Thursday, July 7, 2011
(Transcript of For the Birds for July 8)
I love watching chickadees every day of the year, through every season, and it seems especially fun in summer. Watching my neighborhood chickadees splitting into pairs and raising families is very fun. The males start out so solicitous of their mates, feeding them before they take a bite themselves, during courtship and while the female is incubating their eggs. Then the babies hatch out, and dad gets totally focused on providing food for the young. He may start ignoring his mate’s plaintive begging, knowing she’s perfectly capable of finding her own food. Some females don’t seem to mind at all—they are just as focused on feeding their young as the male is. But there’s a lot of individual variation in chickadee behaviors, and it’s fun to watch each pair work out their priorities.
This year when I was at Hunt Hill Audubon Sanctuary, I got to watch Bruce Bacon, a wonderful bird bander, band an adult chickadee, and I took photos of her enormous brood patch. Right when summer heat makes extra insulation unnecessary, birds that incubate eggs tend to lose all the down feathers from their bellies. You can’t notice this when they’re flying about because their outer feathers are broad enough to cover the bald area, but a chickadee can part the feathers away so while she’s incubating, her hot skin can be pressed directly on her eggs. And because she lays as many as 13 eggs, her brood patch is very large, allowing her tummy to be in contact with the entire clutch.
During the two weeks that the chicks are in the nest, both parents are run ragged flying here and there in a constant search for food. Keeping all those mouths filled from sunup to sundown is exhausting work. And the parents also have to keep the nest clean, which they do by carrying away the babies’ fecal sacs as quickly as they produce them. I got photos of that process at Hunt Hill, too.
Once the babies finally leave the nest, the parents’ duties are far from over. Before they’re good at flight, the little fledglings stick together and their parents bring food to them. But it doesn’t take more than a few days for the little ones to get impatient and start following their parents everywhere, constantly begging by fluttering their wings, opening their wide mouths, and making insistent little sounds.
The parents don’t have time to rest or preen, and their feathers grow increasingly ratty looking. This coincides with the parents starting to molt, giving them an even more disheveled appearance. In my neighborhood, the baby chickadees from this year are full sized now, even their tails full length, but they’re easy to distinguish from the adults because the young birds have perfect plumage and still have yellow mouth linings. The adults look ridiculously bedraggled right now—I’ve taken some photos that are on my blog. [Well, THIS is that blog.]
During August, chickadee families will all be breaking up and the young dispersing. Regardless of how devoted and attentive the parents are right now, the young will each head off on their own to join a flock different from the flocks of each of their brothers and sisters and their parents. No one knows what triggers this—the parents continue to feed the young and don’t act aggressively toward them, but suddenly the young will be gone. By then the parents will be wearing new plumage again, and rejoining their old winter flock and welcoming in new young chickadees, unrelated to any of the adults, and working out a new flock hierarchy. No matter where today falls on the calendar, today is the ideal time to watch chickadees.
Posted by Laura Erickson at 11:33 PM