Olive-sided Flycatcher 269 



abdomen and under tail-coverts somewhat less pale ; the sides of the 

 neck, breast and flanks ashy-brown, indistinctly streaked with darker ; 

 a patch of pale yellowish, fluffy feathers on the flanks, generally con- 

 cealed but sometimes very clearly visible on either side of the rvunp ; 

 iris brown, bill and legs brownish-black. Length 6-5 ; wing 4-20 ; 

 tail 2-5 ; tarsus -55 ; culmen -85. The sexes are alike, and the young 

 essentially like the adults, but the pale tips of the coverts and 

 secondaries are brownish. 



Distribution.^ — Breeding throughout the coniferous forest regions 

 from Alaska and Hudson Bay southwards to New York and Minnesota, 

 and thence along the Alleghanies, Rockies and subsidiary ranges of 

 the west to northern Mexico, migrating southwards to Columbia, 

 western Ecuador and Peru. 



A fairly common siunmer resident in the moimtains of Colorado, 

 but only a migrant in the plains and not so often met with. It is noted 

 as a migrant in the plains of Boulder co. by Henderson, and is not very 

 abundant in El Paso co. on the plains, but Scott found it not uncommon 

 near Twin Lakes at about 9,300 feet, and Minot at 10,000 feet on Pikes 

 Peak. Gale found nests from 8,000 to 9,500 feet in the mountains of 

 Boulder co, ; Lowe records it nesting at about 9,500 feet in the Wet 

 Mountains in Huerfano co., and Henshaw met with it from 7,000 feet 

 to timber line near Fort Garland. In Mesa co. it is stated by Rockwell 

 to be quite rare ; he only observed it once in Plateau Valley at 6,800 feet. 



It arrives from the south in May ; W. G. Smith notes it once at 

 Loveland on the 11th ; Allen and Brewster first saw it on the 17th ; 

 Aiken's earliest record is the 21st. It departs south again at the end 

 of August or beginning of September. 



Habits. — ^The Olive-sided Flycatcher is never very 

 abundant, possibly owing to its quarrelsome and un- 

 sociable nature. Its favourite resort is the top of a bare 

 spruce, whence it makes constant sallies after passing 

 insects, clicking its bill as it catches them on the wing. 

 It has a loud whistle-like call-note, as well as a " Chip, 

 chip, chip." 



The nest is usually saddled far out on the horizontal 

 limb of a fir, and is completed about the middle of June ; 

 it is small and flat, and appears fragile though constructed 

 of strong material. The eggs are generally three in 

 number, with a white to pale pinkish ground-colour, 

 thickly blotched and spotted with chestnut and purple. 



