LIFE HISTORIES OF NORTH AMERICAN PETRELS AND PELICANS. 175 



Behavior. — Companitivel}^ little has been published on the habits 

 of the white-bellied petrel. Gould (1865) says of it: 



Like the F. mclanogasfer, the white-belliecl storm-petrel is a fine and power- 

 ful species, fluttering over the glassy surface of the ocean during calms with an 

 easy butterfly-like motion of the wings, and buffeting and breasting with equal 

 vigor the crests of the loftiest waves of the storm ; at one moment descending 

 into their deep troughs and at the next rising with the utmost alertness to 

 their liighest points, apparently from an impulse communicated as much by 

 striking the surface of the water with its webbed feet as by the action of the 

 wings. Like the other members of the genus, it feeds on moUusca, the spawn 

 of fish, and any kind of fatty matter that may be floating on the surface of 

 the ocean. 



Mr. John Treadwell Nichols writes to me in regard to it : 



In habits it resembles the Wilson petrel. It follows a ship for scraps, about 

 which a little flock gatliers, pattering on the water with their feet, their wings 

 extended fluttering over their backs, so that they make a twinkling white spot 

 in the distance. Its note, which I have heard at such times, is a funny little 

 squeak. 



Dr. E. A. Wilson (1907) writes of his experience with it in the 



Antarctic : 



This petrel is to be recognized on the wing mainly by its small size and 

 white belly, the chin, throat, and tail alone being black on the under part. 

 We obtained no specimens, though we saw it on several occasions. On Septem- 

 ber 18th, 1901, Ave had several in our wake, and again on Septeniber 20th we 

 saw them continually dropping to touch the water v^'ith one foot, steadying 

 themselves while they daintily took their minute crustacean food from the 

 surface of the water. At these times their tails become much hollowed out on 

 the dorsal surface, so that each half is at right angles to the other. 



Mr. Beck has also sent me the following notes on the habits of 

 the white-bellied petrel : 



The first specimens of this form were noted about 150 miles offshore on 

 the 400-mile trip across from Valparaiso to Juan Fernandez, and were found 

 commonly within 100 miles of the islands. An interesting characteristic of 

 this bird is the manner in which it strikes the water with one foot. In a breeze 

 or wind it was always the leeward leg that was used, the windward one being 

 stretched out behind. As our schooner was always on the wind, the petrels 

 usually had but little use for the leg on the southern side of the body. When 

 the birds flew directly into the wind either one or the other or both legs 

 might be used. 



DISTRIBUTION. 



Breeding range. — Known to breed only on Santa Clara and Goat 

 Islands, near Juan Fernandez Islands, off the coast of Chile. 



Range. — Southern temperate oceans. North in the Indian Ocean 

 to the Bay of Bengal; in the Pacific Ocean to about 4° south; and 

 in the Atlantic Ocean to about 33° south. Southern limits not 

 clearly defined. 



