[86] BIRDS OF OREGON 



at rising over breakers or dipping down into the troughs as the vagrant 

 air currents permit. When the wings are used in flying, the beat is some- 

 what slower and more deliberate than that of the shearwaters but carries 

 the same impression of power and expertness found in the more slender- 

 bodied birds. 



We have only one stomach examination of this bird taken off the Ore- 

 gon coast. This stomach contained bits of beaks and eye lenses of three 

 squids, feathers, lining of eggshell, and coniferous needles, the latter two 

 obviously debris, as the bird was collected on December 2.9. 



Storm Petrels: Family Hydrobatidae 



Forked-tailed Petrel: 



Oceanodroma jurcata (Gmelin) 



DESCRIPTION.- "Body light bluish gray, fading to white on chin, throat, and under 

 tail coverts; bend of wing, quills, and space around eye, dusky." (Bailey) Downy 

 young: "The downy young when first hatched is covered with long, soft, thick down 

 foreshadowing the color of the parent, except on the chin and throat, which are 

 naked. The color varies from 'deep mouse gray' or 'light mouse gray' above to 

 'pale mouse gray' below." (Bent) (See Plate n, A.") Sz%e: "Length 8.00-9.2.0, 

 wing 5.90-6.40, bill .60, tail 3.75-4.00 forked for about i." (Bailey) Nest: A small 

 enlargement of an underground burrow, sometimes lined with a little dried grass. 

 Eggs: i, dull white, with a cloud of faint minute dark specks forming a wreath or 

 patch on the large end. 



DISTRIBUTION. General: Breeds on north Pacific from Kurile and Aleutian Islands 

 south to northern California. Winters over north Pacific as far south as southern 

 California. In Oregon: Breeds on Three Arch Rocks and possibly other offshore 

 islands. Probably winters sparingly. 



THE ONLY definitely known breeding place of the little Forked-tailed Petrel 

 in Oregon is on Three Arch Rocks, where it is much the less common of 

 the two breeding petrels. Like others of its race, it excavates burrows 

 in the earth on the upper parts of the rock and lays a single dull white 

 egg that is more or less wreathed at the upper end with minute dark spots. 

 In the colonies, these burrows sometimes intersect each other until it is 

 almost impossible to form any idea of the extent of a single excavation. 

 Finley, first in 1902. and later in subsequent publications, wrote of this 

 petrel as an Oregon bird. Numerous specimens have been collected on 

 Three Arch Rocks and on the beaches, and Jewett had one bird brought 

 to him alive that was captured on the Columbia above Astoria on January 

 30, 1916. This is the only winter specimen, but winter collecting condi- 

 tions off the Oregon coast are not the best. 



These petrels are beautiful birds, with soft gray plumage and forked 

 tails, reminding one very much of small dainty terns in shape and general 

 appearance. As they are almost entirely nocturnal in their habits while 



