DEAR JOAN: I just came from Heather Farm Park in Walnut Creek, where I saw the Canada geese behaving in a way I'd never seen before.

At least 50 in various groups landed on the lake. Every few seconds one would rise up and frantically beat its wings, then another and another would do the same. Those that weren't beating their wings were rolling over in the water.

They looked as if they were trying to rid their feathers of something unpleasant. A few of them made it to the island and began madly grooming themselves. This went on for well over 20 minutes.

Any idea of what could have caused this behavior?

Lisa Franklin

Is this Canada goose saying howdy or back off?
Is this Canada goose saying howdy or back off? (Jim Steves/Bay Area News Group)

Walnut Creek

DEAR LISA: The geese are participating in the latest fad -- goose twerking. Actually, they are just being geese.

That sort of behavior can indicate a couple of things. Because it's migration time, the incoming flocks may have been warning birds from outside of the flock to keep away.

Canada geese not only mate for life, their children tend to hang around with them as well as what might be considered close family friends. The flapping of wings, as if attempting to take off from the water, is a universal goose sign of "back off, bud."

Conversely, the wing flapping is also a sign of greeting. I suppose the geese know which is which.


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The rolling in the water probably indicates they were just happy to settle into the pond, get some water on their bodies and have some lunch.

Although most people don't think of Canada geese as being playful, some experts think all of this activity is a sort of game the geese play.

It's a happy thought.

DEAR JOAN: Today I saw as many as 10 woodpeckers swooping around, screeching and landing near each other on the trunk of my neighbor's ash tree.

I'm used to seeing woodpeckers one or two at a time. Any explanation for their behavior?

Our neighbor had his ash tree heavily pruned about a month ago, and on closer observation, the woodpeckers seem to be eating something -- maybe the sap released after the pruning. Is this another example of birds competing for some tasty morsel, as I often see robins or other kinds of birds fighting over pyracantha or other berries?

It continued off and on for several hours.

Steve Evangelou

Walnut Creek

DEAR STEVE: Our area is home to three species of woodpeckers -- acorn, Nuttall's and hairy. The birds you saw were acorn woodpeckers (thanks to Mike Williams' keen eye for the identification).

Acorn woodpeckers visit an ash tree.
Acorn woodpeckers visit an ash tree. (Courtesy of Steve Evangelou)

The acorn woodpecker eats insects, sap, fruit, seeds, lizards and bird eggs. You'll most likely find them nesting in or near oak woodland.

Because it's been a while since your neighbor's tree was pruned, I'd say the birds were after insects that were taking advantage of the freshly exposed wood, but they may also have been having sap for dessert.

This isn't a case of birds fighting over food. Instead, it was an example of birds sharing a meal. Acorn woodpeckers, unlike most of their woodpecker brethren, form communal groups. It helps them ward off danger and, working together, find and share food.

Contact Joan Morris at jmorris@bayareanewsgroup.com or 1700 Cavallo Road, Antioch, CA 94509. Follow her at Twitter.com/AskJoanMorris.