The South American Skua 



The two specimens in the Berkeley Museum (viz., #17758 and #17759), upon 

 which the California record in part rests, were taken in the early fall of 1910, and are 

 both of the melanotic phase. Their measurements, wing 368.3 and 381 (14.50 and 1 5.00) ; 

 culmen 44.5 and 47 (1.75 and 1.85); tarsi 59.7 and 59.2 (2.35 and 2.33), would further 

 indicate them to be immature. Both on this account and because of their melanism 

 it is impossible to discriminate as between C. skua and C. chilensis. 



Recognition Marks. — Gull size and shape; dark plumage varied by rufous; 

 black bill and feet. Any very dark gull-like bird appearing off our shores, especially 

 if engaged in pursuing other gulls, should be carefully scrutinized, as this Skua is 

 probably not as rare as the few specimens would indicate. 



Nesting of C. skua. — Nest: On the ground, a mere depression in moss or else 

 lined with grasses and moss. Eggs: 2; dark olive-buff or buffy brown, sparingly 

 spotted or blotched with brownish olive, sepia, or, rarely, black, and dull violet-gray. 

 Av. size 71. 1 x 48.3 (2.80 x 1.90). Season: June. 



General Range of C. chilensis, — The coasts of southern South America north to 

 southern Brazil and Peru. 



Occurrence in California. — An occasional visitor from the South. Three 

 specimens taken by Beck off Monterey (Aug. 7, 1907; Aug. 4 and Sept. 21, 1910). 

 Other "sight records" probably correct. 



Authorities. — Lawrence (Stercorarius catarractes) , Ann. Lye. Nat. Hist. New 

 York, vol. vi., 1853, p. 7 (coast of Calif., "off Monterey") ; Beck, Proc. Calif. Acad. 

 Sci., 4th ser., iii., 1910, p. 61 (Monterey Bay); Bent, Condor, vol. xxiii., 1921, p. 78 

 (status of Pacific Coast birds); ibid., U. S. Nat. Mus., Bull. no. 113, 1921, p. 7 (distr.; 

 status). 



LAWRENCE'S record, published in 1853, of the taking of a Skua 

 J 'off the coast of California, near Monterey," was probably a good one, 

 but it was regarded with suspicion by timid closeteers until Rollo H. 

 Beck, prince of pelagic collectors, reestablished its presumptive value 

 by the capture of a specimen in Monterey Bay on the 7th of August, 

 1907. Two others, now in the Museum of Vertebrate Zoology, were 

 taken by the same collector on August 4th and September 21st, 1910. 

 The riddle was not resolved, however, until Mr. Bent's investigations 1 , 

 following Ridgway's suggestion 2 , made it clear to us that the species 

 represented was not Catharacta skua of the northern Atlantic, concerning 

 which science was, naturally, so skeptical, but C. chilensis of the western 

 coast of South America. Stanton Warburton, Jr., of Tacoma, took three 

 specimens off the coast of Washington and Vancouver Island, on June 

 28th and 30th, 1917; and it is altogether probable that the South American 

 Skua is a not infrequent wanderer along our entire coast line. 



Bloodthirsty, ruthless, and terrible is this marauder of the seas, who 

 not only pursues other gulls or Procellarids and obliges them to disgorge 

 their finny prey, but feasts upon their eggs and young as well. Nothing 



■A. C Bent in "The Condor." Vol. XXIII.. May. 1021, pp. 78-80. 



2 Robert Ridgway. " Birds of North and Middle America," part 8, 1010, p. 678. 



1354 



