Robert Siegel of NPR's "All Things Considered" interviewed naturalist Jennifer Soles of the Gulf Branch Nature Center in Arlington, Va., on Monday about the shortage of acorns in some parts of the country.

Q

uestion:

From Northern Virginia to Maryland to Pennsylvania and, according to the Washington Post, all the way to Kansas and Nova Scotia, there is a mysterious shortage of acorns. Not a catastrophe just yet, unless you are a squirrel. . . . How bad is it for the squirrels?

Answer:

It will be a really hard winter, I think. Right now, they're doing all right. They've just eaten a lot of pumpkins. Everybody left them out at Halloween. But as we go further onto the winter, I think their plight is going to become more and more severe.

Q:

When did you notice that there were no acorns around?

A:

I noticed a few months ago, actually, but I kept thinking that some would come along. We have a pet flying squirrel here at the Nature Center that we feed, and I was starting to look out for acorns for it. I have in my front yard in Arlington a large, white oak tree, a large red oak tree, and we've had really good acorn crops the last few years. So I was just sort of expecting to see those acorns and start collecting them, and they never arrived.

Q:

What do scientists say about a year without acorns? Has this happened before?

A:

There are certainly years with low acorns. Oak trees go through a sort of natural cycle where they some years produce a really heavy crop, other years produce a light crop. The heavy crop overwhelms acorn eaters, and then the light crop also knocked back the number of acorn eaters, so, you know, it's a light crop of acorns for fewer squirrels, fewer squirrels born in the spring. And there are fewer squirrels to eat the acorns next year, when the oak tree produces a really heavy crop. So it's normal for oak trees to produce a varying number of acorns. Not to see any is a little disturbing.

Q:

Now, I want to read to you what I read on a wildlife Web site about squirrels. It says, the average adult squirrel needs to eat about a pound of food a week to remain healthy. They're omnivores. So they will eat such things as birdseeds, spring bulbs, tree buds, frogs, small birds, eggs, insects, insect larva, fruits, conifer cones, small children that throw sticks at them, and nuts. Are they really in trouble given that diet?

A:

Yes, because a lot of those things aren't available during the winter months. During the winter, they really rely heavily on the acorns and other nuts they have cached and stored. So even though like in the spring, you know, the ones that have made it will be fine in the spring. They can eat the buds. They can eat the eggs, grubs and caterpillars and things like that. It's getting through the lean winter months, which are always the hardest.

Q:

Now, especially someone who keeps a pet flying squirrel . . . you would find a world without squirrels a horrible thought, but it sounds like it wouldn't be too bad for the birds or the frogs.

A:

Well, you know, there's always a balance. You know, mice eat acorns, and when you don't have the mice and the squirrels and the chipmunks, that reduces the number of hawks and owls. So, it's all sort of connected up.