MANAGING WHITE-TAILED DEER PROBLEMS IN KENTUCKY
Thomas G. Barnes
Extension Wildlife Specialist
Deer are a valuable natural resource
in Kentucky, providing many hours of enjoyment for the public. The white-tailed
deer (Odocoileus virginianus) is the most sought after big game
animal in North America. Whitetails were abundant in our country when European
settlers first arrived. By 1900, however, uncontrolled hunting had reduced
the U.S. white-tailed deer population to around 300,000. The deer population
has since rebounded as a result of strict hunting laws, intensive reestablishment
and restoration efforts, and changing habitat to favor deer. Today, it
is hard to imagine white-tailed deer populations not being abundant.
In fact, in many circumstances, we
have too many deer in the wrong place at the wrong time. Occasionally,
the approximately 450,000 deer in Kentucky may cause unacceptable economic
losses to farmers and orchard owners. High deer populations in rural areas
may result in damage to orchard trees, soybean or corn fields, and vegetable
crops. Deer may also hamper forest regeneration and interfere with small-scale
Christmas tree production. High deer populations also contribute to the
many deer/vehicle collisions on our highways. In our urban and suburban
areas, high deer populations may result in damage to ornamental trees,
gardens, and parks or greenways.
While most of us enjoy seeing deer,
sometimes it is necessary to manage the herd in an effort to reduce the
damage they can cause. Unlike chipmunks, moles, starlings, pigeons, or
other nuisance wildlife, deer cannot be casually eliminated when they come
into conflict with a landowner's intended land use. Thus, deer damage management
becomes a social and political problem as well as a biological and logistical
Animal Facts and Biology
The easily recognized white-tailed
deer is the only native ungulate (hoofed mammal) remaining in Kentucky.
Most people are familiar with the reddish brown summer coat and grayish
brown fall and winter coat of the adult whitetail. Likewise, most people
are familiar with the rust-colored fawn that is dotted with white spots.
By three to four months of age, the fawn replaces this coat with a fall/winter
coat. The underparts of the tail, belly, chin, and throat are white.
It is easy to tell the difference between
male and female whitetails because bucks grow antlers from April through
August. The growing antlers are nourished by a soft exterior tissue called
"velvet." Once the antlers have reached their maximum size, the dried velvet
is rubbed off and the antlers are polished during the fall breeding season.
Antler size depends on the deer's age, genetics, and nutrition. White-tailed
deer lack upper incisors which results in a distinctive feeding pattern
that looks like the plant was torn. Rabbits and rodents, on the other hand,
make a sharp, clean, knife-like cut on plants.
Whitetails breed from October through
January. Peak breeding activity in Kentucky usually occurs in mid-November.
Females cycle every 28 days and will remain in heat for 24 hours. One buck
may mate with a number of does and no pair bonds are formed. Most deer
breed their second fall, although about 40% of fawns may breed the first
fall. After a gestation period of about 200 days, adult does will typically
bear twins in June. Fawns will usually bear a single fawn. The reproductive
potential of white-tailed deer is greatly influenced by the amount and
quality of food present the preceding year. Once the fawns are born, they
gain weight quickly and reach an adult weight that varies from 180 to 250
Deer are browsing animals and over
650 different plant items have been identified in their diets. Broadleaved
"weeds" or forbs are preferred food items and are eaten whenever available
in the spring and summer. Most of the time deer eat the leaves, stems,
and buds of woody plants because they are available year round. During
the fall, acorns, beechnuts, hickory nuts, persimmon fruits, and other
nuts or berries are favorite food items.
Deer can be selective feeders eating
only certain plants or plant parts. However, when too many deer live in
an area they will consume almost every piece of vegetation within reach
to survive. Grasses are relatively unimportant in a deer's diet, although
they will eat agricultural grain crops and fruit trees if these are available.
The soybean plant is a highly preferred food for white-tailed deer. They
also relish other agricultural crops such as corn, grain sorghum, milo,
Deer are most active early in the morning
and late in the evening. In most areas of Kentucky, deer will roam about
640 acres. In the mountainous east, the home range size may be as large
as 1,000 acres or more. Under conditions of suitable habitat, an area of
1,000 acres may support 40 or more deer; however, the deer will travel
on and off that amount of land at different times of the year looking for
the best food and cover available.
Deer are habitat generalists and prefer
the forest edge over dense, old-growth forests. They do exceptionally well
in most parts of Kentucky because agricultural lands are mixed with timbered
stream drainages and woodlots or small forested tracts. They favor brushy
areas because these areas provide large amounts of cover and food.
