Young were found for the first time on June 4. Both male and female at this time were highly excited, the female approaching within 10 feet of us. All the young had left the nest and had taken refuge in the shade of a log to escape the burning rays of the sun. No eggshells were found in the nest or near by. As we retired from the immediate locality the female flew down to the ground and softly "kipped" as if to rally the scattered young. On the succeeding day a nest was found which at 10 a. m. contained one young and two eggs. At 12.30 p. m. all the birds had hatched and had left the nest, being found quite a distance away. One bird was walking, readily indicating that the migration to the water must start within a few hours of the time that the young are out of the eggs.
After June 6 all the same excitement that characterized the action of the adult birds at the nesting site was transplanted to the meadow lands. One uninitiated in the ways of the species might easily suppose that he was now upon the breeding grounds, for the young keep well concealed and are difficult to discover. Perhaps the exhibition of the adults at this time and the secretive habits of the birds during the early days of the mating have tended to keep the nesting habits of the lesser yellow-legs so long a mystery.
Plumages.—In natal down the young yellow-legs is "pinkish buff" on the back, shading off to "cartridge buff" on the crown, to paler buff on the forehead and sides of the head and to pure white on the under parts; there is an indistinct frontal black stripe; the crown is heavily mottled with brownish black; a black stripe extends from the bill through the eye to the nape; and there are three broad bands on the center and sides of the back and large patches on the rump and thighs of brownish black.
Young birds develop rapidly, the juvenal plumage coming in first on the sides of the breast, scapulars, and wings. A young bird, taken July 10, is nearly fully grown; the crown and neck fully feathered, the breast nearly so, and the wings and tail nearly grown. In this fresh juvenal plumage the feathers of the crown are tipped with whitish, and those of the back, scapulars, and wing coverts are edged, tipped, or notched with pale buff to white.
Subsequent molts and plumages are similar to and very much like those of the greater yellow-legs. I have seen a number of birds in what I call the first nuptial plumage migrating northward; they may breed in this plumage. I have seen several adults molting their primaries in January and February.
Food.—The favorite feeding grounds of the yellow-legs are on flat marshes near the coast, where the grass is short and where the high course of tides or heavy rains leave the marshes partially covered, or dotted, with shallow pools or splashes; away from the coast it is equally at home in wet, short-grass marshes, mud flats, shallow ponds and even wet places in cultivated fields. In such places it walks about in an active manner, usually in shallow water, but often up to the full length of its long legs, gleaning most of its food from the surface of the water or mud and seldom probing for it. During one season on Monomoy large numbers of yellow-legs frequented the drier parts of the meadows where the long grass had been beaten down flat by the storms of the previous winter. These places seemed to hold some strong attraction for them, for they repeatedly returned after being driven off. While we remained partially concealed in some clumps of tall grass, they frequently alighted near us and ran nimbly about over the flattened grass, darting rapidly in various directions to pick up food. The grass was full of minute grasshoppers and other small insects on which they were feeding. Evidently this food was unusually abundant that season, for I have never seen them there in any numbers since 1921.
Arthur H. Howell (1924) says that, in Alabama, "this bird feeds mainly on insects, including ants, bugs, flies, and grasshoppers, and on small crustaceans, small fishes and worms." Dr. Alexander Wetmore (1916) reporting on the food of four birds, taken in Porto Rico, says that "water boatmen found in each of the four make 57.5 per cent, and two stomachs contained nothing else. Crustacean remains, among which were several crabs, were identified in two stomachs, and make the remainder, 42.5 per cent."
The contents of nine stomachs taken by Stuart T. Danforth (1925) in Porto Rico were examined:
Dytiscid larvae formed 26.6 per cent of the animal matter, and Hydrophilid larvae, 1.8 per cent; Bloodworms, 5.1 per cent; Planorbia snails, 5 per cent; Fleabeetles 1.1 per cent; Hydrophilid adults, 3.1 per cent; Dytiscid adult, 0.7 per cent; grasshoppers, 0.22 per cent; Bupestrid beetle, 0.55 per cent; Lycosid spider, 0.55 per cent; Notonectidae, 1 per cent; fish scales, 0.33 per cent; Carabid beetle (Stenous sp.), 0.55 per cent; and other beetles, 3.2 per cent.
Behavior.—Either in flight or on the ground the two yellow-legs are so much alike that one is often mistaken for the other, unless a direct comparison in size can be made. William Brewster (1925) has expressed it very well, as follows:
The summer yellow-legs seems an exact counterpart of the winter in respect to general appearance and behavior. It has the same firm, measured step, when walking about in quest of food; the same perfection of form and outlines, and grace of position, when standing erect and watchful; the same habit of tilting its body and alternately lengthening and shortening its neck with a bobbing motion, when suspicious of danger and about to take wing. Its flight, also, is essentially similar to that of its big cousin, but somewhat slower and more buoyant, and hence not so suggestive of momentum as that of the larger, heavier-bodied bird.