24 WATER BIRDS 



is nocturnal in habits, feeding and flying only after dark- 

 ness has settled over the sea, and enjoying a storm as 

 the robin enjoys the sun. Its notes are a high plaintive 

 call or a queer, low, purring coo. The latter is heard 

 only during the nesting season. The name " Petrel " 

 means Little Peter, and has been given this bird be- 

 cause of its curious habit of skimming over the surface 

 of the water with feet just touching it in a quick, patter- 

 ing motion, as if trying to walk upon the waves. All the 

 time it flutters its wings like a huge butterfly. 



108. ASHY PETREL. — Oceanodroma homochroa. 



Family : The Fulmars and Shearwaters. 



Length: 8.00-9.00. 



Adult: Grayish slate-color, merging to lighter on wing-coverts; qnills 



and tail blackish, merging to ashy slate-color on rump and upper 



tail-coverts. 

 Geographical Distrihdion : Coast of Califormia. 

 Breeding Range: Islands off the coast of California, including the 



Farallones and Santa Baibara. 

 Breeding Season: June and July. 

 Nest: In crevices under rocks, under driftwood, in stone walls, in 



burrows. 

 Eggs: Creamy white, sometimes faintly spotted about the large end. 



Size 1.19 X 0.93. 



The Ashy Petrels were breeding abundantly on the 

 South Farallone Islands at the time of a recent visit I 

 made to the spot, but few of the birds were in evidence 

 during the daylight hours. The nests were well hidden 

 under loose rocks, in crevices and in all sorts of crannies ; 

 they were betrayed only by their disagreeable odor. In 



