160 BULLETIN 121, UNITED STATES NATIONAL MUSEUM. 



in the level ground in front of the keepers' houses. In investigating the drift 

 area on Pranconia beach, we found almost as many petrels as auklets skulking 

 under logs and planks. In point of abundance they are easily third, possibly 

 second, on the island. 



It is evident that these petrels have a lengthy season of courtship during 

 which, they speiid their nights, ashore, chiefly In their bui;ro,w^, ,an4 return .to the 

 sea daytimes. This is follov/'ed by a " honeymoon " period of some duration, 

 presumably a week or inofe, in which both birds remain ashore all the time. 

 As' soon k's the egg'is laid Incubation begins, aiid the other bird retites to sea to 

 forage. Precisely what the divisi-On of labor iS'from this point on as between 

 male and>female remains to be determined, but it is certain that theimalejls 

 often found alone upon, the eggf 



Mr. Chester' Barlow (1894a,) describes a few nesting sites, as 

 follows : : 



In 1892 I found an e^g on the floor of a' cav6 about ten feet from the entrance 

 v(>ith the parent' bird incubkting it. The Cave was dark and damp, and the egg 

 was laid on a little moss growing on the ground. It was about to hatch. This 

 year while climbing about on the summit on East End I secured, a young auklet 

 (Ptychorafnphus oZeWicMs), and after' examining it let it go into a crevice in 

 the cliff. While watching it disappear I observed a forked tail of a bird vibrat- 

 ing as it breathed, ^nd on tearing away thp rocks found a petrel sitting on its 

 fresh egg. The bird vvas sitting with its bead as far into the creyice as possible, 

 thus bpiiig protected from the light, but its tail was in view. The elevation was 

 about 200 feet aboy^ the !;)cea,n. , 



I have found the petrels nesting beneath the stone walls within a few inches 

 of Cassin's auklet, Ijjit have never, found any sign of a burrow made by the 

 petrel. In 189? I took an egg from a petrel at the base of an elevated footpath 

 of phe West End,, and carefully, replaced the stones. This year on going by 

 the place I remembered the incident and thought I would try again., On 

 stQppihg down I detected the familiar niusky odor, and soon had a fresh egg. 

 It is possjbie that this was the same bird I found in 1892,^ and -that it had 

 clung to thi^ nesting site the,se two years. Within a foot of this petrel was a 

 pigeon guillemot (Gepphus coUimha) sitting on her two eggs. I found one egg 

 about two feet in a crack in a cliff plainly in view, and it proved to be fresh. 

 I suppose the bird did not discover she had selected such an open place to nest 

 in until after she had laid the egg and. daylight came, when no doubt she left 

 for more .secluded quarters. , , i , 



Mr. Osgood discovered a petrel of decided tasjes, as regards nesting, for on 

 the brink of a clifC, beneath several loose boulders, she had constructed, a nest, 

 of coarse Farallon weed, perhaps four inches in diameter. , It was naturally 

 rough, but was undoubtedly cpnstructed by the bird, as, it was in such a posi- 

 tion that a larger bird could not have gained access to it. It must be understood 

 that the nest and egg were ptirely concealed by numerous rocks, which had to 

 be removed to. permit of. the photogri^p'h being taken. _ The egg was bsjdly 

 Incubated. 



In one instance I found a.n egg laid, on an accumulation of pebbles, and 

 again quite a collection of small granite chips were used. As in the former 

 case, everything points to the bird gathering them. ' ■ " ■" 



The male incubates the egg as well as the female, as two males were foupd 

 performiiig this duty. The mate^..o:e the birds, incubating were never obse^-ved. 

 I believe that; when an egg is taken that the petrel dpes no,t lay a second egg 

 the same season. ' ' ' 



