Every lover of feathered kind is interested in what may be called comparative ornithology, and therefore I wish to speak of another western form and its eastern prototype--Bullock's oriole, which in Colorado takes the place of the Baltimore oriole known east of the plains all the way to the Atlantic coast. However, Bullock's is not merely a variety or subspecies, but a well-defined species of the oriole family, his scientific title being _Icterus bullocki_. Like our familiar Lord Baltimore, he bravely bears black and orange; but in _bullocki_ the latter color invades the sides of the neck, head, and forehead, leaving only a small black bow for the throat and a narrow black stripe running back over the crown and down the back of the neck; whereas in _Icterus galbula_ the entire head and neck are black. Brilliant as Bullock's oriole is, he does not seem to be anxious to display his fineries, for he usually makes it a point to keep himself ensconced behind a clump of foliage, so that, while you may hear a desultory piping in the trees, apparently inviting your confidence, it will be a long time before you can get more than a provoking glimpse of the jolly piper himself. "My gorgeous apparel was not made for parade," seems to be his modest disclaimer. He is quite a vocalist. Here is a quotation from my lead-pencil, dashes and all: "Bullock's oriole--fine singer--voice stronger than orchard oriole's--song not quite so well articulated or so elaborate, but louder and more resonant--better singer than the Baltimore." It might be added that Bullock's, like the orchard, but unlike the Baltimore, pipes a real tune, with something of a theme running through its intermittent outbursts. The plumage of the young bird undergoes some curious changes, and what I took to be the year-old males seemed to be the most spirited musicians. Maurice Thompson's tribute to the Baltimore oriole will apply to that bird's western kinsman. He calls him:-- "Athlete of the air-- Of fire and song a glowing core;" and then adds, with tropical fervor: "A hot flambeau on either wing Rimples as you pass me by; 'T is seeing flame to hear you sing, 'T is hearing song to see you fly. * * * * * "When flowery hints foresay the berry, On spray of haw and tuft of brier, Then, wandering incendiary, You set the maple swamps afire!" Many nests of Bullock's oriole rewarded my slight search. They are larger and less compactly woven than the Baltimore's, and have a woolly appearance exteriorly, as if the down of the Cottonwood trees had been wrought into the fabric. Out on the plains I counted four dangling nests, old and new, on one small limb; but that, of course, was unusual, there being only one small clump of trees within a radius of many miles.