Birds Found on the Arctic Slope of Northern Alaska Part 7

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 a brown 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, 16115'30", 6854'50", 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 sh.o.r.e, 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 thala.s.sina lepida+ Mearns: 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 princ.i.p.alis+ Ridgway: Common raven.--Specimen, 1: Umiat, 15208', 6922', 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 hara.s.sed 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 circ.u.mnavigated the sh.o.r.e 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.

+t.u.r.dus migratorius migratorius+ Linnaeus: 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 s.p.a.ced 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, 14658', 6908', 2350 ft., 1, No.

31321, ad. female, July 11, 1952; Chandler Lake, 15245', 6812', 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 14510'02", 6920'30", 2920 ft., 1, No.

31322, juv. female, August 1, 1952; Chandler Lake, 15245', 6812', 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, 15000', 6935', 460 ft., 2, Nos. 31323 and 31328, males August 22, 23, 1952; 9/10 mi. W and 9/10 mi. N Umiat, 15210'58", 6922'53", 380 ft., 1, No. 31324, ad. female, June 30, 1952; Driftwood, Utukok River, 16112'10", 6853'47", 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, 16014'51", 6956'00", 178 ft., 1, No. 30757, ad. female, July 27, 1951; Umiat, 15209'30", 6722'08", 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 coa.r.s.e stems of gra.s.ses 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 gra.s.ses 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, 14510'02", 6920'30", 2920 ft., 1, No. 31330, juv. female, August 3, 1952; Wahoo Lake, 14658', 6908', 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 sh.o.r.e. 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 sh.o.r.e 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 sc.r.a.ps 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, 15548', 7034', 10 ft., 1, No. 30767, ad. male, July 9, 1951; Kaolak River, 15947'40", 7011'15", 30 ft., 5, Nos.

30762-30766 including 4 ad. males and 1 ad. male (?), July 12, 14, 16-18, 1951; Kaolak, 16014'51", 6956'00", 178 ft., 4, Nos. 30758-30761 including 1 ad. male, 2 ad. females and 1 ad. of unknown s.e.x, July 21, 23, 1951; Umiat, 15209'30", 6922'08", 352 ft., 1, No. 31333, ad.

female, June 26, 1952; Wahoo Lake, 14658', 6908', 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-gra.s.s, 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.