House Finches are small-bodied finches with fairly large beaks and somewhat long, flat heads. The wings are short, making the tail seem long by comparison. Many finches have distinctly notched tails, but the House Finch has a relatively shallow notch in its tail. They measure 13 to 14 centimeters in length, with a wingspan of 20 to 25 centimeters. Adult males are rosy red around the face and upper breast, with streaky brown back, belly and tail. In flight, the red rump is conspicuous. Adult females aren’t red; they are plain grayish-brown with thick, blurry streaks and an indistinctly marked face. House Finches are gregarious birds that collect at feeders or perch high in nearby trees. When they’re not at feeders, they feed on the ground, on weed stalks, or in trees. They move fairly slowly and sit still as they shell seeds by crushing them with rapid bites. Flight is bouncy, like many finches. House Finches frequent city parks, backyards, urban centers, farms, and forest edges across the continent. In the western U.S., you’ll also find House Finches in their native habitats of deserts, grassland, chaparral, and open woods. This species is of low conservation concern.
The House Finch was originally a bird of the western United States and Mexico. In 1940 a small number of finches were turned loose on Long Island, New York, after failed attempts to sell them as cage birds (“Hollywood finches”). They quickly started breeding and spread across almost all of the eastern United States and southern Canada within the next 50 years.
The total House Finch population across North America is staggering. Scientists estimate between 267 million and 1.4 billion individuals.
House Finches were introduced to Oahu from San Francisco sometime before 1870. They had become abundant on all the major Hawaiian Islands by 1901.
The red of a male House Finch comes from pigments contained in its food during molt (birds can’t make bright red or yellow colors directly). So the more pigment in the food, the redder the male. This is why people sometimes see orange or yellowish male House Finches. Females prefer to mate with the reddest male they can find, perhaps raising the chances they get a capable mate who can do his part in feeding the nestlings.
House Finches feed their nestlings exclusively plant foods, a fairly rare occurrence in the bird world. Many birds that are vegetarians as adults still find animal foods to keep their fast-growing young supplied with protein.
Source: House Finch Overview and Identification Information, All About Birds, The Cornell Lab of Ornithology