Is a soured romance the cause of vandalized tree in Walnut Creek?

DEAR JOAN: I was walking the Sousa Trail in Acalanes Ridge Open Space and I came across an oak tree that had chunks of bark removed in two places.

At first I thought it was kids with a hatchet, but on closer inspection, it looks more like an animal with very strong claws was responsible. Could one of the rumored mountain lions from Briones be staking out new territory?

I always keep my dogs on leash when we are in the open space because there are many coyotes, but a mountain lion is a whole different ballgame.

— Tom Warriner, Walnut Creek

DEAR TOM: Good job on keeping those dogs on leash. It’s for everyone’s safety.

While we don’t know for certain what caused the damage, we can look at possibilities and determine the likely cause. While mountain lions do leave marks around their territories, they don’t normally look like what you described.

I couldn’t find any evidence that the Briones mountain lions are extending their territory into the area.

I considered the marks might be left by deer, scraping the velvet off their antlers, but while the marks seem somewhat like the damage deer cause, the size of the tree makes it an unlikely option. Deer normally choose trees with small circumferences. It’s sort of like if we had something in our teeth, we’d choose a slender toothpick, not a two-by-four. The deer needs a thinner tree so they can get into nooks and crannies.

Others suggested it could be the work of a beaver, a bear, or a woodpecker as well as deer nibbling on the bark. None of those options seem valid either. Beavers wouldn’t tackle a tree that large, and gnawing marks would be up that high. As far as I know, we don’t have bears in Walnut Creek, and it would need to be a lot of woodpeckers, or one elephant-sized one, to create that amount of damage.

That leads us back to your original thought — a two-legged animal. City of Walnut Creek park rangers checked out the tree and determined the damage wasn’t caused by a vehicle strike, and there has been no damage to other trees in the open space. They believe it was vandalism.

Why anyone would take a hatchet to such a beautiful, old oak is a mystery, but one theory is that the tree was marred by someone trying to remove evidence of an arborglyph, the term for initials carved into a tree to memorialize an occasion, most likely a romance.

Rangers will be keeping an eye on the tree to make sure it recovers.

DEAR JOAN: I see a lot of empty snail shells around my garden. Do snails outgrow their shells and find larger ones? Should I leave the shells for other snails?

— Susan J., Los Altos

DEAR SUSAN: Snails do not outgrow their shells because the shells grow right along with them. If you’re finding empty ones, then something has forcibly evicted the snail and eaten it.

You can leave the shells where you find them as they will eventually break down and help feed your soil, and they are a good source of calcium for birds and other wildlife.

The Animal Life column runs on Mondays. Contact Joan Morris at [email protected].