PETRELS. 91 



TTTBE-NOSED SWIMMERS. (ORDER TTJBINARES.) 



rETRELS. (Family Procellariid^.) 



Petrels, or " Mother Carey's Chickens," are true chih 



tlren of the sea. Their home is tlie oceau, and they come 



to land only when nesting. To the 



Petrels, landsman, therefore, they are strangers, 



Plate 1\ . ' ,11 1 



but to most people who ha\'e been to 

 sea they are known as the little, white-rumped swallow- 

 like Ijinis who on tireless Aving follow in the wake of the 

 ship day after day, j^atiently waiting f(ir the food which 

 experience tells them will be thrown overboard. 



Two species of Petrels are found off our coasts, Wil- 

 son's and Leach's. The former has a yello^v area in the 

 wel)s of the toes and a square tail, while Leach's Petrel has 

 the webs of the toes wholly lilaek and a slightly forked 

 tail. These differences, however, would not be appre- 

 ciable at a distance. Wilson's Petrel nests in certain 

 islands uf the southern hemispliere ill Feljruary, and 

 later migrates northward, reaching our latitude in May 

 and spending the summer, or what in fact is its wdnter, 

 in the North Atlantic. It is, therefore, probably the 

 Petrel most frequently seen by transatlantic voyagers at 

 this season. 



Leach's Petrel nests on our coasts from ]\Iaine north- 

 ward, arriving from the South in May. The nest is 

 made in a burrow in the ground or lieneath a rock, and 

 a single white egg is laid. Generally one of the birds 

 s]iends the day on the nest while its mate is at sea, but 

 at night the incubating bird leaves the nest, its place being 

 taken probably by the one who has been feeding during 

 the day. 



