While the thunderstorms and fog kept every other bird subdued, one species sang out boldly through the Smoky Mountain forests: my friend the junco. In North Carolina these juncos were not the birds I did my PhD work on, however; those were in the Oregon Junco group, with chestnut backs and sides and dark hoods, while these were in the Slate-colored Junco group, as all-over grey as their name implies. I was extremely excited when one of these new juncos decided to fly into our net so that I could take a closer look and hold a new subspecies of junco.
We head for the Smoky Mountains full of confidence: the Kentucky Warblers may have proved to be elusive, but every source suggests that our new quarry will be more forthcoming. The Canada Warbler is known to be a particularly aggressive bird, likely to respond quickly to our calls; the American Redstart is a common and easy-to-find species. We will catch them easily while enduring less moisture and fewer mosquitos than before.
We were targeting Kentucky Warblers in Howell Woods, but a few other species seem to have missed that memo. Perhaps they wanted us to study their migratory routes, too.
We have ten days in North Carolina to get DNA samples from three species breeding there. Our target for the first five days is the Kentucky Warbler, a golden bird with a black mask whose population is declining. It is a highly local bird, meaning that we can’t just find them anywhere within the shaded region of a large-scale range map: we need specific location information. We get this information from eBird, following birders’ reported sightings to a place about an hour south of Raleigh called Howell Woods.
“How did y’all find us?” asks the manager of Howell Woods. “There’s folks on our road that don’t know we exist, but somehow we get birders from Europe asking about Kentucky Warbler and Mississippi Kite. I never understand it.”
I got my start in ornithology studying the love lives of House Wrens. House Wrens pair up to raise their babies in a manner compellingly analogous to the human “nuclear family;” but, like most birds, both partners also often “cheat” on each other (i.e., copulate with other birds). This means that the male wren may have chicks in other nests besides his own, and he may end up caring for chicks that are not biologically related to him. (Note: edited. The original version of this sentence had a mistake.)
This sets up a number of interesting questions, such as: why cheat on your partner? Are the chicks sired by outside birds somehow better? Do males know when they are caring for chicks who aren’t their own? The answer to the latter question seems pretty clear (no, the males do not know), but the former two are more challenging.
I was supposed to be done with field work after summer 2015, but you know how it is. The birds call. You realize that a few more blood samples would put the patterns you’re seeing in context in an illuminating way. You miss those feathery little dudes.
The small amount of field work I did this year took place much earlier than my usual field work because I was sampling juncos at a much lower elevation. Down here, the juncos are breeding in mid-March. Up at my usual sites, they wait until late May. That early start happened to be convenient for me, since I needed to analyze any data I got in time to file my dissertation in mid-May.
This nest is a great example of juncos’ love of sloping ground. In some cases, like this one, the sloping ground is slope-y enough to call a wall. I wouldn’t call this a typical junco nest, but it’s not really surprising either: juncos are reliably creative with their nesting choices, which must make it difficult for predators to find them. This nest certainly seemed well-hidden—and it didn’t have to worry about being stepped on, either.