232 'hlhiiA.XKR.T), Nesting of the Fork-tailed Petrel. Vj"^ 



Mr. J. Grinnell visited this island a day or two later and passed 

 the night upon the summit. He said that it was impossible to keep 

 a fire alight in the middle of the night as the Petrels flew into it in 

 such numbers as to extinguish it. We went ashore again at 3 

 A. M., but not a Petrel was in sight. Their twittering had ceased 

 about 1.30 or 2 o'clock, as it was getting rather broad daylight by 

 that time. It would be interesting to know in the still higher lati- 

 tudes, where there is no twilight, at what time this exchange of the 

 duty of incubation takes place. 



Sending the men on a tour of investigation around the island, 

 I went at once to work on the Petrels, unfortunately with no 

 implements but fingers. The burrows seemed to run in any 

 and every direction except directly downwards. The area that 

 I worked in was covered with bunch grass and low salmon- 

 berry bushes, the roots of the latter being greatly in the way. 

 The peat was so loose and wet that it was difficult to clearly 

 define the burrows, but it seemed certain that' they frequently 

 intersected when on the same level, and also that there were 

 tiers of them on different planes and running diverse ways. I 

 could, however, form no idea of the length of any particular one. 

 Their depth varied from four to eighteen inches from the surface 

 of the ground. The diameter of the burrows was from about 2 J 

 to 3^ inches, but frequently they were hollowed out in the interior 

 to a greater size. The nests were merely small hollows in slightly 

 enlarged portions of the galleries, with sometimes a little dry grass 

 on the bottom, and were placed at irregular distances apart, — fre- 

 quently an O. funata within a foot of a nest of O. leucorJioa, and 

 then again perhaps several of one species in succession at varying 

 intervals. It was difficult to discern much removed material at 

 the entrances to the burrows, the same ones being in all probabil- 

 ity used year after year, the excavated earth having in the course of 

 time become assimilated with the surrounding surface. It seemed 

 as if one could dig down and strike burrows anywhere, and in fact 

 I gave up looking for the entrances proper, and simply dug up the 

 peat in any spot that seemed likely to be free from roots. Unless 

 violently disturbed each bird would be found sitting upon its &gg, 

 or, perhaps it would back away a few inches. In some instances 

 the bird had been frightened, and leaving its ^gg had run along 



