THE BIRDS OF THE PEIBILOF ISLANDS. 423 



"Au abundant bird on the island in summer but rare or absent in winter. This 

 bird is the vocalist par excellence of the Pribilof group, singing all through the month 

 of June in the most exquisite manner, rising high in the air and hovering on fluttering 

 wings over its setting mate." — {Elliott.) And this is certainly true. It could always 

 be found, and its song was a most beautiful variation on the usually monotonous 

 stretches of foot wearying tundra. The male invariably spends his time in the close 

 vicinity of the setting female but never lends his assistance to the ornithologist in 

 finding the nest. He either sits close by on a little eminence, watching silently, or 

 flies off to a little distance, and when we move follows us for some distance. 



No constant dift'erences are noticeable in the sexes of the young of this species in 

 the nestling plumage, like the suowflake; variation in the amount of sjiotting ou the 

 breast and in the general amount of paleness and darkness is noticeable, but it is 

 individual. An immature male, August 15, that I took at Unalaska is acquiring the 

 new teleoptile plumage, a streak of half-grown pale-chestnut feathers having appeared 

 down each side of the neck, and under the nestling feathers of the breast the tips of 

 new feathers can be seen as jet black as in the adult, with rather broad edgings 

 of tawny. Many new feathers can be seen all over the back by lifting the feathers of 

 the nestling plumage. An adult female, July 29, St. Paul, has many new pinfeatbers 

 of the new plumage just jutting out from the skin, and easily felt. Nests were found 

 as follows: June 20, 5 eggs; June 21, same; same date, 3 eggs, 2 young; July 2, 6 

 young, well feathered; July 5, 5 young, just from the nest. The down is very pale, 

 tawny in color, almost white, and is quite long. A bunch is shown in fig. 5, PI. XL, 

 attached to the nestling feather, and another somewhat separated. At a is shown a 

 single ramus with its down attached and the slight swelling between. 



The nest is placed on a slight slope, usually under a tall plant, but sometimes ou 

 the open tundra where a bunch of dried sedge or grass at its upper side partly or 

 wholly conceals it. It is sunk even with its rim. The female will not leave it until 

 almost stepped upon, and then tries her utmost, by feigning lameless, to entice the 

 intruder away. This undoubtedly works very well with the numerous foxes. Her 

 colors harmonize so well with the surroundings that it is certainly difficult to detect 

 her when on the nest and only a few feet away. The young are to be found by the 

 end of June. Externally the nest is composed of old coarse grass and plant stems, 

 inside of fine grass tops compactly interwoven and lined with a few white and dark 

 small feathers. It measures 4J inches in diameter, with the opening 2i by IJ inches 

 deep. The eggs agree well with those from other places — a confusion of faint brown- 

 ish blotches on a slightly paler base, with a few spots, and irregular, wavy, short lines 

 of dark brown generally about the center of the eggs. My series varies from 0.80 by 

 0.63 to 0.91 by 0.63. The small young have the bill dark, with the edges yellowish 

 white. In some the tip was yellowish. Feet yellow ocher, with the upper sides dark- 

 est. Stomach contents, six species: ''These birds were nestlings, and, save one in 

 which there were a few bits of insect cuticle, they contained nothing but pieces of 

 red and black volcanic lava." — {S. D. J.) 



67. Passerina townsendi (Ridgw.). Pribilof Snowfiake, "/Swaj/iMsfeie." 



Plectrophmies nivalis, Dall and Bann., Trans. Chic. Ac. Sci., 1869, 282 (part). — Dall, Proc. 

 Cal. Ac. Sci., 1874, 273.— Couks, in Elliott's Ept. Afl. Alaska, 1873; Reprint, 1875, 176; Key, 

 1890, 356.— Elliott, Mon. Seal Ids., 1875, 128.— Nelson, Bds. Alaska, 1887, 180 (part). 



Plectroplienax nivalis, Townsend, Cruise Corwin, 1887, 100. — Sharpe, Cat. B., Br. Mus. XII, 

 1888, 579 (part). 



Plectroplienax nivalis townsendi Ridgway, Man., 1887, 1st ed., 405. — A. O. U. Ch. List, 1895, 220. 



I have been unable to find any examples of intergradation between this form and 



