59 
the name of ‘‘ Mother Carey’s Chickens” and their appearance is said to 
presage a storm. In spite of their diminutive size they are met with far 
out at sea and are seldom seen by the longshoreman except in the vicinity 
of their breeding grounds. 
Economic Status. The Petrels though feeding on fish are too small 
and their regular habitat is too far removed from man’s usual activities 
to be of measurable economic importance. 
106. Leach’s Petrel. FrR.—LE PETREL DE LEACH. Oceanodroma leucorhoa. L, 8. 
A small, sooty-brown bird, very slightly lighter below, with a white rump. Tail forked 
about one-half an inch deep. 
Distinctions. Forking of the tail, slightly lighter general coloration, and all black 
feet will separate this from Wilson’s Petrel, the only one likely to be confused with it. 
Field Marks. The slight forking of the tail is perhaps the surest specific guide in life. 
Nesting. In burrows in the ground or under rocks. 
Distribution. Inhabits both the north Pacific and north Atlantic oceans, breeding 
on the eastern side of the continent, from Greenland to Maine. 
This is the only Petrel breeding on our coasts. It may be locally very 
abundant in the nesting season and its burrows may riddle the ground 
without the observer having a suspicion of its presence. It remains in its 
burrow through the day, but at night comes out in great numbers, wheeling 
about the deserted neighbourhood, uttering a low, wierd oft repeated little 
song with most eerie effect. 
Economic Status. Of no economic importance. 
109. Wilson’s Petrel. MOTHER CAREY’S CHICKEN. FR.—LE PETREL DE WILSON. 
Oceanites oceanicus. L, 7. A slightly smaller bird than Leach’s Petrel, of same general 
colour but averaging slightly darker, less forked tail, and with toe webs mostly yellow 
instead of all black. 
Distinctions. Smaller size, slightly darker coloration, square instead of forked tail, 
and the yellow foot webs will separate this Petrel from Leach’s. The Stormy Petrel also 
is said to occur off the Atlantic coast, but is too rare to be considered here. Unimpeachable 
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. 
ae Distribution. From the Antarctic to Labrador and to the British Isles across the 
tlantic. 
Wilson’s Petrel is notable as being one of the very few North American 
species that nest at the southern end of their migratory range. Hence 
individuals seen here in the summer time are migrants and do not breed. 
Order—Steganopodes. 
Totipalmate Swimmers. Full-webbed Swimmers. 
General Description. Birds with webs between all four toes, making three webs in- 
stead 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: Sulidew, the 
Gannets; Phalacrocoracide, the Cormorants; and Pelecanide, the Pelicans. 
There are other families that have occurred or may occur accidentally 
in Canada but are too rare to be included here. 
57172—5 
