Splitting Jays

California Scrub Jay_ToroPark-Salinas-CA_LAH_6692Heinlein said that there’s no such thing as a free lunch.* He must not have been a birder. When the American Ornithological Union met this year, many birders added a new species to their life lists without even leaving their arm chairs. It’s time to update our field guides—even the brand new Sibley’s. The Western Scrub-Jay has now been split into the California Scrub-Jay (Aphelocoma californica, left)  and the Woodhouse’s Scrub-Jay (Aphelocoma woodhouseii).

“California” is easy to remember—it’s the one in California, Oregon, Washington, and south into Baja California. It’s also uncommon in western Nevada, near Reno. “Woodhouse’s” is a bit trickier to remember. That’s the species we have here in Colorado, as well as Nevada, Utah, Arizona, New Mexico, parts of western Texas, and central Mexico. From Kaufman’s map, you might also find a few birds east if the Sierras in central and southern California, as well as southern Idaho and the Oklahoma panhandle.

Since their ranges overlap so little, most of the time we’ll have no trouble telling the two species apart. However, it’s not that hard if you’re familiar with one or the other. The California jays are darker, with much more vivid colors and more contrast with their white throat. Their lower belly is white, too, as is the area under their tail (the undertail coverts). Their upper back is a brownish gray. The white “eyebrow” is more distinct. Woodhouse’s Scrub Jays are more of a medium blue with gray, not white, undersides. Their upper back is blue-gray, and their eyebrow looks as if their pen was running out of ink. In the photos below, the California bird is on the right.

Florida Scrub Jay_MerrittIslandNWR-FL_LAH_4150Interestingly, the Island Scrub-jay, found only on Santa Cruz Island, off the coast of southern California, continues the trend, looking like a very contrasty California Scrub-Jay. But the fourth scrub-jay in North America, the Florida Scrub-Jay (left), is in many ways more like the California bird than its nearer neighbor, with a whiter throat and brown-gray upper back. Go figure.

The AOU’s “Committee on Classification and Nomenclature—North and Middle America” (aka the Checklist Committee) has considered this split for some time. Those opposed pointed out that the birds interbreed where they come together in western Nevada, but apparently this happens less often than previously thought. As a result, we now recognize two species where before we thought there was only one.

There were a few other splits. The Leach’s Storm-Petrel (Oceanodroma leucorhoa) that is found off the west coasts of the US and Canada has now been separated from its close relatives found off the coast of western Mexico, and the Mexican species have been divided as well. While the California birds got to keep their name, the Mexican birds are now either Ainley’s Storm-Petrel (O. cheimomnestes) or Townsend’s Storm-Petrel (O. socorroensis). The latter has also been seen off southern California, so if you see a storm-petrel in that area, you’ll need a really good look at it to know which one it is.

Finally, if you’re into hummingbirds, note that the Green Violetear is now the Mexican Violetear (Colibri thalassinus), while the birds found farther south, from Costa Rica into South America, are Lesser Violetears (Colibri cyanotus).

There was also a list of birds given new scientific names based on current genetic studies. Thankfully, the common names remained unchanged. In conjunction with the renaming, the list of species has been rearranged. We can probably ignore this for now, but future field guides, which are typically arranged in phylogenetic order, will conform to the new sequence. For example, instead of finding Loons in the front, they’ve been moved back to spot #20, and the Flamingos have taken the lead. You can see the new sequence below.

Of course, I’m thrilled to add another checkmark to my life list, but my victory will likely be short-lived. It didn’t happen this year, but there is a growing consensus that the Hoary Redpoll and the Common Redpoll are in fact the same species. Since I’ve seen—and counted—both these birds, I’ll likely lose a bird next year. Oh well, easy come, easy go.
*From his classic sci-fi novel, The Moon is a Harsh Mistress.


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