PLATE 9Pl_9 Fig_1_2Fig. 1.A male yellow-billed loon setting on eggs in nest at Wahoo Lake on July 9, 1952.Fig. 2.Nest and eggs shown in figure 1, July 9, 1952. Incubation had just begun.Pl_9 Fig_3_4Fig. 3.Arctic loon (upper) and red-throated loon (lower) from Teshekpuk Lake, August 1, 1951.Fig. 4.Nest and eggs of white-fronted goose at Umiat, July 1, 1952. Incubation three fourths completed.Pl_9 Fig_5_6Fig. 5.Adult male surf scoters, July 16, 1952, at Porcupine Lake. Scoters are uncommon on the Arctic Slope.Fig. 6.Arctic tern shot at Teshekpuk Lake on August 1, 1951. A common breeding bird in northern Alaska.
PLATE 9
PLATE 10Pl_10 Fig_1_2Fig. 1.Shore of Arctic Ocean at Point Barrow, June 19, 1952. Many birds already were nesting on the tundra.Fig. 2.Tundra and oriented lakes 80 mi. S Point Barrow, August 28, 1952, are breeding places for water birds.Pl_10 Fig_3_4Fig. 3.Luxuriant vegetation used by breeding birds in intermontane valley at Porcupine Lake, July 18, 1952.Fig. 4.Willow-lined creek at Chandler Lake, August 25, 1951. Willows and alders offer nesting sites for birds.Pl_10 Fig_5_6Fig. 5.NW face of Mt. Chamberlin, 9131 ft.; terrain inhospitable to most breeding birds. August 5, 1952.Fig. 6.Destruction of bird communities by caribou trampling south of Lake Peters. August 8, 1952.
PLATE 10
Somateria spectabilis(Linnaeus): King eider.—Specimen 1: Point Barrow, 156°27'25", 71°23'11", 3 ft., No. 31306, ad. male, August 25, 1952.
Robert McKinley told us that in the last week of April of 1952, eiders (king?) arrived in the vicinity of the Arctic Research Laboratory in large numbers and continued to pass to the east for the next three weeks. King eiders were observed at Point Barrow on July 3, 1951.
Ninety king eiders and 30 Pacific eiders were resting on the shore of the Arctic Ocean at Point Barrow on August 25, 1952. The following day 200 king eiders were in the same area. A male, shot there, measured 560 millimeters in total length. The muscles were only a third the size of those on a normal bird. Another eider found dead also was emaciated and may have died from gun shot wounds inflicted by the guns of the Eskimos. For every bird killed by Eskimos, several are injured; many of these die along the migration route. On July 28, king eiders were flying northwest along the shore of Elson Lagoon, thence across the Point Barrow Peninsula at Birnirk, and thence southwest along the coast of the Arctic Ocean. This day was foggy and wind was from the east. On clear days and especially when wind blows from the northwest, king eiders cross the peninsula a fifth of a mile or so nearer Point Barrow, which is the most northern extension of the Peninsula. More eiders moved by on clear days than on cloudy or foggy days. In one hour, ten flocks, averaging 400 birds each, passed overhead at Birnirk (July 28); three days earlier flocks of from 50 to 300 passed approximately every 20 minutes. Eskimos on this date were shooting into these flocks of eider and bagging them in excess of the winter needs of the hunters. One Eskimo had 40 king eiders undressed and hanging on a drying rod at his home at Barrow Village (Sept. 2, 1952).
On July 29, 1951, we flew from Point Barrow to Teshekpuk Lake and observed (2:00-3:00 P.M.) only two small flocks of king eiders. On August 1, 1951, at Barrier Lake, three large flocks were flying west beyond the north end of the lake. This was the first day since July 29, on which we had seen such large flocks so far inland.
On September 11, 1952, eight king eiders were resting on the shore of the Arctic Ocean at Point Barrow.
Lampronetta fischeri(Brandt): Spectacled eider.—On July 28, 1951, at Birnirk, several flocks were flying along the Arctic Ocean.
Melanitta perspicillata(Linnaeus): Surf scoter.—Specimens, 2: Porcupine Lake, 146°29'50", 68°51'57", 3140 ft., No. 31307 and 31308, ad. males, July 15, 1952.
Two males shot at Porcupine Lake on July 15, 1952, measured as follows: Total length, 489 mm, 495 mm; length of testis, 9 mm, 11 mm; weight, 1134 grams, 998 grams. These birds were frequently seen together along the south side of the lake. At Lake Schrader (July 27, 1952), 15 scoters, in loose groups of two to six, fed in the southwest corner of the lake.
Buteo lagopus s. johannis(Gmelin): Rough-legged hawk.—On July 2, 1952, a nest of three young approximately six days old was examined ½ mile southeast of Umiat Mountain. The young were being fed small mammals. Another nest containing three addled eggs was also examined near Umiat. Many infertile and addled eggs of several kinds of birds were noted on the Arctic Slope.
Aquila chrysaëtos canadensis(Linnaeus): Golden eagle.—Marvin Mangus told us that he had seen young in nests at the following localities: Kurupa River, 155°11', 68°38', on July 1, 1946; 10 miles south of Driftwood in latter part of June, 1950; 11 miles NW from the north end of Chandler Lake, 152°56', 68°25' on June 10, 1951; Awuna River, 157°03', 69°12' July 4, 1952. Single adult birds were seen by us at Gavia Lake (Aug. 21, 1952) and at Driftwood (Aug. 31, 1952).
Atanak and his companions from Wainwright saw 12 eagles while hunting (July 16-18, 1951) from the junction of the Avalik and Ketik rivers to a point seven miles up the Kaolak River, but no eagles were seen between the junction of the above rivers and Wainwright.
Golden eagles daily hunted prey along ridges where Arctic ground squirrels (Spermophilus undulatus) were abundant, for example, at Wahoo Lake (July 3-12, 1952) and at Porcupine Lake (July 13-18, 1952). This species of eagle hunted also in areas where marmots (Marmota caligata) were abundant, as on the slopes adjoining Lake Peters. There (August 6, 1952) three eagles soaring at 3800 feet elevation south of the mouth of Chamberlin Canyon elicited from each of four marmots three warning calls. Thereafter the marmots remained silent until the eagles had left the area. One eagle that consistently hunted (July 17, 1952) on the lower slope of Mount Annette along the Canning River was three times harassed by two ravens.
At the south end of Lake Peters (July 31, 1952), a pair of adult eagles soared along the slopes of Mount Mary approximately 1000 feet above the lake. Twenty minutes later these birds flew by camp at the base of the mountain. On August 2, at 8:00 P.M., two birds, one a large dark adult and one a bird of the year (?) dropped with partly closed wings from high on the east side of the lake to an undisturbed meadow on the west side. After circling the meadow once, the two birds spiralled upward to approximately 4500 feet elevation in one steep canyon, leveled off and after gaining the head of the next canyon, plummetted down to the base of the mountain some 1500 feet below. The high-speed flight continued across the ridge to the mouth of the next canyon where they circled twice and then soared upward to repeat the act. The objective probably was to surprise and prey upon small game at the mouths of each canyon. On August 13, the eagles were still in the area at the south end of Lake Peters in spite of an abrupt seasonal change; snow and rain increased and the temperature dropped.
On August 15, a Dall sheep (Ovis dalli) crossed the canyon from Mount Mary to the mouth of Chamberlin Canyon. As the sheep reached the east side of the canyon an eagle flew across the canyon and alighted approximately 150 feet from the sheep. A large group of small birds immediately harassed the eagle.
Two eagles fed on a dead caribou on a delta on the east side of Lake Peters. Eagles were noted every day at Lake Peters from July 31 to August 15 inclusive.
