Six pairs of Arctic terns, constituting less than one per cent of the avian population in the area, were nesting on small islands of the larger lakes at Topagaruk in the period July 5-10, 1951. On July 8, one nest held both eggs and young; other nests held either eggs or young. These birds and the Sabine's gulls showed no hostility to one another. On July 9, three miles north of camp 13 terns were among sedges in standing water. They seemed to be nesting but we could not reach them.
On June 23, 1952, at a point 9⁄10 mile east and 8⁄10 mile north of Barrow Village, Arctic terns were in flocks; one of eight flew northeast across the tundra. At a point 105 miles northwest of Point Barrow on an air trip to Kaolak (July 20, 1951) we saw Arctic terns, Sabine's gulls, and several pairs of loons in the same lake. The trip from Point Barrow to Kaolak was characterized by relatively few large birds. On the return trip (July 27) on a straight line flight from Kaolak to Point Barrow, only two terns were seen, one 33 miles northeast of the junction of the Avalik and Kaolak rivers and another 9.7 miles beyond. On our return trip from Teshekpuk Lake to Point Barrow (Aug. 4, 1951) we saw only a single tern; it was 63 miles southeast of Point Barrow. At Gavia Lake (Aug. 21, 1952) there were three pairs of terns. At 8:00 A.M. three other pairs appeared and then left. No young were observed. At Point Barrow (Aug. 26, 1952) 130 terns fished or rested on the lee side of the peninsula. Arctic terns were the second most common bird flying and feeding along the shore line of the Arctic Ocean 10½ miles southeast of Point Barrow on September 6, 1952. Associated species were Sabine's gulls, kittiwakes and glaucous gulls.
Nyctea scandiaca(Linnaeus): Snowy owl.—Harmon Helmericks told us of seeing a snowy owl catch a brown lemming that was swimming in open water 30 nautical miles north of Thetis Island in April of 1946.
On a 1000 linear meter transect (1000 × 1) east of Barrier Lake we collected (Aug. 3, 1951) 19 pellets from the edge of the uplands and from prominent mounds on the lowlands. One pellet contained a complete radius-ulna of an Arctic fox and another a foot of a ptarmigan.
At Kaolak River (July 12, 1951) the only sign of owls was pellets on the upland tundra. They were covered with green algae and fungus several years old.
On an air flight from Point Barrow to Kaolak River (July 11, 1951) we saw one snowy owl on the Coastal Plain and on the return flight (July 19) two more; one was approximately 40 miles south of the Will Rogers monument and the other about one half way between the monument and Point Barrow. When flying from Teshekpuk Lake to Point Barrow (Aug. 4, 1951) we saw one snowy owl flying over the tundra.
Greater abundance was indicated by observations in 1952, a year in which brown lemming were at a high peak in their cyclic fluctuation: Entrails of abrown lemming were on top of a mound used by snowy owls as evidenced by the numerous fresh owl pellets, at the west side of Salt Water Lagoon on June 17; three snowy owls fed in the surrounding area (June 17-27); one owl seen at Driftwood on August 30-31; eight owls recorded on our two mile trip south of Barrow Village on September 6; four owls observed one half mile south of the Arctic Research Laboratory on September 7; three owls seen at Point Barrow on September 11.
Asio flammeus flammeus(Pontoppidan): Short-eared owl.—Specimen, 1: 2 mi. W Utukok River, 161°15'30", 68°54'50", 1275 ft., 1, No. 31319, ad. male, August 31, 1952.
A short-eared owl was seen at Chandler Lake on August 16, 1951. Another flew across the middle of Gavia Lake on August 22, 1952, hunted the south shore, caught two small rodents and pursued one Lapland longspur that escaped. From August 27 to 31, 1952, at Driftwood individual short-eared owls were noted daily. On August 31, a family group of five flew in close formation and fed in the low wet marsh in the valley adjacent to the river. An adult male from two miles west of Driftwood (Aug. 31, 1952) was 370 mm in length and weighed 417 grams.
Chordeiles minor minor(Forster): Common nighthawk.—Clifford Fiscus told us that a nighthawk was seen by an Eskimo in the summer of 1952 at Wainwright.
Tachycineta thalassina lepidaMearns: Violet-green swallow.—At 6:00 P.M. on August 17, 1951, at Chandler Lake, a northern violet-green swallow came to our camp, inspected us at a distance of four feet, fluttered over and around the tent for two minutes, then flew over the water, and continued south.
