What Do Black Squirrels Eat? Diet, Habits, and What to Avoid

Black squirrels eat exactly the same foods as the gray or fox squirrels you see everywhere else, because they are gray or fox squirrels. The jet-black coat comes from a genetic variant, not a different species, so their diet is built around the same nuts, acorns, seeds, tree buds, and occasional fungi that fuel all eastern tree squirrels. What makes their story interesting is not a unique menu but how their darker fur may subtly shift when and how aggressively they forage, and how the growing number of black squirrels in cities face dietary pitfalls that their forest-dwelling relatives avoid.

Black Squirrels Are Not a Separate Species

The most common misconception about black squirrels is that they represent some exotic or rare species. They are melanistic variants of the eastern gray squirrel (Sciurus carolinensis) or, less commonly, the fox squirrel (Sciurus niger). Their dark coloring traces to a small deletion in the gene that controls pigment production. In gray squirrels, a 24-base-pair deletion in the melanocortin 1 receptor gene produces the black coat: animals carrying two copies of this variant are jet black, while those carrying one copy alongside the normal version appear brown-black.¹ The same deletion has been found in gray squirrel populations on both sides of the Atlantic, in North America and in the British Isles, where gray squirrels were introduced in the late 19th century.²

Fox squirrels can also be melanistic, though the genetics are more varied. In western fox squirrel populations, the same 24-base-pair deletion drives the black coat. But in southeastern populations, a completely different mutation in a different gene produces a similar-looking dark phenotype.³ The takeaway for diet is straightforward: a black squirrel’s digestive system, jaw strength, and nutritional needs are identical to those of its gray or orange-furred neighbors. Anything true about what gray or fox squirrels eat applies equally to the black ones.

The Core Wild Diet

Tree squirrels in eastern North American forests are generalists, but they lean heavily on a few staple food groups that shift with the seasons. The backbone of the diet is hard mast, the collective term for tree nuts like hickory nuts, walnuts, and acorns. Research on gray and fox squirrel food preferences has found that hickory nuts and walnuts are the most energy-efficient foods in fall and spring, while acorns become the most efficient choice in winter.⁴ Gray squirrels in particular thrive in hardwood forests where nuts and the winged seeds of maples and other deciduous trees are their primary food.⁵

Beyond nuts, the diet broadens into a surprisingly varied list:

• Tree buds and bark: In late winter and early spring, when cached nuts run low, squirrels strip buds from maples, elms, and oaks. They also gnaw bark, partly for the cambium layer beneath it and partly to meet mineral needs. One hypothesis links bark stripping to a calcium deficit triggered by heavy nut consumption the previous autumn, since seeds tend to have much more phosphorus than calcium.⁶
• Fungi: Squirrels eat both above-ground mushrooms and underground truffles. Studies in boreal forests have documented sciurids consuming spores from multiple truffle genera as well as from above-ground mushroom orders, suggesting fungi are a consistent part of the diet and not just a fallback when nuts are scarce.⁷
• Fruits and berries: Mulberries, wild grapes, serviceberries, and similar soft mast are consumed eagerly in summer when they are available.
• Insects and animal protein: Squirrels are not strict herbivores. They will raid bird nests for eggs, eat insects and caterpillars, and occasionally scavenge small carcasses. These protein sources are opportunistic rather than staple.

The seasonal rhythm matters. Spring is the leanest period, when last fall’s caches are depleted and the new nut crop is months away. That is when squirrels rely most on buds, early flowers, fungi, and whatever insects they can find. By late summer, fruits and early-ripening nuts fill the gap, and by autumn, the all-out nut harvest and caching season begins.

How Dark Fur Changes the Energy Equation

The black coat does not change what a squirrel can eat, but it may change how much it needs to eat and when it forages most actively. Dark fur absorbs more solar radiation, and that thermal difference has measurable consequences. In winter, melanistic gray squirrels lose less body heat and have lower baseline metabolic rates than their gray counterparts at temperatures between about −20 and 25 °C.⁸ A lower metabolic rate means a smaller daily calorie requirement, which could give black squirrels a survival edge in cold northern winters when food is hardest to find.