Falco rusticolus obsoletusGmelin: Gyrfalcon.—At the southwest corner of Barrier Lake on July 29, 1951, a gyrfalcon sat on a bank 10 feet above the water level. A dead Arctic tern was on the beach only 90 feet away and visible to the gyrfalcon. When approached to within 250 feet, the gyrfalcon, rather than flying north over the lake and lowlands, flew south across theupland tundra. On August 3, on the edge of the upland tundra approximately 3½ miles farther east a gyrfalcon ate a Sabine's gull—a bird of the year. Its feathers had been plucked and only the stomach and intestines remained. The gyrfalcon left the feeding area when approached to within 450 feet and, as did the other gyrfalcon, flew south over the upland tundra rather than over the lowlands of inundated sedges. On July 4, one gyrfalcon sat on a promontory at the south end of Barrier Lake. This bird flew south.
At Umiat (Sept. 1-5, 1951) a gyrfalcon each day hunted the same areas of marsh in the river valley where tundra voles (Microtus oeconomus) were numerous and along the side of the valley where ground squirrels were common. On several occasions, this bird hovered 30 feet up and inspected us. This confidence was in contrast to that of the gyrfalcons at Teshekpuk Lake; they evaded us by leaving the ground several hundred feet away and flying out of sight.
Westley Redhead told us that a gyrfalcon was at Umiat as early as the latter part of May, 1952. We saw them there on September 1 and 2 in the same year. Gyrfalcons feed on ptarmigan in the river valley and on ground squirrels and small birds on the uplands by striking their prey on the ground. These falcons fly like prairie falcons and are of the same nervous disposition.
Falco peregrinus anatumBonaparte: Peregrine falcon.—A nest was found on June 27, 1952, on the south slope of Mount Umiat approximately 225 feet above the Colville River, 40 feet from the top of the cliff and 30 feet west of the top of the mountain. The nest, three feet in depth at the front, two feet in depth at the rear, and 2½ feet wide was made of sticks of many years accumulation and was placed on a pinnacled platform 12 feet high. The nest contained one infertile egg and two others in which embryos were approximately one third developed. The female remained near us the one hour that we were in the area. She flew back and forth in front of the nest terminating each flight in an upswing arc and occasionally rested on top of the ridge to the west. She dove at us but never came closer than 10 feet before swerving upward. The male was not present. In a canyon 1⁄5 mile northeast of the nest two dead ptarmigan were at the edge of a willow cotton-grass swale. A nest of a peregrine falcon used three years before was 1 7⁄10 miles east and 1 7⁄10 miles north of Umiat. The nest was eight feet up on the face of a cliff 13 feet in height and easily accessible to either fox or wolf. Along the Colville River the falcon feeds on small shore-birds and other small birds.
Falco columbarius bendireiSwann: Pigeon hawk.—On a benchland between Chandler Lake and mountains to the west on August 12, 1952, a pigeon hawk hunted back and forth across a meadow, fearlessly inspecting us from distances of 20 to 30 feet as it searched the meadow for food. This falcon systematically searched those areas where longspurs were known by us to be most frequently found. Twice it flushed Lapland longspurs and darted at them but without success. Of the four pigeon hawks at Chandler Lake three were moving south and one was moving north down the canyon. We saw this species at Chandler Lake also on August 17, 20 and 21, 1951, and at Driftwood on August 27, 1952.
Approximately 1⁄10 mile north of James Robert Lake (Aug. 8, 1952) a pigeon hawk was harassing five ravens that were feeding on a dead caribou. This falcon flew back and forth above the ravens.
Falco sparverius sparveriusLinnaeus: Sparrow hawk.—One seen in the summer of 1952 at the mouth of the Colville River by Clifford Fiscus.
LagopuslagopusalascensisSwarth: Willow ptarmigan.—Specimens, 5: Topagaruk, 155°48', 70°34', 10 ft., No. 50587, ad. female, July 8, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., No. 30586, ad. female, July 14, 1951 and No. 30585, ad. male, July 15, 1951; Kaolak, 160°14'51", 69°56'00", 178 ft., No. 30583, ad. male and No. 30584, ad. female, July 23, 1951.
Wherever ptarmigan were found, there was evidence that they were resident in the area throughout the year. At Topagaruk, informants said the ptarmigan were not so numerous in the summer (1949-1950) as in the winter. The apparent relative abundance of these birds in these two seasons could conceivably result from the birds being less conspicuous and more seclusive in the summer because of nesting activities. In summer these birds are protectively colored; at times a female only a few feet away is hardly distinguishable from the tundra. We observed only two adults and three juveniles in the area (July 5-10, 1952) although we saw considerable sign associated with the winter season. Sand dunes derived from material along the edge of the river formed a conspicuous feature of the landscape. These dunes, 20 to 30 feet high, were deeply cut by winds from the west-northwest. Ptarmigan tracks and sign were on all sides of the dunes, but the lee side was more commonly used than any other because of the protection from winds and the presence there of large willows and other plants. At Barrier Lake (July 29-Aug. 4, 1952) we noted numerous droppings of ptarmigan on the uplands between Barrier Lake and Teshekpuk Lake but we did not see any birds there. The sign could have been deposited either in the winter or in a previous season.
There are perhaps local migrations of ptarmigan. Harmon Helmericks, for instance, told us that in either April or May of 1946 he saw a ptarmigan on the ice of the Arctic Ocean 10 miles north of Pingok Island. At Gavia Lake (August 22) we observed a local shift of a group of ptarmigan. One day there were 19 birds in an area; the following day only seven birds were counted. On the third day the full complement of 19 birds were again in the area.
Ptarmigan are generally distributed on the Arctic Slope. On an airflight (July 3, 1952) from the mouth of the Canning River Canyon to Umiat the number of ptarmigan increased as we approached the drainage system of the Colville River. On this date, when these birds are nesting, the willows were just starting to grow new leaves and other vegetation of the tundra still was undeveloped. On August 16, along this same route, when young ptarmigan were nearly as large as adults, willows and alders were in full leaf and dominated the vegetation along water courses; the tundra was mature in appearance with considerably more green and yellow color in the landscape. The water in rivers and especially ponds was clear but brownish.
In the river valley at Umiat (June 28, 1952) a nest of seven eggs (½ incubated) was on an elevated mound supporting dwarf willow and birch averaging 1½ feet high. The nest was merely a concavity in sphagnum moss depressed by the weight of the bird. The female refused to leave the nest until bodily removed.
Dusting pits are actively used in the period of nesting. At Umiat (June 25, 1952), ptarmigan were using seven dusting pits on the shoulder of the airstrip. On the upland at Kaolak River (July 12, 1951), ptarmigan developed dusting pits on abandoned diggings made by Arctic ground squirrels. Mostof the mounds were covered with mosses and lichens and other vegetation.
Individuals and family groups were noted at various localities on the Arctic Slope. At Kaolak River (July 15, 1951) on a four hour field trip, we saw three pairs of birds and their families of four to six young. One flock of eight adults was seen from the air at the mouth of the Canning River Canyon on July 22, 1952. At Kaolak (July 21-27, 1951) they were common; ten pairs of adults (males and female) were within a one mile radius of our camp. The families of young were in groups of 1-3-4-6-8-9-10-11-14. One group consisted of one male, two females and four young. While on a flight from Kaolak to Point Barrow (July 27, 1951) we observed several ptarmigan on the tundra. At Gavia Lake (Aug. 21, 1951) ptarmigan were in groups or singles as follows: two adult singles, group of seven young and one adult, group of four young and one adult and one group of five young and two adults. According to Harmon Helmericks, ptarmigan were high in population numbers on the Arctic Slope in 1952.
Ptarmigan were associated with most of the communities of the Arctic Slope but were noted more commonly in the following situations than elsewhere: At Kaolak (July 21-27) and at Kaolak River (July 21, 1951) in damp swales of grasses and sedges in poorly drained areas where soils were damp to supersaturated and among the dwarf willows bordering lakes and creeks; at Gavia Lake (Aug. 21, 1952) among willows and alders (4 feet high) along the edges of ox-bow lakes. On windy, cold days the ptarmigan were mainly on south exposures among grasses and sedges along lakes and on windless days were on flat tundra of polygons but near dwarf shrubs. On June 27, 1⁄5 mile northwest of Mount Umiat, two dead willow ptarmigan were noted along the edge of a willow and cotton-grass swale. The feathers had been plucked by a raptor (?) preparatory to his eating the ptarmigan.
