By Dr. Becker
Search online for “fat squirrels” and you’ll be flooded with images of irresistibly cute chubby squirrels. But these squirrels aren’t your run of the mill, storing fat before winter, squirrels; they’re overweight, some might even say obese, squirrels.
What’s causing the uptick in fat squirrels is a mystery of sorts. One theory is that squirrels are increasingly interacting with people and living in urban areas, like public parks and college campuses.
There, they may become the frequent lucky recipients of various food handouts. Backyard bird feeders also represent an all-you-can-eat smorgasbord for clever and persistent squirrels.
Mild Winters May Lead Squirrels to Pack on Extra Pounds
Another theory suggests warm winter weather may be to blame. Britain just had their warmest December on record, for instance, with temperatures about 7 degrees Fahrenheit warmer, on average, which meant squirrels had access to an abundance of nuts and seeds for longer than normal.
Many U.S. cities also reported extremely mild Decembers, including New York City, where Central Park never dipped below freezing.1
For the record, it’s normal for squirrels to get chubby in the winter months. They may put on one-quarter of their body weight in fat to help them stay warm as the temperatures drop.2 Their thicker winter coats also give them an extra layer of “fluff.”
While some squirrel species hibernate (there are over 200 squirrel species worldwide), many of those commonly found in the U.S. do not. Instead, they bury a store of food to dig up later in the winter when food becomes scarce.
Acorns are a favorite pick for squirrels, full of protein, carbs and fats. In areas where acorns flourish, so, too, will squirrels. Nick Mason, project manager for Red Squirrels Northern England and Northumberland Wildlife Trust, told the Daily Mail that perhaps the fat squirrel sightings aren’t that unusual after all:3
“Squirrels are opportunists and much like humans will take advantage of any food that is available. It is fairly typical for squirrels to put on weight through the year and this can vary depending on the stage of their breeding cycle and their life cycle.”
Squirrels’ Weight Is Typically Self-Regulating
City squirrels also tend to be larger, on average, than rural squirrels because they have access to more food sources and face fewer predators. That being said, the combination of warm, wet weather and a surplus of nuts and seeds has resulted in more fat squirrel sighting than usual.
But the extra weight isn’t likely to pose any long-term health dangers to the squirrels, which are capable of self-regulating their weight. David Sugarman of the Ontario Science Centre told the Toronto Metro:4
"Naturally, if you're an animal that's got to make it through the winter with little or no food, you want to pack in as much as fat as possible … If the squirrel were able to stay chubby all year round, it might decrease its longevity …
But eventually the snow is going to come, the cold weather will increase and they're going to burn off some of that extra fat."
Squirrels Are Found on Every Continent but One
Squirrels are one of the most common animals around the world; they’re found on every continent but Australia, although they vary widely in size and behaviors. The smallest squirrel, the African pygmy squirrel, is just five inches long while the Indian giant squirrel measures in at three feet long.5
There are ground squirrels, flying squirrels and tree squirrels, the latter of which are impressive climbers.
Both tree squirrels and flying squirrels prefer to live in trees, although only flying squirrels have a muscle membrane between their legs and body that allows them to “fly” (or, technically, to glide) up to 160 feet through the air.6
While U.S. squirrels are most known for munching on acorns, squirrels are actually omnivores and are opportunistic eaters. They’ll eat not only nuts and seeds but also happily nosh on insects, fungi, fruit, flowers, bark, eggs and even baby birds.
Are Squirrels Digging Up Your Garden?
Squirrels are a member of the rodent family, and some people consider them a nuisance. Like all rodents, squirrels have front teeth that never stop growing and they’re avid chewers.
Squirrels may cause damage to wooden decks, siding, fencing and electrical wiring, and they may dig up your newly planted seeds or flower bulbs.
Before you engage in a war against them, remember that squirrels are engaging in their natural behaviors and are beneficial for the surrounding ecosystem. For instance, when squirrels forget where they’ve hidden nuts or seeds (which does happen), they may take root and grow new plants and trees.
And if a squirrel is digging in your lawn, think of it as a natural form of beneficial aeration. To prevent a squirrel from digging up your vegetable or flower garden, lay down a piece of wire mesh (with holes big enough for plants to sprout through but small enough to discourage digging).
If squirrels have made a nest in your home, wait until the squirrels are grown enough to vacate, then place a talk radio nearby along with ammonia soaked rags. When you’re sure all the squirrels have left, seal up their entrance point.7
Interestingly, the Netherlands spent more than $165,000 to build a special bridge for squirrels over a busy motorway. Many squirrels passing from the Haagse Bos forest were being hit by motor vehicles, and the squirrels’ population was declining as a result.
Unfortunately, the bridge, which was built in 2012, hasn’t been popular with the squirrels. Only three squirrels were spotted using it in 2014 followed by another two in 2015.8
Do you want to be a citizen scientist? Project Squirrel, a joint partnership between Chicago Academy of Sciences' Peggy Notebaert Nature Museum and the University of Illinois at Chicago (UIC), needs your help.
They’re looking for people to take a look around their environment and report squirrels in the area using their online observation tool. If you’d like to get involved, you can help to further the understanding of your local environment. According to Project Squirrel:9
“Project Squirrel is a long-term study that partners with citizen scientists to collect broad-scale, fine-resolution data about squirrel population density, diversity, and behavioral characteristics. These data can then be interpreted by researchers (and citizen scientists) who wish to learn more about local and regional ecology.
Said another way, Project Squirrel is a way to see the world through squirrels’ eyes — and the more people submitting data, the better our understanding. Squirrels are ideal candidates for understanding ecology on both local and regional scales for a wide variety of reasons.
Squirrels can be found in most American cities, and the different species of squirrels are easily identifiable. Also, squirrels are diurnal (active during the day) and active year round, making them easy for people to observe.
Squirrel survival and behavior can provide information about other wildlife in an area as well; resources that are key to squirrel survival are also important to a wide range of other animals, and, similarly, predators that impact squirrels often impact many other species as well.”