Aleutian Tern

“Sterna aleutica. Aleutian Tern. Bill of ordinary shape, as in hirundo, macrura, etc., entirely black. Feet small, as in the species just named, but the webs more deeply incised; emargination not so great, however, as in Hydrochelidon; much as in Haliplana. Tibia bare to the usual extent. Wings and tail exactly as in Sterna proper, the latter, in its length and depth of fork, recalling macrura and forsteri. Crown and nape black; a large white frontal crescent, the horns of which reach to the posterior border of the eyes, the convexity of which extends into the nasal fossae, the concavity of which is opposite the anterior border of the eyes; thus broader than in most species similarly marked. The black vertex sends through the eye a band that crosses the cheeks and reaches the bill just posterior to the point of greatest extension of the feathers on the latter. The chin, auriculars, and other parts of the head bordering this vitta below, and pure white, presently deepening insensibly into the hue of the under parts. Tail wholly pure white; no pearly wash on either vane of any of the feathers. Upper parts at large dark pearl-gray, with a dull leaden hue, different from the clear pearly of macrura, etc., yet not of the smoky cast of panayensis, etc.; it is a tint intermediate between these, that I find difficult to name satisfactorily. The whole under parts, from the white of the chin, just noticed, to the under tail-coverts, paler and more decidedly pearly, more nearly as in full-plumaged macrura, yet more grayish. Both under and upper tail-coverts, like the tail, white. The color of the back mounts on the neck behind to the black of the nape without intervention of the white. Under wing-coverts and edge of wing pure white; as are all the shafts of the primaries. Primaries blackish lead-color, with silvery hoariness, and each with a large white space on inner web; this white space on the first primary occupies at the base the whole width of the inner web, but grows narrower toward the tip of the feather, ending about an inch from the tip, which is wholly blackish lead-color, this color running down as a narrow margining of the inner vane for two inches or more.” Elliot Coues, 1884

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