Variations in parental display are indicated by the following observations. At Kaolak River (July 12) we flushed a family of adults and young. The male called as he left the ground and then he flew across the lake. The female, when flushed at a distance of 10 feet from the observer, feigned injury for 12 seconds before following the male. Seven young, averaging seven inches in length, left the ground and flew in the opposite direction from that taken by the male and female, to swales of cotton-grass and willow on the hillside. Another adult male and female were at the side of a young bird held in a trap. The female first left the young and fluttered over the vegetation for 40 feet and the male flew out of the area. Four other young were flushed 30 feet from the trap that held the captured ptarmigan. On July 17, while walking through a wet meadow of grasses and sedges, we flushed a male, female and four young (150 mm in length). The female crawled through vegetation for 30 feet and then rose into the air. At this same moment four young left the ground. The female, while in the air, reversed her course and joined the young, which had alighted some 300 feet away. On July 23, 1951, a family of two adults and 10 young were flushed. The male returned and chattered until the female arrived. The male then retreated 15 feet beyond the observer and remained close to the female while she tried to distract our attention from the young by pretending to have an injured wing. In a group of one male, two females and four young at Kaolak (July 21, 1951) the male and young left after the females fluttered along the ground for 30 feet.
Adults and young do not always escape by flying; on July 20, 1951, wewere enroute from the landing lake to Kaolak when an adult male and female with eight young ran 200 feet down established tracks of a weasel vehicle. It was necessary to reduce the speed of the vehicle to spare the young. A male at Kaolak River (July 12, 1951) ran 150 feet under the protection of willows to an opening where it remained until flushed. It flew 50 feet, then alighted in another patch of willows.
At Gavia Lake at 11:30 P.M. a ptarmigan called because one of its young was caught in a trap at the edge of a lake. The juvenal bird, unharmed, was released and inadvertently was dropped into the water where it floated but finally, becoming confused, got its head and bill under water and drowned.
On July 15, 1951, at 11:00 P.M. at Kaolak River, we heard a ptarmigan joining an Arctic tern and several sandpipers in protest to a passing red fox.
For three consecutive days a family (male, female and young) at Topagaruk was within 50 feet of one place.
The following measurements of juveniles show increase in size as correlated with advance of season: Topagaruk (July 6, 1951) two juveniles averaging 110 mm in length weighed 21 grams; Kaolak River (July 17, 1951) young of one family averaged 178 mm in length and another individual was 162 mm in length and weighed 38 grams; Kaolak (July 21-27, 1951) individuals in a group of ninewereapproximately ¾ the size of parents and other groups were 1⁄3 to 2⁄3 the size of adults.
In a brooding female 600 mm long from Topagaruk (July 8, 1951) the largest ovum was two mm in diameter. Females, averaging 650 mm long from Kaolak (July 23, 1951) had ovaries smaller than the normal size for breeding birds; the largest ovum was only ½ mm in diameter. Males of the same size had testes six mm in length.
Lagopus mutus nelsoniStejneger: Rock ptarmigan.—Specimen, 1: Wahoo Lake, 146°58', 69°08', 2350 ft., No. 31309, ad. male, July 11, 1952.
At Wahoo Lake (July 6, 1952), young of one brood for the first time since July 3, called continually throughout the day and part of the night. Members of three other broods, only a few days old, did not call in the same persistent way.
Along a deeply eroded western outlet of Wahoo Lake there was an unusual concentration of fecal droppings, spaced approximately every two or three feet. This sheltered place offered protection from cold and winds of winter. Adults were associated with willows along creeks and on adjoining sidehills where willows gave way to open tundra. One family left the willows and the female flew back and forth behind the young as she herded them. The largest adult male seen here was shot on July 11. It was 365 mm in total length, weighed 460 grams, and had testes 7 mm long.
At the south end of Lake Peters (August 14, 1952), a female and her two young, along with other kinds of birds, were attracted to our tent during snowstorms. On July 18 at Wahoo Lake, a juvenile was 200 mm in total length and weighed 100 grams whereas on August 9 at Lake Peters a juvenal male was 261 mm in length and 226 grams in weight.
Rock ptarmigan were uncommon at Chandler Lake. We observed the first bird in the area on August 22, 1952, 13 days after our arrival. Droppings of the birds were only occasionally seen there.
Grus canadensis canadensis(Linnaeus): Sandhill crane.—In 1952, two sandhill cranes called in the river valley north of Umiat on June 24. On June 26, 27 and 28, a single bird was seen there. It remained in the general area and called occasionally. Sandhill cranes are only occasionally seen along the Colville River. A pair of these cranes was seen near Meade River on August 16, 1952, by Marvin Mangus.
Charadrius semipalmatusBonaparte: Semipalmated plover.—A pair of semipalmated plovers in company with their young along the edge of Seabee Creek at Umiat were seen on four consecutive days, July 18-21, 1952. A male and female measured, respectively, total length, 180 and 175 mm; weight, 50 and 55 grams.
Pluvialis dominica dominica(Müller): American golden plover.—Specimens, 10: Kaolak River, 159°47'40", 70°11'15", 30 ft., Nos. 30592-30596 including 2 ad. males and 3 ad. females, July 12, 14, 18, 1951; Kaolak, 160°14'51", 69°56'00", 178 ft., Nos. 30588-30591 including 3 ad. males and 1 ad. female, July 21-23, 1951; Umiat, 152°09'30", 69°22'08", 352 ft., No. 31312 of an adult of unknown sex, July 21, 1952.
On July 29, 1952, we noted a pair of golden plover 3⁄10 mile northwest of Umiat. At Kaolak River (July 12, 1951) golden plovers could be approached to within 80 feet and were less wary than black-bellied plovers at Topagaruk. When one bird was shot the mate remained near the dead bird.
At Kaolak (July 21-27) four families of plovers were within a radius of ½ mile of camp. Each of these families remained apart from the others whereas at Kaolak River the physiography of the terrain permitted the pairs to form social groups of several families of adults and young. At Kaolak males flew to meet any intruder and attempted to decoy the intruder while the female remained with the young, but at Kaolak River an observer would approach to within 80 feet of a nest or young whereupon the female feigned injury by fluttering her wings and moving on her belly in an effort to decoy the intruder, the male meanwhile remaining within 40 feet of the observer. At Kaolak River, birds stayed in the nesting or feeding territory until approached to within a hundred or so feet. Young birds (July 21) were approximately ¾ the size of adults. The largest bird collected at Umiat (July 21) weighed 155 grams and measured 26 mm in length. Five males, shot on July 12-23 at Kaolak and Kaolak River, averaged 144(130-150) grams. The testes were 4.4(4.0-5.0) mm long. Four females collected at the same time from this area, averaged 144(140-150) grams. The ovaries were 7.7(5.0-10.0) mm long and the largest ovum was 2.0 mm in diameter.
The call of the adult was two distinct curlewlike notes that differed from the slurred call of the black-bellied plover. Golden plovers can be decoyed by imitating their call.
At Barrier Lake, in a two hour field trip (July 29, 1951) we observed a flock of eight birds and one single; golden plovers were active there all day and night.
At Kaolak River (July 12, 1951) six pairs and their young were on open and exposed surfaces.
Squatarola squatarola(Linnaeus): Black-bellied plover.—Specimens, 2: Topagaruk, 155°48', 70°34', 10 ft., No. 30597, ad. male and No. 30598, ad. female, July 9, 1951.