Corvus corax principalisRidgway: Common raven.—Specimen, 1: Umiat, 152°08', 69°22', 337 ft., No. 31320, juv. female, August 19, 1952.
William Wyatte of Umiat told us that ravens were the only birds that remained at Umiat throughout the winter of 1951-52. He observed them flying when temperatures were so low that moisture from the ravens froze into floating ice crystals.
At Wahoo Lake (July 9, 1952) two ravens fed on a dead lake trout (18 inches in length) at the east end of the lake. The fish seemed to have died of malnutrition as it had an abnormally slender body and large head. No other carrion or dead fish was in the area. At 6:00 P.M. on August 8, 1952, in the main canyon 1⁄10 mile north of James Robert Lake, five ravens fed on remains of a dead caribou by extracting flesh from between the vertebrae; carnivorous mammals could not conveniently reach the flesh. A pigeon hawk harassed the ravens. Ravens were at Porcupine Lake, every day from July 13 to 18, 1952, mostly flying along the crest of high mountain ridges. One pair controlled a territory in the Canning River drainage east of Mount Annette and repelled an eagle on three occasions.
At the south end of Lake Peters (Aug. 10) a raven hunted low over the ground. Here, only occasionally were they seen so low in the valley. At Chandler Lake ravens were noted flying high along the crests of the mountains on August 11, 12, 13, and 25, 1951.
One juvenile female that was shot at Umiat on August 19, 1952, was 682 mm long and 1360 grams in weight. Between August 30 and September 4,1951, ravens were noted at Umiat every day; the largest group was six. Most of the time they fed at the refuse pile near camp.
On our first day at Gavia Lake (Aug. 21, 1952) a pair of ravens arrived from the west and calling continually circumnavigated the shore line. They left in the same direction from whence they came.
Clifford Fiscus told us that in the summer of 1952, ravens were seen along the Arctic Coast between Pitt Point and Point Barrow. The largest congregation was at the mouth of the Colville River. Ravens were noted on August 27 and 28, 1952, at Driftwood.
Turdus migratorius migratoriusLinnaeus: Robin.—From the tops of alder trees at the mouth of Bearpaw Creek on June 27, 1952, three robins sang more frequently in the evening between 6:00 P.M. and 11:00 P.M. than at any other period of the 24 hours of continuous daylight.
At Wahoo Lake on July 3, 1952, a nest held four eggs, on July 6 two eggs and two young, and on July 10 one egg and three young. On July 12 the single egg was determined to be infertile. In the canyon south of Wahoo on July 6 two adults and a single young bird were feeding 50 feet from a recently abandoned nest that was superimposed upon an old nest of a previous year. Other robin nests in high willows in the bottom of this canyon were spaced approximately 1⁄5 of a mile apart. Occasionally robins foraged on the open tundra beyond willow-lined creeks. As compared with robins in the temperate regions, those in the Arctic Life-zone were notably less "fearless"; they came to within three feet of the nest when nestlings were being inspected by an observer. The robins at Wahoo Lake on July 3-12, 1952, generally sang at about 10:00 P.M., a time equivalent to twilight in temperate regions to the south.
Hylocichla minima minima(Lafresnaye): Gray-cheeked thrush.—Specimens, 2; Wahoo Lake, 146°58', 69°08', 2350 ft., 1, No. 31321, ad. female, July 11, 1952; Chandler Lake, 152°45', 68°12', 2900 ft., 1, No. 30755, juv. male, August 23, 1951.
On June 27, 1952, we frequently heard thrushes singing on the side of the valley north of Umiat. Large alder, birch and willow gave adequate protection to these birds.
At Wahoo Lake (July 3-12, 1952) thrushes were seen every day along willow-lined creeks. An adult female on July 11, was 191 mm long and weighed 34 grams. A male from Chandler Lake on August 23, 1951, was 186 mm long and weighed 34 grams. It was caught in a mouse trap on an alluvial outwash at the mouth of a canyon in a willow community in which some willows were as high as nine feet. Fifteen tree sparrows, two white-crowned sparrows, one northern shrike, two wheatears and a few redpolls were noted there.
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 tschutschensisGmelin: 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, longspursand 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.
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 invictusGrinnell: 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.
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 Iwalked 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 × 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.
