162 BUTiLETII^ 121, UNITED STATES NATIONAL, MUSEUM. 



Very little is known about the migrations of the ashy petrel or 

 where it goes after it leaves its breeding grounds, but probably it 

 spends the winter wandering over the adjacent ocean. 



DISTKIBUTION. 



Breeding range. — The Farallon Islands and some of the Santa Bar- 

 bara Islands (San Miguel and Santa Cruz Islands). Breeding 

 grounds protected in Farallon reservation. 



Range. — Coast of California. North to Point Reyes and south to 

 San Clemente Island. 



Egg dates. — Farallon Islands : Forty-two records. May 15 to July 

 13; twenty-one records, June 12 to July 2. 



OCEANODROMA MONORHIS SOCORROENSIS C. H. Townsend. 



SOCOBRO PETREL. 



HABITS. 



In Godman's (1907) Monograph O ceanodrorrm socorroensis is 

 treated as synonymous with O. monorhis (Swinhoe) from China; 

 and Count von Berlepsch (1906) described it, from specimens col- 

 lected on the San Benito Islands, as " the American representative 

 of that Asiatic species" under the name O. monorhis chapmani. As 

 J have not been able to examine sufficient material to warrant hazard- 

 ing an opinion on the matter, I shall not attempt to argue the merits 

 of the case. 



The following notes by Mr. Henry B. Kaeding (1905) throw some 

 light on the migration of this and other Lower California petrels : 



It is interesting to note that during the trip south to Socorro Island, prior 

 to May 1st, no petrels were seen except Ocennodroma macrodoctyla at Guada- 

 lupe ; hut after May 1st the least, hlack, Socorro, and Kaeding petrels appeared, 

 becoming more numerous during .June, and apparently passing north to the 

 breeding grounds from regions south of Socorro Island. Mr. Townsend secured 

 but one specimen of Oceanodroma socorroensis at Socorro Island, and saw very 

 few March 9th. so that it is probable that the bulk of the birds were still to the 

 southward at that date. 



Nesting. — Mr. A. B. Howell has contributed the following notes 

 on the habits of the Socorro petrel which he found breeding on Los 

 Coronados Islands : 



In an aggregate of 1,500 miles by sea along the coasts of southern and Lower 

 California I never saw a bird which I took to be of this species. By this I 

 infer that they range farther out to sea than does melania, and it is probably 

 more nocturnal in its foraging also, as they seem to be more greatly distressed 

 by the light when removed from their burrows, which they visit only after night- 

 fall. Mr. A. W. Anthony has recorded the fact that this species comes in from 

 the sea, constructs and occupies the burrows for several weeks before the eggs 

 are deposited, and this assertion surely holds good for the majority of cases, 



