SQUIRREL MANAGEMENT

PLANNING AHEAD FOR WILDLIFE SURVIVAL

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There are several ways to increase squirrels on most farms that have some woods. Certain practices give prompt results; others require several years for effectiveness but give more lasting results as well as economic gains. Interested non-landowners can help produce squirrels by using the short-term practices in cooperation with landowners. The long-term measures of habitat improvement can be carried out best by the landowner through timber management.

Good squirrel habitat can be had for a price. The price is work and patience. Unfortunately, you can't start with nothing and produce good squirrel habitat overnight. It takes a lifetime. Once the elements of good habitat have been present and nurtured, time and a little management will grow plenty of squirrels.

The amount of work needed to start and maintain a squirrel habitat depends on the basic materials at hand. A 35-year-old man planting a barren field with tree seedlings can't expect to see good squirrel habitat in his lifetime. His ten-year-old son will begin to see a few squirrels and great potentialities before he dies. The planter's grandson likely will be amazed by a large, thriving squirrel population, although he might not realize what created the squirrel factory.

There are short-cuts to squirrel production. Any woodland having at least 50 to 75 mast-producing trees of various kinds--oaks, hickories, walnut, elms, maples, mulberry, etc.--is a squirrel producer. The first objective is to improve living conditions for these animals to raise the carrying capacity for squirrels. One must decide how food and cover can be improved.

FOOD

Squirrels are omnivorous; that is, they eat both plant and animal matter, but their primary diet consists of plants.

Abundance of scarcity of foods affects squirrel numbers. Scarcity during population highs triggers some migrations. Also, food scarcities depress squirrel crops, as breeders in poor physical shape fail to bear at their normal rate. This is evident in the ups and downs of squirrel numbers in south Missouri. There squirrels are heavily dependent on native foods, mostly acorns. Shortages of acorns result in small crops of squirrels the following year. Bumper crops of acorns produce big squirrel crops from well-nourished breeding stock.

About the time the first litters arrive in late winter, parent squirrels are feeding on buds and flowers in hardwoods, particularly elms, maples, oaks, and sweetgum. Except in years following heavy acorn yields, most of the acorns are gone by spring. As spring arrives, squirrels shift to mushrooms and mulberries, then to the mid-summer berry crops of bramble fruits, wild cherries, wild strawberries, then to the wild plums and wild grapes of early fall.

Corn in the milk stage is readily used during July and August, as are fungi and leafy parts of herbaceous plants. Some early use of Osage orange hedge balls occurs. During the summer, after the mulberries are gone and before the nuts are ready, squirrels are most difficult to see because they forage on the ground.

About the middle of August the squirrels being "cutting" on the mast crops, usually taking hickory nuts first, along with the staple seasonal food, acorns. Fruits of sugar maple and honey locust are eaten at that time, followed by walnuts, pecans, beechnuts, pokeberries and ripe corn. Where available, squirrels often feed on seeds of cypress and tupelo gum as well as pine on late October.

Acorns and nuts, either as residues or caches, are the foods which must carry the squirrels through the winter. Sometimes these foods are gone before the buds are ready in early spring. On farms corn tides the squirrels over, but soybeans, wheat, oats, and apples are popular, too. Fox squirrels, because of their preference for open timber and small woodlots in farm country, use more grain crop than do gray squirrels. Conversely, grays are more dependent on natural foods. In one week, a squirrel consumes food roughly equal to its own weight.

COVER

In a broad sense, "cover" can be defined as that portion of habitat which gives protection to the animal. Whether it is a hedgerow on the prairie or a dense forest in the Ozarks, ground cover and tree canopy are critical factors in determining quality of cover and kind of squirrels.

The fox squirrel prefers mature hedgerows, small woodlots with openings in the canopy, and park-like woods pastures. Little ground cover is needed; in fact; lightly grazed woodlots with open canopies are accepted by fox squirrels.