Passerculus sandwichensis anthinusBonaparte: Savannah sparrow.—Specimens, 19: Kaolak, 160°14'51", 69°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°00', 69°35', 460 ft., 1, No. 31336, juv. male, August 22, 1952; Wahoo Lake, 146°58', 69°08', 2350 ft., 1, No. 31337, ad. male, July 5, 1952; Porcupine Lake, 146°29'50", 68°51'57", 3140 ft., 1, No. 31339, ad. female, July 13, 1952; Driftwood, Utukok River, 161°12'10", 68°53'47", 1200 ft., 1 (skin) No. 31338, male and 1, No. 31335, ad. female, August 29, 1952; Chandler Lake, 152°45', 68°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 onecreek 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 ochraceaBrewster: Tree sparrow.—Specimens, 10: Gavia Lake, N White Hills, 150°00', 69°35', 460 ft., 1, No. 31340, juv. male, August 22, 1952; 9⁄10 mi. N and 9⁄10 mi. W Umiat, 152°10'58", 69°22'53", 380 ft., 1, No. 31347, ad. female, July 1, 1952; Umiat, 152°09'30", 69°22'08", 352 ft., 1, No. 31341, ad. male, June 26, 1952; Wahoo Lake, 146°58', 69°08', 2350 ft., Nos. 31342-31343, ad. males, July 6, 8, 1952; Driftwood, Utukok River, 161°12'10", 68°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°45', 68°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 supportingLedum,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°10'02", 68°20'30", 2920 ft., 1, No. 31348, juv. female, August 3, 1952; Driftwood, Utukok, 161°12'10", 68°53'47", 1200 ft., 1 (skin) No. 31349, ad. male, August 29, 1952; Chandler Lake, 152°45', 68°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.
Zonotrichia atricapilla(Gmelin): Golden-crowned sparrow.—Specimen, 1: Chandler Lake, 152°45', 68°12', 2900 ft., No. 30787, ad. male, August 19, 1951.
Passerella iliaca zaboriaOberholser: Fox sparrow.—Specimen, 1: Driftwood, Utukok River, 161°12'10", 68°53'47", 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 malewas 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 alascensisRidgway: Lapland longspur.—Specimens, 75: NE Teshekpuk Lake, 153°05'40", 70°39'40", 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, 155°48', 70°34', 10 ft., 13, Nos. 30849-30861 including 9 ad. males and 4 ad. females, July 6, 8, 10, 1951; Kaolak River, 159°47'40", 70°11'15", 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, 160°14'51", 69°56'00", 178 ft., 13, Nos. 30796-30808 including 4 ad. males, 4 juv. males, 5 juv. females, July 20-27, 1951; Gavia Lake, 150°00', 69°35', 460 ft., 1, No. 31351, female, August 22, 1952; Umiat, 152°09'30", 69°22'08", 352 ft., 1, No. 31352, female, June 26, 1952; Chandler Lake, 152°45', 68°12', 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-grass. Fecal pellets of the brown lemming were beneath the nest. The bulk of the nest was soiled grasses which insulated the bottom and sides of the nest from the damp soil. This supporting bulk was lined first with stems of new yellow grass, 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 grasses and feathers of cup, 16. In cross section successive layers of nest material from outside in were as follows: mosses; old, dry, brownish-gray grasses; new, fine, loosely arranged, yellow grasses; 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-grass 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 grasses and dry mosses were outward extensions from the cup.
The greater part of the third nest was stems of the grassDupontia 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 grasses 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 ofDupontia 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 ofRangifer. 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 grass 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 grass, 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 ½ 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.
The testes of adults gradually decrease in size from July to August; their average length was 7.7(4.0-12.0) mm in nine adult males shot in the period July 6-10 at Topagaruk but only 2.2(1.5-3.0) in six adult males shot in the period July 12-26, at Kaolak and Kaolak River. By August 1, at Teshekpuk Lake the testes of nine adult males averaged 1.4(1.0-1.5) in total length, which is only slightly larger than the average size of the testes 1.2(1.0-2.0) of nine juveniles shot in the period July 29-Aug. 2, at Teshekpuk Lake.
Calcarius pictus(Swainson): Smith's longspur.—Specimens, 2: Wahoo Lake, 146°58', 69°08', 2350 ft., No. 31353, ad. male, July 9 and No. 31354, ad. female, July 7, 1952.
