When is a Junco a Junco? Scientists continue to change the names of birds
Why is it that birds of the same species may look very different in various regions but have the same name? For instance, Dark-eyed Juncos in the Pacific Northwest may have a reddish back and a dark “hood” (Oregon race), while Dark-eyed Juncos in the northeast are generally a slate-gray color, without a hood (slate-colored race). Who decides where the lines are drawn between species? Why can birds that look very similar, like Black-capped Chickadees and Carolina Chickadees, be distinct species while others that look obviously different, like Dark-eyed Juncos from the Oregon and slate-colored races, be the same species?
A history of name changes
Committees of 8-10 highly experienced ornithologists and taxonomists make official changes in species names. For North American birds, the Committee on Classification and Nomenclature of the American Ornithologists’ Union (AOU) maintains the official checklist. AOU checklists are updated every few years as new information on bird biology leads the committee members to either divide one species into two or more species (splitting), or to group species together under one name (lumping). Changes are often made based on new information regarding the genetics of the birds, how birds communicate (song-types), or the frequency of hybridization. Some groups of birds have been split and lumped several times. For instance, Dark-eyed Juncos had been split into as many as 7 different species before being lumped together under one name. Members of the titmouse family have been split from 3 species to 5 species since 1983 (see taxonomy flow charts below).
How to report subspecies to FeederWatch
While the Oregon, pink-sided, white-winged, slate-colored, and gray-headed races are all considered Dark-eyed Juncos, Project FeederWatch would like participants to report which subspecies you see. The same is true for other species that have identifiable races, like Red-shafted and Yellow-shafted flickers. Your reports allow us to map the geographic distribution of the various races in the winter. Although subspecies do not automatically appear on the checklist of likely species found in your region, you may easily add the subspecies you are seeing by clicking on the “Add a Species” button. Then enter the part of the species name, like “junco” or “flicker” to bring up a list of available subspecies.