The gray squirrel prefers the more extensive and densely wooded areas, usually with closed canopies but with good ground cover of herbaceous plants, shrubs, and saplings. A few windfalls of tree tops lopped off by wood cutters attract gray squirrels. By nature, this species is more secretive than the fox squirrel, thus it needs more cover.

Cover also includes specific shelters in the form of leaf nests and tree cavities. Both species use these shelters from the weather and predators. Cavities are scarce in timber less than 30 years old, so leaf nests are used for shelter. Cavities become more numerous as the age of the stand increases; also older trees yield more acorns. Therefore, mature and over-mature stands provide the most homes and food for squirrels. Leaf nests are cooler in summer and offer respite from the fleas which often infest dens during winter, but they are not as durable nor as safe as dens. Whether the enemy is weather, owls, hawks, or gunners, dens are the safest shelter for squirrels.

A good den may require about ten years to develop from a natural cavity and it may last ten to fifteen years, sometimes longer. Some species of trees tend to have a high number of cavities. These offer the greatest potential for dens. They include the oaks, maples, elms, ash, sweet gum and Tupelo gum. Osage orange and hickories are examples of trees which are generally sound, even when mature. These species have few cavities.

Typical squirrel dens are formed by self-pruning of trees within the forest stand as lower limbs are shaded, die and drop off. Decay may begin at these spots before the opening heals over. Trees growing in the open are less susceptible to this type of den formation.

WATER

Exact requirements of squirrels for water are not known. Gray squirrels usually live near open water, yet both species can survive for many days without trips to pools or streams. Succulent foods, snow, frost and dew are other sources of water. Convenience seems to determine which sources are used most often. However, permanent water should be available to squirrels for drought emergencies. Squirrels can be expected to live within a quarter to a half mile of permanent water during droughts. If permanent water is not available at such times, squirrels will migrate to an area where it is present.

MANAGEMENT

The most effective management of oak-hickory habitat for squirrels is one of restraint; let it grow to maturity. The speed with which squirrel habitat develops and the degree of success attained depends upon overall objectives, perseverance and the use of special techniques such as nest boxes.

FOR QUICK RESULTS

Provide additional dens - Dens are most effective in woodlots averaging fewer than three or four natural dens per acre. Dens can be built from auto tires, rough lumber, sawmill slabs, nail kegs, or small hollow logs cut in sections. Minimum specifications for boxes should be followed to assure that squirrels will use the den:

Kegs and logs need only to have the top, bottom, and entrance hole added. Plans for building "Dens for Squirrels" are available from the Missouri Department of Conservation, Box 180, Jefferson City, MO 65102.

Excellent dens can also be made from 14 or 15 inch automobile tires. Remove the beading and cut the tire in half. Each half makes one den. On each tire half, make a 3-inch cut in the wall on each side, 12 inches from one end. Do the same thing again on each side, 14 inches from the same end. (These cuts will let the tire bend.) Bend the shorter end up and inside the longer one to form a "canopied" opening. Fasten in two places on each side with hog rings, heavy wire, or bolts and wing nuts. This den will be weather-tight. It may take more work than a wooden box, but the rubber den lasts much longer. Excelsior, dry wood shavings or sawdust should be used as a nest starter. Dens should be loosely filled about halfway with nest material.

Allow three dens for each family of squirrels, but use only one den per tree, spaced several yards apart. Use trees not having natural dens. Fasten the den against the tree trunk, about 15-30 feet above the ground, with the entrance hold nest to a limb or the trunk for accessibility.

To avoid damage to valuable trees, use heavy, soft wire instead of nails to fasten the dens. It's best to face the entranceways south, but easterly or westerly approaches are satisfactory. A more elaborate entranceway may be provided on boxes by substituting a small board for the lath cleat to form a porch beneath the hole.

