Thursday dawned buggy, humid, and windy (from the South). We've started hearing some Killdeer making morning flight calls which is fun, but otherwise it was painfully slow in the morning. We recaptured a male Prothonotary warbler in the first round, but the site was pretty quiet after that (one Ruby-throated Hummingbird, which we release without banding because they require a special permit).
Then Nakita comes back to the banding tent with a large bird in his hand- a nice change from the little warblers and gnatcatchers we've been catching. Since Nakita's banding and birding experience is predominantly Russian/European, it is always nice for him to see something new, and he now he had just extracted his first cuckoo.
Cuckoos are unmistakable with their downward curved bills, long tails with well-defined white spots, and slender but medium-sized bodies. Also, cuckoo feet are zygodactyl, with two toes pointing forward and two toes pointing back, a characteristic shared by woodpeckers. (Most other birds have three toes pointing foward and one pointing backward).
This was a pretty exciting bird for us: Mason had never banded a Yellow-billed Cuckoo before and enjoyed handling this unusual bird. Jaci and I were a little surprised when he identified it as an after hatch year bird, because it's underside was a buffy color, not the white of an adult Yellow-billed Cuckoo. We also thought it was unusual that the bird was molting.
Some birds molt flight feathers individually, showing different lengths or colors of feathers in the wings and tail.
Molting, migration, and breeding are so energetically expensive for birds that they primarily occur independently of each other. Not to mention, it is hard to fly long distances without a full set of feathers! But it is not unheard of for some birds to do two at once, and we are familiar with molting birds because several of the resident Northern Mockingbirds at our site have been molting when banded.
We finish banding the cuckoo, taking some photos for scientific and personal use, and send it on its way. And then we start joking about what a funny looking Yellow-billed Cuckoo it was, and what if that's what it wasn't? Jaci used to play this game with her banders last season, and it is pretty easy to get stuck in the routine of identifying and banding birds based on what you expect to see.
We saw a cuckoo with a yellow bill, thus it was a Yellow-billed Cuckoo.
A close-up of our cuckoo's head.
The only other cuckoo present in the area during migration is the Black-billed Cuckoo. Which means it had to be a Yellow-billed, right? I mean, what else looks like a Yellow-billed Cuckoo with a buffy underside?
Jaci joked about the remaining species of cuckoo in the continental US, and flipped open a bird guide to see the chest color. Sure enough, the Mangrove Cuckoo has a yellow beak and a buffy chest.
When the realization that we had just released a non-migratory bird endemic to mangrove swamps, found in the US only on the Southern tip of Florida, and rarely documented outside that state dawned on us. The molting made sense in the context that this was a resident bird (in Florida!): Mangrove Cuckoos aren't migratory so this bird wasn't spreading its energy resources too thin by molting this time of year. We were all glad we had taken some personal photos- here was a bird none of us had ever seen before, much less handled, and wouldn't be likely to see again while we were at Fort Morgan. But even those photos weren't going to be enough to prove we had a Mangrove Cuckoo. We needed more measurements, particularly of the bill and tail.
Which meant we had to catch it again.
The next wild goose (or cuckoo?) chase was finding the bird in our site. I went on another net run before the rest of the team decided to go off on this errand, but apparently the bird was easy enough to find. Joanna noted that vagrants often are recorded as being rather docile and easy to photograph in their non-native locales, so perhaps the bird was more concerned with why and how it was here than the fact that it was being encouraged back into a net. By the time I got back, Nakita returned yet again with a cuckoo in hand.
Mason took some extra measurements, and there was no doubt it was a vagrant Mangrove Cuckoo. We took many more photos of the bird before letting it go this time.
I guess these South winds have brought us something!
The distinctive buffy underside of the Mangrove Cuckoo.
Mason STILL hasn't banded a Yellow-billed Cuckoo, but this was a pretty great trade-off : )