Preventing and Controlling Deer Damage
There are no easy answers, quick fixes,
or inexpensive control methods for managing deer damage problems. Each
situation is different and requires a different solution. Often, a combination
of techniques may produce the best results. In one Oregon study, the best
protection for large-scale conifer production was to use a chemical repellent
in combination with plastic flagging. Like many agricultural ventures,
deer damage management must be viewed as a long-term commitment and possible
investment. For consistent control, a five- to ten-year damage management
program is advisable.
Urban control methods differ drastically
from rural control methods because deer cannot be harvested by the general
public in urban areas. In addition, urban homeowners have smaller acreages
and neighbors may not tolerate unsightly fences. One way to reduce deer
damage to ornamental trees is to select plants that deer do not like to
eat. For more information on which plants are unpalatable to deer contact
the Cornell Cooperative Extension Service, Cornell University, Ithaca,
NY 14853, and ask for a copy of the fact sheet "Resistance of Woody Ornamental
Plants to Deer Damage."
Deer that live in urban parks and greenways
present a difficult social and political problem that will not be discussed
in this publication. Contact the Kentucky Department of Fish and Wildlife
Resources for assistance with these problems. Information on managing deer
problems in Christmas tree plantations is available from the Kentucky Cooperative
Extension Service. Ask your county Extension agent for publication number FOR-27,
"Pest Control: Animals."
Significant deer damage usually means
the area has too many deer. The proper time to take care of this problem
is during the fall hunting season before the next growing season.
Even if you get a permit to destroy problem deer during the summer, doing
so will not help that year's soybean crop because yield-reducing damage
occurs in the first 7 weeks of plant growth.
You should be aware that any agricultural
field of soybeans, corn, or alfalfa that is smaller than 15 acres and located
next to wooded or brushy habitats is just like a food plot to attract deer.
In these cases entire fields can be destroyed. Deer present less of a problem
in large soybean fields. Most damage is concentrated within 30 feet of
field edges, and less than 2% of the plants will be damaged to the point
where their yield will be reduced. Soybeans can withstand a removal of
up to two-thirds of their leaves without affecting bean production. In
some cases when the plants are less than 3-weeks old, deer browsing actually
increases yield. If you can protect your soybeans until they are 4- to
7-weeks old, you will substantially reduce any potential yield losses.
Landowners should consider the following
options for reducing or preventing deer damage to their crops: (1)
obtain a permit from the Kentucky Department of Fish and Wildlife Resources
Conservation Officer or District Wildlife Biologist to harvest antlerless
deer; (2) plant a crop that is not palatable to deer; (3)
plant the soybean crop early in spring so if the beans are browsed they
will have time to recover (late-seeded beans may have reduced yields because
they have not had time to recover from browsing); (4) plant a variety
of soybeans that may have some resistance to deer browsing; (5)
erect a temporary or permanent electric fence; or (6) use a chemical
repellent to deter the animals.
A permit may allow you to harvest deer
at times other than during the legal hunting season. Another permit may
allow you to harvest extra does during the legal hunting season. When using
special permits, contact local hunters in the community and assist their
help. Many eager hunters would gladly harvest the extra deer and possibly
pay for that privilege during the hunting season. Information on lease
hunting is available from your county Extension office. This method helps
you solve your damage problem, provides extra farm income, and creates
good landowner-hunter relationships. The most effective, long-term,
and practical solution to managing large-scale deer problems is fall hunting.
You can use a propane exploder to discourage
deer from using the fields before you construct fencing. Propane cannons
can be set to detonate at regular, timed intervals. It is important to
set the cannons out when the plants appear above ground and continue for
4 to 7 weeks. Move the cannons every few days and alter the time when they
detonate to prevent deer from becoming accustomed to the sound.
You can also use a shellcracker to
frighten deer away from crops. Shellcrackers are special 12-gauge shotgun
shells that use a firecracker in place of lead or steel shot. When you
fire these shells, they travel 75 to 150 yards and explode in the air with
a loud bang. Remember: Frightening devices will only temporarily alleviate
the problem until you decide on a more permanent solution.
If hunting is not a viable option,
fencing is the other valuable tool that will keep deer away from cropland.
Fencing can provide consistent and effective deer damage control. Historically,
farmers used the 8-foot woven wire fence (figure
2) to control deer damage. This is an extremely expensive option and may
be too costly for most agricultural use. It still remains a viable option
under the right circumstances. One easy way to create a mesh wire fence
is to join two 4-ft x 8-ft hog panels together supported by a 12-foot post.
