Have you seen a male house finch lately that seems a little brighter red and a little bigger than usual? If so, you may be seeing a Cassin's finch. Several birds, including the Cassin's sparrow and Cassin's kingbird, are named for Pennsylvania-born John Cassin, who specialized in birds of the West and was one of the best known American ornithologists in the mid-19th century.

During the Civil War, Cassin survived the harsh conditions of the Libby Confederate prison camp. After the war, he published the first comprehensive work on birds of the West. He noted 198 birds not mentioned in any prior work, including those by John James Audubon. As a result, his name is given to several of his "discoveries", despite the fact that Cassin is unfamiliar to many present-day birders.

At our store, many customers have reported seeing Cassin's finches in the last couple of weeks. The male Cassin's finch is very similar to the male house finch but is slightly larger and often a bit redder (although male house finches also brighten up in the spring). The bright-red crown on the Cassin's head is better defined than on the house finch and sometimes looks as though it's slightly raised, almost like the beginning of a little crest. The Cassin's bill is a bit longer and straighter than the house finch's upper bill, which curves slightly downward. The male Cassin's finches also sports a slightly longer tail.

The female Cassin's also is similar in appearance to the female house finch, with a few notable differences. Like the male, the female Cassin's is about a half-inch larger than the female house finch, with a longer tail and straighter bill. Neither females have any red color. Both sport brownish-gray streaks, but the Cassin's streaking is more sharply defined.

Northern New Mexico is on the extreme southern edge of the Cassin's finch year-round range, but in the Santa Fe area we do see them in the winter — usually at winter's end, in small flocks, as they move north for nesting. Cassin's finches live mostly in high-mountain forests of the West, where plenty of mixed conifers are found. Their year-round range extends from Northern New Mexico at the southern edge to Canada along the Rockies at the northern edge. Cassin's finches forage for food mostly on the ground, so watch for them under your feeders, shrubs and trees.

Enjoy the Cassin's finch while you can, and if you think that house finch in your backyard looks a bit bigger or brighter, or more crisply streaked, then you may be seeing a bird named for a Civil War veteran who loved Western birds.

Anne Schmauss is co-owner of Wild Birds Unlimited in Santa Fe. She is the author, with her sisters, of the book For the Birds: A Month by Month Guide to Attracting Birds to Your Backyard. Her articles appear in Birds and Blooms magazine.