Oak trees are sturdy, beautiful plants. But did you know that hundreds of wildlife species depend on oak trees for survival? Read on to learn more about what animals eat oak trees, the various species that depend on oaks for shelter and survival, and what to do if oak pests are getting out of control.
What You'll Learn Today
How Many Species Does an Oak Tree Support?
It is impossible to say just how many species of wildlife depend on oak trees for their survival, but the number is likely in the hundreds or thousands.
Different species of oak grow natively in many regions throughout the world, and in every area, the local wildlife depend on the sturdy oaks for food, shelter, shade, and support.
It isn’t just animals and birds that use oak trees. There are over 530 species of caterpillar that feed on various parts of the oak tree, not to mention other insects such as beetles, acorn weevils, and gall wasps.
Many types of lichens, moss, and fungi also grow on oak trees. Various species of mushroom grow on decaying oak trunks, while others develop a symbiotic relationship with oak roots.
What Animals Rely on Oak Trees?
The animals that rely on oak trees will vary from region to region.
Many small mammals eat acorns from oak trees and may also eat their leaves and twigs if food is scarce. Some of these mammals include:
Many of these small mammals also use leaves and twigs from oak trees to build their nests. Larger mammals such as deer may eat various parts of the oak tree as well as find shade under its wide canopy during the hot summer months.
Salamanders often take shelter in the cool, moist litter at the base of oak trees, while in drier regions, lizards can often be found scampering up oak branches looking for shade. Larger animals like bobcats, bears, alligators, coyotes, foxes, and mountain lions don’t eat oak trees, but may use them for shade on hot days.
Even neighborhood cats may use the tall, widely-branching oaks to escape from playful dogs.
What Birds Nest in Oak Trees?
As you might imagine, oak trees are highly popular among the bird population. Oaks make ideal trees for building nests, finding food, and taking shelter from storms or predators.
Because so many types of insect live in oak trees, insect-eating birds such as warblers and orioles love oak trees. Other birds, such as woodpeckers and blue jays, eat acorns throughout the fall and winter months.
Many types of birds build nests in oak trees. Some of these birds include:
- Baltimore Orioles
- Scarlet tanagers
- Tufted titmice
- Northern flickers
- Brown thrashers
- Various owls
- Downy and red-bellied woodpeckers
- Ruby-throated hummingbirds
- Various hawks
Do Animals Eat Oak Trees?
Yes, many animals rely on oak trees for food. More than 100 animal species eat acorns, according to the National Wildlife Federation.
Most animals prefer the acorns from trees in the white oak group, as these mature more quickly and are less bitter than acorns in the red oak group. That said, red oak acorns store better throughout the winter, so many animals will turn to eating the fruit of red oaks when other acorns have been used up.
Mostly birds and small mammals feed on oak trees, but even some larger mammals may snack on the leaves, twigs, bark, or acorns if there isn’t much else to eat.
Do Deer Eat Oak Trees?
Oak trees are not a deer’s favorite food source, but deer are not too picky when food is scarce. They will eat acorns, leaves, small branches, and bark off of oak trees, especially during the fall and winter.
Like most animals who feed on acorns, deer prefer the acorns from white oak trees because they have fewer tannins, which makes them sweeter and less acidic. But again, deer aren’t too picky, so they will eat whatever’s available to them.
Deer may also cause some damage to oak trees by rubbing their antlers on the bark or getting them tangled in low-hanging branches. Young oak trees are most susceptible to damage because their bark is still soft and their branches are typically lower to the ground.
Do Squirrels Eat Oak Trees?
They mostly eat the acorns, but they will eat just about anything if food is scarce. They will eat the galls off oak trees, and they may also chew on the bark and on small twigs.
That said, squirrels are a bit more picky when they have plenty of food.
During a good acorn year, they may only eat the acorns from one tree but not from another. This could be because some acorns are higher in tannins, which makes them more bitter.
What Eats Oak Tree Leaves?
If you’ve been noticing small holes in your oak leaves, you may have been able to rule out larger pests such as deer and birds. But what about insects?
A variety of insects feast on oak leaves and, as you can see from the video below, some bugs may eat quite a bit in a relatively short amount of time.
Is there any way to tell what, exactly, is eating your oak tree leaves? More importantly, is there anything you can do about it?
Let’s take a look at some common oak pests that may be causing damage to your tree.
Tent caterpillars attack a number of different hardwood trees, including oaks. They live in colonies that create characteristic “tents,” which may look similar to clustered spider webs.
Tent caterpillars are highly destructive, eating large amounts of leaves and damaging small twigs. The leaves often take on a brownish and lace-like appearance by the time these worms are finished.
Oak Leaftier Caterpillars
These caterpillars are very small but can sometimes be seen hanging from oak branches on silk threads. They are light green to yellowish in color and have brown heads.
Trees with oak leaftier infestations will have sparse, deformed leaves. The leaves will likely be filled with holes, similar to swiss cheese.
Sawfly Wasp Larvae
The larvae of the sawfly wasp are small, black, and slimy in appearance. They can be found feeding on the underside of oak leaves and will eat everything except the veins of the leaves.
If sections of your tree look like the leaves have turned to skeletons, you may be dealing with sawfly wasp larvae.
What to Do
If you notice tree damage on young, small trees, it’s important to remove the pests before they stunt the tree’s growth. You can look for the pests and remove them by hand, or spray on an insecticide such as bacillus thuringiensis.
If you have larger trees and there is extensive damage, you may need to call for professional help. A tree care specialist will have methods and equipment for treating larger trees, and they should be able to kill current infestations while preventing future ones.
Many species of wildlife depend on oak trees for survival. Animals, birds, and insects all eat acorns, leaves, twigs, and bark from oak trees, while moss, lichens, and fungi grow on and near the trunks and roots.