This fence can be slanted at a 45-degree angle (figure
3). The high end of the fence should be 6 feet from the ground and
slanted so deer can walk under the fence without being able to jump over
An excellent alternative is to use
low-cost electric fence designs. Current prices for these fences vary from
10 to 25 cents per running foot based on design and materials used. The
most expensive component will be the charger. Electric fences act as a
barrier and are based on the idea that deer have a tendency to go through
an obstacle even though they could easily jump over or crawl under it.
Upon contact with the fence, the deer receives a shock and is deterred.
While it may appear the initial cost
of constructing an electric fence is high, when you prorate the cost over
a number of years, it can pay for itself in increased yields. Electric
fences can be either permanent or temporary. Be aware electric fences require
more maintenance and are not effective when not electrified. These fences
must be inspected regularly and the vegetation must be controlled to prevent
grounding of the charged wires. In addition, the following guidelines will
increase the effectiveness of electric fences:
•Build the fence before deer damage
begins. It is easier to prevent a feeding pattern than it is to break one.
•Attach additional strands to the fence
if deer pressure justifies the cost.
•Use a voltmeter to ensure the charge
is a minimum of 3,000 volts.
•Use a New Zealand style energizer
to supply high voltage while resisting grounding by vegetation.
•Control all vegetation under the fence.
•Do not place the fence directly adjacent
to old woven wire fences, woody fence rows, or brushy cover that deer might
normally have to jump over.
•Clear a 6- to 8-foot open strip outside
the perimeter of the fence.
Temporary Electric Fence Designs
These fences are relatively inexpensive
to construct because they do not have rigid corner assemblies and can be
made of whatever materials are around the farm. These are low-profile fences
and usually have 1 or 2 strands of wire. Fence lines are strung with 50
lbs of tension. If possible, use 2 x 2 insul timbers (self-insulating posts
made of eucalyptus wood) as corner posts to reduce the cost and increase
the effectiveness of these fences.
The peanut butter baited fence design
is made of a single 17-gauge smooth wire strung 30 inches above the ground
4). The wire is connected to insulators attached to 4-foot stakes.
The stakes are placed at 50-foot intervals. Attach 3-inch x 4-inch strips
of aluminum foil with cloth adhesive tape at 3-foot intervals. Apply a
1:1 mixture of peanut butter:vegetable oil to the tape strips. Connect
the single wire to the positive post of the energizer. The idea is to attract
deer to sniff the wire with its muzzle and receive a shock that acts as
Another design is to use bright yellow
or orange electric polytape (figure 5). Polytape
is a 1/2-inch wide plastic strip that contains 5 interwoven thin wires.
This design can be made more effective by coating the tape with peanut
butter. The polytape should be strung 36 inches above the ground. Use a
fiberglass "T" post at each corner and secure the tape to these posts using
a square knot or half hitch. Set 4-foot fiberglass rods along the fence
at 60-foot intervals. Attach the polytape to insulators on the rods and
connect it to the positive post on the charger.
Permanent High-Tensile Electric Fence Designs
These electric fence designs should
be used with pressure- treated posts that have a life-expectancy
of 35 to 40 years. High-tensile electric fences are useful in protecting
orchards, vegetable crops, nurseries, and other high dollar crops. These
fences are powered by high voltage, low impedance chargers (New
Zealand style) capable of charging 5,000 feet of fence with reduced susceptibility
of grounding by vegetation. These fences use high-tensile smooth wire
(200,000 psi, 12 1/2 gauge) and special accessories help to maintain
a 150 to 250-lb tension so the fence can absorb the impact of running
deer and spring back to its original position.
These components eliminate many of
the problems associated with traditional electric fence designs, including:
•The wire absorbs the impact without
stretching or breaking.
•A single wire is used to determine
proper wire tension.
•Inline wire strainers are used to
tighten the wire.
•Crimping sleeves are used to splice
wire or fasten the ends.
•Tube insulators insulate the wire
from line posts, provide strength, and allow the wire to slip through during
•Wrap-around insulators fasten the
wires at the ends and allow for continuous wire stringing outside the posts
at the corners.
The 6-wire vertical high-tensile electric
fence design is a modification of the Penn State 5-wire design (figure
6). The lowest wire should be 8 inches above the ground and the remaining
wires are spaced at 10-inch intervals. The bottom wire is "hot" and the
remaining wires are alternating ground and hot. Rigid corner assemblies
(figure) must be installed. Fiberglass battens are placed at 30-foot intervals
along the fence to maintain wire spacing. Eight-foot line posts are placed
every 60 feet for structural support. For specific instructions on how
to assemble this fence, contact the West Virginia Cooperative Extension
Service, West Virginia University, Morgantown, WV 26506. Ask for publication
number 814, "Deer and Agriculture in West Virginia: 6-Wire Vertical High-Tensile
Electric Anti-Deer Fence."
