July 13 – Squirrel!

Today’s factismal: The common tree squirrel can rotate its back ankles 180° in order to climb down a tree head-first.

Squirrels are fun, frolicsome, and fascinating critters. They jump from limb to limb in search of nuts and acorns that they bury in profusion and they crawl on the forest floor hoping to find some tasty insects, slugs, and small birds, or snakes.Because they move from climbing up to climbing down to crawling around with such frequency, they have developed some special adaptations. Perhaps the most interesting of these is their back ankles which rotate 180°; in effect, they can put their feet on backward. Though that would make them a little awkward if they did it on the ground, it is perfect for when they want to head down a tree head-first.

A squirrel using its adaptable ankles to balance on a fence (My camera)

A squirrel using its adaptable ankles to balance on a fence
(My camera)

But why would a squirrel want to go head-first down a tree? Because squirrels have a lot of things that like to feast on them. By going down head-first, they can keep an eye out for snakes, birds, raccoons, and automobiles to name but three. Automobiles are particularly deadly; the jerky, back and forth evasion pattern that gray squirrels have evolved to escape from predators in a forest makes it very hard to automobile drivers to avoid hitting the poor beast. As a result, the leading cause of death for gray squirrels in a city is being run over.

A black squirrel taking a break from the never-ending search for nuts (My camera)

A black squirrel taking a break from the never-ending search for nuts
(My camera)

Despite their predator problems, squirrels remain plentiful. In part, that’s because of their fecundity. Tree squirrels become sexually mature at six months and a female can have two litters of two to six baby squirrels each year. As a result, even though they only live a short time, squirrels are in no danger of dying out. But they do provide biologists with a puzzle: where do they live? What do they eat?

A grey squirrel finds himself out on a limb (My camera)

A brown squirrel finds himself out on a limb
(My camera)

And the biologists would like your help in solving the puzzle. All it takes is a pair of binoculars, a few hours, and a willingness to spy on our tree-dwelling neighbors. If you’d like to help, then why not join Project Squirrel? http://www.projectsquirrel.org/

April 15 – A little squirrely

Today’s Factismal: Gray squirrels in forests live about six years but most gray squirrels in cities live less than one.

The earliest example of a squirrel showed up more than 40 million year ago. Looking a lot like a modern flying squirrel (but with no moose to keep it company), the early squirrel got the acorn and soon diversified. Today there are 285 different species of squirrel, spread over six continents. It used to be five, but then someone decided that Australia needed squirrels.

A squirrel at lunch (Image courtesy Laughing Squid)

A squirrel at lunch
(Image courtesy Laughing Squid)

Most squirrels feed on plants with occasional bouts of nibbling on insects, slugs, and small birds and snakes. Because they cannot digest cellulose, squirrels prefer the same parts of plants that we do: leaves, buds, nuts (including acorns), and fungi. But unlike people, squirrels have a lot of things that like to feast on them, such as snakes, birds, raccoons, and automobiles to name but three.

And that last predator is why a gray squirrel in an urban environment typically lives less than a year even though the same squirrel would last for six years in a forest. The jerky, back and forth evasion pattern that gray squirrels have evolved to escape from predators in a forest makes it very hard to automobile drivers to avoid hitting the poor beast. As a result, the leading cause of death for gray squirrels in a city is being run over.

A smug grey squirrel with bird food he stole from my feeder (My camera)

A smug gray squirrel with bird food he stole from my feeder
(My camera)

Fortunately for the species, they are exceedingly prolific breeders. A gray squirrel becomes sexually mature at six months and a female can have two litters of two to six baby squirrels each year. As a result, even though they only live a short time, the species is in no danger of dying out. But they do provide biologists with a puzzle: where do they live? What do they eat?

And the biologists would like your help in solving the puzzle. All it takes is a pair of binoculars, a few hours, and a willingness to spy on our tree-dwelling neighbors. If you’d like to help, then why not join Project Squirrel?
http://www.projectsquirrel.org/