Chickadees, woodpeckers, owls: Subtle changes in season trigger variations in bird behavior
The signs are subtle, but they're there. Chickadees switching to their Hey, sweetie calls. Mallards moving about. Woodpeckers drumming on resonant tree trunks.
We're out of winter's deepest dark now. We can sense it. The critters know it. We're all basking in a luxurious 2½ minutes more daylight each day.
We asked Duluth birder and birding author Laura Erickson to talk about the subtle changes taking place in the avian world this time of year. Here's a species-by-species look at what she had to say:
"Chickadees start singing in earnest in late January and February. They begin calling Hey, sweetie! (instead of chickadee-dee-dee). Virtually all the songs are by males, and in this case, they're virtually all a hormonal thing that revs up their romantic impulses. Chickadees are the Norwegian bachelor farmers of the bird world, and in the same way that they have trouble eating side-by-side (which is why at our feeders they grab a seed and run), they just don't feel comfortable getting too close to one another in any social setting. Their songs increase until by late April or early May they can finally overcome their inhibitions and do what birds and bees and educated fleas must do to make new little chickadees."
"I'm seeing lots of mallards, several times a week, flying over my house," Erickson said. "Because the water is freezing here and there, they're just checking out where to go if they do get frozen in, or they're moving around because the ice is sloshing around them."
Great-horned and other owls
"The only owl that feels romantic around Valentine's Day is the great horned owl. They'll be on eggs in February. Usually, they lay four eggs and raise one or two young. If food gets short, the bigger chicks sometimes resort to eating the smaller ones. It's called siblicide.
"Great horned owls mate for life. Usually, the female stays on the nest (when sitting on eggs), and the male brings her food."
You might hear great horned owls calling more at this time — hoo-hoo, HOO, hooo hoo.
"They call back and forth to each other," Erickson said.
"Boreal owls and barred owls will call later in the winter, typically in March or even April. Male boreal owls call after they find a really good nest hole that they're advertising."
"We're not seeing the numbers they're seeing other places (around the country). But people have seen them on the Aerial Lift Bridge, the high bridge (Blatnik Bridge), along highways. I've seen them in Canal Park. You have to be lucky to see them."
Snowy owls began showing up last fall, coming down from their home territory in the Arctic.
Though fewer eagles are around in winter than in summer, it isn't uncommon to see them, Erickson said.
"As we know, they love to eat fish. When most of the water is closed where fish are close to the surface, they do very little fishing. They're mainly going to the roadside cafes (feeding on road-killed critters such as deer)."
Roads are good for eagles in another way. Bare roads hold a bit more heat than the surrounding snow-covered woods or fields. "You don't need to have much temperature difference to get a thermal — rising air current — over a road, even if it's 20 below. That holds them aloft. It's very convenient. They can be circling above highways looking for road kill."
"White-breasted nuthatches are feeling a bit more romantic, usually on sunny days. Every day, when you pay attention, you'll hear them making their yenk, yenk, yenk call."
"Downy and hairy woodpeckers are the first to start pairing off and doing their drumming (on dead trees). And I'm hearing pileated woodpeckers making their calls. That's kind of territorial and for mating. They're getting a little bit territorial. They call back and forth in a pair, as communication."
The drumming of hairy woodpeckers is very fast and long, according to "The Sibley Field Guide to Birds of Eastern North America." The drumming of downy woodpeckers is relatively short and slow. The drumming of pileated woodpeckers is slow and powerful, trailing off at the end.