314 BIRDS OF NEW ENGLAND AND EASTERN NEW YORK 



parents were found in the burrow if the egg was not yet 

 laid. The presence of the birds on the island would not 

 be suspected during the daytime, for one bird keeps close 

 within the burrow and the otlier is presumably feeding far 

 out at sea. At night, however, the air is filled with the 

 twittering of birds, coming and going to and from the 

 burrows. 



Petrels are attracted to vessels that pass across the Bay 

 of Maine, and also follow trans-Atlantic liners far out over 

 the ocean ; they may be observed from the stern of the 

 boat, but it is very difficult to see the tail clearly enough 



Fig. 89. Leach's Petrel 



to distinguish between the forked tail of this species and 

 the square tail of Wilson's Petrel. In flight the feet are 

 commonly extended back under the tail, and, as Dr. Town- 

 send has pointed out, the short legs of Leach's Petrel do 

 not project beyond the tail or even the apex of the fork. 

 The absence or presence of feet projecting beyond the tail 

 may therefore serve to distinguish the two species. Leach's 

 Petrel is occasionally found on inland waters, apparently 

 blown in by a storm. (See preceding species.) 



