migrants, not 

 breeders. 



Order — Steganopodes. 



Totipalmate Swimmers. Full webbed Swimmers. 



General Description. Birds with webs between all four toes, making three webs 

 instead of the usual two as in other orders (Figure 6, p. 19). 

 Distinctions. The feet characters are always distinctive. 



Canadian Totipalmates are divided into three families: Sulidce, the 

 Gannets; Phalacrocoracidce, the Cormorants; and Pelecanidce, the Pelicans. 

 There are other families that have occurred or may occur accidentally 

 in Canada but are too rare to be included here. 



Economic Status. This order, being composed of large birds, all fish- 

 eaters, and many of them frequenting inshore or inland waters in consider- 

 able numbers, is open to a certain amount of suspicion as to its economic 

 effect. However, no step should be taken against any species until careful 

 investigation has proved its necessity. 



FAMILY SULID^. GANNETS OR BOOBIES. 



General Description. Large birds, mostly white when adult, bill sharp and straight 

 without hook or pronounced throat or gular pouch. 



Distinctions. The bill characters of this family serve to distinguish it from all except - 

 ing Tropic Birds, one species of which has been taken off Newfoundland. As the Tropic 

 Birds, however, have enormously elongated middle tail feathers there is little chance of 

 confusion, even if they were not too rare in our waters to merit detailed consideration here. 



The Gannets are strictly marine birds never seen away from the sea 

 except as stragglers. The family on the whole is tropical and only one 

 species occurs in Canada. 



117. Gannet. solan goose, fb. — le pou de bassan. le mahgot. Sula bassana 

 L, 35. A fully-webbed swimmer with straight bill without pronounced hook or conspi- 

 cuous throat or gular pouch. 



Distinctions. The bill characters are distinctive. The adult is pure white except for 

 the black primaries and a rich creamy suffusion over the crown and hindneck. The 

 young bird of the year is greyish-brown, lighter below, and each feather has a small white 

 V at the tip that gives an even speckling over all. Several intermediate spotted stages 

 occur between these plumages. 



28587— 5i 



