Like most Northern Hemisphere birders, I’ve been monitoring the signs of spring like a dog watching the driveway for a beloved owner. My ears perk up with every new song, my tail wags (ok, not literally, but darn close) every time I see or hear about a newly-returned migrant. And reports of birds nesting – not owls, of course, those weirdo snow fetishists, but other birds nesting – light up my life.
So right now I’m feeling pretty good about Eurasian Collared-doves. With a hardiness that belies their delicate looks (but helps explain their phenomenal success), these pioneering pigeons are already sitting on eggs at at least one location in Montana.
A Eurasian Collared-dove photographed by Mike in the Bahamas, which is pretty different from midwinter Montana
Eurasian Collared-doves, as you may have gathered from the name, are not part of our native avifauna. Originally from India and the vicinity, it is believed that they had already undergone two major expansions – through Asia Minor in the 1600s, and then across Europe in the 1900s – when they first appeared in North America. The Collared-doves were introduced to the Bahamas in the 1970s, and from there apparently leapfrogged to the U.S. under their own steam (although other populations, escaped from captivity, may have joined up with the originals later.)
Most exotics, at least in the bird world, stick close to their point of arrival and barely hang on – or don’t – over the generations. It’s just that the exceptions are so much more attention-grabbing. We remember starlings not skylarks, House Sparrows not Eurasian Tree Sparrows, Cattle Egrets not… well, whatever we’ve forgotten because it didn’t do as well as the Cattle Egrets. The Eurasian Collared-Doves joined the illustrious (or notorious) few, and got firmly established in the Southeastern U.S., and if the story had stopped there it would be interesting enough.
But the story, and the birds, did not stop there. In 1998 W. M. Hochachka noted that one had spent the winter “as far north as eastern Montana”. The agricultural nature of the area seems to suit the Eurasian Collared Dove. Here – in a state so far removed from their native land that the entire city of Missoula doesn’t even have an Indian restaurant – they are now hunkered down amidst lingering snow to make more Eurasian Collared-doves. They appear regularly on our Christmas Bird Counts and number in the hundreds. Whatever they used to be, they are now a bird of Montana. And of Wyoming. And eventually, of who knows how many Western states?
Like any good ecologist, I couldn’t help but be suspicious when I first heard of this. “Invasive” is an ugly word, and ugly consequences have come from many of the explosive range expansions we’re most familiar with, whether of exotic species or even of native species with their normal restraints removed. A 2006 study found no evidence thus far that the Eurasian Collared-dove was out-aggressing Mourning Doves, though, and our other large native Columbiforme is gone through no fault of the new kid. The full impact of this particular expansion is still to be determined — in part because the full scope of the expansion is still to be determined — but provisionally the Eurasian Collared-Dove seems to be sitting with the Cattle Egret and the Monk Parakeet in the ranks of our better-behaved new birds. And after all, some birds have to expand their range sometimes.
So, tentatively, welcome spring and new life.