Feeding stations - Use feeding stations in the winter and early spring, if natural foods (acorns, nuts) are scarce. This is a critical time of year for squirrels, and the abundance or lack of suitable food makes the difference between good and poor squirrel production in the spring and summer.

Feed corn and most any kind of nuts. Figure at the rate of three pounds of unshelled corn a week per squirrel. To keep the squirrels from carrying away and hoarding the corn, fasten ear corn to a spike driven through a board or wired to a tree; or string ears of corn on a wire and anchor to a solid object. Wire baskets or hoppers fastened to a tree can be used, as well as other special feeders (see diagram). A row of corn bordering the woodlot can be left standing as a natural feeder, or the corn may be placed in shocks at the feeding station. Usually it is more economical to feed corn in the specially constructed feeders. One feeding station per 25 acres is sufficient. Once feeding has begun, food should be provided regularly; otherwise a feeding station can cause more harm than the absence of one.

LONG-TERM MANAGEMENT

High food production is necessary for big squirrel populations. Trees yield better if provided space to grow. In appraising a timber stand for food production, follow this rule of thumb with individual trees: The number of feet in the crown diameter should be roughly twice the number of inches in the diameter of the trunk. To achieve this desirable ratio, it may be necessary to thin the stand or make a light commercial cut.

Use the axe and saw to create better squirrel habitat - Solid stands of even-aged timber can be improved for squirrels by cutting an occasional tree to open up the solid canopy and allow seedlings to grow. This encourages different kinds of trees and promotes the growth of uneven-aged stands, insuring a more dependable food supply and den development. Squirrels and timber can be grown in the same woodlot by practices beneficial to both crops. Some trees having no commercial value as sawtimber are important to squirrels. These should be allowed growing space. Mulberries, wild cherry, elms, maples, hackberry, sweet gum, and ash are food producers for squirrels. Most of these develop den cavities more rapidly than do some of the commercial hardwoods, and they are also useful as fuel.

An average of one elm or maple, one mulberry and about six hickories per acre, along with the oaks, provides a stable food source, particularly if the oaks are evenly divided as to group. Acorns of the white oak group mature in one year; those of the black oak group require two growing seasons.

A good undergrowth of hazel, hawthorn, dogwood, redbud, brambles, and wild grape is desirable. Windfalls or downed trees help create ground cover, which is necessary if gray squirrels are wanted. A protective strip of low cover, such as brambles, sumac, hazel, and mixed saplings bordering the edge of the timber keeps down wind movement on the forest floor. This reduces evaporation and temperature extremes, thus promoting growth of forest plants. Woodlot borders can be improved by cutting a strip of timber and allowing it to regenerate naturally. Field borders can be improved by planting a variety of shrubs in clumps or strips. Cattle must be excluded.

The "wolf" trees (trees with large spreading crowns which dominate nearby trees) are objectionable to foresters in timber management. But rather than felling these commercially unprofitable trees, they can be girdled and allowed to stand. As they die, they often provide dens for several years before they fall, and the openings in the forest canopy permit other beneficial plants to grow.

Plant berries, shrubs, and trees to produce squirrel foods - This takes several years to produce results, but once natural production gets going, food supplies are more permanent and the natural "feeding stations" require little attention. The greater the variety of plants, the more dependable the food supply and the more stable the squirrel population.

If plant diversity is lacking or only a few trees are present, planting may be necessary. Three to five of each of the following species can be planted in fencerows, field corners, or associated woodlots to provide excellent squirrel food:

1) Mulberry	5) Pecan
2) Osage orange	6) Shagbark hickory
3) Northern red oak	7) Black Walnut
4) White (or sawtooth) oak	8) Soft and hard maple

Squirrels eat an amazing variety of foods. The spring diet is mostly buds and flowers from elms, maples, sweet gum, ash, and oaks. In late spring and early summer, mulberries and bramble fruits are staples: Summer fruits include wild cherries, wild grapes, and wild plums. Late summer brings in mast foods---acorns, hickroynuts, walnuts, pecans, hazelnuts, fruits of sugar maple, honey locust, Osage orange and box elder, fall grapes, and pokeberries. Squirrels must live on these until spring.

