OLIVE-SIDED FLYCATCHER 295 



ochraceous salmon, but the markings of the eggs are odd. Instead of 

 being wreathed about the larger end with clusters of fairly well 

 defined spots, all four eggs have a single heavy splotch or smudge, 

 six by ten millimeters in extent in one case, on one side or surface 

 of the egg, while the opposite surface is practically unmarked. These 

 splotches are light vinaceous drab, fading about the edges to cinna- 

 mon-rufous." 



The measurements of 50 eggs average 21.7 by 16.1 millimeters; 

 the eggs showing the four extremes measure 23.7 by 16.9, 23.1 by 17.3, 

 20.1 by 15.5, and 21.2 by 15.2 millimeters. 



Young. — Burns (1915) gives the period of incubation as 14 days. 

 Bendire (1895) says "not over fourteen days. The young are said 

 to remain in the nest about three weeks." In the nest that Nuttall 

 (1832) watched, "the young remained in the nest no less than 23 days, 

 and were fed from the first on beetles and perfect insects, which 

 appeared to have been wholly digested without any regurgitation. 

 Towards the close of this protracted period the young could fly 

 with all the celerity of the parents; and they probably went to and 

 from the nest repeatedly before abandoning it. The male was at this 

 time extremely watchful, and frequently followed me from his usual 

 residence, after my paying him a visit, nearly half a mile." 



Anna Head (1903) watched a brood of fully fledged young, of 

 which she writes: 



They were a pretty sight as they stretched their little wings, craned their 

 necks, and tip-toed along the fir-twigs. They were rather more brightly 

 colored than their parents, whose plumage was somewhat worn at that 

 season. * * * Only the Yellow Gape showed immaturity, and they spent a 

 great deal of time preening their glossy feathers. The parents visited them 

 often, catching insects and delivering them on the wing, with a light, swaUow- 

 like action. * * * 



The next morning the young took their first flight, already seeming quite 

 expert, and choosing bare twigs to perch on, like all their race. They gave the 

 characteristic, three-syllabled call clearly the first day, though more softly 

 than their parents. For more than a week the family kept together near the 

 nest. The last part of the time there seemed to be a good deal of flutter 

 and scolding going on. I think the old ones were trying to induce the young 

 to catch their own game. 



Dr. Mearns (1890) says: "Like many other mountain species [in 

 Arizona] it ranges down hill with its young after the breeding sea- 

 son. On Oak Creek, in the cypress belt below the pines, it appears 

 in families during the first half of August." Probably before the end 

 of that month, both old and young have started on their southward 

 migration. 



Plumages. — I have not seen the natal down or any but fully fledged 

 young. In full juvenal plumage the young bird is essentially like 