A modification of this design is the
7-wire slanted fence. The wires are spaced 12 inches apart; the bottom
wire is located 10 inches from the ground. The wires are strung along a
7-foot rail slanted up and away from the crop (figure
7). Set angle braces at 30-foot intervals. Apply 150 lbs of tension
to the wires. All seven wires should be connected to the positive post
on the charger and the second, fourth, and sixth wires are connected to
Other Exclusion Devices for Orchard, Ornamental, or Nursery Trees
Homeowners and small orchard owners
may decide to protect individual high value trees using a plastic tree
guard tube or mesh netting (plastic or 1/2-inch hardware cloth). Each tree
is covered or enclosed by a device designed to prevent deer from browsing
on the young seedlings (figure 8).
Sometimes deer damage valuable orchard
or ornamental trees by rubbing their antlers against the tree trunk to
scrape off the velvet. The Europeans have cleverly designed a physical
deterrent to prevent deer from rubbing antlers on tree trunks. The structure
is made from a 3- to 4-foot length of steel rebar. Weld numerous 12- to
18-inch pieces of rebar in a spiral arrangement to the original rod (figure
9). Drive the completed structure into the ground next to the trunk
of a small tree. The cross pieces discourage deer from rubbing their antlers
on the tree trunks.
A repellent is a distasteful or foul-smelling
chemical that an animal avoids. There are two types of repellents: area
and contact. Area repellents are applied next to plants and repel by smell.
Contact repellents are applied directly to the plant and repel because
the animal dislikes their taste. The effectiveness of repellents depends
on a number of factors including the deer's appetite, weather conditions,
and thoroughness of application. Many repellents do not weather well and
must be reapplied after a heavy dew or rain, or on new plant growth, to
be effective. The amount of preferred food available also influences a
repellent's effectiveness. If the deer population is high and under food
stress, repellents will be less effective. Not every repellent will be
effective in every situation.
The success of a repellent is measured
by how much damage it reduces. The effectiveness of different repellents
has been shown to vary from a 15% to 80% reduction in damage. You must
decide if this amount is acceptable. Commercial repellents are more effective
than home remedies such as human hair, soap, feces, or animal remains.
These home remedies have been concocted in hopes of keeping deer out of
crops, but they realistically offer little relief from the problem.
Always follow the manufacturer's directions
and label instructions before applying a chemical repellent. Never apply
repellents to any portion of a plant likely to be eaten by humans unless
the label permits it.
Contact or Taste Repellents
Repellents containing 37% putrescent
whole egg solids as an active ingredient are available as sprays or ready-to-apply
powders. They are used on fruit trees prior to flowering and ornamental
trees during the dormant season. These repellents should be applied to
new growth and are claimed to be effective for two to six months.
Thiram is a fungicide that acts as
a taste repellent. The amount of active ingredient varies from 5% to 42%
depending on brand name. Thiram is used on dormant trees and shrubs, including
fruit and nut trees, nursery stock, seedlings, and conifers. It can be
sprayed or brushed on trees. You can make your own thiram-based repellent
by combining 2 quarts of 42% thiram, 1 gallon water, and 2 quarts Rhoplex
AC-33 as a sticking agent.
There is a chemical repellent registered
for use on edible crops. The active ingredient is 15% ammonium soaps of
higher fatty acids. It can be applied as a spray to fruit trees, vegetables,
field crops, ornamentals, nursery stock, and forage or grain crops. In
large agricultural fields, apply the repellent over an 8- to 15-foot strip
around the perimeter of the field. You will have to reapply after a rain
and every 2 to 4 weeks after initial application.
There are other commercially available
repellents including those with an active ingredient of 97.5% bone tar
oil, 2.5% capsaicin, and benzyldiethyl ammonium. Several research studies
have shown these chemicals reduced damage by less than 35%. Before you
decide to use repellents, conduct a cost/benefit analysis of all possible
solutions. If you are having repeated heavy deer damage problems, it may
be more cost effective to build a fence than to continually apply repellents.
Deer damage complaints and conflicts
will likely continue as long as we have healthy deer populations. Perhaps
the best way for a grower to co-exist with deer is to consider the benefits
of the deer resource and treat deer as another crop (economic assest) of
the land. By allowing regulated hunting you provide people with access
to a public resource while at the same time reducing deer damage problems
and reaping economic rewards. Contact your county agent for more information
on lease hunting.