Squirrels are perhaps our most popular small game animals. Millions of hunters pursue them. Many people also enjoy feeding, watching and photographing squirrels.
Count the number of acres of good squirrel habitat on your property and multiply that number by three -- that's a good population.
If you would like to increase squirrel numbers on your property, you can. Squirrels can be managed, just as deer can be managed. All you need are a basic understanding of squirrel biology and the means to provide a year-round food supply, sufficient nesting sites and a nearby source of water.
Gray squirrels and fox squirrels occur throughout much of the U.S. Adult grays weigh up to 1.5 pounds. Adult fox squirrels tend to be larger, up to 3 pounds. Both species often live in the same areas, but fox squirrels prefer more open woods, usually near forest edges. Gray squirrels prefer dense stands of trees in deeper woods.
Squirrels do best in deciduous forests and stands of mixed conifers and hardwoods, especially those with mature, nut-bearing trees. Populations vary with food abundance. When nut crops are good, mortality of young is low, and a high population survives through the winter. Poor mast crops may be accompanied by population declines through starvation or migration in search of food.
To improve your squirrel woods:
Encourage a variety of food-producers in addition to oaks and hickories, including elm, maple, walnut, mulberry, black cherry, wild plum, hawthorn, hackberry, Osage orange and wild grapes. Some plants bear when others fail or are out-of-season.
Grow uneven age stands of timber to ensure having some trees coming into food production each year.
If necessary, thin timber stands to enhance mast production. Where nut-producing trees grow in the woods, cut competing trees away to increase their vigor. For maximum production, the number of feet in the crown diameter of a nut-bearing tree should be roughly twice the number of inches in the diameter of the trunk. For example, a tree with a 20-inch trunk should have a crown of 40 feet. Thin in such a way as to allow crowns to reach this size.
Keep numbers of oaks about evenly divided between the white oak group and the red oak group to ensure production of some acorns each year. (White oaks require one growing season and red oaks two growing seasons to produce acorns.)
Where there are no food trees and a long-term management program is being planned, plant nut- and fruit-bearing trees where competition with other forest species will be least.
Planting a few rows of corn at the woodland edge provides a supplemental food source during years of poor mast production. You also supplement natural foods with ears of hard corn provided at feeding stations throughout your woods.
Control fire and grazing to ensure a good understory of shrubs and saplings for ground cover and replacement.
Ups and Downs of Squirrel Numbers
Squirrel numbers may fluctuate dramatically from year to year. Understanding this phenomenon is largely a matter of understanding squirrel reproduction and its relationship to food supplies.
When supplies of hard mast and other foods are good, most adult female squirrels will produce two litters per year--one during the period of late February through mid-May, another from June through September. Each female in the litter can produce one litter of young, sometimes two, during her first year and two litters during each year thereafter. Therefore, squirrel numbers can quickly skyrocket when food supplies are good.
During years of poor food production, squirrel litters are few and their average size is less. Also, fewer squirrels survive through the winter, and many of these migrate to areas where food is more plentiful. There are fewer squirrels to breed, and those that do produce fewer and smaller litters. Squirrel numbers plummet.
This population decline will be remedied the next year if the mast crop is good. Then two litters will once again be the rule, and the average litter size will be greater, quickly restoring the population to it optimum number.
The effect of a good or poor mast crop is not immediately evident. For example, let's say in 2004, your hunting season started off good. Squirrels were plentiful, even though the mast crop was poor. You hunted several times and killed enough squirrels for dinner each time out. Unfortunately, due to the poor mast crop, squirrels that survived that season were in poor breeding condition when the January rut started. Many females produced no litters at all in February, and those that did had only one or two young per litter. The continued lack of food caused high mortality in the young. Few survived past their first few weeks. Conditions during the second breeding period that year were similar. Few females produced litters, and most litters were small.
By the fall of 2005, when squirrel season opened again, hunting was horrible. Trees were loaded with acorns and hickory nuts but very few squirrels. Fortunately, the few squirrels remaining found plentiful food. When rutting season arrived, they were fat and healthy. More had survived the winter to reproduce. Most females produced litters in February, and each litter had three to six young. When summer breeding season started, females that bore young in February produced a second litter, and females born in February produced their first litter. Once again, most females produced litters, and each litter was large. Squirrel numbers rebounded, and by the opening of the 2006 squirrel season, squirrels were once again plentiful, and hunting was good.
Get the idea? The abundance or lack of mast this year affects next year's squirrel crop. Good mast this autumn means a good squirrel crop next autumn. A poor mast crop this autumn means fewer squirrels next autumn.
Will squirrels be plentiful this year or hard to find? Think back to last year. How good was the mast crop? Therein lays your answer.
Leaf nests are suitable short-term dwellings, but squirrels rear more young in den holes protected from weather and predators.
To promote a larger squirrel population:
Leave 3-5 den trees per acre during timber cuts. Good dens have small openings (less than 4 inches diameter) and a cavity 1-3 feet deep to exclude moisture and predators.
Select den trees in such a manner as to give good den distribution throughout the woodlot. Allow at least 3-4 dens per acre.
Use den boxes to ease cavity shortages. This is important in woodlands comprised largely of immature trees lacking natural cavities. Install 7-8 boxes per acre, 10-30 feet high in trees. Where natural dens are available but unevenly distributed, supplement them with a few den boxes placed in strategic locations.
Squirrels, like all species of wildlife, require water in some form. This is obtained normally from succulent fruits, nuts, buds and berries, but squirrels prefer living quarters where they can drink at a creek, river, pond or lake, especially during periods of drought. If water is not readily available on your property, consider constructing small water holes or ponds in key locations.
Count the number of acres of good squirrel habitat on your property and multiply that number by three. That's a good population. You can then plan on hunting mortality as high as one-half the existing population each year and still maintain a healthy population.
As you work to improve your land for squirrels, remember, wise woodlot management equals wise squirrel management. The essentials are food-producing trees and shrubs, den sites and water. If these three essentials are present, you should have a healthy population of squirrels. If you want more squirrels, provide more of the essentials. Squirrel management is as simple as that.