Geographic range: C. mexicanus ranges from southern Canada to Mexico.

Physical characteristics: Medium -sized finch, approximately 14 cm in long, with wingspan of 8 - 8.5 cm. Male is bigger than female. The male has a rosy-pink throat, front of head and rump. Back is lightly streaked as well as abdomen, wings and tail. The female has an overall gray-streaked brown appearance.

Food Habits: Exclusive herbivore. Diet consist entirely of seeds and fruit. Often forages on the ground.

Reproduction: Nest made of grasses, hair, or other fiber has a shape of as a shallow cup and is placed on tree branch, inside tree cavity and even on a building, or in a bird box in urban areas. A typical clutch consists of three to six bluish or greenish-white eggs that are black-spotted near the large end.

Behavior: The most aggressive behavior among male House Finches occurs while mate guarding. The male will lower his back and tilt his head upward to display his dominance. Pair formation begins in the winter, culminating in pairbonds established just before the breeding season begins. Females are most likely to choose a mate that has the most brightly colored plumage rather than the dominant male. Since plumage color is directly related to intake of carotenoid-rich foods, male competitive and foraging capabilities may be reflected in carotenoid coloration, and this may be a good indication of overall male quality, inducing female mate choice.

Habitat: House finch is highly adaptable to urban and suburban environments. It is also found in the open desert and desert grassland, chaparral, oak savannah, riparian areas, and open coniferous forests.

Biomes: temperate forest & rainforest, temperate grassland