Attracting Squirrels With Mast-Producing Trees
Mast is the most important source of food for squirrels, including gray squirrels, fox squirrels, and red squirrels. Squirrel populations are closely tied to the level of mast production. After a good mast year, female squirrels are in excellent breeding condition and can produce two litters over the summer. After a poor mast year, squirrel populations plunge. Fewer squirrels survive the winter and the females who do are in poor breeding condition, so they produce one small litter, instead of two larger ones.
For this reason, if you are interested in attracting squirrels to your property, the most important thing to do is to plant a diverse mix of mast-producing trees and shrubs. The more species you plant, the less likely it is that all your trees and shrubs will have a poor mast year at the same time.
The most important type of mast for squirrels is hard mast, especially acorns. A stand of trees managed for squirrels should ideally contain at least 50% oaks, preferably a mix of several different species from the red oak and white oak groups. Other types of hard mast favored by squirrels include hickories and pecans, walnuts and butternuts, and beechnuts. A good variety of hard mast producing trees and shrubs is especially important in autumn and winter.
Pine seeds are another favored food of squirrels, especially red squirrels and grey squirrels, whose preferred habitat is stands of mixed hardwood and conifer trees.
Soft mast is also an important food source, especially in spring, when squirrels gorge on the buds of trees such as maple, birch, oak, and basswood, and summer, when they enjoy fruits such as wild cherry, osage orange, wild grapes, persimmons, and mulberries. Though hard mast is the most important autumn and winter food source, fruits and berries that often linger into winter, such as crabapples and hackberries, are also beneficial for squirrels.
Another important consideration for people who want to attract squirrels is nest trees. Squirrels prefer to raise their young in small cavities found in mature trees. The best cavity tree species include ash, oak, beech, basswood, and maple. Cavity trees in woodlots and other tree stands should be preserved at a rate of about 4-5 per acre.
Finally, though squirrels typically receive most of their water needs from their food, it is a good idea to ensure a secondary water source for them, especially in drought years. Natural streams, creeks, and lakes are the best sources, but squirrels will also make use of water gardens, bird baths, and similar man-made water sources.