Birds Found on the Arctic Slope of Northern Alaska Part 8

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 a.s.sociated 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 gra.s.ses 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 gra.s.s stems; the main body of the nest was fine gra.s.s 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 12.9, 18.3 12.5, 18.3 12.8, 17.7 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.

+Pa.s.serculus sandwichensis anthinus+ Bonaparte: Savannah sparrow.--Specimens, 19: Kaolak, 16014'51", 6956'00", 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, 15000', 6935', 460 ft., 1, No. 31336, juv. male, August 22, 1952; Wahoo Lake, 14658', 6908', 2350 ft., 1, No. 31337, ad. male, July 5, 1952; Porcupine Lake, 14629'50", 6851'57", 3140 ft., 1, No.

31339, ad. female, July 13, 1952; Driftwood, Utukok River, 16112'10", 6853'47", 1200 ft., 1 (skin) No. 31338, male and 1, No. 31335, ad.

female, August 29, 1952; Chandler Lake, 15245', 6812', 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, gra.s.ses, and hummocks of cotton-gra.s.s, 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, 15000', 6935', 460 ft., 1, No. 31340, juv. male, August 22, 1952; 9/10 mi. N and 9/10 mi. W Umiat, 15210'58", 6922'53", 380 ft., 1, No. 31347, ad. female, July 1, 1952; Umiat, 15209'30", 6922'08", 352 ft., 1, No. 31341, ad. male, June 26, 1952; Wahoo Lake, 14658', 6908', 2350 ft., Nos.

31342-31343, ad. males, July 6, 8, 1952; Driftwood, Utukok River, 16112'10", 6853'47", 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, 15245', 6812', 2900 ft., 2, Nos. 30783, juv. male, 30784, a juv. of unknown s.e.x, 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 gra.s.s. 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 gra.s.s. The cup weighed four grams and rested directly on the ground. The outer part of the nest was coa.r.s.e stems of a gra.s.s 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 gra.s.s stems and ptarmigan feathers. The down-slope side of the nest was protected by 29 mm of sphagnum, old gra.s.s stems and other dry plant material. The third nest of four eggs was among gra.s.ses 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, gra.s.ses and hummocks of cotton-gra.s.s. 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, 14510'02", 6820'30", 2920 ft., 1, No. 31348, juv. female, August 3, 1952; Driftwood, Utukok, 16112'10", 6853'47", 1200 ft., 1 (skin) No.

31349, ad. male, August 29, 1952; Chandler Lake, 15245', 6812', 2900 ft., 1, No. 30786, an ad. of unknown s.e.x, 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.

+Zonotrichia atricapilla+ (Gmelin): Golden-crowned sparrow.--Specimen, 1: Chandler Lake, 15245', 6812', 2900 ft., No. 30787, ad. male, August 19, 1951.

+Pa.s.serella iliaca zaboria+ Oberholser: Fox sparrow.--Specimen, 1: Driftwood, Utukok River, 16112'10", 6853'47", 1200 ft., No. 31350 (skin), male, August 29, 1952.

At 1/10 mile west and 9/10 mile east of Umiat (June 30, 1952) a nest the top of which was flush with the ground in a clearing among willows and alders, both bare of leaves, had four young approximately five days old. At Driftwood (Aug. 29, 1952) a male was caught in a mouse trap in the same area where a male was singing on the previous day. At the time the male was trapped a female sat on low vegetation only a few feet from the trap that held the dead bird.

+Calcarius lapponicus alascensis+ Ridgway: Lapland longspur.--Specimens, 75: NE Teshekpuk Lake, 15305'40", 7039'40", 8 ft., 22, Nos. 30827-30848 including 10 ad. males, 9 juv. males, 2 ad.

females and 1 juv. female, July 29, 30, August 1, 3, 1951; Topagaruk River, 15548', 7034', 10 ft., 13, Nos. 30849-30861 including 9 ad.

males and 4 ad. females, July 6, 8, 10, 1951; Kaolak River, 15947'40", 7011'15", 30 ft., 18, Nos. 30809-30826 including 2 ad.

males, 10 juv. males, 3 ad. females and 3 juv. females, July 12, 14, 17, 1951; Kaolak, 16014'51", 6956'00", 178 ft., 13, Nos. 30796-30808 including 4 ad. males, 4 juv. males, 5 juv. females, July 20-27, 1951; Gavia Lake, 15000', 6935', 460 ft., 1, No. 31351, female, August 22, 1952; Umiat, 15209'30", 6922'08", 352 ft., 1, No. 31352, female, June 26, 1952; Chandler Lake, 15245', 6812', 2900 ft., 7, Nos.