The picture is slightly different in fox squirrels. When researchers compared melanistic and orange fox squirrels, they found no difference in metabolic rate between the two color forms. However, melanistic fox squirrels maintained higher skin temperatures in both sunny and cloudy conditions, while orange squirrels’ skin temperatures dropped on cloudy days. In winter, the black fox squirrels were roughly 30% more active during morning hours compared to their orange counterparts, possibly because their warmer surface temperatures let them start foraging earlier on cold days. The black fox squirrels also entered winter in better body condition, though by the end of winter the two color forms converged.⁹

The practical upshot is that a black squirrel in a northern city or forest may burn fewer calories to stay warm on a frigid January morning and can start foraging earlier in the day. Over a long winter, that adds up. It helps explain why black squirrels are disproportionately common in northern parts of the gray squirrel’s range and in cold cities like Toronto, where melanistic individuals sometimes outnumber the gray form.

What Black Squirrels Eat in Cities

If you are noticing black squirrels, you are probably seeing them in an urban or suburban setting, since that is where most people encounter them. City squirrels still eat natural foods when they can get them: park oaks produce acorns, street maples shed seeds, and suburban yards often have walnut or hickory trees. But the urban diet inevitably gets supplemented by human-sourced food, and that is where things go sideways.

Researchers comparing urban and rural gray squirrel populations found no difference in overall body condition, meaning urban squirrels were not obviously malnourished or obese. But blood chemistry told a more troubling story. Urban squirrels had higher blood glucose, lower potassium, lower phosphorus, lower chloride, and shifted protein ratios compared to their rural counterparts. These markers are consistent with a diet higher in sugar and processed foods, and they suggest that urban squirrels face greater metabolic stress even though they are not visibly starving.¹⁰

The sugar problem is real and documented. Research on red squirrels in urban parks found that city squirrels consumed markedly more sugar than their forest-dwelling relatives. High sugar intake in rodents has been linked to impaired memory and spatial learning, and researchers have raised concerns about potential addictive properties through changes in brain reward chemistry.¹¹ A squirrel that becomes habituated to candy bars and doughnut crumbs is not just getting empty calories. It may be altering its own foraging behavior in ways that make it less effective at finding and caching the natural foods it actually needs to survive winter.

What You Should Not Feed Black Squirrels

If you enjoy watching squirrels in your yard or park, you may be tempted to put out food. Some options are harmless or even helpful, but several common offerings cause real harm:

• Bread, crackers, and chips: These are nutritionally empty for squirrels. They fill the stomach without providing the fats, minerals, or protein that nuts and seeds deliver. Squirrels that fill up on bread may cache less natural food for winter.
• Candy, cookies, and sugary snacks: Given what the research shows about elevated blood glucose in urban squirrels and the cognitive effects of high sugar intake, sugary human foods are among the worst things you can offer.
• Salted peanuts or roasted nuts: Raw, unsalted peanuts in the shell are acceptable in moderation, but salted or flavored varieties deliver sodium levels that a small mammal’s kidneys are not designed to handle.
• Corn: Dried corn is a common squirrel feeder fill, but it is low in calcium and high in phosphorus. That imbalance is the same one implicated in bark-stripping behavior, where squirrels attack tree trunks apparently to compensate for a mineral deficit.⁶ Corn is also susceptible to aflatoxin, a mold toxin that can be lethal to small mammals.
• Chocolate and caffeine: Both are toxic to squirrels, just as they are to dogs. Theobromine in chocolate causes cardiac and neurological symptoms.

If you do want to put out food, the best choices mirror what squirrels eat naturally: raw hazelnuts, walnuts, or acorns in the shell. The shell matters because it slows consumption, provides jaw exercise, and encourages the squirrel to cache some for later rather than gorging on the spot. Sunflower seeds are also a reasonable option. The goal is supplementation, not replacement: squirrels that become dependent on a feeder lose the foraging skills and caching instincts that keep wild populations healthy.

Caching Habits and Why They Matter for Diet

Black squirrels, like all gray and fox squirrels, are scatter-hoarders. Rather than building one large food store the way a red squirrel might defend a central midden, gray squirrels bury individual nuts in thousands of separate shallow holes across their home range. This strategy spreads the risk: losing one cache to a competitor does not mean losing everything.

The system is not as reliable as it sounds, though. A field experiment tracking hazelnuts cached by squirrels in an urban park found that roughly half of cached nuts disappeared within a single day, and after 50 days the probability of a nut still being in its cache was just one in a hundred.¹² Other squirrels, birds, mice, and even chipmunks are all raiding caches constantly. Urban parks compound this problem because squirrel densities are higher and cache theft is rampant.

