518. =Cassin's purple finch.= CARPODACUS CASSINI. Common resident; winters from plains to 7,000 feet; breeds from that altitude to 10,000 feet.
519. =House finch.= CARPODACUS MEXICANUS FRONTALIS. Abundant resident.
521a. =Mexican crossbill.= LOXIA CURVIROSTRA STRICKLANDI. Resident; not uncommon; has been seen in summer at 11,000 feet; breeds in mountains, perhaps in winter like its eastern antitype.
522. =White-winged crossbill.= LOXIA LEUCOPTERA. Rare winter visitor; one record.
524. =Gray-crowned leucosticte.= LEUCOSTICTE TEPHROCOTIS. Rare winter visitor; western species.
524a. =Hepburn's leucosticte.= LEUCOSTICTE TEPHROCOTIS LITTORALIS. Rare winter visitor; summers in the North.
525. =Black leucosticte.= LEUCOSTICTE ATRATA. Rare winter visitor; summer range unknown; winters in the Rockies.
526. =Brown-capped leucosticte.= LEUCOSTICTE AUSTRALIS. This little bird and the white-tailed ptarmigan have the highest summer range of any Colorado birds.
528. =Redpoll.= ACANTHIS LINARIA. Common winter resident; lives from plains to 10,000 feet.
528b. =Greater redpoll.= ACANTHIS LINARIA ROSTRATA. Rare or accidental winter visitor; one record.
529. =American goldfinch.= ASTRAGALINUS TRISTIS. Resident; quite common in summer; sometimes reaches 10,000 feet.
529a. =Western goldfinch.= ASTRAGALINUS TRISTIS PALLIDUS. Migrant; probably common; added by Mr. Aiken.
530. =Arkansas goldfinch.= ASTRAGALINUS PSALTRIA. Common summer resident; breeds from plains to over 9,000 feet.
530a. =Arizona goldfinch.= ASTRAGALINUS PSALTRIA ARIZONÆ. Summer resident; not common.
530b. =Mexican goldfinch.= ASTRAGALINUS PSALTRIA MEXICANUS. Rare, but believed to be a summer resident at Trinidad.
533. =Pine siskin.= SPINUS PINUS. Common resident; breeding range from plains to timber-line.
000. =English sparrow.= PASSER DOMESTICUS. Rapidly increasing in numbers; has settled at points west of the range.
534. =Snowflake.= PASSERINA NIVALIS. Rare winter visitor; one record west of the range; several east.
536a. =Alaskan longspur.= CALCARIUS LAPPONICUS ALASCENSIS. Common winter resident; breeds far north.
538. =Chestnut-collared longspur.= CALCARIUS ORNATUS. Rare summer resident; winter resident, not common; common in migration.