30789-30795 including 1 ad. male, 1 juv. male, 1 ad. female, 4 juv.

females, August 11, 12, 16, 18, 23, 1951.

The Lapland longspur and snow bunting were two of the early arrivals on the Arctic Slope of northern Alaska. Robert McKinley told us that this species of longspur arrived at Barrow Village shortly after April 20, 1952. On our arrival at Point Barrow on June 14, 1952, longspurs already were established on territories, and many of the birds had full complements of fresh eggs, although snow still covered the lakes and all but a few mounds and high points of the tundra.

On June 17, 1952, on the west side of Salt Water Lagoon, in an area of approximately six acres of raised polygons we located eight nests of the Lapland longspur. The first contained five fresh eggs, and its top was flush with the bare ground in an old excavation made by brown lemmings between three bunches of cotton-gra.s.s. Fecal pellets of the brown lemming were beneath the nest. The bulk of the nest was soiled gra.s.ses which insulated the bottom and sides of the nest from the damp soil. This supporting bulk was lined first with stems of new yellow gra.s.s, and then with white down feathers of the snowy owl. The female repeatedly repelled the male from the immediate vicinity of the nest.

After observing the nest for a few minutes I moved it one foot. The female returned three times to the original site of the nest, ignoring the nest nearby. On the fourth trip, six minutes after the original nest was taken, she returned with feathers in her bill and started to line the original depression.

The second nest, superimposed on a nest of the previous year, held six fresh eggs and was under an overhanging piece of tundra sod. The cup was entirely beneath the sod but the outer rim of the nest was exposed. The nest faced northwest and was 100 centimeters above the general level of the tundra. Measurements, in millimeters, of this nest were: height, 52; width, 120; inside diameter of cup, 50; depth of cup, 30; width of layer of fine gra.s.ses and feathers of cup, 16. In cross section successive layers of nest material from outside in were as follows: mosses; old, dry, brownish-gray gra.s.ses; new, fine, loosely arranged, yellow gra.s.ses; down feathers of the snowy owl. The first two layers were on only one side and did not extend under the cup of the nest. The cup was lined with 12 down feathers of the snowy owl.

The third nest, containing six fresh eggs, was at the edge of a clump of cotton-gra.s.s and was exposed from directly above. The lining of the cup of white feathers and dry lichens was against the soil. Two layers of dry brownish-gray gra.s.ses and dry mosses were outward extensions from the cup.

The greater part of the third nest was stems of the gra.s.s _Dupontia fischeri_; newer yellow stems were near the cup and the older stems were toward the periphery. The measurements (in millimeters) of this nest were: height, 60; width, 210; width of cup, 50; depth of cup, 40.

A fourth nest of three fresh eggs held four eggs the following day. A fifth nest of six fresh eggs was only 10 centimeters from a well-used trail of a brown lemming and within 1/3 of a meter from the underground nest of the lemming. This longspur nest, among polygons of low hummocks, was bordered by mosses and gra.s.ses nine inches high. The sixth nest held five fresh eggs. Its top was flush with the ground and the nest was protected by an overhead canopy of _Dupontia fischeri_. A seventh nest, containing six fresh eggs, was among pieces of tundra displaced by a vehicle. Only the outer edge of this nest was exposed from above. The cup was lined with white feathers and with the hair of _Rangifer_. On June 20, an eighth nest of five fresh eggs was located near the above. The nest was 1/3 concealed under overhead protection.

