I just added bird #19 to my yard list. That may not sound like very many, but we only moved into our new house in May, and we had no landscaping until August. Birds are rarely attracted to bare dirt!

Not surprisingly, #19 was a Dark-eyed Junco. Vertical migrants, Juncos spend the summer up in the mountains, nesting in the conifers, and descend to lower elevations for the winter. At 7,100 feet , our house barely qualifies as a lower elevation; the park up the road, a mere 200 feet higher, hosts juncos all year.

Juncos are common birds. While I was pleased to welcome them to our feeder, and happy to add another species to my fledgling yard list, we normally don’t get too excited about Juncos. However, these everyday birds cause a lot of confusion when it comes to taxonomy.

Although they may not look like sparrows—adults have no stripes and aren’t brown—their size, shape, and ground-feeding behavior are all clues that they are indeed in the sparrow family (Emberizridae). Everyone agrees on that. However, various ornithologists argue that there are anywhere from three to twelve species in the genus Junco.

Currently, the “lumpers” are winning, designating two species for North America: the ubiquitous Dark-eyed Junco, and the Yellow-eyed Junco, whose range barely protrudes north into southern Arizona and New Mexico. A third species, the Volcano Junco, lives in Central America. Some taxonomists consider the nearly extinct Guadalupe Junco, endemic to Guadalupe Island (off the west coast of Mexico), a fourth species. Others lump it in with the Dark-eyed Junco.

Current field guides break the two North American birds into multiple subspecies. (The confusion comes when “splitters” want to make these all separate species). There are six Dark-eyed Junco subspecies in North America: Oregon (top photo), Pink-sided (below), White-winged, Slate-colored (above), Gray-headed (shown here), and Red-backed. (For once, whoever named the subspecies actually based their names on characteristics a birder can see in the field.) To make things even more confusing, the slate-colored junco sub-species have been further sub-divided into two sub-sub-species!

You never know when the splitters will have their way and all those subspecies will become countable birds, so when I see a junco in the field, I always try to determine which subspecies it belongs to—just in case.

All this controversy about junco species and subspecies is fascinating for taxonomists, but what about the rest of us? It’s easy to disregard common species as being, well, common, and therefore conclude that they’re not interesting. But the very fact that these birds are common means that we have more opportunity to observe their behavior. Every so often, I have to remind myself that “interesting” is more than feather-deep.

For example, I wondered if all these different-looking birds sound the same. It turns out that yes, their songs and calls are pretty similar—with one exception. The gray-headed and red-backed juncos, which look much like the Yellow-Eyed Junco except with dark eyes (and a few less-obvious differences in plumage), also sound much like the Yellow-Eyed. Since their non-breeding ranges can overlap, it makes one wonder how closely they’re related.

I was also surprised to learn that these birds are often ground nesters. Nests may also be near the bottom of a tree or shrub, but they’re always thoroughly hidden. The females do all the work of incubating, keeping them busy for almost two weeks. Then the young stay in the nest about the same amount of time before taking up life on their own. When the first brood is gone, the parents will often start a second family before calling it quits for the winter.

Juncos may not be as colorful as finches or as exotic as an accidental from Mexico or Canada, but we can still enjoy their antics under the feeder. I scatter millet, which they seem to prefer over sunflower seeds. Pulling up the sprouted seeds they m