FORKED-TAILED PETREL. 645 



In its habits, as far as observed in this country, it re- 

 sembles the Storm Petrel, breeding in sandy burrows, or 

 holes of rocks, and laying one white egg of a roundish 

 oval form, large for the size of the bird, measuring one inch 

 four lines in length, and eleven lines in breadth. 



Mr. Audubon, who has enjoyed many opportunities of 

 observing these swallow-like Petrels during his ornitholo- 

 gical researches in various parts of North America, as well 

 as on his various voyages across the Atlantic, says,' 4 ' The 

 species of this genus with which I am acquainted, all 

 ramble over the seas, both by night and by day, until the 

 breeding-season commences; then they remain in their 

 burrows, under rocks, or in their fissures, until towards 

 sunset, when they start off in search of food, returning to 

 their mates, or young, in the morning, and feeding them 

 then. When you pass close to the rocks in which they 

 are, you easily hear their shrill, querulous notes ; but 

 the report of a gun silences them at once, and induces 

 those on the ledges to betake themselves to their holes. 

 The Forked-tailed Petrel emits its notes night and 

 day, and at not very long intervals, although it is less 

 noisy than Wilson's Petrel. They resemble the syllables 

 pewr-wit, pewr-wit. Its flight differs from that of the 

 other two species, it being performed in broader wheelings, 

 and with firmer flappings. It is more shy than the other 

 species, and when it wheels off after having approached 

 the stern of a ship, its wanderings are much more ex- 

 tended before it returns. I have never seen it fly close 

 around a vessel, as the others are in the habit of doing, 

 especially at the approach of night ; nor do I think that 

 it ever alights on the rigging of ships, but spends the 

 hours of darkness either on the water, or on low rocks, or 

 islands. It also less frequently alights on the water, or 

 pats it with its feet, probably on account of the shortness of 