At a point 1-2/5 miles south and 3/5 of a mile east of Barrow Village (June 20, 1952) we examined a ninth nest, containing six fresh eggs, among raised polygons. It was circular and the cup was centrally placed. The entire nest weighed 14 grams; the inner cup of fine stems of gra.s.s and white feathers weighed two grams. The nest was 118 mm wide; the cup was 56 mm wide and 38 mm deep. The outer structure of last year's nest, mosses and larger gray stems of gra.s.s, was 30 mm wide. Enroute to this locality from Barrow Village we saw only two longspurs (2:00 P.M.) and only three on the return trip.

At a place 9/10 mile east and 8/10 mile north of Barrow Village (June 23, 1952) a tenth nest, containing five fresh eggs, was noted in a lemming runway that had been enlarged from a soil fracture. The top of the nest was flush with the surface of the ground and there was no overhead protection. This nest had the least nesting material of any nest of this species examined to date; there was no nesting material of any kind on the sides adjoining the walls of the fracture. At Umiat (June 26, 1952) an eleventh nest, containing six eggs, was so placed that its top was flush with the surface of a raised polygon, and closely resembled those at Point Barrow except that the cup was lined with brown and white feathers of the willow ptarmigan. Additional data are as follows: weight of entire nest, 20 grams; weight of inner cup, 7 grams; diameter of cup, 65 mm; depth of cup, 30 mm; width of entire nest, 100 mm. As was usual with other nests of this species, the outer edge of one side was covered with moss.

In the period July 13-August 15, from several localities on the Arctic Slope, Lapland longspurs were caught in traps (20 feet apart) set in linear lines among sedges. The average distance between traps catching longspurs was 1400 feet. Other Lapland longspurs observed in the same period at these same localities averaged one per 400 feet of walking on my part. The greatest number of longspurs trapped was at Kaolak on July 24, 1951; 100 traps yielded 6 longspurs. The greatest number observed--one per 100 feet--was at Topagaruk on July 5, 1951. Although the longspur on the Arctic Slope is the most common bird, it is absent from some areas there. On each of two trips (July 29-30) across one mile of upland plateau between Barrier Lake and Teshekpuk Lake, we did not see longspurs. This plateau is a travel lane maintained by caribou.

Juveniles were first trapped on July 5, 1951, at Topagaruk; others were observed on this date but they could not fly. The first juvenile noted in flight was on July 9, also at Topagaruk. The increase of juveniles there caused the longspur to be the most common bird in the field (50 per cent in abundance). On July 15 at Kaolak River, most of the longspurs noted were juveniles, but they were able to fly well.

The adult males and females, which were molting at this time, were more secretive in their movements than longspurs at Topagaruk on July 5. Adult males were molting as early as July 2 at Kaolak. On July 25 at Kaolak longspurs were mainly in groups of five or six; others were in groups of 18 or more. As late as August 21 (Gavia Lake) longspurs were still in family groups or occurred as singles.

At Chandler Lake, the decrease in numbers of Lapland longspurs was synchronized with autumnal changes in weather. On August 15, 1951, the longspurs were numerous; 40 or 50 individuals were seen in the course of an hour's walk. On August 19 there was a noticeable decrease in numbers of individuals and by August 22, only three were seen. In this period of decreasing numbers, they were more numerous and active in the morning than in the evening or in inclement weather. The behavior pattern of leaving the ground with an audible commotion and flapping of wings on the vegetation also was characteristic of this period of decreasing numbers of the longspur population. At mile south of the Arctic Research Laboratory (Sept. 7, 1952) only a single longspur was noted.

The short-eared owl and especially the pigeon hawk consistently preyed on longspurs.

Only one longspur (an adult female No. 30854) in 75 specimens examined had the bone of the skull damaged by parasites.

Adult males are larger than adult females (July). In the breeding season adult females average 3 grams lighter than males. In the latter part of summer, however, females "catch up" in weight with the males.

As early as the middle of July, juveniles are nearly as large as adults in cranial measurements. The increase in weight in juveniles was from 21.5(18-25) in ten juvenal males shot in the period July 12-16, at Kaolak River to 25.2(22-27) grams in nine juvenal males shot in the period July 29-August 2 at Teshekpuk Lake.