Haemorhous mexicanus

The house finch (Haemorhous mexicanus) is a bird in the finch family Fringillidae. It is native to western North America, and has been introduced to the eastern half of the continent and Hawaii. This species and the other 'American rosefinches' are placed in the genus Haemorhous. This is a moderately-sized finch. Adult birds are 12.5 to 15 cm (4.9 to 5.9 in) and span 20 to 25 cm (7.9 to 9.8 in). Body mass can vary from 16 to 27 g (0.56 to 0.95 oz), with an average weight of 21 g (0.74 oz). Among standard measurements, the wing chord is 7 to 8.4 cm (2.8 to 3.3 in), the tail is 5.7 to 6.5 cm (2.2 to 2.6 in), the culmen is 0.9 to 1.1 cm (0.35 to 0.43 in) and the tarsus is 1.6 to 1.8 cm (0.63 to 0.71 in). Adults have a long, square-tipped brown tail and are a brown or dull-brown color across the back with some shading into deep gray on the wing feathers. Breast and belly feathers may be streaked; the flanks usually are. In most cases, adult males' heads, necks and shoulders are reddish. This color sometimes extends to the belly and down the back, between the wings. Male coloration varies in intensity with the seasons and is derived from the berries and fruits in its diet. As a result, the colors range from pale straw-yellow through bright orange (both rare) to deep, intense red. Adult females have brown upperparts and streaked underparts. Their song is a rapid, cheery warble or a variety of chirps. This bird belongs to the genus Haemorhous, together with the purple finch and Cassin's finch. These three species are not closely related to the Old World Carpodacus rosefinches. These birds are mainly permanent residents throughout their range; some northern and eastern birds migrate south. Their breeding habitat is urban and suburban areas across North America, as well as various semi-open areas in the west from southern Canada to the Mexican state of Oaxaca; the population in central Chiapas may be descended from escaped cagebirds. Analyses of nest records from House Finches in California spanning more than a century found that egg‐laying occurred significantly earlier in warmer springs. Originally only a resident of Mexico and the southwestern United States, they were introduced to eastern North America in the 1940s. The birds were sold illegally in New York City as 'Hollywood Finches', a marketing artifice. To avoid prosecution under the Migratory Bird Treaty Act of 1918, vendors and owners released the birds. They have since become naturalized; in largely unforested land across the eastern U.S., they have displaced the native purple finch and even the non-native house sparrow. In 1870, or before, they were introduced to Hawaii and are now abundant on all its major islands. There are estimated to be anywhere from 267 million to 1.7 billion individuals across North America.