At Barrier Lake, on July 4, 1951, two adults were feeding together in a bare lane which had been made and maintained by caribou. At Topagaruk on July 7, 1951, these plovers made up less than one per cent of the avian population. They were frequently on polygons having raised centers. Non-nesting or non-breeding birds were on bare wind-blown knolls adjacent to the river. On these knolls they fed with semipalmated sandpipers, pectoral sandpipers, and ruddy turnstones. On July 9, we visited polygons having raised centers and young called continually but we could not locate them. The call resembles that of the long-billed curlew but is more plaintive. Ordinarily these plovers kept beyond the range of our collecting gun but when one of the pair was killed the other, especially the male, remained near the dead bird until the collector approached to within 20 feet. Of a pair shot on this date the male weighed 207 grams and had testes 7 mm long; the female weighed 232 grams and the largest ovum was 3 mm in diameter. The species was recorded at Topagaruk from July 4 to 10, 1951, inclusive.
At the west edge of Smith Bay on July 29, 1951, while flying from Point Barrow to Teshekpuk Lake, we observed one group of approximately 40 black-bellied plovers flying along the edge of the lake. At Gavia Lake on August 21, 1952, two young were just able to fly but preferred to run on the ground.
Arenaria interpres interpres(Linnaeus): Ruddy turnstone.—Specimens, 5:TopagarukRiver, 155°48', 70°34', 10 ft., No. 30599-30603 including 4 ad. males and 1 ad. female, July 6, 8, 9, 1951.
Four males shot at Topagaruk July 6-9, 1951, weighed 105(96-116) grams. The testes were 2.8(2.5-3.0) mm long. A female from the above locality, shot on July 6, weighed 125 grams. These birds constituted less than one per cent of the avian population at Topagaruk and were more frequently on polygons with high centers and on high windswept knolls than elsewhere and were in company with black-bellied plovers, pectoral sandpipers and semipalmated sandpipers. One bird was observed on July 3, 1951, at ¼ mile southeast of the Arctic Research Laboratory at Point Barrow.
Capella gallinago delicata(Ord): Common snipe.—At Umiat (June 25, 1952) at 11:00 P.M. a female was sitting and calling from the top of a leafless alder tree some 210 feet from any favorable nesting grounds. A male was performing a nuptial flight overhead. Three other birds in the air were heard.
On July 13, 1952, at Porcupine Lake, we flushed a female from a damp meadow of grasses and sedges at the west end of the lake. She pretended to have a crippled wing. Seventy-five feet from this bird an abandoned nest and fragments of egg shells rested on top of a mound six inches from water and 10 feet from the west end of the lake. Two dwarf willows on top of the mound partly concealed the nest. Two days later (July 15), juveniles were caught in a line of traps set in this marsh. Four tree sparrows, one savannah sparrow and three species of small mammals also were taken from this marsh. At this time of year (July 15) all the terrain was free of snow and ice except that two patches of snow, one 8 × 12 feet and another 6 × 6 feet remained on the protected south shore of the lake and a few ice slivers remained in the deep crevasses on some mounds in the marsh. One bird was seen on August 13, 1952, in wet low polygons between Lake Schrader and Lake Peters.
Actitis macularia(Linnaeus): Spotted sandpiper.—At the south end of Lake Peters on August 15, 1952, after snow covered the valley, a juvenal spotted sandpiper remained along the shore line nearer camp than it had been for four previous days.
Heteroscelus incanum(Gmelin): Wandering tattler.—On each of the days July 3-11, 1952, a wandering tattler was flushed from dense high willows along an 8-foot-deep creek channel that carried water from the west end of Wahoo Lake into the East Fork of the Ivashak River. The bird was at home in the willows and had considerable dexterity in perching on limbs. Although the bird favored one section of the creek, an exhaustive search for young, eggs or nest was fruitless. A loud call was given by this bird when disturbed.
Erolia melanotos(Vieillot): Pectoral sandpiper.—Specimens, 52: Barrier Lake, NE Teshekpuk Lake, 153°05'40", 70°39'40", 8 ft., 33, Nos. 30616-30636, 30638-30648, 30754 including 5 ad. males, 12 juv. males, 1 ad. female and 15 juv. females, July 30, Aug. 1-3, 1951; Topagaruk, 155°48', 70°34', 7, Nos. 30649-30655, including 3 ad. males and 4 ad. females, July 6, 8, 9, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 6, Nos. 30610-30615 of ad. females, July 12, 14, 15, 18, 1951; Kaolak, 160°14'51", 69°56'00", 178 ft., 6, Nos. 30604-30609 including 1 juv. male and 5 ad. females, July 20-23, 1951.
The earliest record of young (135 mm in length and 26 grams in weight) was at Kaolak River on July 14, 1951. On July 9, 1952, at Topagaruk the oviduct of an adult female, 86 grams in weight, contained an egg in a shell 200 mm in diameter. Her second largest ovum was 10 mm. Breeding males on this date had testes averaging 11 mm in length. The average length of testis of 15 juveniles shot on August 3, 1951, at Teshekpuk Lake was 1.9 (1.5-2.0) mm. The average weight of these juveniles was 60(50-81) grams. A comparison of male and female juveniles shows no significant differences. Nevertheless, adult males in both the breeding and post-breeding seasons are longer bodied and heavier than adult females.
In the period June 14-25, 1952, in the Point Barrow area, pectoral sandpipers were puffing their throats and cooing. On June 23, several birds were defending territories, and one half mile northeast of Barrow Village (June 23, 1952) we noted a male pectoral sandpiper that crouched low when a pomarine jaeger flew directly overhead. After the jaeger passed, the sandpiper assumed normal posture and continued feeding.
At Topagaruk (July 7, 1951) these birds represented less than one per cent of the avian population, were common on polygons having low centers, and frequently joined black-bellied plovers, ruddy turnstones, and semipalmated sandpipers to form discrete flocks.
On a four hour field trip at Kaolak River (July 15, 1951), the pectoral sandpipers (45 by actual count) were the most common of the sandpipers and were always calling overhead. The young on this date were not yet capable of flight and were being fed by adult females. One of the immatures bathed in water at the edge of the beach. On July 18, females were still attempting to decoy intruders by pretending to have broken wings. Eight adults with young were observed at Kaolak (June 21-27, 1951) but the species was not so aggressive as at Kaolak River, nor so numerous. The fewer birds may have been correlated with lack of sand dunes, river beaches and open areas.
A group of five pectoral sandpipers frequented the shore of Barrier Lake (July 29, 1951) but the group was not seen the following day. On August3, there was a sudden increase of pectoral sandpipers in the area; most of them were in flocks of six to 50. From one point along edge of the uplands, we shot 20 birds from several different flocks consisting mostly of juveniles. They seemed curious about our presence. When a bird was shot from the flock, the entire group circled back and forth over the dead or injured bird, sometimes only three or four feet above our heads. In the late evening of this same day, the number of pectoral sandpipers increased and although some were moving westward, most of them were moving eastward. On the following day they were still present in great numbers. The day before the arrival of these migrating birds, two adults (Aug. 2) acted as if they were still attending young. On July 30, we shot at a lone bird as it flew by and thereupon it climbed upward until nearly out of sight as they frequently did when chased by falcons.
At Lake Schrader (July 23, 1952) pectoral sandpipers were active 24 hours of the day.
On August 4, 1952, at the south end of Lake Peters, a group of eight pectoral sandpipers fed near camp. On August 5, one was shot and on the following day only seven were seen, suggesting that they were established in the area and were not migrants. They left on August 12.
At James Robert Lake (3600 feet elev., August 8, 1952), which is the most southern body of water in the canyon south of Lake Peters, several pectoral sandpipers were feeding along the edge of the lake and on the alluvium outwash below James Robert Glacier.
At Gavia Lake there was a decided trend in movement of groups of pectoral sandpipers. On August 22, 1952, groups of 2, 4, 6, 8, 8, 8, 16, 17, 18 flew by to the east. The day before there were only a few sandpipers and these were not especially on the move. Comparison between dates of active movements of sandpipers in 1951 and 1952 indicate that migration was considerably earlier in 1951 than in 1952.
Erolia bairdii(Coues): Baird's sandpiper.—Specimens, 5: Topagaruk, 155°48', 70°34', 10 ft., 4, Nos. 30657-30660 including 2 ad. males and 2 ad. females, July 7, 9, 10, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 1, No. 30656, ad. male, July 12, 1951.
