BLACK-NECKED STILT 349 



water demands it. It is probable that only incubated sets are so eared 

 for (Tyler, MS). A nest of this type found at Los Bafios, May 12, 

 1914, was seven inches in height and composed of pieces of tules about 

 two inches in length, the eggs being just at the surface of the water. A 

 tj'^pical nest measures about seven inches in diameter. 



Stilts commonly nest in colonies of five to twenty pairs, and their 

 aggregate numbers in any general area consequently do not seem so 

 great as would be the case if they all nested in one large colony. On 

 a small island in Buena Vista Lake, Lamb and Howell (1913, p. 117) 

 found Stilts and Avocets nesting together, and curiously enough cer- 

 tain of the birds seemed to consider themselves members of one large 

 family, as nests were found containing five to eight eggs and some 

 nests held eggs of both species. H. C. Bryant (MS) found a set at 

 Los Baiios which contained five eggs, and Tyler (MS) found a similar 

 set near Fresno. 



The eggs of the Stilt number four in a eom})lete set, but in 

 exceptional cases more, as above. The eggs average 1.70 by 1.24 

 inches, the extremes being 1.59 to 1.84 by 1.16 to 1.26. The ground- 

 color is a. medium buff or clay with superficial spots of deep reddish 

 brown or brownish black and deeper ones of gray or lavender. The 

 spots are commonly over 0.08 inches in diameter, and are usually a 

 little more numerous about the larger end where they are sometimes 

 so thick as to fuse. The eggs of the Stilt differ from those of the Avo- 

 cet by their smaller transverse diameter, slightly shorter average 

 length, and somewhat darker general tone of coloration. 



Both male and female are said to incubate (Coues, 1874, p. 466). 

 The period of incubation is not known, but is probably about three 

 weeks or slightly longer. The young are able to run about at birth, 

 but are carefully attended by the parents for some time. Murphy 

 (MS) says that the downy young Stilts seen by him at Calexico, 

 Imperial County, were swimming. Chapman (1908, p. 288) thus 

 describes the behavior of the Stilts at Los Baiios: 



. . . The Stilts, because of their abundance, vociferousness, and remarkable 

 actions were the most conspicuous and interesting [of all the water birds]. 

 They nested on the little islands formed by slightly elevated bits of ground, 

 often selecting a site which, under irrigation, subsequently became submerged — 

 a misfortune [which] artificial conditions had not prepared the birds to 

 anticipate. 



On May 2.3, their eggs were hatching, and in June the Snipe like young 

 were widely distributed over the marsh. They invariably attempted to escape 

 observation by squatting with neck outstretched, but the parents, whether 

 one approached their eggs or young, expressed their solicitude by a surpris- 

 ing extravagance of motion, all apparently designed to draw attention to them-, 

 selves. I was at times surrounded by hopping, fluttering Stilts, all calling 

 loudly, waving their wings, bounding into the air to hang there with dangling 

 legs and beating pinions. . . . 



