It’s right on the shore of the Saint Lawrence River, which runs more or less from the Great Lakes near its west end to the Atlantic on its east. North of there is a huge area which is, as far as I can tell, overwhelmingly unpopulated and undeveloped. The acreage appears to be larger than the combined total of all of New England, New York, Pennsylvania, Nova Scotia, and New Brunswick, combined; but without most of the cities, highways, sprawl, fragmentation, etc. So I think the phenomenon is one where the weather (Ian comments about the wind direction and rain in his eBird report) and geography bottlenecked, in both space and time, the breeding bird population of a really large and healthy ecosystem. The only other similarly large and healthy ecosystems are further west in Canada and Alaska, and have mostly land south of them without any really large bodies of water, so the migrants headed there can spread out over much wider areas on their way north.
That’s my hypothesis anyway. Maybe Ian himself will weigh in on the topic, after he catches up on his sleep, which might be in November or so knowing him.
As for your lack of Cape Mays, I’ve managed to miss both that *and* Bay-breasted, and Mourning too, not just this year but pretty much entirely since I left Texas and moved back to Massachusetts. Not that I’ve made concerted efforts to target those species, but I’ve seen 27 other warbler species in the state during the same span of time, you’d think I’d have blundered into one or two of that trio by now. I’d worry that my hearing was declining, but I’m not having any trouble hearing Black-and-Whites, Blackpolls, or Brown Creepers as far as I can tell… yet…
> On May 29, 2018, at 9:21 AM, Childs, Jackson <jchilds...> wrote:
> Big year for this species continues. One was singing vigorously by Lamont library this morning, getting late.
> The report from Quebec has broken my brain. I couldn’t find one Cape May myself this spring lol. Does anyone have any insight into this phenomenon?
> Jackson Childs
> <jchilds...> <mailto:<jchilds...> > Arlington, MA