In the column “Since You Asked” in every issue of BirdWatching, Contributing Editor Julie Craves answers readers’ questions about birds and bird behavior. Here’s a question from our April 2014 issue:
Why are Evening and Pine Grosbeaks not listed with the other grosbeaks in bird guides? — Lois Bingley, Endicott, New York
While some field guides organize birds by plumage color or other field marks, most list birds in taxonomic order, a sequence that reflects evolutionary relationships. Birds are grouped into major categories, including order, family, genus, and species. Taxonomic lists start with birds considered to be the most primitive, or oldest, on the evolutionary tree. Currently, ducks and geese are presented first on North American lists, so they appear at the beginning of most recent field guides.
All of the birds we call grosbeaks are found in the order Passeriformes, or perching birds, but North American grosbeaks belong to two different families. Pine and Evening Grosbeaks are in the family Fringillidae, along with the goldfinches, redpolls, and crossbills, to name a few. Rose-breasted, Blue, Black-headed, Crimson-collared, and other grosbeaks are in the family Cardinalidae, which also includes familiar birds like cardinals and tanagers. Therefore, the grosbeaks are described in separate sections of most field guides.
As you can see, common names may not be good indicators of close relationships among different species. Our classification of organisms into taxonomic hierarchies isn’t perfect either, since discoveries made through genetic and molecular studies continually result in new understanding of the relationships. The American Ornithologists’ Union’s checklist has had a dozen updates in as many years, making it difficult to keep up with name changes and reshuffling of the taxonomic order.
About Julie Craves
Julie is supervisor of avian research at the Rouge River Bird Observatory at the University of Michigan Dearborn and a research associate at the university’s Environmental Interpretive Center. She writes about her research on the blog Net Results, and she maintains the website Coffee & Conservation, a thorough resource on where coffee comes from and its impact on wild birds.