Coexist! Learning to live with squirrels, nature's neighborhood nuisance

The UF/IFAS Leon County Extension Office and I have been receiving a lot of calls lately about squirrels.

This is no surprise, as Tallahassee is a city within a forest, and the most common herbivore in the area is the eastern gray squirrel ( Sciurus carolinensis ). Our only other squirrel species is the fox squirrel ( Sciurus niger ), but this much larger squirrel is far less abundant in our urban forest.

The eastern gray squirrel is native to eastern North America but has unfortunately been introduced to other parts of the world, including South Africa and Europe, where it is considered an exotic pest. Though currently abundant in our urban areas, human predation and habitat destruction through deforestation once drastically reduced their populations in parts of the U.S., to the point where they were nearly absent from Illinois by 1900.

Gray squirrels shape our forests in many ways. First and foremost, they have a significant impact by burying seeds like acorns, making them essential natural forest regenerators. They harvest and store tree nuts in various ways, especially by burying them in caches in the ground.

To protect their stored food, they use diversion tactics to deter other squirrels and competing animals. Of course, many of these caches are forgotten, resulting in the squirrels planting many oaks and other trees. Our forest would look quite different without gray squirrels – many of our century-old live oaks owe their existence to squirrels from the past planting their seeds.

Squirrels also enjoy the sugary sap of trees, which they access by chewing off the bark. In our area, they tend to prefer thin-barked trees like maples. The tree I get the most calls about is the Japanese maple ( Acer palmatum ), a smaller tree that seems to offer an ideal combination of thin bark and sweet sap.

Homeowners often don’t notice the damage until the leaves begin to brown, at which point the squirrel is long gone. By then, it has chewed through the bark and the phloem layer down to the xylem, the woody part of the tree. The phloem layer is where the sugary sap that nourishes and quenches a squirrel's thirst is found, while the xylem contains the water and minerals drawn up by the roots. We do something similar when tapping maple trees to make syrup.

So, what can be done about this? On trees that squirrels favor, you can loosely wrap a ¼-inch screen wire mesh, like chicken wire, around the trunk to prevent squirrels from chewing through the bark. You can also try spraying cayenne pepper or garlic spray directly on the tree to deter them. However, both methods can be challenging if the tree is very large.

Commercial squirrel repellents, such as methylnonyl ketone crystals or fox urine crystals, are another option. Keep in mind that squirrels are excellent jumpers, so they don't need to approach your tree by climbing the base. Additionally, both pepper sprays and commercial repellents need to be reapplied after rain, which is common not only during the summer but also frequently throughout the year.

Some people turn to trapping squirrels to remove them. However, doing so could mean you’re removing the parents of nesting babies, which may then starve. Additionally, releasing the squirrel in a new location merely moves the problem to someone else's neighborhood, and you’ll likely invite new squirrels to your yard once they realize the territory is vacant.

In the end, fighting squirrels is often a futile effort.

It’s better to coexist with this abundant and important rodent herbivore and avoid planting trees like Japanese maples. Instead, consider planting a tree like the beautiful and native rusty blackhaw ( Viburnum rufidulum ), which doesn’t invite as much squirrel damage.

Stan Rosenthal is a forester with Natural Resources Planning Services and Forestry Agent Emeritus with UF/IFAS Extension Leon County, an Equal Opportunity Institution. For gardening questions, email the extension office at AskAMasterGardener@ifas.ufl.edu.

This article originally appeared on Tallahassee Democrat: Coexist! Learning to live with squirrels, nature's neighborhood nuisance