How Many Bones Does A Squirrel Have

How Many Bones Does A Squirrel Have

A squirrel’s many bones are unique and more challenging to maintain than you might expect. Sadly, squirrels are sensitive to Metabolic Bone Disease if they don’t have the correct amounts of calcium and phosphorous in their bodies.

As a result, they have been known to gnaw on the bones of other creatures, including humans. How many bones does a squirrel have?

Squirrels have an average of 78 bones in their body. The exact number can vary slightly because arboreal squirrels have more tail bones than ground squirrels. There are 289 species of squirrels that have a unique, identifiable skeleton with bones specially adapted to its lifestyle and home environment.

Do Squirrels Have Bones In Their Body

Squirrels do have bones in their bodies. As vertebrate animals and mammals, squirrels are members of a larger order that is defined by their spines.

However, the exact number of bones varies from species to species. With almost three hundred species, that’s a lot of variation.

At most, some squirrel species may top out around two hundred bones. Two hundred is average for many mammals like humans who have two hundred and six.

However, different lifestyles lead to much more varied skeletal compositions, and two hundred is only ordinary, not universal.

Regrettably, there haven’t been many studies on the relative numbers of squirrel bones. Still, it’s easy to infer some things.

For example, the long-tailed arboreal squirrels likely have far more bones in their tails than the ground squirrels with their shorter tails.

How Many Vertebrae Does A Squirrel Have

The cervical vertebrae or neck bones are the same in almost every mammal species. Squirrels have the same number of cervical vertebrae as giraffes, humans, and bears. Specifically, we all have seven neck bones. Only the size varies.

It doesn’t appear that any biologists are out there counting squirrel bones and comparing them among species.

However, since we know squirrels are mammals, we can infer a few things about their vertebrae. Luckily, most mammals share a mostly consistent number of backbones.

Although there are few scientific resources about squirrel bones, the Ecology and Evolution Community offers this insight, “Consistency in the number of thoracic and lumbar vertebrae is not quite as stark as in the neck, and there are a larger number of exceptions, but the majority of mammals possess 19 or 20, for a total of 26 or 27 “CTL” vertebrae (for “Cervical, Thoracic, and Lumbar” vertebrae)… most mammals – including animals as diverse as most rodents, rabbits, deer, kangaroos, koalas, cows, monkeys, and others – all have 26 CTL vertebrae while dogs, cats, bears, weasels, otters, and their relatives all have 27. There is little variation in these numbers either within species or across different species…”

How Many Bones In A Squirrel’s Paw

Squirrels have four paws. The set on the front looks more like little hands, and they use these to pick up food and even throw things.

These front paws have four digits and a tiny thumb. However, Calosacrus ground squirrels lack the thumb.

Alternatively, the back paws are more oversized and foot-like. Squirrel’s back paws have five, more even digits. The ‘fingers and toes are usually made up of three bones each and connect to the wrist bones.

The seven wrist bones are the centrale, lesser and greater multangular, scapholunate, triquetrum, hamate, and capitate.

Altogether, that means most squirrels have 15 toe or 12 to 13 finger and thumb bones, plus the 7 in the wrist for 20 to 22 total. The number can vary by one to three bones.

How Many Bones Are In A Squirrel’s Tail

Ground squirrels have fluffy tails, but they tend to be shorter and less lush than arboreal or tree squirrels. Therefore it is safe to assume they have slightly fewer bones in their tails.

However, there is no way to know for sure without killing a ground squirrel and then counting for yourself.

Regrettably, like other squirrel bone-related questions, the biologists studying these almost three hundred species have been less than forthcoming about their skeletal makeup.

Fortunately, I am not one to give up so easily. I found a picture of a reassembled squirrel skeleton from Kelvingrove Museum in Glasgow. You can take a look for yourself right here.

I counted the bones so I can say with fair certainty that this grey squirrel has nineteen bones in its tail.

Helpful Tips To Know About How Many Bones A Squirrel Has

Squirrels average around eighty to two hundred bones, but it depends on the species. Not only is that less than average for many mammals, but it can be less than half of what a human has.

Some squirrels have additional bones in their tails, and others have tiny nub-tails with almost no bones in them.

Here are some helpful tips to know about how many bones a squirrel has.

  • Sadly, squirrels are prone to bone disorders. Having the correct balance of three essential nutrients makes all the difference to these furry rodents. Too much phosphorous and the squirrel won’t absorb the calcium they need to prevent Metabolic Bone Disease. According to Squirrel Nutrition, “Unfortunately, vegetation and nestling birds and eggs are only available for a short time every year, so squirrels are vulnerable to low blood calcium most of the year… When their bones become depleted of calcium, they become lame and usually fall out of the trees and shatter their brittle, calcium-depleted bones… Sunlight is also needed to help squirrels synthesize Vitamin D. Vitamin D also plays a key role in the absorption of Calcium. Hence, 20 minutes of direct sunlight per day is imperative for squirrels.”
  • Most arboreal squirrels have a skull that is approximately two and a half inches long, and their bones are incredibly light weight which makes it easier for them to jump from limb to limb and climb trees.
  • While squirrels have the standard number of cervical vertebrae for mammals, some creatures don’t. Bizarrely, only three species have more or fewer neck bones than the rest of the mammal family. Manatees, two-toed sloths, and three-toed sloths are the only mammals on earth without seven cervical vertebrae.
  • Arguably, the most famous bones of any squirrel are their cute and perpetually growing front teeth. There’s just one problem with this; teeth are not bones. Although they store calcium, teeth are not made of bone. Plus, they contain nerves, blood vessels, and specialized cells instead of bone marrow. More importantly, teeth cannot heal when broken, which all true bones possess.

Final Thoughts

Squirrel bones are an under-studied subject. Or, more accurately, they are not often written about. That said, the nearly three hundred species of squirrels have a wide range of bone configurations, affecting the exact number of bones they possess.

Each squirrel type is uniquely suited to their climate and lifestyle, so their bones reflect those needs and make up the framework for the rest of their bodies.

Ted Smith

My name is Ted Smith and I’m the creator of AnimalThrill.com. I have a passion for educating people about animals and wildlife. I have been working with the National Wildlife Federation for the past 10 years and I became a wildlife blogger to help people become excited about animals and encouraged to care for these wonderful creatures.

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