The author's preference would have been to begin the roll with the most interesting birds, those to which he gave the largest share of his attention, namely, the oscines, but he has decided to follow the order and nomenclature of the Check-List of North American birds as arranged by the American Ornithologists' Union. In deference to the general reader, however, he has placed the English name of each bird first, then the scientific designation. The numbers correspond to the American Check-List. By noting those omitted, the reader will readily discover what species have not been found in Colorado.
1. Western grebe. Æchmophorus occidentalis. Rare migrant; western species, chiefly interior regions of North America.
2. Holboell's grebe. Colymbus holboellii. Rare migrant; breeds far north; range, all of North America.
3. Horned grebe. Colymbus auritus. Rare migrant; range, almost the same as the last.
4. American eared grebe. Colymbus nigricollis californicus. Summer resident; rare in eastern, common in western Colorado; breeds from plains to 8,000 feet; partial to alkali lakes; western species.
6. Pied-billed grebe. Podilymbus podiceps. Summer resident, rare; common in migration; breeds in northern part of State; sometimes winters in southern part.
7. Loon. Gavia imber. Migrant; occasionally winter resident; not known to breed in State.
8. Yellow-billed loon. Gavia adamsii. Migrant; rare or accidental.
9. Black-throated loon. Gavia arctica. Rare fall and winter visitant.
37. Parasitic jaeger. Stercorarius parasiticus. Fall and winter resident; rare.