House Finches

In late December, there was a gathering of House Finches around the backyard feeders. The numbers thinned in January and February, but last week they were seen again at the feeders, although not yet in the numbers seen earlier. These photos were taken last December. More detailed information on House Finches can be found here.

During the winter, House Finches form medium to large flocks, often mixing with other small birds including American Goldfinches, Pine Siskins and House Sparrows.
House Finches are aggressive enough to drive other birds away from the feeders.
Like all  other finches in its family, the House Finch is dichromatic by gender, which means that males and females are distinguishable by differences in color. And like many songbirds, the male house finch is the one that sports the colorful plumage.

Adult males vary in color from orange yellow to bright red. The color is derived from carotenoid pigments obtained from their diet of seeds, flowers, and fruits and added to the feathers during normal periods of feather replacement.

Studies have shown that brightly colored males are more successful at attracting mates than duller males (so what else is new?)

Brightly colored males also survive the winter better – wonder why.
During courtship, the male will touch bills with the female and may then present the female with choice bits of food and, if she imitates the posture of a hungry chick, actually feed her. The male also feeds the female during the breeding and incubation of both eggs and young,and the male is the primary feeder of the fledglings.House finches are monogamous. The female will incubate a brood of 3-6 eggs for 12-14 days, and both parents feed the altricial (birds that hatch naked and blind, lacking any feathers) young for 12-19 days. A pair may raise 1-3 broods per year, with multiple broods more common in southern populations. (Altricial birds include most songbirds, including American robins, northern cardinals and blue jays.)

Female House Finches have blurrier streaks and grayer undersides than their male counterparts.
Originally residents of Mexico and the southwestern U.S., House Finches were introduced to eastern North America in the 1940s.
The eastern population is descended from cage birds released near NYC in the 1940s. The birds were sold illegally and marketed as “Hollywood Finches.”  To avoid prosecution under the Migratory Bird Treaty Act of 1918, vendors and owners released the birds.

They quickly started breeding and spread across almost all of the eastern U.S. and southern Canada within the next 50 years.