House Finches are a very common sight year-round in our area. They occur in every county in Colorado and they breed in all but 3 high mountain counties. Originally, House Finches resided only in Mexico and southwestern U.S. But they were illegally sold as caged birds in the east in the early 1900s. In the 1940s, the Migratory Bird Treaty Act made it illegal to capture or sell most wild birds. With increasing enforcement of this law, some pet shop owners on Long Island, NY, allegedly just released their inventory of House Finches. The House Finches found that they rather enjoyed the Atlantic seaboard. And the rest, as they began to spread westward across the continent, is avian history.
Female and juvenile House Finches are rather drab brown with streaked breasts and bellies. But a male House Finch typically has a red forehead and a red stripe over his eyes, as well as red on the breast and the rump contrasting with rather drab, streaky brown elsewhere. However, you might occasionally see a male that has yellow or orange feathers where most males would show red feathers. This color variation primarily reflects a diet that is low in carotenoid pigments—yellow, orange, or red fruits and vegetables. Females seem to prefer the reddest male available, perhaps reflecting the odds that that fellow will be able to provide lots of appropriate food for her and the kids.
In the winter, you might see both House Finches and their cousins, Cassin’s Finches. Cassin’s Finches are a bit larger and bulkier-looking than House Finches. As mentioned in last month’s newsletter, a male Cassin’s has a bright red cap that he often raises in a crest. Both sexes have finer brown streaks on their chests and bellies than House Finches do; and the whiter background under these streaks sets up a more dramatic contrast than does the duller background and wider streaks of the House Finches.
A House Finch’s diet is more than 95% vegetable matter—buds, grain, seeds, and fruit. Their main source of animal matter is probably whatever insects they eat while they’re gobbling up plant parts. Parents initially feed their young through regurgitation of whatever is in their crops (an enlarged portion of their throats where they store seeds). As a result, even their babies receive a vegetarian diet—a rare occurrence among songbirds, since most seed- and fruit-eating adults feed protein-rich insects to their fast-growing youngsters. The female lays a clutch of 2 – 6 eggs, which hatch in 13 – 14 days. Nestlings typically leave the nest 13 – 16 days after hatching and follow their parents, begging noisily, for another 2 weeks. Early in the breeding season, the male will continue to feed the fledglings while the female starts a 2nd brood; late in the season, both parents feed the noisy little beggars.
The House Finch’s common name refers to its frequent occurrence around houses and other human-built structures; as with last month’s Cassin’s Finch, the term “finch” derives from the Anglo-Saxon finc, which was their word for these birds. Based on recent DNA analyses, the scientific name of the House Finch has now been changed to Haemorhous mexicanus. The genus name (Haemorhous) refers to the red rump patch in Greek—“haem” for “blood” and “orrhos” for “rump.” The species name, mexicanus, reflects the bird’s original range. House Finches used to be classified in the genus Carpodacus, which I always liked. Carpodacus means “fruit biter,” from the Greek words “karpos” (fruit) and “dakos” (biter). Despite the genus name change, that characteristic still fits. Fruit is definitely a staple, especially during breeding season for feeding the growing “fruit biters.”
You can learn more about the House Finch here.