On July 27, 1951, seven days after our arrival at Kaolak, a male and female were seen for the first time. They flew back and forth overhead and called as if defending a territory but probably were not as we had been through this same area many times without either seeing or hearing these birds; also the female's ovary was undeveloped.
Anthus spinoletta rubescens (Tunstall): Water pipit.—Specimens, 3: Mount Mary, S end Lake Peters, 145°10'02", 69°20'30", 2920 ft., 1, No. 31330, juv. female, August 3, 1952; Wahoo Lake, 146°58', 69°08', 2350 ft., 2, Nos. 31331, female, July 7, 1952 and 31332, ad. male, July 8, 1952.
On July 8, 1952, approximately two miles south of Wahoo Lake on a high divide an adult was feeding a young bird 114 millimeters in total length and just able feebly to fly. On July 17, 1952, an adult female was feeding young on top of Mount Annette south of Porcupine Lake. Numerous insects had converged there—the highest point in the range of mountains. At Porcupine Lake, we observed water pipits on each of the five days July 13 to 18, 1952.
At Lake Peters there was a definite increase in numbers and in movement of water pipits with the approach of winter. This increase was correlated with a decrease in temperature and an increase in rain and snow. The many individuals and family groups, which, prior to our arrival, were generally distributed on the higher slopes and in the canyons of the Brooks Range, left the lower snow-covered slopes and congregated on the lake shore. On July 19, 1952, at the north end of Lake Peters, for example, we did not see water pipits in their usual haunts. On July 31 a single individual was noted at the south end of Lake Peters and on August 3, a single family appeared. On August 10, the water pipits were the most common bird at the edge of the lake, five or six usually being seen in a half hour trip. One flock of 14 bathed in shallow pools along the edge of the lake. These birds in the last few days had been congregating in small and large groups. On August 13, on a trip along the west shore line from the south end to the north end of the lake, the only birds seen were water pipits and these were in great numbers. On the morning of August 15, there was a dramatic increase in the number of pipits along the edge of the lake. Twenty of these birds fed 10 feet in front of our tent and others perched on its top. A juvenile shot on August 3 on Mount Mary was approximately the size of the adults, being 162 mm in length and 17 grams in weight.
At Chandler Lake (Aug. 12, 1951) pipits fed along the sandy edge of the lake and among short sedges. These birds also fed on scraps of food at the entrance of our tent door. From August 10 to 25, water pipits were more commonly found in the east-west canyons whereas other kinds of small birds were almost wholly confined to the north-south valley and were of only accidental occurrence in areas inhabited by water pipits.
Lanius excubitor invictus Grinnell: Northern shrike.—A bird was noted on August 23 and 25, 1951, in an extensive stand of willows at Chandler Lake.
This bird was one of a few birds that had not yet departed from the area with the advent of winter.
Acanthis flammea holboellii (Brehm): Common redpoll.—Specimens, 12: Topagaruk River, 155°48', 70°34', 10 ft., 1, No. 30767, ad. male, July 9, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 5, Nos. 30762-30766 including 4 ad. males and 1 ad. male (?), July 12, 14, 16-18, 1951; Kaolak, 160°14'51", 69°56'00", 178 ft., 4, Nos. 30758-30761 including 1 ad. male, 2 ad. females and 1 ad. of unknown sex, July 21, 23, 1951; Umiat, 152°09'30", 69°22'08", 352 ft., 1, No. 31333, ad. female, June 26, 1952; Wahoo Lake, 146°58', 69°08', 2350 ft., 1, No. 31334, ad. male, July 11, 1952.
At Umiat on June 26, 1952, a nest of five eggs (embryos with natal down) was located in a patch of willows that covered approximately two square meters. As these willows had not as yet acquired leaves, the nest was clearly visible. It was 300 millimeters from the ground and so compactly made as to support its own weight. The outer structure was of various plant fibers and other stems of willows. The cup had an inwardly reflected rim, was made of stems of cotton-grass, and was well insulated with 15 mm of down feathers. The measurements of this circular nest were: entire nest, 78 mm in diameter and 50 mm in depth: cup, 42 mm in diameter and 35 mm in depth; weight, 9 grams. Another nest of three eggs from the same area was in a dwarf willow 350 mm from the ground. The leaves of the willow were undeveloped. A third nest of six young approximately three days old, was two feet up in a dwarf willow having no leaves. The young birds in the nest were three days old. One female 123 mm in length shot on June 26 had ova up to two mm in diameter. At Umiat (June 28, 1952) a nest of three young and two eggs was found and on June 30 another nest with one fresh egg.
At Wahoo Lake (July 3-12, 1952) the redpolls were observed every day but we considered them relatively uncommon there.