Part 12

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 deg.48', 70 deg.34', 10 ft., 1, No. 30767, ad. male, July 9, 1951; Kaolak River, 159 deg.47'40", 70 deg.11'15", 30 ft., 5, Nos. 30762-30766 including 4 ad. males and 1 ad. male (?), July 12, 14, 16-18, 1951; Kaolak, 160 deg.14'51", 69 deg.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 deg.09'30", 69 deg.22'08", 352 ft., 1, No. 31333, ad. female, June 26, 1952; Wahoo Lake, 146 deg.58', 69 deg.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.

At Topagaruk (July 5-10, 1951) redpolls were among willows growing on the sides of a creek channel ten feet below the level of the tundra. This creek had overflowed in early spring covering the willows. One of the birds approached us to within five feet and after making a close inspection returned to the willows.

Upon our arrival at Kaolak River (July 12, 1951) most of the redpolls were living among willows and only occasionally flew overhead. On July 15, they were flying in small groups about 100 feet above the ground and were calling continually. On July 15, on a four hour field trip, we counted 28 birds. The young birds on this date could fly well.

At Porcupine Lake these birds were uncommon but a few were seen (July 17, 1952) flying south across divides in the higher mountains.

At Kaolak (July 20-27, 1951) redpolls were associated with willows along creeks that had cut channels 20 feet deep. In late July the flowing water was six feet wide and from a few inches to three or four feet deep. The first erosional bench supported grasses and sedges and the slopes were covered with willows from a few inches to seven feet high. These willows afforded nesting sites for redpolls. In a two-mile stretch along this creek, which drained east into the Kaolak River (July 21), there were approximately 200 redpolls, 100 Lapland longspurs, 80 savannah sparrows, six willow ptarmigans, six pintail ducks and several other smaller unidentified birds. On this same date when I walked four miles on the open tundra, there were, of the smaller birds, only six redpolls, 20 Lapland longspurs and 13 savannah sparrows. In one interval of 1/3 of a mile, I did not see a single individual of any of these three species. In the two miles of creek bottom that I examined, there were several nests that had been used that spring, several that had been used the year before, and one that held four eggs containing embryos nine millimeters in length (no feathers or bone development). Most of the nests were approximately three feet above ground in willows near the creek. The nest of four eggs was three feet above the ground, three feet from the edge of the willows bordering the creek, and 10 feet from the creek proper. The nest was 10 cm in diameter and 55 mm in height. The cup was 5 cm in diameter at the upper rim, six cm in width and 35 mm in depth. The outer base and side were constructed of dry willow sticks, twigs and grass stems; the main body of the nest was fine grass stems, rootlets and a few mosses. This lining was a layer 18 mm thick of white feathers. The weight of this nest was 12 grams. The four eggs measured 19.2 x 12.9, 18.3 x 12.5, 18.3 x 12.8, 17.7 x 12.9. This nest of four eggs was either a second nesting or an interrupted or exceptionally late first nesting of redpoll on the Arctic Slope. Two abandoned nests 200 feet apart were in willows along the edge of an oxbow lake at Gavia Lake (August 23, 1952).

On August 10, 1952, at the south end of Lake Peters, there was only a slight increase in the number of redpolls over the previous week. At Chandler Lake (Aug. 25, 1951) a few redpolls were among willows, this was the first time in 15 days that we had noted these birds. One redpoll was taken in a trap at Umiat on August 30, 1951.

The testes of six adult males (average 14(13-15) grams in body weight and that were shot at several localities on the Arctic Slope from July 9 to July 28, 1951) averaged five mm in length.

+Spinus pinus pinus+ (Wilson): Pine siskin.--An adult male, which weighed 12 grams, was caught in a trap at Chandler Lake on August 14, 1951. The testes were two mm long.

