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Outside my window there stands an oak tree. I’d rather watch birds but sometimes I’m entertained by the antics of squirrels.
For some reason most of the squirrels here in my town are black. Head out of town and they are red or brown and smaller. Where I grew up they were all grey.
But they all have one thing in common, a big bushy tail. In fact the entire species in named for it’s tail.
As often as not these little rodents are using my oak tree for a highway moving from a garage nearby to a pine tree next door. In so doing they fearlessly fling themselves into the air and catch onto a branch of the tree they are landing in.
I had always assumed that the reason a squirrel had a big bushy tail was that as they careened through the space between branches they used it to wave around and keep from tumbling out of control. And they do, I’ve seen them enough times to know.
I did a little web searching and found one site that claimed a squirrel uses its tail to communicate. That makes sense, my dog uses her tail to communicate too and it’s certainly true that we humans have various body parts evolved for one purpose and used as communication tools as well.
Think of people who wave their hands around when the talk. More to the point think of your eyebrows designed to keep dust and rain out of your eyes but very useful in sending signals to other people.
But last year I heard of a study of squirrels using their tails in a completely different way.
Rattle snakes like to eat squirrels and because rattle snakes are equipped with heat sensing organs to help them hunt, squirrels that live in the same environment as rattle snakes have evolved an ability to heat up their tails when confronted by a snake so that when the snake strikes it tends to misfire toward the hotter tail and miss the main meal.
These are ground squirrels so their tails aren’t quite so bushy.
Squirrels in South Africa have also been studied and found to be using their tails in another temperature related way.
These guys hang their bushy bottle brushes overhead like some kind of parasol to keep the sun off. The study found that tail shading in sunny 40ºC heat allowed the little tree rats to drop their body temperatures to 35 ºC and extend their nut hiding to a full 7 hour day.
Overheated rodents knocked off after only 3 hours.
And believe it or not this is exactly why a squirrel is called a squirrel.
When the French invaders arrived in England in 1066 the Anglos were calling the things aquerne. But the French soon changed that to esquirel which they had gotten from Latin.
The Romans before them had chosen their word because the Greeks before them had used skiouros to describe these little rascals.
In Greek skiouros means “shade tail.” In fact the uros part is related to our English word arse.
It’s worth touching on that Old English word for squirrel aquerne.
It, as most Old English words, came from Germanic and like the modern German word for squirrel essentially means “oak horn.” No one knows why these little guys might be called horns, but the oak part is obvious enough, I can see it through my window.
Five days a week Charles Hodgson produces Podictionary – the podcast for word lovers, Thursday episodes here at OUPblog. He’s also the author of Carnal Knowledge – A Navel Gazer’s Dictionary of Anatomy, Etymology, and Trivia as well as the forthcoming short format audio book Global Wording – The Fascinating Story of the Evolution of English.
