Chandler Lake (Aug. 9-25, 1951). Longitude and latitude taken from World Aeronautical Chart (63) Brooks Range, U. S. Coast and Geodetic Survey, 5th ed., February 2, 1949. Chandler Lake, 152 deg.45', 68 deg.12', 2900 ft. ACCOUNTS OF SPECIES +Gavia adamsii+ (Gray): Yellow-billed loon.--Specimens, 3: Kaolak (Kuk) River, 159 deg.47'40", 70 deg.11'15", 30 ft., No. 30571, ad. female, July 18, 1951; Wahoo Lake, 146 deg.58', 69 deg.08', 2350 ft. (a breeding pair), No. 31301, ad. male and No. 31302, ad. female, July 9, 1952. Upon our arrival at Wahoo Lake (July 3, 1952), two yellow-billed loons were swimming, side by side, on the east end of the lake. On July 8, the pair were seen swimming close together 400 feet distant from the nest. It was located on July 4 and held two fresh eggs. Three days later at 3:00 A.M. one of the pair called directly in front of our camp, which was approximately 4000 feet from the nest at the other end of the lake. The call was the first uttered in the area since our arrival. Except for the two instances noted above, only a single loon was seen at any one time almost certainly because the other was sitting on the eggs. At 3:00 P.M. on July 9, by means of a boat, we visited the nesting area; the male was incubating and the female was absent from the area. As we approached to within 30 feet of the nest, the male, conspicuous as it sat upon the nest with neck held low and extended, became nervous. When we were 25 feet away the bird plunged into the lake. His feet and wings beat the water, increasing his speed; he flew to our right approximately 30 feet from the nest and was shot. The nest and eggs were photographed and we left the area. At 5:30 P.M., the female was swimming on the lake in the general area of the nest. In an effort to obtain the bird we pursued her down the middle of the lake, approximately 1000 feet from her nest and in the direction from which we came. Turning shoreward she dived and resurfaced approximately 300 feet in the opposite direction from which she was being pursued. Two additional dives brought her to the vicinity of the nest. No cry was uttered by either of the birds during our pursuit. Although the female had been incubating two nearly fresh eggs, her ovary, 35 mm long and 19 mm in diameter, contained ova of various sizes up to six mm in diameter. The female measured 850 mm in total length and weighed 4536 grams; the male was 900 mm in total length and weighed 6804 grams.