+Passerculus sandwichensis anthinus+ Bonaparte: Savannah sparrow.--Specimens, 19: Kaolak, 160 deg.14'51", 69 deg.56'00", 178 ft., 12, Nos. 30770-30781 including 3 ad. males, 3 juv. males, 4 ad. females, 1 juv. female and 1 ad. female (?), July 21-23, 25, 26, 1951; Gavia Lake, 150 deg.00', 69 deg.35', 460 ft., 1, No. 31336, juv. male, August 22, 1952; Wahoo Lake, 146 deg.58', 69 deg.08', 2350 ft., 1, No. 31337, ad. male, July 5, 1952; Porcupine Lake, 146 deg.29'50", 68 deg.51'57", 3140 ft., 1, No. 31339, ad. female, July 13, 1952; Driftwood, Utukok River, 161 deg.12'10", 68 deg.53'47", 1200 ft., 1 (skin) No. 31338, male and 1, No. 31335, ad. female, August 29, 1952; Chandler Lake, 152 deg.45', 68 deg.12', 2900 ft., 2, Nos. 30768-30769, 1 ad. male and 1 juv. male, August 10, 15, 1951.

Savannah sparrows were caught in traps in the following communities: damp meadow of sedges, Chandler Lake, August 10, 1951; among sedges bordering a lake, Wahoo Lake, July 5, 1952; damp to wet meadow of sedges, grasses, and hummocks of cotton-grass, Porcupine Lake, July 14, 1952; along the edge of a deeply incised stream running through a marsh, Porcupine Lake, July 16, 1952.

At Kaolak (July 21, 1951) on a windy day the greater number of savannah sparrows were in protected valleys of willows along the creeks and not on the open tundra where they are normally found. In a two mile course along one creek there were 80 birds, whereas on the open tundra there were, in four miles, only 13 birds.

Weights of 10 males and 10 females, shot in the period July 14-August 29, 1951, at several localities on the Arctic Slope were: male 20(17-24), female 18(16-20) grams. In an adult male, shot on July 22 at Kaolak, the testes were two mm long but in other males, shot in the period July 14-August 29, the testes averaged 1.2 mm. The ovaries of adult females for this same period also had receded to normal non-breeding size. Juveniles on July 13 at Porcupine Lake averaged 20 grams in weight; the shortest was 125 mm in total length and the largest 140 mm. Adults in this same period averaged 144 mm in total length. Two adult males collected on July 22 and 24, 1951, at Kaolak, were molting.

+Spizella arborea ochracea+ Brewster: Tree sparrow.--Specimens, 10: Gavia Lake, N White Hills, 150 deg.00', 69 deg.35', 460 ft., 1, No. 31340, juv. male, August 22, 1952; 9/10 mi. N and 9/10 mi. W Umiat, 152 deg.10'58", 69 deg.22'53", 380 ft., 1, No. 31347, ad. female, July 1, 1952; Umiat, 152 deg.09'30", 69 deg.22'08", 352 ft., 1, No. 31341, ad. male, June 26, 1952; Wahoo Lake, 146 deg.58', 69 deg.08', 2350 ft., Nos. 31342-31343, ad. males, July 6, 8, 1952; Driftwood, Utukok River, 161 deg.12'10", 68 deg.53'47", 1200 ft., 2 (skins) Nos. 31345, ad. male, August 29, 1952, and 31346, ad. female, August 28, 1952, and 1, No. 31344, ad. male, August 28, 1952; Chandler Lake, 152 deg.45', 68 deg.12', 2900 ft., 2, Nos. 30783, juv. male, 30784, a juv. of unknown sex, August 19, 1951.

Four adult males shot in the period July 1-15, at Umiat, Wahoo and Porcupine lakes averaged 158(155-165) mm in total length and 18(16-18) grams in weight whereas 12 adult males (Aug. 14-31) from Chandler Lake, Umiat, Gavia Lake and Driftwood averaged 161(156-165) mm in length and 19(16-21) grams in weight. A male (June 26) from Umiat was 160 mm long, weighed 15 grams, and had testes 4 mm long. Males from Wahoo Lake (July 6 and 8) had testes 9 and 5 mm long. Males (August 19) from Chandler Lake were molting on the entire body.

