A Rare Inter-Species Pairing
In the past I’ve been known to refer to June as the birding doldrums. In a way, it is – the flashy, globe-trotting migrant songbirds and shorebirds have passed us by, and we’re a month away from seeing the first southbound shorebirds and peak numbers of offshore seabirds. But to call it the doldrums is a slap in the face to our local breeding birds.
It also overlooks that this is the time to find and document interesting records of birds that don’t typically breed around here. Birds like the scandalous, tabloid-worthy interspecies pair of rare warblers shacking up in the forests around Santuit Pond in Mashpee right now.
Kentucky Warblers are bright yellow, black masked songbirds of southern broadleaf forests. If you got in a car and started driving southwest, you wouldn’t find them breeding commonly until you hit West Virginia and Ohio, and after that Missouri. So we certainly don’t expect to find them on a stroll through the Cape Cod woods. Though they are brightly colored and loud, they are nevertheless cryptic – they skulk in low vegetation and their two-note song is easily confused with that of our backyard Carolina Wrens. So it was fortuitous that local physician and rare bird hound Peter Crosson found one in the woods east of Santuit Pond in Mashpee back in late May. While the old jokes about doctors canceling appointments always involved golf, if Peter cancels there’s likely a rare bird around, and he’s often the one who found it.
This warbler has been singing in the same spot for over three weeks now, which is certainly noteworthy. Even more noteworthy is that he has attracted a female. But the noteworthiest fact of all is that the female is not a Kentucky Warbler – it’s a Worm-eating Warbler, a drably colored species in a totally different genus. She has been observed fawning over this male Kentucky – she follows him around and chips excitedly when he sings like some tween at a boy band concert. Worm-eating Warblers are uncommon breeders on the Upper Cape and a few other places in the state, and they have likely bred at this spot before, so it’s possible her mate was a no show this year. As I’ve said before, with rare birds it’s sometimes a “love the one you’re with” situation. The ornithological literature is full of weird warbler hybrids, including an astounding three species hybrid found in Pennsylvania last year when a Blue-winged/Golden-winged Warbler hybrid bred successfully with a Chestnut-sided Warbler. So if these crazy kids can make it work, we could play host to the next scientifically significant and possibly unprecedented warbler hybrid.
There are no doubt other uncommon breeding birds to be discovered out there. Birders in Plymouth recently discovered a singing Hooded Warbler and Acadian Flycatcher in the middle of some seldom-visited forest near the Pine Hills. We still have some surpassingly big forest tracts remaining in places like Falmouth, Mashpee, West Barnstable, Brewster, and Harwich, not to mention the Cape Cod National Seashore, and all of them likely hold surprises for the enterprising birder. Maybe some of the Red Crossbills or even Evening Grosbeaks left over from this winter’s irruption have set up shop somewhere, or more of the southern visitors from April and May have stayed to cast their lot with us. I still firmly believe that Mississippi Kites, that southern hawk we see each spring, are going to breed in Massachusetts if they aren’t already. That nearby marshy pond or cattail marsh up the road could hold a pair of Pied-billed Grebes or Blue-winged Teal.
Mid-June may not have the caché of May, with it’s torrent of colorful migrants arriving every day, but it’s when the average person has the best chance to contribute interesting breeding records. Just keep your ears and eyes peeled on your next woodland hike or visit to your local swimming hole. And if you do find another scandalous mixed-species breeding pair, please call me before you call the National Enquirer. I have an exclusive deal with TMZ and I want to give them first dibs.