Encourage natural plant reproduction and, if necessary, plant a variety of the plants listed. Some of them can be secured from the Department of Conservation, and others from commercial nurseries. Orders must be placed in early winter before seedling supplies are exhausted.

Direct seeding works if you can prevent squirrels from eating the seed before it sprouts. Plant nuts singly, at a depth equal to twice the thickness of the nut. Protect it from squirrels by putting a small tin can over the nut and push the can into the soil flush with the ground. With a heavy knife, cut an X in the bottom (now the top) of the can. Pry up the points of the X enough so the sprout can come through. The non-aluminum can will rust away before it damages the seedlings.

Other smaller shrubs and trees beneficial to squirrels include: Redbud, persimmon, pawpaw, hawthorn, apple, pear, sassafras, dogwood, sumac, and serviceberry.

Manage fencerows and odd corners for squirrels - Leave mast-producing trees in the fencerows and odd corners where possible. Trees and shrubs growing in the open, with less competition, are more thrifty and yield more food than those in forests. Grape, sumac, hazel, brambles, and other shrubs furnish ground cover and food. These also provide protection for squirrels using fencerows as travel lanes.

Keep fire and livestock out of squirrel habitat - Burning destroys ground cover, shrubby food producers, and slows regeneration of timber stands. Fire scars on trees develop into butt cavities, which are not suitable for squirrel dens. Grazing removes ground cover and herbaceous and shrubby food producers. Acorn-eating hogs compete with squirrels and other mast-consuming wildlife.

A good forest is a poor pasture - a good pasture is a poor forest. Even fox squirrels do not prosper in heavily-grazed woods. The future of such an area as squirrel habitat is as short as the life of the mature trees present.

Maintain a dependable water supply - This greatly improves an area for squirrels. A farm pond or waterhole near or in a woodlot benefits squirrels when other dependable sources of water are lacking.

SUMMARY

Tree squirrels depend upon the right combination of trees for existence. Squirrels thrive best in a climax or sub-climax oak-hickory forest where trees are nearing maturity or are over-mature. Here, squirrels have sufficient food and cover for year 'round living. Variety of trees lends stability, and maturity of the trees adds volume to food production. Also, more cavities are associated with the mature of over-mature forest, usually providing homes for squirrels in excess of two per acre.

Squirrels can and do live in sub-optimum habitat, but life is more hazardous, production more uncertain, and populations more variable. Proper management can do much to relieve some of the shortcomings of habitat by directing natural development and implementing special practices to achieve optimum conditions more rapidly. Good squirrel habitat comes with work and patience--seldom with indifference, and never overnight.

LIFE HISTORY AND MANAGEMENT HIGHLIGHTS

1. A family of squirrels uses three dens: One for the female, one for the male, and later, one for the litter.

2. About one-third of the females drop two litters per year if in good physical condition; others drop one litter.

3. Most litters are dropped in February and July.

4. Gestation period is about 45 days.

5. Average litter size is three.

6. Squirrels are born naked.

7. Squirrels are weaned by the twelfth week.

8. Each squirrel eats about 100 pounds of food a year.

9. Fox squirrels weigh one to three pounds and can live four to seven years.

10. Gray squirrels weigh 3/4 to 1 1/2 pounds and can live six to ten years.

11. Fox squirrels outnumber gray squirrels two to one in Missouri.

12. Two to three squirrels per acre is a high population density.

13. There are some 80 thousand squirrel hunters in Missouri.

14. About two million squirrels are bagged annually.

15. Less than one-third of the squirrels are taken annually.

16. Over half of the squirrels could be taken yearly.

17. Missouri has 13.5 million acres of squirrel lands.

18. Hunting opportunities are available on over 1 1/2 million acres of public land.