As we approach mid-April, spring migration is heating up, literally and figuratively. The warm weather predicted for later this week could bring all sorts of early migrants to the region. Or it could be a total bust - predicting day-to-day bird migration on Cape Cod is a fool’s errand, sort of like predicting the weather, but harder. But I will stick my neck out, nevertheless, and recommend some species to watch for in the warmth of this week. Because as we speak, a river of birds is flowing north from South and Central America - one branch forks east through the Yucatan Peninsula and across to Florida, while another heads straight up through East Texas. The birds so flowing are destined to breed in our temperate forests, grasslands, and backyards come May and June.
We should see our first Ruby-throated Hummingbirds of the year by this weekend, if not sooner. I’m not talking about every feeder on Cape Cod - we still have to wait until early May for them to saturate the area - I mean the first few scouts, so don’t curse me if you don’t see one. But it’s not a bad idea to get your feeder up now, even though as of Monday none had been seen north of Philadelphia. That will change very quickly with this weather.
When we see this sort of warm bubble of southern air in April we often see some “southern overshoots”, birds that didn’t mean to come this far north. These include some of the more flamboyant birds in the eastern US, like Swallow-tailed Kites, Hooded and Prothonotary Warblers, Summer Tanagers, and Blue Grosbeaks. We could also see some of our handsomest local breeders ahead of schedule this week, like Indigo Buntings, Scarlet Tanagers, and Rose-breasted Grosbeaks. Several of these may end up in yards and even at feeders – if you have oriole feeders, just like with hummingbird feeders, it’s not too early to put them up.
Sunny, swampy wetlands, like the famed Beech Forest in Provincetown, offer some of the best chances to see newly arrived songbirds. Red Maples and various willows are in full bloom in our local swamps right now, and attracting many insects. These trees are the most important early spring pollen and nectar sources for several species of native bees, including recently emerged bumblebee queens, not to mention various flies and wasps. All this insect activity attracts hungry birds. For example, an early Summer Tanager was already hawking insects in the swamps around Santuit Pond in Mashpee last week, often in blooming red maples. And the flowering willows around the Beech Forest parking lot up in Provincetown are often the best place to see fancy early migrants.
The regularly scheduled mid-April migrants are also worth watching for – some fog or rain could bring a fallout of things like White-throated Sparrows, Hermit Thrushes, Ruby-crowned and Golden-crowned Kinglets, and both Yellow-rumped and Palm Warblers. Don’t forget to look up, because after a winter in some South American cloud forest, the first returning Broad-winged Hawks and Chimney Swifts should be passing overhead on tired wings.
So there you have it, a bunch of near-worthless bird migration predictions based on an ever changing weather forecast for the rest of the week. Hopefully you’ll be outside as much as possible anyway, so at least you’re prepared for these theoretical birds. If none of this comes to pass, feel free to scream at your radio next week, but my plan will be to deny any knowledge of this bird report.
