ROADRUNNER 41 



perfectly fresh eggs and newly-hatched young may be found to- 

 gether; and by the time the last young are breaking the shell the 

 others may be graded up to half the size of the adult." 



[Author's note: The measurements of 55 eggs average 39.2 by 

 30.1 millimeters ; the eggs showing the four extremes measure 44 by 

 30, 41 by 32, and 34 by 27.5 millimeters.] 



William L. and Irene Finley (1915) describe a typical nest in 

 which there were "one fresh egg, one egg just ready to hatch, two 

 featherless, greasy, black 3'oung, and two young ones about grown 

 and ready to leave home." These authors were in a position to watch 

 this nest almost continuously for several days. They did not observe 

 more than one female parent. If, then, the several eggs were laid 

 by more than one female, it may be supposed that the species is to 

 some extent parasitic or promiscuous in this regard, as the yellow- 

 billed and black-billed cuckoos also are thought to be. 



Frank L. Burns (1915) also gives the period of incubation as "18 

 days." It is supposed that only the female incubates. That incu- 

 bation sometimes begins with the laying of the first egg rather than 

 "as soon as a few are deposited" (see above quotation from Coues) 

 has been observed by M. French Gilman (1915), who tells us of a 

 nest with four eggs in which "one hatched July 20, the others on the 

 three succeeding days." In cases of this sort it is natural to suppose 

 that all eggs are laid by the same female. 



Eggs are usually laid in April and May. W. E. D. Scott (1886) 

 tells us, however, of several nests found on the San Pedro slope of 

 the Catalina Mountains in Arizona, the earliest of which, discovered 

 March 17, 1885, at an elevation of 3,000 feet, contained two fresh 

 eggs. That two broods of young are sometimes, if not frequently, 

 reared in one season has been reported by numerous authors, though 

 I believe it has not been proved beyond doubt that fresh eggs found 

 in July are laid by females that have already succeeded in bringing 

 out one brood. 



Young. — Newly hatched young are odd, "featherless, greasy, 

 black" creatures with a reptilian appearance. I had a good deal 

 to do with young roadrunners in the vicinity of Fort Worth, Tex., 

 as a boy, so I quote my own description here (1922) : 



The nestling bird, be it ever so young, has an unmistakable cuckoo-like expres- 

 sion in its face, though its eyes, upon which a good portion of the facial expres- 

 sion depends, are quite different from those of the adult, being of a deep dull 

 brown with a bluish pupil. * * * The eyelashes are small, in fact scarcely 

 apparent. Its whole external appearance is very sombre, and rather dirty- 

 looking, as though the creature had been bathed in some unrefined oil, which 

 had not been properly administered. The white hairs, each of which marks a 

 coming feather, all lie in rows and look as if they had been rudely combed into 

 place. The rather large, pale blue-gi'ay feet are strong in the toes, but very 

 178223 — 10 4 



