How do animals know which mushrooms are safe to eat?

DEAR JOAN: Recently I noticed mushrooms growing at the base of one of the juniper trees in the backyard. It was interesting, so I took a picture.

A couple of days ago, I noticed that the mushrooms were gone, and there were scratch marks in the damp earth at the base where the mushrooms had been.

I am curious as to what animal could have eaten the mushrooms and if that animal is in any danger from poisoning. I see raccoons, possums, squirrels and birds on my backyard camera.

Who is the most likely culprit, or victim?

— Nancy McKiernan, Sunnyvale

DEAR NANCY: The winter rains can turn our Bay Area yards into fairylands with mushrooms popping up all over. While it is never a good idea to eat one without knowing exactly what type it is, animals don’t have the benefit of being able to call on a mycologist to determine the identity.

RELATED: California officials warn against foraging wild mushrooms after deadly poisoning outbreak

Instead, they rely on taste, outcome and experience. If a wild animal eats a mushroom that later makes it ill, it will avoid those mushrooms in the future, provided the animal survives. They’ll likely also stay away from anything that has the same or a similar taste. That provides them with some protection against eating the poisonous ones.

In the Bay Area, there are two mushrooms that are unsafe for any creature, and those are the death cap (Amanita phalloides) and the western destroying angel (Amanita ocreata). Both are commonly found near and around oak trees.

As for what animal would eat the golden-hued mushrooms you observed, the list is long. Mushrooms are a treat for wildlife, as they have a high water content and are a good source of protein, vitamins and phosphorus.

Rats, squirrels, deer, box turtles, wild turkeys and wild boars, just to name a few that might be visiting your yard, all love mushrooms. The scratches you observed lead me to think of turkeys, but there’s no way to know for certain.

DEAR JOAN: I’m already thinking about spring and what I’ll be planting in my vegetable garden. Last year, much of the garden was eaten by rats, birds and squirrels. I’m wondering if one of those plastic owls would scare them away?

— Alice B., Clayton

DEAR ALICE: Decoys do work, however briefly, against the birds, but it’s unlikely the rats and squirrels will even raise an eyebrow.

Stationary owl statues and other decoys might keep the birds away for a day or two, but then the birds figure out there’s no threat, and before you know it, they’re perching on the fake owl’s head and having a good laugh.

You want something that will move unpredictably. Objects that are pushed and pulled by the wind and that add unexpected flashes of light have a better and longer track record of success. You can hang reflective ribbons or old CDs throughout the garden.

For the rats and squirrels, the only thing stopping them is physical barriers. Surrounding your garden with a hardware cloth fence and a shock wire on top will do wonders.

The Animal Life column runs on Mondays. Contact Joan Morris at AskJoanMorris@gmail.com.