Squirrels compensate with a combination of memory and deceptive behavior. They remember the general locations of their most important caches, and they perform fake burial displays when they suspect they are being watched by a competitor. The high loss rate means that squirrels need to cache far more food than they will eventually eat, which has major implications for forests, as the next section explains.

The Accidental Gardener

Every nut a squirrel buries and fails to retrieve is a seed placed in near-perfect germination conditions. This makes gray squirrels, including the black morph, one of the most important seed dispersal agents in eastern deciduous forests. In these forests, squirrels shift from being primarily seed predators (eating the nuts) to being critical dispersal agents, because the sites they choose for caching often happen to be ideal for seedling establishment, with the right soil depth, light exposure, and distance from the parent tree.¹³

Squirrels are also selective about which acorns they carry the farthest. Research has shown that they preferentially transport high-quality acorns away from the parent tree, promoting oak recruitment and woodland expansion.¹⁴ Meanwhile, lower-quality acorns tend to get eaten on the spot or cached nearby, where they face more competition from the parent tree’s shade. The net effect of squirrel activity on oaks is what ecologists describe as conditionally mutualistic: it falls somewhere on a spectrum between pure seed predation and genuine seed dispersal, depending on how many cached acorns survive long enough to sprout.¹⁵

The fungi-eating habits of squirrels serve a parallel ecological function. When squirrels consume truffles, the spores pass through their digestive tracts intact and get deposited across the forest floor. Those truffle fungi form partnerships with tree roots that help trees absorb water and nutrients. So by eating truffles and scattering the spores, squirrels are effectively inoculating the forest with beneficial fungi.⁷

Competition at the Bird Feeder

If you have a backyard bird feeder, you already know that squirrels treat it as their personal buffet. This creates real competition between squirrels and birds for supplementary food, and research in the UK has documented gray squirrels both raiding bird feeders and predating bird nests, potentially influencing local bird diversity across different levels of urbanization.¹⁶

From the squirrel’s perspective, a bird feeder full of sunflower seeds is an incredibly efficient food source. It requires no digging, no shell-cracking, and no cache-versus-eat decision. That efficiency is exactly the problem: it concentrates squirrels in one spot, drives away smaller bird species, and disrupts the natural foraging patterns that keep squirrels dispersing seeds through the landscape. Squirrel-proof feeders with weight-activated perch closures or cage surrounds work reasonably well, though determined squirrels are famously creative. If you want to feed squirrels and birds separately, a dedicated squirrel feeder stocked with whole nuts in the shell, placed well away from bird feeders, can reduce conflict at both stations.

Black squirrels have no special advantage or disadvantage in feeder raiding. Their behavior at feeders is indistinguishable from that of gray-furred squirrels, because, as with diet, the color difference is literally skin deep. The same acrobatic determination, the same preference for high-fat seeds, and the same willingness to chew through plastic housings all apply equally regardless of coat color.

Seasonal Feeding Patterns Worth Watching

If you are observing black squirrels through the year, the seasonal shifts in their behavior track closely with the diet changes described above. In spring, you will see them gnawing on buds and spending more time high in trees where fresh growth appears first. They may also dig in lawns and garden beds more frequently, looking for last fall’s forgotten caches or grubs near the soil surface. Summer brings a visible shift to fruit and berry consumption; squirrels raiding tomato plants and strawberry patches are exploiting the same seasonal availability.

Autumn is the most dramatic season. Squirrels become frantic hoarders, spending the majority of their active hours collecting and burying nuts. You will see them carrying acorns or walnuts in their mouths, digging small holes, pressing the nut in with their paws, and then sweeping soil and leaf litter over the top. A single squirrel may create thousands of caches over the course of a few weeks. Their body weight peaks in late autumn as they build fat reserves alongside their food stores.

Winter activity varies with geography and coat color. As noted earlier, melanistic squirrels in cold climates may have an edge in early-morning foraging because their dark fur absorbs more sunlight and warms them faster. On mild winter days, you will see squirrels retrieving caches; on bitterly cold days, they stay in their nests (called dreys) conserving energy. They do not truly hibernate and will emerge to feed whenever conditions allow, but deep cold snaps can keep them inactive for days at a time.

Understanding these rhythms helps if you are thinking about when and what to offer at a feeder. Raw nuts in the shell are most valuable in late winter and early spring, when natural caches are depleted and new food sources have not yet appeared. In autumn, feeders are less critical because natural food is abundant, and in fact feeding squirrels heavily in fall may discourage the caching behavior that both the squirrels and the forest depend on.