The sites chosen often are subject to inundation by sudden floods, when the birds scurry about, seemingly in confusion, but in reality working actively to build up the nest in order to support the eggs above the level of the encroaching water. In some cases it may be necessary to erect a structure 12 or 15 inches in height. Weeds, small sticks, bones, or dried bodies of ducks or other birds, feathers, or any other materials available are utilized as building materials. _Eggs._--The American avocet lays three or four eggs, usually four and occasionally five. Numerous nests have been found containing seven or eight eggs, but these are probably products of two females. Edwin Beaupré writes to me that, in a colony of five pairs found by him on an island in a small lake in southern Alberta, the five pairs were occupying three nests; one contained eight eggs, another seven and the third four. The eggs vary in shape from ovate (rarely) to ovate pyriform and they are usually much elongated. The shell is smooth, but not glossy. The ground color varies from "Isabella color" to "deep olive buff." This is more or less evenly covered with irregular spots and blotches, in various sizes, of brownish black, blackish brown, or black, rarely "warm sepia" or "bister"; there are occasionally a few blackish scrawls, and numerous underlying spots of various shades of drab. The measurements of 55 eggs average 49.8 by 34 millimeters; the eggs showing the four extremes measure =56.3= by 34.6, 51.5 by =36.6=, =43.2= by 33.4 and 47 by =31= millimeters. _Young._--The period of incubation of the American bird has apparently not been determined, but that of the European bird is said to be 28 days. I have no data as to how the sexes incubate. Young avocets are very precocial and leave the nest soon after hatching. They are expert at hiding, even on the open flats and beaches; and they take to the water at an early age, where they can swim and dive like young ducks. I have seen a brood of four young, that could not have been hatched more than a few hours, swimming out in a lake, as if very much at ease. They soon learn to tip up in shallow water and probe on the bottom, like their parents, for their insect food. _Plumages._--The downy young avocet is well colored for concealment on an open beach or alkaline flat. The colors of the upper parts are "cinnamon buff," "cream buff," and buffy grays, lightest on the crown and darkest on the rump; there is a distinct but narrow loral stripe of black; the crown is indistinctly spotted with dusky. Two parallel stripes of brownish black distinctly mark the scapulars and two more the sides of the rump; the wings, back, rump, and thighs are less distinctly spotted or peppered with gray and dusky. The under parts are buffy white, nearly pure white on the throat and belly.