LOOK FOR: Squirrels (It's Squirrel Appreciation Day!)

I'll admit it: we here at Natural Capital headquarters have a love-hate relationship with squirrels. They're fun to watch, chasing each other around our yard -- especially when they leap heroically from tree to tree. It's adorable when they squat on their hind legs to nibble on a tasty morsel. It's not so adorable when that tasty morsel is a tomato from our garden, somehow lugged all the way across our yard and nibbled on in front of our sliding glass door, seemingly just to taunt us. And it's been years since we've attempted to keep a birdfeeder -- the birds don't have a chance against our squirrels (and the English sparrows, but that's a complaint for another day).

But today is Squirrel Appreciation Day, or at least, wildlife rehabilitator Christy Hargrove of Asheville, NC, thinks it should be. It seemed like a fitting time to reflect a little on these furry sometimes-friends.

The squirrels you see running around in woods and yards in the DC are generally Eastern gray squirrels (Sciurus carolinensis). They've got brownish grey fur with white-tipped hairs, and lighter grey bellies.

Except when they don't have grey fur at all: the Washington, DC, area has a unique genetic diversity amongst its Eastern grey squirrels. In the early 1900's, several Canadian squirrels were released on the grounds of the National Zoo, probably in an effort to boost the local population (which had been depleted from hunting).

Those Canadian squirrels were the same species as our locals, but they looked different -- they were all black, not grey, possibly as an adaptation to gather a little extra heat in the winter. These black squirrels have integrated with our local squirrel population, and slowly increased their range -- you can now see their offspring throughout the area.

It's easy to see squirrels, and everyone knows what they look like. But do you know what they sound like? Listen to these clips -- they're probably familiar sounds. But you may have thought the chirps and chatters were birds when you heard them. Keep an eye out the next time you hear one of these noises in the woods -- you'll probably be able to find a squirrel perched in a branch, unhappy about your presence or some other happening in the area.

Do you have any good squirrel stories? Post them as a comment for Squirrel Appreciation Day!

Like the photos in this post? Mouse over for credits; a click takes you to the photographer on Flickr.