LIFE HISTORIES OF NORTH AMERICAIT PETRELS AND PELICANS. 105 



The burrows are in great mnnbers on the hillsides from sea level up to 

 about 400 or 500 feet, and extend on an average four or five feet in the soft 

 soil the nesting chamber being sparingly lined with portions of tussoclf grass. 

 The burrow apparently always extends a little beyond the nesting cliamber, 

 because, if a sitting bird were disturbed, it usually got out of reach by moving 

 further in. If a burrow be in use, a few blades of tussock grass will be 

 noticed in the entrance. 



The birds generally go to sea at daylight, which, on account of the latitude, 

 occurs there about 2 o'clock in midsummer, returning about dusk (10 p. m.) ; 

 but, just before laying season, usually two birds (presumably a mated pair) 

 were found in the burrows during the day. 



The call of the brown petrel, when flying, is a single whistle-like cry. In 

 the burrows they coo like prions, only of course, louder. 



The measurements of 7 cg-gs, furnished by Mr. Campbell, average 

 70.6 by 50.9 millimeters ; the eggs showing the four extremes measure 

 71.5 by 51.4, 71.1 by 51.8, 69.1 by 51.2 and 69.2 by 49.8 millimeters. 



Behavior. — Darwin (1889) relating his experience with this shear- 

 water on the cruise of the Beagle^ writes : 



I do not think I ever saw so many birds of any sort togetlier, as I once saw 

 of these petrels behind the island of Chiloe. Hundreds of thousands flew in 

 an irregular line for several hours in one direction. When part of the flock 

 settled on the water, the surface was blackened ; and a cackling noise proceeded 

 from them as of human beings talking in the distance. At this time the water 

 was in parts colored by clouds of small Crustacea. * * * At Port Famine, 

 every morning and evening, a long band of these birds continued to fly with 

 extreme rapidity up and down the central parts of the channel, close to the 

 surface of the water. Their flight was direct and vigorous, and they seldom 

 glided with extended wings in graceful curves, like most other members of 

 this family. Occasionally they settled for a short time on the water; and they 

 thus remained at rest during nearly the whole of the middle of the day. When 

 flying backwards and forwards at a distance from the shore, they evidently 

 were fishing, but it was rare to see them seize any prey. They were very wary, 

 and seldom approached within gun shot of a boat or of a ship, a disposition 

 strikingly different from that of most of the other species. The stomach of 

 one, killed near Port Famine, contained seven prawn-like crabs, and a small 

 fish. In another, killed off of the Plata, there was the beak of a small cuttlefish. 

 I observed that tbese birds, when only slightly winged, were incapable of 

 diving. 



Captain Hutton (1865) says of its diving habits : 



This bird is by far the best diver of all the sea-going petrels. It seems even 

 fond of it, and often remains under water for several minutes, when it comes 

 up again shaking the water off its feathers like a dog. Sometimes I have seen 

 it, as it flies past, poise itself for a moment in the air (and hence perhaps its 

 name) at a height of about twenty or twenty-five feet above the sea, and, shut- 

 ting its wings, take a header into the water. It dives with its wings open, and 

 uses them under water much in the same manner as when flying. 



Captain Hutton (1865) observes that "its cry is something like 

 the bleating of a lamb." He writes that " the young bird has been 



