The Long-tailed Jaeger 



birds. It is also very fond of eggs, and destroys great numbers of them 

 in the course of a season, not only those of kittiwakes and murres, but of 

 ducks and snipe as well. On cloudy days or in the Arctic twilight pre- 

 ceding the time of departure for the South, these birds are said to utter 

 doleful wailing cries, interspersed with harsh shrieks; and these are 

 among the most characteristic sounds to be heard in the teeming, tragic 

 North. 



No. 269 



Long-tailed Jaeger 



A. 0. U. No. 38. Stercorarius longicaudus Vieillot. 



Synonyms. — Arctic Jaeger. Buffon's Jaeger. Teaser. Boatswain. 

 Marlinspike. Gull-chaser. 



Description. — Adult: Top of head, including eyes and lores, black, the f ibrillse 

 of occipital feathers parted; remainder of head, neck all around and breast white, tinged 

 on sides of head and on neck all around with straw-yellow; remaining plumage slaty, 

 shading on cervix, sides, and belly, blackening on exposed wing-quills and tail, definitely 

 black on exposed tips of greater wing-coverts; the shafts of the quills white or straw- 

 yellow, as in other species; primaries and tail with some basal white on webs; central 

 pair of tail-feathers normally greatly produced, 6 to 10 inches beyond lateral feathers. 

 Bill dusky, blackening on tip; tarsi leaden blue; tibiae and feet black. There is also a 

 melanotic phase wherein the entire plumage becomes slaty or sooty, as in other species 

 of Jaegers, but this is very rare, almost negligible. Young birds differ materially from 

 the adult, being smaller, darker, and more varied in plumage, and with the central 

 pair of tail-feathers not at all, or only slightly, projecting. A typical example, male 

 of the 2nd (?) year, has head and neck all around streaked dusky and dull buffy; cervix 

 and remaining under-plumage throughout mottled and barred with same colors, 

 clearing to white on breast centrally, buffy strengthening on under tail-coverts, where 

 black-white-and-buff-banded, buffy wanting in black-and-white-barring of under wing- 

 coverts and axillars; remaining upperparts sooty black, heavily margined with fulvous 

 on back and wings; black-white-and-cinnamon-buffy-barred on upper tail-coverts; 

 blackening on wing-quills and rectrices, as before. Length of adult 508-609.6 (20.00- 

 24.00), of which the tail 254-406.4 (10.00-16.00), the lateral tail feathers about 158.75 

 (6.25); wing 304.8-330.2 (12.00-13.00); bill 27.4 (1.08); tarsus 44 (1.73). 



Recognition Marks. — Small crow size; smaller in body than the Parasitic 

 Jaeger; the greatly lengthened and tapering central pair of tail-feathers distinctive. 



Nesting. — Does not breed in California. Nest: A depression in moss or 

 heather. Eggs: 2; dark olive-buff, marked with light brownish olive to black and 

 dull violet-gray. Av. size 52.8 x 36.8 (2.08 x 1.45). Season: June. 



General Range.— Northern portions of Northern Hemisphere. Breeds in the 

 highest latitudes south to the Arctic shore of the American Continent and Siberia. 

 Sparingly and irregularly south in winter to coasts of California, Florida (one record), 

 Italy, and Japan. 



Occurrence in California. — A rare migrant coastwise, so far recorded only in 

 autumn. 



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