Minot on Colorado Birds. 
227 
song and the Redstart’s as alike : but the first always has a falling, and 
the second a rising inflection. 
16. Dendrceca striata, Baird. Black-polled Warbler. — Local 
summer residents about Seven Lakes. Recorded by Mr. Henshaw from 
Denver in May. 
17. Dendrceca auduboni, Baird. Western Yellow-rump. — A 
summer resident, irregularly distributed, but preferring high willow swamps 
and spruce timber. Yet June 1, at Boulder, I found some, singly or in 
pairs, several miles out from the hills, — perhaps migrating however, 
though so often gregarious. Habits like those of the Eastern Yellow- 
rump ; same chip , and cliup (sometimes repeated rapidly) ; song similar, 
a weak little warble, but often pretty. June 24, at Seven Lakes, I found 
four eggs, almost ready to be batched. These are curiously like a com- 
mon type of the Yellow Warbler’s, being greenish-white, marked, chiefly 
about the crown, with olive-brown and neutral tint, and averaging about 
.70 X '.55 of an inch (but I have no instrument here for precise measure- 
ment). The nest, composed of shreds and feathers, with a few twigs 
without and hairs within, was built in a dead, bare spruce, about twenty 
feet from the ground-, compressed between the trunk and a piece of bark 
that was attached beneath and upheld above, where a bough ran through a 
knot-hole, — so compressed that the hollow measures 2J x 1 J, and 
inches deep. Such a position for the nest is probably not unusual, for I 
more than once saw the birds about dead timber, though, on the other 
hand, an old nest that I attributed to this species was in a live spruce, 
— against the trunk, in a crotch at some height. 
18. Siurus auricapillus, Swain. Orange-crowned “ Thrush.” — 
Boulder and Nederland in May : identified by notes only. Recorded from 
Denver. 
19. Siurus naevius, Coues. Water “ Thrush.” — Present at Boul- 
der, Nederland, etc., in the latter part of May. Probably a summer resi- 
dent. 
20. Geothlypis macgillivrayi, Baird. Western Mourning 
Warbler. — At Boulder, abundant along creeks, in the latter part of 
May. At Manitou, as summer residents, less numerous. Their ordinary 
song-notes, chee-chee-chee-chee , I could not positively discriminate from 
those of Wilson’s Black-cap, when the two sang on either side of me in 
a thicket. To these chee -che-chu, or a few terminal notes, may be added. 
Sometimes, however, in May, this little Warbler has a fit of ecstasy, and, 
with a short, nervous flight, bursts into sweet song, though not so liquid as 
his Eastern cousin’s. He is not at all shy. An old nest that I attributed 
to this species was built of shreds, lined with hairs, and situated in a 
thorn-bush, a foot from the ground. June 21, 1 took a nest near Manitou, 
remarkable for being five feet from the ground, and three feet from a 
travelled road. It was in a scrub- oak, rather bulkily built of shreds and 
stalks, with a thick lining of hairs, in a hollow about two inches across 