On July 7, 1952, at Wahoo Lake, a single longspur was trapped in one of 200 traps set for small mammals. On July 9, a line of 120 traps set in a community of cotton-grass, other sedges, grasses and dwarf willow also yielded one longspur—an adult male 172 mm long that weighed 28 grams. Smith's longspurs were uncommon at Wahoo Lake from July 3 to July 11, and when seenwere associated with open tundra supporting cotton-grass, generally on flat areas adjacent to the lake. Singing from the air was heard on several occasions. On the alluvial outwash, between Lake Peters and Lake Schrader, two Smith's longspurs were recorded on July 24, 1952, and flocks of 11-16-18-20 were seen there in the damp meadows on August 13, 1952. Those seen on the latter date had moved into the area since July 23, when we first arrived.
Plectrophenax nivalis nivalis(Linnaeus): Snow bunting.—Specimens, 6: Topagaruk, 155°48', 70°34', 10 ft., 5, Nos. 30862-30866 including 4 ad. males and 1 ad. female, July 6, 7, 9, 10, 1951; Mount Mary, S end Lake Peters, 145°10'02", 69°20'30", 2920 ft., 1, No. 31355, August 1, 1952.
Robert McKinley reported to us that snow buntings were at Barrow Village at least as early as April 20, 1952, when snow covered most of the ground. On June 14, 1952, at Birnirk mounds when snow still covered most of the ground, snow buntings were already established on territories.
At Point Barrow (June 21, 1952), the most northerly extension of land on the Arctic Slope of northern Alaska, five pairs of snow bunting were nesting in abandoned subterranean Eskimo houses. The houses were in different stages of deterioration from one almost usable by man to one that was no more than a flattened mound. Sides of some houses were exposed by the sea cliff that was advancing inland. Logs and skulls of baleen whales had been set on end for walls, and mandibles and ribs of whales had been used as rafters. This framework had been covered with tundra sod. Most of the nests were between the roof support and the upper ends of the whale skulls. Each nest contained five fresh eggs and was completely protected from rain, sun and wind. One nest weighed 24 grams and measured (in millimeters) 155 wide, 68 high, 38 in depth of cup, 70 in width of cup, and was in the brain cavity of the cranium. Another nest on top of a skull in the interior room, weighed 24 grams. This nest was built upon material of a nest of the previous year. The old material weighed four grams and the new inner mass weighed 20 grams. The new nest consisted of successive layers of new yellow grass stems and feathers. The lining of the cup had feathers in the 20 mm-thick layer of fine hairlike plant fibers. The feathers were from birds larger than the bunting. The nest was well insulated in comparison with those of the Lapland longspur, but like most of those had the cup offset toward the inner side of the nest, and more nest material of large size outward toward the entrance,thanelsewhere. In the same area, especially in grass on and around low mounds, there were approximately 50 brown lemmings (18 lemming nests examined), many of which used the mounds inhabited by the bunting. On August 26, in the same area at Point Barrow, we noted 28 birds feeding and resting but on September 11 found none there.
A nest of five young (July 4, 1951) at a place 1⁄5 mile south of the Arctic Research Laboratory was under an overhanging ledge of an unused burrow of a brown lemming. The burrow had been excavated by lemmings on a mound of earth thrown up by a bulldozer. An adult female snow bunting was carrying insects to the nest and fecal pellets away from it. Another nest of five young (July 4) was in a fifty gallon oil drum. An adult female gained entrance to the nest through a small hole on the side of the container, the only hole present. Other nests on this date were examined that contained both eggs and young, or eggs, or young. Most of these nests were in holes in the ground or under the protection of overhanging ledges of earth. On July 4, snowbuntings were in their black and white plumage, but on July 27, were in brown-white plumage.
At Topagaruk (July 5, 1951) a nest containing young birds fully feathered was noted five feet above the ground in a horizontal pipe six inches in diameter. One dead bird, two to three days old, was in the water and mud at the base of the stack of pipes. Other young birds from other family groups had short tails and were capable of feeble flight. Adults were seen only in the immediate vicinity of the camp.
The average weight of four adult males shot in the period July 6-10, 1951, was 36 grams. The average length of their testes was 9.2(7.0-11.0) mm.
At Kaolak (July 21-27, 1951) we did not see the snow bunting. The camp, however, was built the previous winter and was inhabited (July 10) for the first time in summer. The birds were at Topagaruk, our collecting station next nearest to the eastward in the same general type of environment and we assumed that eventually the birds would become established at Kaolak.
A juvenal female shot on August 1, 1952, at Mount Mary was 183 mm long and weighed 34 grams.
Transmitted November 14, 1957.