On June 24, 1952, at Umiat, we examined three nests. One of the three contained incubated eggs; skeletal elements were present in the embryos. This nest, 150 mm in diameter and 52 mm in depth, was on the side of a mound three feet high covered with grass. The cup was 55 mm in diameter. The lining, 14 mm thick, was ptarmigan feathers averaging one inch long mixed with successive layers of stems of fine grass. The cup weighed four grams and rested directly on the ground. The outer part of the nest was coarse stems of a grass and was 30 mm thick. The edge and upper side, away from the mound, had a 40-millimeter thickness of mosses and lichens that may have served primarily as camouflage rather than as insulation. The nest, minus the lining weighed nine grams. The second nest held four eggs containing embryos. The top was flush with the surface of the ground on a slightly elevated bench on a hillside supporting Ledum, Vaccinium, Alnus, mosses and lichens. The greatest width of the nest was 120 mm; the lining, 11-millimeters thick, was of ptarmigan feathers succeeded by 13 mm of alternating layers of new dry grass stems and ptarmigan feathers. The down-slope side of the nest was protected by 29 mm of sphagnum, old grass stems and other dry plant material. The third nest of four eggs was among grasses at the base of a willow. The new leaves on this willow were just visible and the catkins had attained full growth.

The earliest date that juvenal tree sparrows were noted in the field was on July 10, 1952, at Wahoo Lake. One juvenile shot on this date was 85 mm long and could not fly. The parent bird was still attending the young bird.

Tree sparrows on the Arctic Slope usually live among high dwarf willows at the mouths of canyons. At Porcupine Lake (July 13-18, 1952) however, they inhabited marshes of sedges, grasses and hummocks of cotton-grass. At night they roosted in depressions in the ground or between hummocks of sedges, where, without overhead protections they endured temperatures of as low as 34 degrees Fahrenheit.

In one mile of a glaciated canyon southwest of the south end of Chandler Lake (Aug. 19, 1951) tree sparrows were the commonest species but there were few birds of any kind there. This canyon extended in an east-west direction and was bordered by high mountains, the sun being excluded in early morning and late afternoon. In the valley of Chandler Lake, on the same day, the tree sparrows were numerous especially among willows on the side of the valley. On this date there was an abrupt increase in numbers of tree sparrows; the number of Lapland longspurs and wheatears was less than a week before. On August 22, we did not see tree sparrows at Chandler Lake whereas three days earlier there were hundreds in the area. On August 23 only 15 were noted and these were in willows. On August 25, only a single bird was noted.

At Umiat (Aug. 30, 1951) a few tree sparrows were present. In this area (Sept. 1) the birches were turning a brilliant red, even more brilliant than on the previous day. The large alders were nearly all yellow. The season was not so far advanced here, however, as at Chandler Lake on August 25. At Driftwood tree sparrows were noted from August 27 to 31 inclusive. On August 28 a flock of 12 was observed.

+Zonotrichia leucophrys gambelii+ (Nuttall): White-crowned sparrow.--Specimens, 3: Mount Mary, S Lake Peters, 145 deg.10'02", 68 deg.20'30", 2920 ft., 1, No. 31348, juv. female, August 3, 1952; Driftwood, Utukok, 161 deg.12'10", 68 deg.53'47", 1200 ft., 1 (skin) No. 31349, ad. male, August 29, 1952; Chandler Lake, 152 deg.45', 68 deg.12', 2900 ft., 1, No. 30786, an ad. of unknown sex, August 19, 1951.

On the north side of the valley at Umiat, the white-crowned sparrows were calling (June 27, 1952) throughout the day. At Wahoo Lake (July 3-11, 1952) singing birds were frequently heard on south-facing slopes of the valley. At Lake Peters (Aug. 3, 1952) one bird was at the base of a moraine some distance from willows or high vegetation. Only two birds were seen at Chandler Lake (Aug. 19 and 25, 1952); they were feeding in a dense growth of willows. The juvenal female shot on August 3, 1952, at Mount Mary was 180 mm long and weighed 26 grams.