On June 14, 1952, at Birnirk mounds, when snow still covered most of the ground, Baird's sandpipers were already established on territories. A nest of four eggs was examined ¼ mile southeast of the Arctic Research Laboratory on July 4. The female left the nest when the observer approached to within 20 feet and flew directly toward him and then dropped to the ground and pretended to have a broken wing. We pursued this bird for 50 feet before she took flight. The male, which flew at a much greater speed than the female, was nearby and soon joined her in flight. The female repelled her mate by chasing him, but the male persisted in accompanying her. If one or more males of this species (on one occasion as many as five) approached the territory of these nesting birds, the male would leave the female and chase the trespassers. On one occasion, after we left the nesting area, the female returned to the nest after approximately four minutes. Her approach to it was direct and without hesitation. After ½ hour we returned to the nest and the male was standing one foot away from the brooding female with his head resting on his wing. The male, followed by the female, left the nest and feigned injury. Shore-birds and water birds were more numerous on this date on thetundra and lakes nearer the Arctic Ocean (in the Point Barrow area) than in the direction of the Brooks Range.
At Topagaruk (July 5-10, 1952) adults of this species were the fourth most common bird, representing four per cent of the avian population. They were near lakes among polygons some of which had low centers whereas others had high centers. One bird had a nest and four eggs approximately 150 feet from an oil derrick, surrounded on all sides by the tracks of vehicles. This bird feigned injury at the nest notably more than did Baird's sandpipers that inhabited undisturbed tundra beyond. Three adult males, shot at Topagaruk (July 7-10, 1951), averaged 44(42-47) grams in weight and had testes averaging 3.5(3.0-4.5) mm long. Two females, collected in the same period and at the same place averaged 44 grams in weight. The largest ovum was one mm in diameter and the largest ovary three mm long.
Other occurrences were: Kaolak River, July 12-18, 1951 (four juveniles observed in one four hour field trip July 15); Lake Schrader, July 24-28, 1952; Point Barrow, July 27, 1951 (most common shore-bird at fresh-water ponds adjacent to the Arctic Ocean); 2 mi. S Wahoo Lake, on a high divide between the Ivashak and Sadlerochit rivers, July 8, 1952; Lake Schrader, July 23-31, 1952 (active at all hours); S end Lake Peters, August 1 and 2 but not seen there later.
Erolia alpina pacifica(Coues): Dunlin.—Specimens, 21: Barrier Lake, NE Teshekpuk Lake, 153°05'40", 70°39'40", 8 ft., 1, No. 30661, ad. male, Aug. 1, 1951; Topagaruk River, 155°48', 70°34', 10 ft., 20, Nos. 30662-30681, 12 ad. males and 8 ad. females, July 6-9, 1951.
Specimens shot at Topagaruk River (July 6-9, 1951) yielded weights of 57(53-64) grams for eleven adult males and 59(55-65) grams for six females. Testes were 3.5(2.0-5.0) mm long, the largest ova were 1.2 (.5-2.0) mm, and ovaries were 3.5(3.0-4.0) mm long. An adult female from Teshekpuk Lake (August 1, 1951) weighed 48 grams. Her largest ovum was one mm in diameter and the ovary was 3.5 mm long.
At Topagaruk we observed the species every day (July 5-10, 1951) and on July 7, located a nest and four eggs. Each of the seven times that the brooding female was approached she left the nest when we were approximately 80 feet away and she flew approximately 150 feet before alighting at which time she called. The call resembled that of the western grebe. The wary nature of this sandpiper was in contrast to that of the other smaller shore-birds; they left the nest only when almost stepped on. On July 9, the nest still held four eggs. Adults were the fifth most common bird and made up three per cent of the avian population. They frequented polygons having low centers adjacent to stabilized lakes. At Kaolak River (July 17, 1951) a dunlin was feeding and flying with a group of four semipalmated sandpipers. At Point Barrow (July 27, 1951) dunlins were congregating in small groups at ponds and small lakes adjacent to the Arctic Ocean. At Barrier Lake (July 29-Aug. 4, 1951) three dunlins fed in the area but did not show territorial behavior.
Limnodromus scolopaceus(Say): Long-billed dowitcher.—Specimens, 5: Topagaruk River, 155°48', 70°34', 10 ft., 2, Nos. 30687, ad. male, July 7, 1951 and 30688, ad. female, July 8, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 3, Nos. 30684-30686, 3 ad. males, July 12, 14, 1951.
Four males shot at Topagaruk and Kaolak River (July 7-14, 1951) averaged 104(100-110) grams in weight and had testes 4.7(4-6) mm long. Anadult female (July 8) from Topagaruk, weighed 130 grams and her ovary was 7.8 mm long. Her largest ovum was 3.5 mm in diameter. A juvenile from Kaolak River on July 14, 1951, was 150 mm in length and weighed 28 grams; thirteen days later, at Kaolak, a juvenile was shot that measured 265 mm in length and weighed 70 grams.
At Kaolak on July 15, 1951, we saw eight pairs of adults in a four hour field trip. Their young were approximately ½ grown. One pair of adults and four young, the size of parents, were seen daily in the same general area at Kaolak (July 21-27). One bird was observed on August 4, 1951, at Teshekpuk Lake.
Ereunetes pusillus(Linnaeus): Semipalmated sandpiper.—Specimens, 28: Barrier Lake, NE Teshekpuk Lake, 153°05'40", 70°39'40", 8 ft., 4, Nos. 30692-30695 including 3 juv. males and 1 juv. female, July 30, August 1, 3, 1951; Topagaruk River, 155°48', 70°34', 10 ft., 21, Nos. 30682, 30683, 30696-30714 including 12 ad. males and 9 ad. females, July 6-9, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 3, Nos. 30689-30691 including 2 ad. males and 1 ad. of unknown sex, July 12, 14, 15, 1951.
Eleven adult males and nine adult females shot at Topagaruk from July 5-10, 1951, weighed 29(22-30) and 28(25-31) grams, respectively. The greatest length of skulls of each of the above sexes averaged 39.2 mm. The shortest juvenile, having a skull measuring 35.9 mm long, was a male shot at Kaolak River on July 15, 1951. Juveniles shot at Teshekpuk Lake on August 1 and 3, 1951, averaged 25 grams in weight and 28.4 mm in greatest length of skull. Testes of adults decreased in size from an average of 4 mm on July 6, to an average of 2 mm on July 14. Testes of juveniles on August 3 averaged 1.3 mm in length. The ovaries of seven adults from Topagaruk, shot on July 8 and 9, averaged 2.4 mm in length and the average diameter of the largest ovum was 7⁄10 mm.
A nest of four eggs, first examined on July 5, 1951, ¼ mile southeast of the Arctic Research Laboratory, was abandoned on July 11.
At Topagaruk (July 7, 1951) we flushed several adult semipalmated sandpipers whose behavior suggested that they were nesting. Two days later one nest held newly hatched young. This species was third in abundance there, adults constituting 15 per cent of the avian population. They were numerous on polygons having low centers and on high windswept knolls in association with black-bellied plovers, ruddy turnstones and pectoral sandpipers. The call resembled that of the Hammond flycatcher and was accompanied by wing vibration.
At Topagaruk (July 9, 1951) a female semipalmated sandpiper fluttered off a nest, uttered a sharp cry, feigned injury by fluttering around the observer, became seemingly indifferent but refused to return to her nest, uttered sharp cries, came to within seven feet of the observer who was sitting within three feet of the nest and alternately chattered, ate several large dipterous insects from the ground and in approximately five minutes went back on the nest, within easy reach, although she still was not completely quiet. When the observer rose to leave she again fluttered off the nest and feigned injury (the bird was preserved as a specimen). The nest was concealed in a small depression surrounded on all sides by tufts of vegetation and contained four young, one of which had hatched no more than three hours before.
