What Do Squirrels Eat? Nuts, Seeds and Surprising Foods

The staple foods: nuts and seeds

For most of the year, tree squirrels depend on the seeds of trees. Nuts and seeds are packed with fat and protein, and many can be stored for months, which makes them ideal winter fuel.

The eastern gray squirrel is a specialist of broadleaf woods. Its key foods are acorns, hickory nuts, walnuts, beechnuts and hazelnuts, along with maple seeds, pine seeds and the seeds of trees such as elm and tulip tree. A squirrel opens a hard nut by gnawing a hole through the shell with its chisel-like incisors, which never stop growing.

The red squirrel of Europe and northern Asia is more of a conifer specialist. It strips the scales from pine, spruce and larch cones one by one to reach the small seeds underneath, leaving a neat cone core and a pile of scales below a favorite feeding perch. Hazelnuts, beechnuts and sweet chestnuts are important too.

How the squirrel diet changes through the year

A squirrel’s year is a sequence of feasts and shortages.

Late spring and early summer are often the hungriest time. Last year’s buried nuts are running out or have sprouted, and the new crop is not ripe. This is when squirrels eat the most buds and flowers, strip bark to lick the sugary sap beneath, and are most likely to take eggs or nestlings.

Autumn is harvest time. Squirrels eat as much as they can and bury or store the surplus. Gray squirrels scatter thousands of nuts in separate holes, while red squirrels tend to stash food in small caches in the ground, in tree crevices and, in the case of fungi, wedged on branches to dry. How they find them again is explained in do squirrels remember where they bury nuts?

Fungi, fruit and other plant foods

Mushrooms and truffles are a surprisingly important food. Squirrels sniff out underground truffles and dig them up, and in doing so they spread the fungal spores through the forest. Red squirrels in northern Europe dry mushrooms on branches before storing them.

Squirrels also eat berries, apples, cherries, mulberries and other soft fruit, and in gardens they help themselves to strawberries, tomatoes, sweet corn and flower bulbs. Gray squirrels sometimes eat only the seeds of a tomato and leave the rest.

Do squirrels eat meat?

Yes, occasionally. Tree squirrels are best described as omnivores that eat mostly plant food. Gray squirrels eat insects such as beetle larvae and caterpillars, and they are known to raid the nests of small songbirds for eggs and chicks. There are records of gray squirrels eating frogs and even young rodents, but these are rare events.

Red squirrels eat animal food even less often. A Swedish study of about 600 red squirrel stomachs found bird or egg remains in only four.

Squirrels also gnaw bones and shed deer antlers. They are not eating meat here; they are probably getting calcium and other minerals that nuts and seeds cannot supply.

Gray squirrels vs red squirrels at the dinner table

The two species overlap in Britain, Ireland and northern Italy, and their diets help explain why gray squirrels win.

• Acorns: Gray squirrels digest acorns efficiently despite their bitter tannins. Red squirrels gain much less energy from them, so in oak and beech woods the grays have a big advantage.
• Conifer seed: Red squirrels are skilled at extracting small seeds from cones, so large conifer forests remain their strongholds.
• Stealing: Gray squirrels raid red squirrel caches, taking food the reds were relying on for spring.
• Fat reserves: Grays can store much more body fat than reds, which helps them survive a hard winter.

The wider story is told in why gray squirrels are invasive in the UK.

Squirrels and bird feeders

In towns, many squirrels get a large share of their food from bird feeders, taking sunflower seeds, peanuts and corn. They are famously good at reaching feeders, climbing poles, hanging upside down and leaping from nearby branches.

This easy food can change local wildlife. In the UK, studies have found that gray squirrels can take a large proportion of the food put out for birds and keep birds away from feeders. Squirrels that gather around feeders are also more likely to find and raid nearby songbird nests.

Bread, salty snacks and sweet human food are not part of a squirrel’s natural diet. Squirrels that live in a natural setting find everything they need in trees, fungi and the forest floor.

Records and surprising facts

• A single gray squirrel can bury several thousand nuts in one autumn.
• Squirrels often shake and turn a nut before deciding what to do with it, and they tend to eat nuts with insect damage straight away and bury sound ones.
• Forgotten acorns and walnuts sprout, so squirrels are among the most important planters of oak and walnut trees in North America and Europe.