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. 539. =McCown's longspur.= RHYNCOPHANES MCCOWNII. Common winter resident, dwelling on the plains. 540a. =Western vesper sparrow.= POOCÆTES GRAMINEUS CONFINIS. Abundant summer resident; breeds from plains to 12,000 feet. 542b. =Western savanna sparrow.= AMMODRAMUS SANDWICHENSIS ALAUDINUS. Common summer resident; breeds from base of foothills to almost 12,000 feet. 545. =Baird's sparrow.= AMMODRAMUS BAIRDII. Migrant; not common; a number taken east of the range, and one west. 546a. =Western grasshopper sparrow.= AMMODRAMUS SAVANNARUM PERPALLIDUS. Not uncommon summer resident; breeds on plains and in lower foothills. 552a. =Western lark sparrow.= CHONDESTES GRAMMACUS STRIGATUS. Common summer resident; breeds on plains and in mountain parks to 10,000 feet. 553. =Harris's sparrow.= ZONOTRICHIA QUERULA. Rare migrant; abundant migrant in Kansas. 554. =White-crowned sparrow.= ZONOTRICHIA LEUCOPHRYS. Abundant summer resident.