The Leach Petrels 



No. 413 



Leach's Petrel 



No. 413a Beal's Petrel 



A. O. U. No. 105.2, part. Oceanodroma leucorhoa beali Emerson. 



Synonyms. — Western Leach Petrel. Pacific White-rumped Petrel. 

 "Kaeding Petrel" (extensively miscalled in earlier literature). 



Description^ — Adult: General plumage sooty brown, clearest on belly, darken- 

 ing on head, back, and breast, blackening on lesser wing-coverts, flight-feathers, and tail, 

 lightening to grayish brown on middle and greater coverts, especially upon the edges of 

 the latter; the longer upper tail-coverts chiefly white, with sooty shaft-lines, the longest 

 ones also narrowly tipped with blackish, the lateral lower coverts more or less extensively 

 white in continuation of that of the upper coverts. Bill and feet black. Downy young: 

 Entirely sooty black. Length 203.2 (8.00); wing 144.8 (5.70); tail 76.2-88.9 (3.00- 

 3.50); forked 15.2-20.3 (.60-. 80); bill (chord of culmen) 15.2 (.60); tarsus 22.4 (.88). 



Recognition Marks. — Towhee size but appearing larger by reason of long 

 wings; dark brown plumage with white rump; fluttering erratic flight. 



Nesting. — Nest: A few grasses or none, at end of burrow 2 to 3 feet in 

 length, in soil of sea-girt rock. Egg: Single, nearly equal-ended; white, nearly im- 

 maculate, or with ring of reddish brown dots about larger end. Av. of 30 specimens 

 in the M. C. O. coll.: 30.2 x 22.4 (1.19 x .883); index 74.2. Season: June-July. 



Range of Oceanodroma leucorhoa. — North Pacific and North Atlantic oceans. 

 Breeds from southern Greenland south to Ireland and Maine, and from the Copper 

 and Aleutian islands south to the Kuriles and Lower California. 



Range of 0. I. beali. — Breeds from Sitka, Alaska (with relations to the northward 

 undetermined), south to the Farallon Islands, California. 



Distribution in California. — Breeds abundantly upon the islands off the 

 coast of Del Norte, Humboldt, and Mendocino counties, and, less commonly, upon the 

 Southeast Farallon, with records from adjoining areas and possibly down the coast. 



Authorities. — Cooper (Oceanites oceanica), Proc. Calif. Acad. Sci., vol. iv., 

 1868, p. 11 (San Nicholas Id.); Oberholser, Proc. U. S. Nat. Mus., vol. 54, 1917, p. 168 

 (syst. ; meas. ; distr. ; etc.); Grinnell, Condor, vol. xx., 1918, p. 46 (status in Calif.) 

 Loomis, Proc. Calif. Acad. Sci., ser. 4, vol. ii., p. 2, no. 12, 1918, p. 160, part (syst.) 

 Howell, Condor, vol. xxii., 1920, p. 41 (coast of Del Norte County; breeding habits) 

 Bent, U. S. Nat. Mus., Bull. no. 121, 1922, p. 147 (life hist.). 



No. 413b Kaeding's Petrel 



A. O. U. No. 105.2, part. Oceanodroma leucorhoa kaedingi Anthony. 



Synonyms. — Kaeding's Leach Petrel. Kaeding's White-rumped Petrel. 



Description. — Similar to 0. I. beali, but smaller, and with tail somewhat less 

 deeply forked. "Wing 145 mm; central rectrices 73; lateral rectrices 83; tarsus 21; 

 middle toe and claw 20; culmen 15." (Orig. desc.) 



Range of 0. I. kadingi. — This supposedly smaller race is known chiefly from a 

 series of birds taken at sea near Guadalupe Island, Lower California, July 25, 1897, by 

 A. W. Anthony. A specimen taken March 22, 1904, by L. H. Miller on the Fish 

 Commission boat, Albatross, while off San Clemente, entitles this form to recognition 



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