On a four field trip at Kaolak River (July 15, 1951) we counted 14 juveniles in large stands of willows among sand dunes. These juveniles were makingshort flights of from 15 to 40 feet. In contrast to the situation at Topagaruk (July 5-10), there were fewer semipalmated sandpipers than Baird's sandpipers at Kaolak River (July 12-18, 1951). July 16 was the first date on which family groups of sandpipers here ventured out on the exposed sand bars along the river for feeding. One juvenile was carried by wind over the river where it dropped into the water. When last seen the juvenile was being floated upstream by the wind. Next day in the same general area where winds had driven water on the sand, four semipalmated sandpipers were feeding with dunlin. These five birds kept together both on the ground and in flight.
At Point Barrow (July 27, 1951) semipalmated sandpipers were forming small groups and feeding on small lakes and ponds adjacent to the Arctic Ocean. At the south end of Lake Peters (Aug. 3, 1952) several semipalmated sandpipers were feeding in dry areas of alluvium trampled by caribou.
Limosa lapponica baueriNaumann: Bar-tailed godwit.—At Kaolak River on July 18, 1951, one godwit was in company with a pair of golden plovers on a bare slope of an old sand dune along the edge of the river. The godwit when approached flew 150 feet and alighted and when pursued again flew another 150 feet and then departed for a lake 1⁄5 mile away.
Phalaropus fulicarius(Linnaeus): Red phalarope.—Specimens, 11: Topagaruk River, 155°48', 70°34', 10 ft., 11, Nos. 30715-30725 including 10 ad. males and 1 ad. female, July 6-9, 1951.
At Topagaruk (July 5, 1951), we located a nest and four eggs on the edge of a small drainage channel on the tundra. The nest was among mosses and lichens, one foot from open water. The bird left the nest when the observer was only four feet distant but on a second approach one hour later, left when the observer was 20 feet away. In each instance the bird pretended to have an injured wing. On July 7, this nest held four eggs. On July 8, there were four young, hatched either the previous afternoon or night and the female left the nest when the observer was 30 feet away. Ten adult males, shot at Topagaruk (July 5-10, 1951), averaged 50(45-54) grams in weight. These birds had testes that averaged 6.5(2.5-9.0) mm long. The red phalarope on July 7 was the fifth most common bird in the area, making up two per cent of the avian population and was commonly seen on polygons having high centers.
At Kaolak River (July 12-18, 1952) red phalaropes were uncommon. On July 15, a female was noted but seemed not to have young or to be nesting. A juvenile from Kaolak (July 22, 1951) was 180 mm in length and weighed 31 grams. On September 6 and 7, we observed hundreds of these birds, mostly juveniles, feeding in the ocean two to three feet beyond beaches at Point Barrow. Small lakes and open water in marshes had been frozen over since September 5, but larger lakes still were open. Except for a few birds around edges of open bodies of water, the great bulk of red phalaropes was (Aug. 7, 1951) on the Arctic Ocean. On September 11, there was none at Point Barrow. Thomas Brower, a resident at Barrow Village, stated that he had never before seen this species congregate on the Arctic Ocean bordering the shore.
Lobipes lobatus(Linnaeus): Northern phalarope.—Specimens, 5: Topagaruk River, 155°48', 70°34', 10 ft., 2, Nos. 30729, ad. male, July 9, 1951, and 30730, ad. female, July 8, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 3, Nos. 30726-30728 including 2 ad. males and 1 ad. of unknown sex, July 14, 15, 1951.
In the period July 8-15, 1951, four adult males at Topagaruk and Kaolak River averaged 31(28-33) grams in weight. Their testesaveraged2.3(2-3) mm long. A female (July 8) weighed 37 grams. Her largest ovum was 2 mm in diameter. A juvenile from Kaolak River (July 16) was 176 mm long and weighed 35 grams. Young northern phalaropes at Kaolak River (July 12-18, 1951) were more numerous than at Topagaruk (July 4-10, 1951) and were almost the size of adults. On July 15, on a four hour field trip, we counted 24 individuals including adults and juveniles. On this date the juveniles were almost ready for flight. At Kaolak (July 22, 1951) a young bird 212 millimeters in length was flying and feeding alone. In our seven day stay at Teshekpuk Lake only one northern phalarope was seen. It was near camp on August 3, 1951. Between Birnirk and Point Barrow (Aug. 25, 1952), approximately 3000 northern phalaropes had collected on fresh water ponds, salt water lagoons and on the Arctic Ocean. Many of them were feeding while others were nesting on matted green mosses bordering ponds. Their habit of spinning in water was noted. Those feeding on the Arctic Ocean were on the relatively smooth water immediately beyond the point where the breakers formed. On September 11, at Point Barrow, we did not see the species.
Stercorarius pomarinus(Temminck): Pomarine jaeger.—At Birnirk (June 14, 1952) while snow still covered most of the ground, pomarine jaegers hunted for lemmings by flying approximately 20 feet above the tundra and occasionally hovering. On June 15, one had eaten parts of two large lemmings caught in traps along the edge of a snow-bound lake. On June 17, these birds were preying on live lemming and swallowing them whole. One flew 50 meters with a brown lemming in its mouth and after alighting, consumed it. The backs of several lemmings caught in traps had scars probably made by jaegers or conceivably by snowy owls. West of Salt Water Lagoon (June 17, 1952), 12 jaegers were counted with the aid of a 6 × 30 power binocular in a 90° arc to the southward. Three snowy owls also were hunting in this area. In traveling one and three-eighths miles south by east from Barrow Village on June 20, 1952, we counted eight single pomarine jaegers in the air and on the return trip the same day, five pomarine jaegers (one was dead, another was resting on a lake and 3 were in flight).
At Point Barrow (June 21, 1952) two pomarine jaegers left the land and flew north out of sight over the Arctic Ocean. At a point 9⁄10 mile east and 4⁄5 mile north of Barrow Village (June 23, 1952) we observed a pomarine jaeger cruising three feet above ground. It dropped to the tundra and picked up a lemming by its back and after adjusting the lemming swallowed it tail first. On a lake one mile southwest of the Arctic Research Laboratory a group of six and two pairs all facing into the wind were resting on ice. In an area of 240 acres (outlined by the tripod communication line to the west, "Y" line to east, and row of 50 gallon drums following the ground line to south), we counted 19 pomarine jaegers in groups of from one to four or one per 12 square acres; one snowy owl was in the area.
At Kaolak River (July 12-18, 1951) pomarine jaegers were the second most common jaeger in the area. In walking for four hours on July 15, two pairs were noted. Ordinarily, however, these birds are seen singly not in pairs. At Lake Schrader (July 23-31, 1952) pomarine jaegers were active both day and night, especially at night. At Barrier Lake (Aug. 2, 1951) two pomarinejaegers flew close together along the edge of the south end of the lake. As they left the lake and flew over the extensive marsh to the east they separated and flew as single individuals. On August 4, a pomarine jaeger was chasing an Arctic loon that had a fish in its bill. On August 10, 1951, a single pomarine jaeger was noted at Chandler Lake. As late as September 7, 1952, one half mile south of the Arctic Research Laboratory, seven pomarine jaegers were foraging for brown lemmings.
Stercorarius parasiticus(Linnaeus): Parasitic jaeger.—Specimens, 3: Topagaruk River, 155°48', 70°34, 10 ft., 2, Nos. 30732-30733, ad. females, July 6, 8, 1951; Kaolak, 160°14'51", 69°56'00", 178 ft., 1, No. 30731, ad. male, July 21, 1951.
At Topagaruk (July 5-10, 1951) parasitic jaegers ranged over nearly all plant and animal associations, but flew more frequently over polygons with low centers than elsewhere. Data on two adult females, shot on July 6 and 8, in that order are as follows: weight, 525, 320 grams; largest ovum, 3, 1 mm; length of ovary——, 5.5 mm. The bird killed on July 6 was in the black color phase.
At Kaolak River (July 12-18, 1951) the parasitic jaeger was the least common of the three species of jaegers.
