House Finch
Haemorhous mexicanus
Compiled by Niyati Acharya
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. 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.
While the male house finch is easy to identify with its rosy red head and chest, the female blends in more easily, often resembling other brown-streaked birds. Andrea Debbink, the author of Bird Watching: Press Pause and Admire the Avian World, has some advice. “The vertical streaks on their chests help distinguish them from female house sparrows, and their boldness around people also sets them apart.”
The eastern population of House Finches has developed a consistent annual and often long-range migration pattern, while the native western population is primarily residential, occasionally migrating only short distances. Many House Finches from the Northeast U.S. and Great Lakes regions migrate to the southern U.S. to spend the winter.
A groundbreaking genetic study, published in Proceedings of the National Academy of Sciences, on house finches, has unveiled a major DNA inversion that may have helped the small birds develop resistance to disease. The research utilized decades of DNA samples from the Museum of Comparative Zoology, allowing scientists to observe how the species evolved disease resistance over time. The findings not only shed light on avian evolution but could also offer clues about how other species, including humans, genetically respond to infectious diseases.
Identifying genes influenced by natural selection can provide information about lineage-specific adaptations, and transcriptomes generated by next-generation sequencing are a useful resource for identifying such genes.
In a study led by Heather Watts, associate professor at Washington State University, investigated if temperature-related shifts in egg-laying dates were experienced by seed-eating species. Her team gathered around 950 nest records from multiple historic sources on California’s House Finches. The Finches advanced their laying date when spring temperatures were warmer. For every 1 °C (1.8 °F) increase in average spring temperature, egg-laying started an average of 4.6 days sooner.
