House Finches are among the most reliable and frequent visitors to feeders in the Flathead Valley. At our home south of Kalispell, 30 to 40 of these cheery, sparrow-sized birds spend most of the day perching in the top of a larch tree near the house and making frequent visits to the feeders and water on our deck. If you are not familiar with these colorful birds, the males are easily identified by the red coloring on their head, chest and rump, while the females are less colorful with a uniformly brown-streaked head and broad brown streaking on the breast and belly. Both have the short chunky bill typical of seed eaters and they commonly travel together in small flocks, especially in the winter months. Both males and females have two thin white wing bars, a square tipped tail, black eyes and dark brown legs.

As you observe a group of House Finches, you’ll probably notice that the males display a wide range of color variation, perhaps all the way from pale yellow to bright red. Our small group has males ranging from pale orange to bright red. This occurs because the coloring depends on the amount of carotenoid pigments in the bird’s food source during the molting period. Also, studies show that the females prefer the reddest males, suggesting that intensity of color is an indicator of the male’s fitness.

My research at www.birds.cornell.edu tells me that House Finches are native to the western United States and occur in a wide variety of habitats ranging from desert to chaparral and open coniferous forest to cities. Since House Finches prefer edge habitat and require water as well as structures for nesting and perching, their range expansions have been facilitated by man’s changes to the environment. As suitable habitat was created by man, the western populations have expanded north into British Columbia and into central and eastern Montana over the past hundred years. There is a close correlation between House Finch abundance and the size of local human population.

As you’re watching those flocks of House Finches devour the sunflower seeds in your feeders, be sure to look for some similar species that may have joined the group. In our area, the Cassin’s Finch and also the Purple Finch are regularly seen, sometimes mixed in with flocks of the more common House Finch. Cassin’s Finch is distinguished from the House Finch by its slightly larger size (6-6.5 inches), its more pointed bill, and shorter, notched tail. Male Cassin’s also has a bright red crown on the top of its head, as compared to the male House Finch which has a more overall red appearance to the head. Male Purple Finch is a darker raspberry red with red on the nape, back and flanks and little or no brown streaking on the breast or flanks. For more detail on distinguishing these three finches, check out the information on-line at the Cornell Lab website.

Eastern populations of House Finches descend from the 1940 release of illegally caged birds by pet shop owners on Long Island, New York. These birds are thought to have been trapped in the Los Angeles area and proved to be extremely prolific in their new environment, spreading north into southern Ontario, south to northern Florida and the Gulf of Mexico and west into the Great Plains where they are now meeting the native western birds. Interestingly, these introduced eastern birds developed a migratory behavior that is absent in the native western birds and House Finches from the Great Lakes and the northeastern United States now migrate south in the winter (perhaps searching for that California weather that their ancestors came from?) while the native western birds are non-migratory.

Sadly, since January 1994, the House Finch population in the eastern United States has been decimated by an avian eye disease called Mycoplasmal Conjunctivitis, a disease known previously only in poultry. Over the twelve years since this disease was first observed in the east, it has spread rapidly through the whole eastern population, killing an estimated forty percent of the House Finch population there. Although occurrences in other species such as American Goldfinch have been reported, the common and colorful House Finch seems to be the primary victim.

Starting in 2002-2003, when House Finches captured in Missoula, Montana, carried the conjunctivitis bacterium, Cornell Lab determined that this disease has reached western House Finch populations. Currently the Cornell Lab of Ornithology is conducting a House Finch Disease Survey in order to determine the extent of the infection in western birds. Data collected thus far indicates that the disease may not be spreading as quickly in the western United States as it did in the east, but Cornell is encouraging everyone who observes birds to be on the lookout for its appearance and to report their findings to their research team. Through data collected, researchers hope to determine if there are geographical differences in the prevalence of this disease, if the disease is spreading to other species, and if the House Finch numbers are declining in the West as they did in the East.
 

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	Male House Finch with diseased eye--taken south of Kalispell in February 2006 by Jeannie Marcure

If you would like to help Cornell researchers learn more about this disease, you can sign up on the net at www.birds.cornell.edu/hofi, or by calling 800-0843-2473. Mail inquiries can be sent to Membership Services, Cornell Lab of Ornithology, 159 Sapsucker Woods Rd., Ithaca, NY 14850. Data may be submitted via the Internet or by sending in paper forms and there is no charge to participate.

Please consider taking part in this important project. All you need to do is attract birds to your yard, record the presence or absence of sick House Finches, and then submit your observations to the Cornell Lab. By contributing your findings you will help scientists determine how this disease is affecting the House Finches in the west and this information will be used to help manage future outbreaks of wildlife disease.