I’ve watched squirrels eat a huge diversity of foods from mushrooms to insects, tree buds, bird eggs & even small mammals.
But there’s one major category of food that squirrels value above all else (and it’s a big part of why squirrels are so successful at surviving harsh winters).
So what is this critically important squirrel food?
Almost all food eaten by squirrels is seeds and nuts harvested from mast trees and shrubs. This includes deciduous nuts like acorns, hazelnuts, walnuts as well as seeds of coniferous trees like spruce, fir & hemlock.
For many individuals, these seeds and nuts account for more than 90% of everything a squirrel will eat in a given year.
These foods are incredibly important to squirrels because they can be stored through the winter in underground food caches. It’s also why fatty seeds and nuts are always the best foods for squirrel watchers who want to attract more squirrels to their yard.
Aside from their core diet, squirrels also eat a wide diversity of seasonal and opportunistic foods including:
- Tree buds
- Tree flowers
- Bird eggs
- Small mammals
- Tree sap
Even though squirrel diets mostly consist of plants, they are technically omnivores (eating both plants and animals).
Dietary Associations With Different Types Of Squirrels
It’s interesting to note that depending on which seeds or nuts are most abundant in a landscape, it’s possible to predict which squirrel species you are most likely to have.
Different types of squirrels (like red and gray squirrels) will specialize in their own favorite types of nuts and seeds.
Let’s go through the favorite foods of squirrels first, and then touch on some other less common but equally fascinating seasonal additions to the squirrel diet.
Small territorial squirrels like Red Squirrels and Douglas squirrels are particularly noted for eating the seeds of coniferous trees like spruce, fir, hemlock & pine (Learn how to identify coniferous trees)
Each cone contains dozens to hundreds of fatty seeds.
These small territorial squirrels will cache huge volumes of cones in central locations underground, often at the base of trees.
A good indicator of this type of squirrel presence in the forest is large piles of discarded cone fragments that collect at the base of stumps, boulders or trees.
The feasting squirrel will grab a cone from their cache, move to an accessible viewpoint like a big rock or a stump, and then pull apart the cones eating seeds one by one.
Because they store so much food, red squirrels and douglas squirrels become deeply invested in protecting the territories around their caches from other squirrels.
While all squirrels enjoy eating nuts, gray squirrels and fox squirrels are particularly associated with nut-bearing deciduous trees and shrubs such as:
- Oak trees (Acorns)
Gray squirrels employ a food caching technique called scatter hoarding, which means they bury individual nuts in many different locations around their territories.
This can even result in the further propagation of their favored nut-bearing species.
Many of the oak trees in any natural oak forest will have been inadvertently planted by squirrels who simply didn’t reach the cached nut before it sprouted in spring.
Perennial & Annual Seeds/Foliage
Ground squirrels are known for living in non-forested habitats, and live chiefly off the seeds and foliage of herbaceous plants like sunflowers and grains.
While some ground squirrels like chipmunks will still cache food, the vast majority of their food is eaten immediately to be stored as fat on their body which aids hibernation.
This page focuses mostly on tree squirrels, but if you live in a desert or grassland you are much more likely to have ground squirrels.
Larger ground squirrels like groundhogs/woodchucks are in a whole different category, focusing more on fresh vegetation like forbes and vegetables.
Squirrel Diets In The 4 Seasons
Squirrel diets also vary tremendously in different seasons.
In winter, tree squirrels like red and gray squirrels enter a state of torpor during cold conditions.
Torpor is a state of reduced metabolism, like a mix between sleep and hibernation that enables squirrels to go days without food if necessary.
In cold weather they may disappear into their nests for days at a time, but will emerge during warmer and sunnier weather to eat, mate and explore.
This time of year, tree squirrels are surviving almost exclusively by eating their stored caches of seeds and nuts.
A lucky squirrel may come across some food left by humans or a dead animal to scavenge, but this would be a rare opportunity.
In late winter, I often observe squirrels eating sap from the young trunks and branches of maple trees.
I shared this video on YouTube to show you how to recognize the signs and behaviors associated with squirrels feeding on maple sap:
Ground squirrels like prairie dogs, chipmunks and groundhogs/marmots survive the winter by hibernating.
Hibernation is an extended period of extremely low metabolism that enables animals to sleep for many months without food or water.
In early spring, squirrels shift their core diet to capitalize on the abundance of trees by eating the swelling buds.
As the season progresses, those same trees will put on a flush of flowers and early season seeds (like maple and elm seeds) that squirrels eat in abundance.
Spring is also the time when birds start nesting, so it’s not uncommon to observe squirrels opportunistically disturbing bird nests and eating bird eggs.
In summer, squirrels further diversify their diet with many varieties of fruit & insects including:
It’s also extremely common to see squirrels continuing to eat from their winter caches in the middle of summertime.
I’ve observed this many times in red squirrels and douglas squirrels. It’s a funny thing to see a squirrel eating from a ripe cone while the current years cones are still developing.
Fall is the busiest time of year for squirrels because they are so occupied with feasting to put on fat while also storing away all the food they need for winter.
Some squirrels will even cache enough food to last for multiple years.
If there are ripening fruits like apples & pears nearby, squirrels will spend a lot of time fattening up on their energy rich fruits.
One of the most interesting squirrel foods is mushrooms harvested with the autumn rains. This can also happen in late summer if you live in a cold and wet climate like I do.
Squirrels will pick the mushrooms and transport them into tree branches to dry before storing them in underground caches. They may also eat them fresh.
If you’re interested in learning more about squirrels, you may want to start by understanding the major differences between gray squirrels and red squirrels.