At Kaolak (July 21-27, 1951) two birds nested near camp while others passed through the area. These passing birds generally were seen singly or in pairs; long-tailed jaegers commonly are in groups of four or five. The parasitic jaegers were not so noisy nor so much given to chasing others of their own species as were long-tailed jaegers. Several single birds hunted in areas of sedges and grasses that yielded lemmings. On July 21, a parasitic jaeger was flying with three glaucous gulls, and demonstrating its usual flight tactics of gliding, climbing and swooping as it accompanied the gulls. An adult male shot on July 21, weighed 460 grams.
On alluvial outwash at the southwest end of Lake Schrader (July 27, 1952) a male and female parasitic jaeger defended their territory by diving at us. Periodically both birds alighted approximately 60 feet away and each pretended to have a crippled wing for approximately a minute. The female acted as if herding the young but was not. On each of our daily inspections an adult defended the area. In a period of four days the area defended was shifted approximately 1⁄5 of a mile south in the marsh area adjacent to the lake. Parasitic jaegers were noted in the Lake Schrader area from July 23 to July 31 inclusive.
At Barrier Lake (July 30, 1951) two parasitic jaegers were harassing a glaucous gull that responded as if being attacked by a hawk. The plunging of the jaeger continued while the gull was flying 300 feet horizontally. One other jaeger chased a glaucous gull for one-fourth of a mile and finally having caught up with it dove at the gull several times, each time almost making contact. From our camp on Barrier Lake (July 29-Aug. 4, 1951) we watched parasitic jaegers hunt along the south end of the lake, following precisely the edge of the water. The wind drove debris to the south end of the lake. The long-tailed jaeger was the more numerous here; it flew along ridges and over marshes. On July 30, a single jaeger flew over the lake and after hovering above a young Arctic loon, which had strayed from its parent, dove down and picked it up. Three other parasitic jaegers arrived and competed for the prey.
A single parasitic jaeger was noted at Chandler Lake on August 10 and one on August 11, 1951. At Gavia Lake (Aug. 21, 1952) there were six jaegers in one group.
Stercorarius longicaudusVieillot: Long-tailed jaeger.—Specimens, 5: Kaolak River, 159°47'40", 70°11'15", 30 ft., 1, No. 30738, ad. female, July 12, 1951; Kaolak, 160°14'51", 69°56'00", 178 ft., 4, Nos. 30734-30737 including 2 ad. males and 2 ad. females, July 21, 1951.
The long-tailed jaeger was the second most abundant of the three jaegers at Topagaruk (July 5-10, 1951). The greatest number seen on any one day was three. At Kaolak River (July 12-19, 1951) this species was the most common jaeger. On a four hour field trip (July 15 and 18) we saw six birds. When in groups of three or more, they frequently chased each other and called vigorously. One adult female shot on July 12, weighed 300 grams. The largest ovum in the female was 1.2 mm in diameter and the ovaries were 5 and 6 mm long.
Within 1⁄5 of a mile of our camp at Kaolak (July 21-27, 1951) there were three breeding pairs of jaegers. On a four hour trip beyond this limit we saw as many as 14 individuals. Most of these were in groups of three and were commonly seen flying over meadows and along ridges. Single birds hunted by hovering or swinging upward. Territories vacated by our collecting adult birds were not immediately filled by other nesting jaegers. One pair of jaegers nested in a broad grassy meadow. The female was aggressive and demonstrative and called continually above her young. The male was less demonstrative but joined the female when she began calling. On July 24, four jaegers flew over areas where brown lemmings had been trapped in greatest numbers. Two adult males shot on July 21, weighed 270 and 250 grams. The testes of these two birds were 5.5 and 8.0 mm long. Two adult females from the same area, and shot on the same date as the males, were larger than the males. The females weighed 285 and 298 grams.
At Barrier Lake (July 29, 1951) we observed three long-tailed jaegers, all chasing and harassing a glaucous gull. These jaegers hunted mostly along ridges and over marsh. At midnight these birds were still hunting and flying about. Other long-tailed jaegers were on the lake from July 29 to August 4 inclusive.
At Gavia Lake (Aug. 21-23, 1952) two long-tailed jaegers fed from our refuse pile only 30 feet from our tent. A single individual was noted at Lake Peters on July 25, 1952, and one at Driftwood on August 27, 1952.
Larus hyperboreus barrovianusRidgway: Glaucous gull.—Specimen, 1: Topagaruk, 155°48', 70°34', 10 ft., No. 30739, ad. male, July 9, 1951.
Robert McKinley told us that on May 16, 1952, approximately 25 gulls, probably glaucous gulls, arrived at the Arctic Research Laboratory and remained until May 25. On July 4, 1951, there, we recorded all gulls passing over the ice from 8:45 A.M. to 9:45 A.M. At this time the shore line and first 100 feet of water was free of ice; beyond, seaward, the ice was rough and dark for ¼ mile, succeeded by white ice for ¼ mile, next the high pressure ridge, and then open water of the Arctic Ocean. Glaucous gulls, singly, passed to the southwest and to the northeast at intervals of 6(3-10) minutes at a distance of 500(300-800) feet from the shore line, except for one bird that was approximately one mile off-shore.
On July 10, 1952, off-shore from the Laboratory, where garbage from campwas deposited on the ice, approximately 130 glaucous gulls were present—some resting on the ice and some flying. At six P.M., four hours later, 84 gulls including several immatures remained. Birds in groups were constantly walking about or flying short distances, but lone individuals stood perfectly still for long periods. On July 11, only 22 birds remained; they were flying up and down the shore line. At Topagaruk (July 5-10) glaucous gulls fed on the refuse pile at camp. The number varied from day to day, from as few as 10 to as many as 22; a few remained at the feeding grounds at all times.
The testes of an adult male (30739), shot on July 9, 1951, at Topagaruk were 15 mm long and 9 mm thick.
At Kaolak River (July 12-19, 1951) gulls occasionally cruised up or down the river, but did not remain in the area. When we flew from the mouth of Canning River Canyon to Umiat (July 16, 1952) the only glaucous gulls noted were in the vicinity of the Colville River. At the Will Rogers Monument 12 miles southwest of Barrow Village (July 18, 1951), 275 glaucous gulls were at the mouth of one of the streams entering the Arctic Ocean, and 50 miles southwest from Point Barrow along the ocean six gulls flew over the water where a muddy stream from the land was discharging into the Arctic Ocean. On July 20, 400 of these gulls were near the Arctic Research Laboratory and in the large lake southwest of camp. At Kaolak (July 21-27, 1951) five to eight birds remained near camp. Along the larger creeks they flew by approximately every two hours.
On an air trip along the Arctic Ocean 56.2 miles southwest of Barrow Village (July 27, 1951) we counted 312 gulls, most or all glaucous gulls, in small groups as follows: average size of flock, 34(2-70); average distance between flocks, 5.8(1.9-13.6) miles. A large flock of 188 glaucous gulls, on this date, was in the environs of Barrow Village and the Arctic Research Laboratory. On an airflight between Point Barrow and Smith Bay (July 29, 1951) we observed three groups (1-2-7) equally spaced between the two points. The glaucous gulls were seen in only small numbers at Barrier Lake (July 29-Aug. 4, 1951) generally as individuals or groups of two or three, and frequently were harassed by jaegers. On August 3, a glaucous gull on three occasions inspected but did not touch a freshly killed pectoral sandpiper floating on the surface of the water. On a flight from Teshekpuk Lake to Point Barrow (Aug. 4, 1951) we observed groups of gulls as follows: one at 40 miles (miles are from Point Barrow), four at 34 miles, four at 10 miles and twenty-three at 8 miles. At Driftwood (Aug. 27-31, 1952) groups of from one to 12 glaucous gulls were seen every day. At Umiat (Aug. 30-Sept. 4, 1951) several birds were flying up and down the river. In 1952 (July 18) at 10 miles east of Umiat we observed a single bird. On August 25, 1952, at Point Barrow, 33 glaucous gullsflewalong the edge of the Arctic Ocean. Between Birnirk and Point Barrow (Sept. 11, 1952) a group of 230 glaucous gulls rested along the shore of the Arctic Ocean. Glaucous gulls were noted also at the following places in the Point Barrow area (1952): west side Salt Water Lagoon, June 17; 9⁄10 mile east and 8⁄10 mile north Barrow Village, June 23; 1 mile southwest Barrow Village, September 6; ½ mile south Arctic Research Laboratory, September 7.
