Some things I can easily explain. Some things I can’t.
I can’t explain what I’m watching right now. At this moment, I’m at Schoodic Point in Acadia National Park. It is swarming with black-capped chickadees. If God had sent a plague of chickadees instead of locusts into Egypt, it would look the way Schoodic Point does today.
It’s a chickadee irruption.
Migrants migrate, typically to someplace warmer. However, some species wander in any direction, looking for the best winter food supply. Finches and waxwings do this a lot. Some species irrupt.
In certain winters, birds that typically remain year-round residents in their breeding range will instead migrate southward. Chickadees, nuthatches and blue jays are among the occasionally irruptive species in our area.
And, boy, are they doing it this year.
I’m standing here with fellow expert Seth Benz, bird ecologist at Schoodic Institute. Over the years, we’ve misled a lot of tours together. We’re supposed to be counting sea ducks as they pass the point, but the chickadees swarming behind us are charmingly distracting. Neither of us has ever seen an irruption this big. There are well over 100 chickadees here, possibly as many as 300.
We’ve seen lesser irruptions. It’s not uncommon to see small flocks of chickadees working their way southward, perhaps 20 at a time. Most songbirds migrate at night, often traveling long distances under the protective cover of darkness. Chickadees move in daylight, basically foraging their way south from treetop to treetop.
Irruptions happen when there’s a shortage of food within the chickadee’s normal territory. It also occurs when they make a bumper crop of babies, and there are too many mouths to feed. In that case, most adults stay home, forcing younger birds to move southward. Snowy owls are famous for this kind of irruption.
There is another explanation for the outlandish size of this particular flock of chickadees. It’s quite likely that smaller flocks have been working their way south independently. They now find themselves bunched together at Schoodic Point, confronted by the wide expanse of Frenchman’s Bay. Most birds are reluctant to cross water without a favorable breeze, so now they have formed one huge flock while waiting.
Seeking more clues, I next drove to Blueberry Hill around the corner. A large flock was gathered there as well.
Blueberry Hill is quite close to Schoodic Point, so likely these birds also were biding their time, waiting for favorable winds. If indeed there was a huge irruption going on, the proof would come at Frazer Point near the park entrance. Any chickadees there would be close enough to the mainland portion of Winter Harbor to continue their southward progression, skirting Frenchman’s Bay. A big flock at Frazer Point would likely indicate a tsunami of chickadees irrupting down from Canada this winter.
Sure enough, I found another big flock there.
All of this is conjecture, of course. I can’t otherwise explain it. I’ve never before witnessed hundreds of chickadees swarming around in one place. I wouldn’t mind seeing it again.
To a lesser extent, red-breasted nuthatches are irrupting, too. That’s unsurprising. It has been obvious for months that the nuthatches produced a ton of babies this year. Many are now on the move.
I can, however, explain the swarms of dark-eyed juncos. Several alert readers have asked about the clusters of sparrows and juncos that seem to rise off the side of the road whenever a car passes. I’ve seen some swarms so thick, they blocked views of all the political campaign signs. Which I appreciated.
It’s typical for seed-eaters to form large flocks this time of year. When food is plentiful and there’s no competition over mates, flocking together presents an advantage. Bigger flocks mean more eyes watching for predators. The odds of being a raptor’s lunch are reduced.
Lots of weeds produce lots of seeds, and the most productive areas are often along the edges of roads and fields. You’ve likely noticed the juncos — gray, sparrow-sized birds that flash white outer tail feathers as they flit roadside.
Many alert readers have informed me that their feeders are being mobbed more than usual this year. Birds are in a rush to fatten up, and stash food for later. Irrupting birds may be swelling the numbers.
I can’t explain what it all means, but I know what you’re thinking. If Maine birds like chickadees think it’s going to be a tough winter, and the Canadian birds are sure about it, can I still book a January room in Fort Lauderdale?
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