Oenanthe oenanthe oenanthe (Linnaeus): Wheatear.—Specimens 2: Mount Mary, S end Lake Peters 145°10'02", 69°20'30", 2920 ft., 1, No. 31322, juv. female, August 1, 1952; Chandler Lake, 152°45', 68°12', 2900 ft., 1, No. 30756, ad. male, August 12, 1951.
On the top of Mount Annette (July 17, 1952), which is the highest peak in the valley and the center of several drainage systems, the insects had collected in unusual numbers. There, an adult wheatear was feeding insects to her young, which were three fourths the size of the parent.
From records kept of trap catches at Lake Peters (July 31-Aug. 15, 1952) the wheatears were always caught in those areas that supported the greatest number of red-backed voles (Clethrionomys rutilus). On August 10, among rocks at the base of moraines, the wheatear was the second most common species. On August 15, after snow had fallen on the mountain and in the valley and the skies there were cloudy, wheatears moved onto the alluvium but always within at least 150 feet of moraines to which the birds retreated when alarmed. An adult female, shot on August 1, on the lower slopes of Mount Mary at the south end of Lake Peters, was 158 mm long and weighed 26 grams.
At Chandler Lake (Aug. 9-25, 1951) the wheatear was characteristically a bird of the rock fields and rockslides and in many places was the only bird present. It did not inhabit the glaciated canyons leading west from Chandler Lake, except at their mouths. From August 10-19, wheatears decreased in numbers. On August 25 the two remaining birds noted were among willows and rock ridges. Three adult males, shot on August 14, averaged 24(23-26) grams in weight and their testes averaged 1.2(1.0-1.5) mm long.
Luscinia svecica svecica (Linnaeus): Bluethroat.—Specimens, 7: Gavia Lake, 150°00', 69°35', 460 ft., 2, Nos. 31323 and 31328, males August 22, 23, 1952; 9⁄10 mi. W and 9⁄10 mi. N Umiat, 152°10'58", 69°22'53", 380 ft., 1, No. 31324, ad. female, June 30, 1952; Driftwood, Utukok River, 161°12'10", 68°53'47", 1200 ft., 3 (skins) Nos. 31326 and 32620, ad. females and 31327, ad. male?, August 29, 1952, and 1, No. 31325, ad. female, August 28, 1952.
The average length and weight of six adult males and adult females from Gavia Lake and Driftwood (Aug. 23-29, 1952) are, respectively, as follows: 153(148-165) mm and 19(18-21) grams. One female from Umiat shot on June 30, 1952, weighed 22 grams. The ovary was 5 mm long and the largest ovum was 1 mm in diameter.
At Umiat (June 30, 1952) a bluethroat was captured in one of 200 traps placed around the edge of a small lake. The trap that held the bird was in a soil fracture 15 centimeters in depth in an area that supported alder, willow, birch and ericaceous shrubs. At Driftwood, a bluethroat was caught on August 28, 1952, in a trap set among willows.
Phylloscopus borealis kennicotti (Baird): Arctic warbler.—On the north side of the valley at Umiat on June 27, 1952, willow warblers sang loudly and continually in accompaniment with white-crowned sparrows, tree sparrows, gray-cheeked thrushes and bluethroats.
Motacilla flava tschutschensis Gmelin: Yellow-wagtail.—Specimens, 2: Kaolak, 160°14'51", 69°56'00", 178 ft., 1, No. 30757, ad. female, July 27, 1951; Umiat, 152°09'30", 67°22'08", 352 ft., 1, No. 31329, ad. female, June 26, 1952.
At Umiat on June 25, 1952, a nest of the wagtail was on the side of a mound of earth three feet high. The nest, 130 mm in diameter and 14 grams in weight, was completely protected overhead. The lower half of the cup, 59 mm in diameter and 35 mm in depth, was lined (3 mm in thickness) with hair of caribou and brown lemming; the upper half was of feathers. Beneath the lining of the cup was 38 mm of moss. The outer nest, 33 mm in thickness, was, of coarse stems of grasses and other material. The nest was not so carefully constructed nor so well insulated as nests of tree sparrows, longspurs and snow buntings; it lacked the fine yellow grasses and symmetrical lamination of the materials and had more large chunks of material thus producing an irregular shape. Both male and female remained in the air directly overhead for 15 minutes as we examined the nest and then followed us for 100 yards as we left the area. An adult male shot on June 26, was incubating four eggs. He was 165 mm in length and weighed 19 grams.