Larus canus brachyrhynchusRichardson: Mew gull.—Specimens, 2: SE Lake Peters, 69°20'56", 145°09'26", 2950 ft., 1 imm. female No. 31314 (Aug. 6, 1952) and one adult female 31313 (Aug. 9, 1952).
At the southwest end of Lake Schrader, from July 23 to 31, 1952, a pair of mew gulls defended a territory and two young in the marsh bordering the edge of the lake and flew to meet us whenever we approached. They were active day and night. On August 3, 4, and 5, the female of this pair fed at the mouth of the river that flowed into the south end of Lake Peters 4.9 miles south of the nesting territory. On August 6, both adults and the two juveniles were at the south end of Lake Peters. The young called frequently and the adults, when we came near their young, called loudly and dived at us, but remained higher in the air than they did when protecting their young on the nesting territory. On August 6, the female (435 mm long and 290 grams in weight) was shot and prepared as a specimen. The two juveniles and the male remained in the area and on August 9, one of the juveniles (female) 422 mm in length and 362 grams in weight, was shot. On August 12 the male and one juvenile were still in the same area, and active day and night.
Pagophila eburnea(Phipps): Ivory gull.—Pete Savolik told us that whenever the pack ice came near shore at Point Barrow, a few ivory gulls were generally present.
Rissa tridactyla pollicarisRidgway: Black-legged kittiwake.—Specimen, 1: 7½ mi. S and 7 mi. W Point Barrow, 156°49', 71°17', sea level, 1 (skin) No. 31315 of an adult of unknown sex, September 6, 1952.
The kittiwakes (Sept. 6, 1952), were in the air along the Arctic Ocean at Barrow Village and all along the coast at least as far as a point 10 miles southwest of Barrow Village (only a few were seen northeast of Barrow Village) and were feeding on material floating in the pre-breaker area of the ocean and to a lesser extent on debris washed up on the sands of the beach.
Xema sabini sabini(Sabine): Sabine's gull.—Specimens, 8: 7½ mi. S and 7 mi. W Point Barrow, 156°49', 71°17', sea level, 1 (skin) No. 31316, ad. male, Sept. 6, 1952; Topagaruk, 155°48', 70°34', 10 ft., 7, Nos. 30740-30746 including 4 ad. males and 3 ad. females, July 6, 8, 9, 1951.
At Topagaruk the species was seen daily from July 4 through July 10, 1951. Six adults were nesting on July 5. They constituted less than one per cent of the avian population inhabiting stabilized lakes of medium size. On July 8, one nest held young. When we approached the nesting grounds they flew 150 feet to meet us and then returned, hovered, or flew directly over their nests. One nest was on an island one foot in diameter; other islands inhabited were as large as one square meter. The vegetation at the nest was bright green and lawnlike because of trampling and fertilization of the grasses and sedges by the birds. Correspondingly green, lawnlike areas of grass were noted on the resting grounds of ducks and geese. The Sabine's gull and Arctic tern are compatible and nest within 20 feet of each other. The young freely circulate through each other's territory. The average weight of three adult males (July 6-8) was 202(190-214) grams. The average length of the testes of these birds was 10(8-14) mm. Four adult females collected at the same place and time weighed 177(158-190) grams. The ovaries averaged 8 mm long and the largest ovum was 2.8(2.0-4.5) mm in diameter.
At Kaolak River on July 17, 1951, one gull flew along the river but did not seem to be nesting in the area. On July 20, 1951, 105 miles southwest of Point Barrow, we observed Sabine's gulls, Arctic tern and several pairs of loons on one lake. On a return trip from Kaolak to Point Barrow by air(July 27, 1951), we found Sabine's gulls generally distributed across the Coastal Plains. On an air trip from Point Barrow to Teshekpuk Lake on July 29, 1951, we noted two Sabine's gulls, one 9.7 miles southeast of Point Barrow and one 5.9 miles northwest of the central western edge of Smith Bay.
Three miles east of our camp on Barrier Lake (Aug. 3, 1951) a Sabine's gull had been eaten by a gyrfalcon. The gull was a bird of the year with the downy feathers extending beyond the ends of seven primary feathers. Three primary feathers were newly molted and of full length.
On an air flight (Aug. 4, 1951) from Teshekpuk Lake to Point Barrow we saw two Sabine's gulls 63 miles southwest of Point Barrow and two at 23 miles southwest of Point Barrow. At Point Barrow (Aug. 26, 1952), 250 Sabine's gulls were resting or flying in the area. On September 6 at 7½ miles south and 7 miles west of Point Barrow, Sabine's gulls constituted 60 per cent of the larger birds that were flying and feeding along the Arctic Ocean. The Arctic tern constituted 20 per cent, the kittiwake 5 per cent and the glaucous gulls 15 per cent of the population. An adult male shot here (Sept. 6) weighed 213 grams. Between Birnirk and Point Barrow (Sept. 11, 1952) we counted 17 Sabine's gulls feeding and resting along the shore of Elson Lagoon.
Sterna paradisaeaPontoppidan: Arctic tern.—Specimens, 11: 7½ mi. S and 7 mi. W Point Barrow, 156°49'15", 71°16'52", sea level, 2, Nos. 31315 and 31318, ad. male, Sept. 6, 1952; NE Teshekpuk Lake, 153°05'40", 70°39'40", 8 ft., 3, Nos. 30750-30752 including 2 ad. males and 1 ad. female, Aug. 1, 1951; Topagaruk River, 155°48',70°34', 10 ft., 3, Nos. 30753, ad. female, July 7, 1951, and 30754, ad. male, July 9, 1951, and 30637, male, July 9, 1951; Kaolak River, 159°47'40", 70°11'15", 30 ft., 3, Nos. 30747-30749 including 2 ad. males, July 14, 18, 1951, and 1 ad. female, July 12, 1951.
Adult males and females prepared for specimens at Topagaruk (July 7, 9, 1951) showed signs of molting, especially in the primary wing feathers. Three adult males averaged 92 (87-93) grams in weight (the largest male collected on the Arctic Slope was from Teshekpuk Lake on August 1, 1951, and weighed 106 grams). The testes of these males averaged 4.2(3-5) mm in length (in late autumn testes recede to approximately 1.0 mm in length). Two females from the same place and shot on July 7 and 12, weighed 99 and 100 grams. The average diameter of the largest ovum was 2.0 mm and the longest ovary was 6 mm.
At Kaolak River (July 12-18, 1951) an adult hunted day and night over shallow water on a sand bar approximately 500 yards from its nest. Water from lakes in an abandoned section of the river valley caused a creek to flow at night into the river. In the day ephemeral pools were formed because more water evaporated or sank into the sands. As pools were formed, small fish one inch in length were trapped. Before the pools disappeared, the tern captured all these fish. One of the terns that had been feeding on these fish flew out over the upland tundra approximately 500 feet from the river valley. This tern dove at us twice and then returned to the river valley and its nest some 800 feet away.
The nest of this bird was on one of three islands in a small lake. The nesting island was three square yards in area and had been built to a height of four feet above the level of the mainland by many years use of the island. The nest was within 30 feet of a nest of a red-throated loon, which was accepted in the territory of the tern without molestation.
Northeast of Teshekpuk Lake (July 29-Aug. 4, 1951) a pair of terns had young on a small island in a chain of lakes opening into the south end of Barrier Lake. The adults hunted small fish along the south end of Barrier Lake but especially in small lakes surrounding their nest. These birds seemed to be the only terns nesting on this large lake. As food was plentiful, available nesting sites may have governed the size of the tern population.