308 BIRDS OF THE ROCKIES 



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. ./ECHMOPHORUS OCCIDENTALS. Rare 

 migrant ; western species, chiefly interior regions of North 

 America. 



2. Holboell'a grebe. COLYMBUS HOLBOELLII. Rare mi- 

 grant ; 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 CALI- 

 FORNICUS. Summer resident; rare in eastern, common in 

 western Colorado ; breeds from plains to 8,000 feet ; par- 

 tial to alkali lakes ; western species. 



6. Pied-billed grebe. PODILYMBUS PODIC-EPS. 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 ADAMSH. 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. 



