KILLDEER 467 



practically the same, the iutervening area being noted for early 

 records. Beck (MS) found a nest with two eggs near Los Bafios, 

 Merced County, March 11, 1912. Tyler (1913&, p. 32) records nest- 

 ing in the Fresno district from March 15 to June 28, and gives one 

 case of early nesting which would indicate the commencement of 

 incubation in late February or very early March. The set of two here 

 recorded is quite unusual, and suggests by its rarity that it may not 

 have been complete. "A typical nest throughout the cultivated sec- 

 tions [in the vicinity of Fresno] is composed of a handful of white 

 pebbles about the size of peas and very uniform in size, mixed with 

 an almost equal number of dry shells of melon seeds of the previous 

 year. Frequently a few dry, broken-up pieces of melon stems are 

 used also, the whole being spread out over a space the size of a saucer, 

 with the eggs resting in the center. As the result of coming in con- 

 tact with a sharp rock that sometimes finds it way into the nest in 

 place of the usual smooth ones the eggs occasionally show small gravel 

 punctures. On the summer-fallow fields only a few dry grass blades 

 line the place where the eggs rest, while around the ponds of the west 

 side the eggs generally lie half covered in the powdered alkali dust 

 without a scrap of nest lining" (Tyler, loc. cit.). 



The eggs usually number four, and never more, so far as is known. 

 Sets of smaller number may result from accidents of various kinds. 

 The ground-color is a light clay or pale dull cream; the superficial 

 markings are numerous and dull dark brown or even black, while 

 the deeper ones are dull lavender and less abundant than the super- 

 ficial ones. The markings consist both of irregular spots and narrow 

 streaks, and in general are more numerous at the larger end, some- 

 times resulting in the formation of a dark zone about that end. The 

 eggs average in size 1.51 by 1.05 inches. On the basis of size alone, 

 the eggs of the Killdeer can be confounded with the eggs of no other 

 shore bird breeding in California, except those of the Wilson Snipe. 

 The much lighter ground-color would be sufficient in this case, however, 

 to distinguish the eggs of the Killdeer. Tyler (loc. cit.) intimates that 

 the period of incubation is a little over two weeks. 



The newly hatched Killdeer are able to run and hide almost on 

 leaving the shell. The color pattern of the back is of excellent service 

 in concealing the young birds whether in motion or squatting motion- 

 less on the ground. Few little chicks have more devoted parents. 

 The old birds exhaust every resource to lead an enemy far away 

 from the nesting site. The two sexes are equally solicitous concerning 

 the welfare of the eggs or young, and it is probable that they share 

 alike the duties of incubation. There is no means known to us of 

 distinguishing the sexes in the field either by color-marks or behavior. 

 The incubating bird leaves the nest far in advance of .the human 



