Frog season is upon us, and for us in the Frog Lab, regular sleeping hours are a luxury of the past. In the day we hide from the sun in basements and prepare our equipment.
Painting frog models to perfectly match real frogs.
Calibrating a speaker so that it ouputs the sound of a frog call at exactly 85.0 dB.
In the night, we don our chest waders, take up our headlamps, hang bags of tupperware from our wader straps, and walk into the ponds to seek our prey.
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.
Or perhaps not.
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.
I just wrapped up what I think will be my last field work on the juncos for my dissertation. It was quite the eventful trip; I saw a few things I’ve never seen before – but more on that in a future post.
We were trying to catch an unbanded male. He was interested in our playback, but had escaped from the net once already, meaning he was likely to be wary of the net now. When he flew into the net the second time, I ran for him quickly, wanting to get to him before he managed to escape again.
…Or I started to run. Then I failed to clear a large rotting log and went down.
“Are you okay?” one of my field assistants asked.
“I’m not sure,” I answered honestly, from the ground. “Get the bird!”
In the field, I become especially attentive to temperature. Is it too cold to catch birds? Are my hands warm enough to not chill a bird when I hold it? Recently, a friend very kindly let me take his FLIR ONE to the field: this is a device that fits over your phone and lets you take photos of heat. (Normal photos are of visible light.) Warmer objects show up as yellows and whites; colder objects are blue and black. The photos it takes aren’t of absolute temperature—that is, 40 degrees F isn’t always the exact same color—but rather of relative temperature: within the same photo, you can use the colors to compare temperatures, but you can’t compare across photos.
This was a lot of fun to use in the field, especially since the weather so generously gave us lots of temperatures to observe by snowing on us. Did you know that snow is cold, and humans are warmer than snow?
Now you do!
As endless as PhDs may seem to those in the thick of them, they do end. I am now almost exactly one year out from my planned graduation date, which means that I need to transition from collecting my data to analyzing and disseminating my results. Practically, this means that I can’t spend the whole summer out in the mountains tracking juncos, like the last three years. I need to also spend the summer running analyses, writing, and presenting at conferences.
Of course, I can go out to the mountains sometimes. Just to see what the juncos are up to. They would probably miss me otherwise, right? I’ll just collect a little more data…
We do not miss you. Look, why don’t you not come here, and we’ll send you a postcard maybe?
Juncos nest on the ground (usually; sometimes they will nest higher, even reusing old robins’ nests, but I’ve never seen this myself. It’s probably because I’m short). This makes their nests tricky to find, since in the first place, there is a lot of “the ground” to search, and in the second place, you have to be really careful where you step while you search.
They don’t just nest on the ground, though: they often hide their nests underneath things. Some of them are quite good at it.
YABI’s nest. What do you mean, you can’t see it – it’s right there!
See, there it is!
Tough Little Birds 