Did you miss them? Well, they’re back. The Canada geese, that is.
The last week of August brings a nearly forgotten sound to the skies overhead. All summer long you might have seen Canada geese lounging about golf course fairways or farm ponds, but the skies have belonged to the swallows and vultures. The geese have been grounded, all the other waterfowl, too. It’s molting time.
Where the hummingbirds, chickadees, finches and doves in your backyard, and even the red-tailed hawk out in the pasture, replace flight feathers one at a time in an orderly progression, ducks and geese have a very different idea of how to get a set of fresh flight feathers. They drop them all at once. A hummingbird or red-tailed hawk that tries this would get mighty hungry. Sitting around grounded for a month or more waiting to grow a new set of flight feathers would present quite a challenge.
For waterfowl it’s not so critical. As long as they have a puddle big enough to provide three square meals a day and a refuge from four-legged predators that can’t swim so well, what’s the big deal?
All waterfowl go through a flightless period each year. For Canada geese, they drop their flight feathers at some point when the goslings are partially grown. Families at this time simply paddle around the marsh together, the young growing and the adults molting.
Why not molt at this time? Mom needs to stay with the kids, and they’re not going anywhere (on the wing that is). About the time the young goslings are ready for their first flight, the adults have a fresh set of flight feathers ready to go. This works well, since families tend to stay together through migration and the winter. Our Canada geese, unlike the Canadian and Alaskan birds, are a bit lazy and are resident. Still, they make good use of their wings commuting back and forth from marsh to pasture in the off season.
Ducks have a slightly different idea of the proper time to hang up the cars keys (so to speak) for a month or so. They wait until after raising the kids. It’s time for a well deserved break. There are some interesting stories here. Some ducks shop around for a good place to hang out without transportation. It’s important to choose wisely. It can be a long waddle to the next pond once a duck has dropped its flight feathers. A duck can’t very well stick the feathers back in if it chooses poorly.
Some have a pre-migration, if you will. For example, researchers were surprised to learn that many canvasback breeding in the Central Valley of California travel north to the Klamath Basin to molt. It gets kind of dry down there, and a duck would not want to get caught flightless as the water gets shallow, or worse.
As fall approaches and the swallows and vultures prepare to leave for the winter, I welcome the calls of the replacements on my morning walk to the newspaper.
Stewart Janes is a biology professor at Southern Oregon University. He can be reached at firstname.lastname@example.org.