When a Young Chickadee's Fancy Turns to Love

Jill King of Fairbanks sent me an email the other day. It seems her local chickadees are acting weird. After watching a few chickadees in and around her birdhouse, King typed up this account:

“One of the chickadees flew from one of the feeders with a sunflower seed in its mouth and flew to the opening of the birdhouse. It didn’t go in, rather it stuck its beak in and another chickadee took the food from inside . . . It was very cool, but I don’t know why one would be feeding the other.”

I didn’t know why one adult chickadee would feed another either, but Susan Sharbaugh did.

“It’s the avian equivalent of taking someone to dinner,” said Sharbaugh, a professor with UAF’s Department of Biology and Wildlife and an expert on chickadees. She said the chickadees were engaging in “courtship feeding,” during which a male chickadee feeds a female to reestablish their bond.

Throughout lives that last as long as 13 years but average about 5 to 7 years, chickadees tend to stick with their mates. Groups of males and females hang out together all winter until the returning sun kicks their hormones into action. Longer days trigger changes in males and females. Males start singing a three-note song to tell others that they’d like some space for themselves and their mates.

“The days are longer, the temperatures are warmer, and the males become more territorial,” Sharbaugh said. “They’re all of a sudden not so happy to be around each other.”

After a chickadee couple moves to a comfortable patch of woods they perhaps lived in last summer, the females react to increased estrogen in their blood by quivering their wings while positioned in a specific crouch. Males recognize this display as their cue to start proving themselves worthy mates. Unlike ducks or other bird species in which the males have nothing to do with raising young, male chickadees feed the female when she’s on the nest and help feed the young. Biologists have noticed chickadee pairs nesting in the same area for five years.

“If the females latch onto a dominant male in good territory with lots of food, they hang on,” Sharbaugh said.

But even chickadee love isn’t perfect. Sharbaugh said divorce is not uncommon in the world of tiny passerines.

“If the male picked a poor territory or if he’s not bringing in enough food, sometimes she’ll pick another male,” she said. “A female chickadee lays six-to-12 eggs a season. She can’t feed all those mouths herself.”

Older, more experienced males make better mates, Sharbaugh said, perhaps because they’ve been through the process of raising young before.

“Sometimes the more experienced females will give the younger males the boot,” Sharbaugh said.

A male has a lot at stake in being a good provider. By feeding his mate, he makes her healthier and increases the chances that their young will survive. But the odds aren’t good no matter how successful the male partner. Sharbaugh said that only one of ten nestlings survives the first winter. Squirrels, sharp-shinned hawks, cats, shrikes, and cold weather tend to kill most young chickadees.

Jill King is probably in for a bird-watcher’s delight, Sharbaugh said. The chickadee’s courtship behavior around the birdhouse means the chickadee pair will likely nest in the box. Soon, the female will begin laying an egg a day in the early light of morning. When she lays her second-to-last egg, she’ll begin incubating, and two weeks later the chickadee population in King’s bird house should increase by about seven or eight.