The pectoral sandpiper usually chooses for its homesite the upland rolling tundra, but an occasional isolated pair was found on the dry grass lands of the tide flats. This species builds the most substantial of any of the shorebirds nests that we met with at Hooper Bay, for even after it was removed from the grassy cavity in which it was built the nest would often hold firmly together. The birds showed exceptional skill in the concealment of their homes and consequently they were very difficult to find for they chose a tract where the curly bunch grass grew abundantly and under its domed protection they constructed an excavation deep in the moss. Here a substantial nest is fashioned of grasses and tediously lined or rather filled with small crisp leaves of the low perennial plants that there, in a dwarf creeping form, are the only representatives of the great inland forests. The dimensions vary between the following extremes: Inside diameter 3 to 3-1/2 inches; depth 1-3/4 to 2-1/2 inches; and outside depth 3-1/2 to 5 inches. We never observed other than the female carrying on the loving duties of incubation and seldom indeed was the male even in close attendance. The female is very difficult to approach on the nest because she invariably leaves it before the ornithologist draws near and consequently we spent many hours endeavoring to watch the shy bird return to her nest. The behavior of parent birds about the nests seems to be variable. W. Sprague Brooks (1915) says: On approaching the vicinity of the nest the bird would leave it quietly and walk slowly about feeding and showing no excitement whatever. This happened several times until I decided to watch the bird and see if by any chance she might have a nest. In a short time she walked to a bunch of grass a few feet from me and settled on the nest. Even while I was packing away the eggs she showed no concern. I had precisely the same experience with the other two nests. On the other hand, Alfred M. Bailey (1926) writes: On July 3 Hendee flushed a female from a set of four slightly incubated eggs. "The nest," he states, "was in a patch of marsh grass, similar to the location usually chosen by the phalaropes, except that the ground was not wet. The female fluttered away to a distance of about 30 feet and went through a remarkable performance in her attempt to decoy me from the nest. She crept about among the hummocks in a very unbirdlike fashion, uttering all the time a mouse-like squeaking." _Eggs._--Mr. Brandt in his manuscript notes has described the eggs so well that I can not do better than to quote him, as follows: