• Topics: Wildlife Ecology and Conservation  | Deer  |  Main, Martin B  | Allen, Ginger M  | Schaefer, Joseph  | Garden Pest Animals 

Coping with Deer Damage in Florida¹

Introduction

Figure 1. 

White-tailed deer, Odocoileus virginianus

Deer are probably the most widely distributed and best-recognized large mammals in North America. The white-tailed deer (Odocoileus virginianus) (Figure 1) is found throughout North, Central and South America.

Because white-tailed deer are herbivores, they sometimes damage food crops and horticultural plantings. Controlling deer damage sometimes poses difficult social, economic and political problems, as well as biological and logistical challenges.

Ideally, control of deer damage is founded on effective management of deer populations through hunting. Unfortunately, effective management of deer is not always possible, particularly in urban and mixed rural-urban settings where the use of firearms to reduce deer populations is not a realistic alternative. Here we suggest other options that may be tried to control or reduce damage from hungry deer. In some circumstances, nothing short of excluding deer with fencing may eliminate deer damage. And, it might be cheaper and less frustrating to simply live with deer and cease attempting to grow plants they like to eat.

Additional information on white-tailed deer in Florida is available through the University of Florida Cooperative Extension Service's publication, Florida's White-tailed Deer (Schaefer and Main, WEC-133). A good general reference on white-tailed deer ecology and management is White-tailed Deer (1984) by Halls, and Deer (1994) by Gerlach and others, both published by Stackpole Books (see Additional Information section).

Identification of Damage by Deer

Deer may feed upon a diversity of row crops, forage crops, vegetables, fruit trees, nursery stock, and ornamentals, and will even feed upon stacked hay during periods of food shortages. In addition to immediate loss, future yields from fruit trees or perennial forages may be reduced and ornamentals and nursery stock may be permanently disfigured. Under high densities deer may severely impact native plant communities and impair regeneration of some species. Besides vegetative damage, deer/ vehicle collisions pose a serious risk tomotorists, and deer have been implicated in being a host for deer ticks that can transmit Lyme disease. Deer damage can be identified from evidence of tracks (Figure 2) and characteristic signs of deer browsing. Because deer lack upper incisors, browsing leaves a jagged tear at the ends of twigs and stems. Rabbits and rodents, which possess upper incisors, leave a clean-cut surface. Also, the height of damage from the ground (up to 6ft [1.8 m]) often rules out any mammal other than deer. Observations during evening and early morning hours, or using spotlights at night, can also help determine if deer are responsible for damage.

Figure 2. 

Deer tracks

Damage Prevention and Control Methods

Exclusion Devices

Where deer are abundant or persistent, fencing may be the only way to effectively minimize deer damage. Although several designs are available, fencing is generally an expensive solution to preventing or reducing damage from deer. If you intend to build a fence yourself, you may wish to supplement the following directions by consulting a fencing contractor. Detailed fencing manual are also available from most fencing manufacturers and sales representatives. Points to consider prior to investing in fencing to reduce deer damage include:

• Local deer abundance--if deer are locally abundant, you may need fences to prevent damage.

• Value of the crop/plants--crops with high market values and perennial crops where damage affects future yields and growth may need the protection fencing can provide.

• Size of area--the size of the area will dictate cost.

• Cost versus benefit--the cost and life expectancy of the fence versus the value of the crop will help determine if the fence will likely pay for itself.

Temporary electric fences

Temporary electric fences are simple to construct and, at approximately $.12/ft, provide a relatively inexpensive way to protect gardens and other small areas. In some circumstances, temporary electric fences may be effective in protecting field crops.

The fence is a psychological rather than a physical barrier. Deer are baited into contacting the fence with their noses and receive a shock, which is a strong negative stimulus that may cause deer to avoid the fenced area. Temporary electric fences should be installed at the first sign of damage to prevent deer from establishing feeding patterns that are difficult to break. Weekly inspection and maintenance of these fences are required. In addition to moderate cost, these fences are easy to construct, light-weight, and materials are readily available. One of the following two designs may work for you:

Peanut Butter-Baited Temporary Electric Fence. This fence is effective for small gardens, nurseries; and 3 to 4ac (1.2 to 1.6ha) orchards subject to moderate deer pressure. The electric wire is baited with peanut butter that attracts deer and promotes nose-to-fence contact to build a peanut butter fence (Figure 3), follow these steps:

1) Install wooden comer posts.

2) String one strand of 17-ga (0.15-cm), smooth wire around the comers and apply light tension.

3) Set 4-ft (1.2-m) 3/8-inch (1-cm) round fiberglass rods along the wire at 45-ft (14-m) intervals.

4) Attach the wire to insulators on the rods 2-1/2ft (0.75m) above ground level and apply 50lb (22.5 kg) of tension.

5) Attach 3 x 4-in (7 x 10-cm) foil strips to the wire at 3-ft (1-m) intervals, using 1 x 2-in (3 x 5-cm) strips of cloth adhesive tape.

6) Apply a 1:1 mixture of peanut butter and vegetable oil to the adhesive tape strips and fold the foil over the tape.Note: You can also apply the peanut butter mixture directly to the wire. This may be more practical than using foil for areas larger than 1ac (0.4ha). Make a simple applicator by mounting a free-spinning, 4-in (10-cm) pulley on a shaft inside a plastic ice cream pail. Fill the pail with a peanut butter-vegetable oil mixture the consistency of very thick paint. Coat the entire wire with peanut butter by drawing the pulley along the wire. Apply peanut butter at least once a month. Attach foil flags to the fence near deer trails or areas of high deer pressure to encourage deer to investigate the fence.

7) Connect the wire to the positive post of a well-grounded fence charger.

8) Check the fence weekly for damage by deer and grounding by vegetation.

Figure 3. 

The peanut butter fence with foil flags.

Polytape Temporary Electric Fence. Various forms of polytape or polywire, such as Visible Grazing Systems® (VGS), Baygard®, and Turbo-tape® are available. Polytape is strong and portable and has been recommended for use to protect up to 40ac (16ha) of vegetable and field crops under moderate deer pressure. Bait the polytape to make it attractive to deer, which receive shocks through nose-to-fence contact when they investigate. Cost, excluding labor, is about $.12/linear ft ($.30/m).

To build a polytape fence (Figure 4), follow these steps:

1) Drive 5/8-in (1.6-cm) round fiberglass posts 2ft (0.6 m) into the ground at the comers.

2) String two strands of polytape (white or yellow are most visible) around the comers and apply light tension [one strand 2 ½ ft (0.75 m) high can be used].

3) Use square knots or half-hitches to make splices or to secure the polytape to comer posts.

4) Set 4-foot (1.2-cm) 3/8-inch (1-cm) round fiberglass rods along the wires at 45-foot (14-m) intervals.5) Attach the two strands of polytape to insulators on the rods at 1 and ft (0.3 and 0.9 m) above ground level and apply 50 pounds (22.5 kg) of tension.6) Connect the polytape to the positive post of a well-grounded fence charger.

5) Use the peanut butter applicator described under the Peanut Butter Fence instructions to apply 2-ft (0.6-m) swathes of peanut butter to the polytape every 6ft (m.) where deer activity is expected to be high.

6) Check fence weekly for deer damage and grounding by vegetation.

Figure 4. 

The polytape fence.

Permanent High-Tensile Electric Fencing

Permanent high-tensile electric fencing can provide year-round protection from deer damage. All designs require rigid corner assemblies and strict adherence to fence construction and configuration guidelines. Frequent inspection and maintenance are required so that high-tensile fences last 20 to 30 years.

Different types of high-tensile electric fences are available. We describe three designs. (see Additional information, Bucklin, Kunkle, and Sand 1992).

Offset or Double Permanent High-Tensile Electric Fence. This fence is mostly for gardens, truck farms, or nurseries up to 40ac (16ha) that experience moderate deer pressure. Deer are repelled by the shock and the three-dimensional nature of the fence. Additional wires may be added to increase protection. Costs, excluding labor, is about $0.35/linear ft ($1/m). Weekly maintenance of the fence and voltage is recommended.

To build an offset or double fence (Figure 5), follow these steps for the outside fence:

1) Install swing corner assemblies where necessary (see the section on fence construction-rigid brace assemblies [Figure 11]).

2) String a 12.5-ga (0.26-cm) high-tensile wire around the outside of the swing comer assemblies and apply light tension.

3) Set 5-ft (1.5-m) line posts along the wire at 40- to 60-ft (12- to 18-m) intervals.

4) Attach the wire to insulators on the line posts, 15in (36cm) above ground level and apply 150 to 250 pounds (68 to 113kg) of tension.

5) String a second wire at 43in (109cm) and apply 150 to 250lb (68 to 113kg) tension. For the inside fence:

6) String a wire around the inside of the swing comer assemblies and apply light tension.

7) Set 5-ft (1.5-m) line posts along the wire at 40- to 60-ft (12-to 18-m) intervals.

8) Attach the wire to insulators on the line posts at 30in (76cm) above ground level.

9) Attach all wires to the positive (+) post of a well-grounded, low-impedance fence charger.

10) Clear and maintain a 6- to 12-ft (1-8- to 3.6-m) open area outside the fence so deer can see it.

Figure 5. 

The offset or double fence.

Seven-wire Vertical High-Tensile Electric Deer Fence. Vertical fences are effective at protecting large truck gardens, orchards, and other fields from moderate to high deer pressures. Because of the prescribed wire spacing, deer either are shocked attempting to go through the fence, or physically impeded by the barrier. Vertical fences use less ground space than three-dimensional fences, but are probably less effective at inhibiting deer from jumping over fences.

There is a wide variety of fence materials, wire spacings, and specific designs available. We recommend you consult a fence contractor. Costs, excluding labor, range from $0.75 to $1.50/linear ft ($2 to $4/m). To build a 7-wire vertical fence (Figure 6), follow these steps:

1) Install rigid corner assemblies where necessary (see fence construction-rigid brace assemblies [Figure 11]).

2) String a 12.5ga (0.26-cm) high-tensile wire around the comer assemblies and apply light tension.

3) Set 8-ft (2.4-m) line posts along the wire at 33-ft (10-m) intervals.

4) Attach a wire to insulators at 8 inches (20 cm) above ground. Apply 150 to 250lb (68 to 113kg) of tension.

5) Attach remaining wires to insulators at the spacing indicated in Figure 9. Apply 150 to 250lb (68 to 113kg) of tension.

6) Connect the 2nd, 4th, 5th, and 7th wires from the top, to the positive (+) post of a well-grounded, low-impedance fence charger.

7) Connect the top, 3rd, and 6th wires directly to ground. Make the top wire negative(-) for lightning protection.

8) Clear and maintain a 6- to 12-ft (1.8- to 3.6-m) open area outside the fence so deer can see the fence. We recommend weekly inspections and voltage checks.

Figure 6. 

The seven-wire vertical deer fence.

Slanted Seven-wire High-Tensile Electric Deer Fence. This fence is used where high deer pressures threaten moderate-to-large sized orchards, nurseries and other high-value crops. It presents a physical and psychological barrier to deer because of its electric shock and three-dimensional nature. Cost, excluding labor, is about $0.75 to $2/linear ft ($2 to $5.50/m). Maintenance includes weekly inspection and voltage checks.

To build a slanted seven-wire deer fence (Figure 7), follow the steps below.

1) Set rigid, swing corner assemblies where necessary, (see construction-rigid brace assemblies [Figure 11]).

2) String 12.5-ga (0.26-cm) high-tensile wire around the corner assemblies and apply light tension.

3) Set angle braces along the wire at 90-ft (27-m) intervals.

4) Attach a wire at the 10-in (25-cm) position and apply 150lb (68 kg) of tension.

5) Attach the remaining wires at 12-in (30-cm) intervals and apply 150lb (68 kg) of tension.

6) Place fence battens at 30-ft (9-m) intervals.

7) Connect the top, 3rd, 5th, and bottom wires to the positive (+) post of a well-grounded, low-impedance fence charger.

8) Connect the 2nd, 4th, and 6th wires from the top directly to ground.

9) Clear and maintain a 6- to 12-ft (1.8- to 3.6-m) area outside the fence so deer can see it.

Figure 7. 

The slanted seven-wire deer fence.

Permanent Woven-Wire Fencing

Woven-wire fences are used for year-round protection of high-value crops subject to high pressure from deer. These fences are expensive and difficult to construct, but easy to maintain. Before high-tensile electric fencing, woven wire fences were used most often to protect orchards or nurseries where the high crop value, perennial nature of damage, acreage, and 20-year life span of the fences justified the initial costs. Cost, excluding labor, is about $2 to $4/linear ft ($5.50 to $11/m). Because these fences are expensive to construct, they are not used as frequently as high-tensile fences. Maintenance is minimal, but fences should be periodically inspected for locations where deer may crawl under the fence.

To build a deer-proof, woven-wire fence (Figure 8), follow these steps:

1) Set rigid comer assemblies where necessary (see Construction-Rigid brace assemblies [Figure 11]).

2) String a light wire between two corners and apply light tension.

3) Set 16-ft (4.9-m) posts along the wire at 40-ft (12-m) intervals, to a depth of 4 to 6ft (1.2 to 1.8 m).

4) Roll out an 8-ft (2.4-m) roll of high-tensile woven wire along the line posts. Attach one end at ground level to a comer post with steel staples.

5) Apply 100lb (45kg) of tension to the wire with a vehicle or fence strainers and attach the wire to line and comer posts with steel staples.

6) Repeat steps 4 and 5, as necessary, around the perimeter of the fence.

7) Attach two strands of high-tensile smooth wire to the top of the fence raising the height of the entire fence to 9 to 10ft (2.7 to 3m).

Figure 8. 

The deer-proof, woven-wire fence.

General Fencing Tips and Information

What type of fence to use? There is no easy answer to this question because every situation differs. But, spending time evaluating costs (and aggravation) caused by damage from deer, versus the level of protection needed to solve the problem and the cost to construct and maintain fences that will prevent damage enable you to make an informed decision that makes economic sense.

Here is a listing of materials and approximate retail prices as of Spring 1999. Table 1 is provided to assist in this decision.

Materials. Do not buy cheap materials to reduce costs. This will only reduce the effectiveness and life span of the fence. We recommend using:

1) Round fiberglass or treated wood posts.

2) High-quality galvanized wire and steel components. For high-tensile fences, use 11- to 14-ga (0.31-to 0.21-cm) wire (minimum tensile strength of 200,000lb [90,000 kg] and a minimum breaking strength of 1,800lb [810 kg]), tension springs, and in-line tensioners.

3) Compression sleeves for splicing wires and making electrical connections.

4) Lightning arresters and diverters to protect chargers.

5) High-quality fence chargers. Chargers must be approved by Underwriters Laboratories (UL) or the Canadian Standards Association (CSA). We highly recommend 110-v chargers. Six-and 12-v chargers require battery recharging every 2 to 4 weeks. Use solar panels in remote areas to charge batteries continuously. For high-tensile fences, use high-voltage, low-impedance chargers only (3,000 to 5,000v and current pulse duration of--at most --1 / 1,000 second).

6) Gates. There is no universal gate design because of the many different fence types. However, gates should be electrified, well-insulated; and practical for the type of farming operation. Gates range from single strands of electrified wire with gate handles to electrified panel or tubular gates (Figure 9).

Figure 9. 

Fence with electrified gate.

A summary comparison (Table 2) shows the three types of fences described here and their characteristics.

Because there are no state-subsidized programs for controlling deer damage in Florida, it is advisable to conduct a viable estimate of the cost versus benefit of control measures that will assist you in deciding whether and how to reduce damage from deer (Table 3).

Construction Guidelines for All Fences. Fences must be properly constructed to be effective. We recommend adhering to instructions and consulting with an experienced fencing contractor. General notes regarding construction include:

1) Prepare fencelines before construction. It is easier and less expensive to install and maintain fences on clear, level runs. Minimize corners to increase strength and reduce costs.

2) Ensure that the electrical system is well-grounded at the fence charger and every ½mi (880m) of fenceline. To ground high-tensile fences, drive four to six ground rods 5 to 6ft (1.5 to 1.8m) deep and 6ft (1.8m) apart.Connect the ground post of the fence charger and the negative (-) wires of the fence to the grounding system (Figure 10).

3) The wiring system in Figure 10 illustrates a positive-negative fence. Such a design is especially useful with dry or frozen ground. A fence with all positive (hot) wires may be advantageous under general crop and soil moisture conditions. Consult with a fencing contractor or expert for the best choice for your needs.

4) Install the grounding systems and fence charger before fence construction. Energize completed parts of the fence when you are not working on the fence to gain early protection.

Figure 10. 

Electrical and grounding system for high tensile fences.

5) Rigid brace assemblies (corners, ends, and gates) are the backbone of all high-tensile fence systems (Figure 11). They must be entirely rigid, constructed of the best materials, and strictly conform to design guidelines. The single-span brace assembly is the basis of all high-tensile strainer assemblies, regardless of location in the fence or fence design. This basic design is then modified to create double "H" braces, swinging corners and gate ends.

Figure 11. 

Rigid brace assemblies.

6) Allow wires to slide freely through insulators on fence posts. Fence flexibility survives frequent temperature changes, deer hits, and obstructions.

7) Identify an electric fence with warning signs (Figure 12) that are affixed at 300-ft (90-m) intervals or less.

Figure 12. 

Warning signs should be attached to all electric fences.

Fence Maintenance. Regular inspection and maintenance are necessary to ensure the effective operation and longevity of most fences.

• Control vegetation near fences by mowing or applying herbicides to avoid excessive fence grounding by weeds.

• On slopes or highly erodible soils, maintain a good sod cover beneath fences to avoid fenceline erosion.

• Always keep the fence charger on. Check the fence voltage weekly with a voltmeter. Maintain at least 3,000v at the furthest distance from the fence charger.

• In late fall and early summer, adjust the fence tension (150 to 250lb [68 to 113kg]) for high-tensile fences.

Haystack Protection. Wooden panels have traditionally been used to exclude deer and elk from hay-stacks. Stockyards have also been protected by welded wire panels and woven wire.

Individual Tree and Shrub Protectors. There are several commercially available products used to protect young trees and shrubs from browsing by deer and other small herbivores. These products are designed more to reduce, rather than eliminate, browsing. As trees increase in size these products become less suitable for protection from deer, but trees and shrubs are also better able to recover from low to moderate levels of herbivory. Protective cylinders (diamond mesh polyethylene) also have been used to protect young trees from herbivory for up to five years. The diameter is 3.25in and cylinders range in height from 18in ($41./250) to 36in ($70./ 250). Larger solid tube cylinders have been used to discourage bucks from rubbing tree trunks with their antlers. The tubes can be joined together to accommodate large diameter trees. Tubes range from 18in ($.79ea) to 5ft ($2.42ea) high.

Selective Planting and Harvest Strategies

Selective Planting. You can minimize damage to ornamental plantings by selecting landscape and garden plants that are less preferred by deer. This is often a trial and error process because deer damage is influenced by the availability and attractiveness of other food items to deer in the area. In situations where deer numbers are too high and browsing pressure reduces availability of native plants, deer may eat almost anything. Consultation with local nurseries and landscape architects may provide some assistance in selecting appropriate plants for your area. At this writing, there is not yet a good, comprehensive list of landscape plants that are ranked for their susceptibility to damage from deer for Florida.

Harvesting and Crop Location Strategies. Harvesting crops is dictated primarily by economic decisions related to marketing windows and environmental factors. Damage to crops from deer can also factor in economic decisions. One strategy is to harvest crops as early as possible to reduce the period of vulnerability to deer. Another is to either plant crops that are favored by deer as far from wooded cover as possible to reduce the potential for damage, or to minimize expenses associated with herbicides and other maintenance activities in areas where deer damage is consistently high. In this respect, it may be less expensive to provide areas where deer will reduce the value of crops than to exclude deer from areas.

Frightening Devices

Frightening devices generally have mixed success, being more successful initially, but often with deer habituating to the devices to the point that these methods become ineffective. One of the keys to success with frightening devices and repellents is to take action at the first sign of a problem and when crops are most susceptible to damage. It is difficult to break the movements or behavioral patterns of deer once they have been established.

Gas exploders. These devices can be set to detonate at regular intervals and probably are the most commonly used devices for frightening deer. They can be purchased for $200 to $500 from commercial sources. These devices are sometimes available on loan from wildlife refuges or agencies, as they also are frequently used to control waterfowl damage. To maximize the effectiveness of exploders, move them every few days and stagger the firing sequence. Otherwise, the deer quickly become accustomed to the regular pattern. The noise level can be increased by raising exploders off the ground. Motion-activated firing mechanisms are now being explored to increase the effectiveness of exploders. Success depends on many factors and can range from good to poor.

Pyrotechnics. Shell crackers, fireworks, and gunfire provide quick, but short-term, relief from deer damage. They also incur higher labor costs. Equip mobile units with pyrotechnics, spotlights, and two-way radios. Patrol farm perimeters and field roads at dusk and throughout the night during times of the year when crops are most susceptible to damage. Note:Such tactics cannot be relied on for an entire growing season.

Dogs. Dogs may be effective for small areas, such as gardens. For example, a dog on a long run or restricted by an electronic invisible fence system can keep deer out of a limited area, but care and feeding of the dog can be time-consuming and in Florida ticks, fleas, and heartworm transmitted by mosquitos needs to be considered. The use of free-running dogs to exclude deer is not effective, can be detrimental to other wildlife, and has legal ramifications.

Repellents

Repellents are best-suited for use in orchards, gardens, and on ornamental plants. High cost, use limitations, and variable effectiveness make most repellents impractical on row crops, pastures, or other large areas. Success with repellents is measured in the reduction, not total elimination of damage. The effectiveness of repellents will be greatly reduced in areas that are frequently wetted by irrigating devices or by frequent rainfall. Repellents are described by mode of action as "contact" or "area." Contact repellents, applied directly to the plants, repel by taste. Area repellents are applied near the plants to be protected and repel deer by odor alone. They are usually less effective than contact repellents but can be used in perimeter applications and some situations where contact repellents cannot be used.

Contact repellents are most effective when applied to trees and shrubs during their dormant period. New growth appearing after treatment is unprotected. Contact repellents may reduce the palatability of forage crops and should not be used on plant parts destined for human consumption unless specifically stated otherwise by the product label. Young trees should be treated completely. It will be more economical to treat only the terminal growth of older trees. Be sure to treat up to a height of about 6ft (2m) above ground. During the growing season, apply contact repellents at about half the concentration recommended for winter use.

The effectiveness of repellents depends on several factors. Rainfall will dissipate some repellents, so re-application may be necessary after a rain. Some repellents do not weather well even in the absence of rainfall. Deer's hunger and the availability of other more palatable food will have a great effect on success. In times of low food supply, deer are likely to ignore either taste or odor repellents. When using a commercial preparation, follow the manufacturer's instructions. Don't overlook new preparations or imaginative ways to use old ones. The following material on common repellents is incomplete and provided only as a survey of the wide range of repellent formulations available. The repellents are grouped by active ingredient. Note:This list is not an endorsement.

Deer-AwayO Big Game Repellent (37% putrescent whole egg solids).This product provides both contact and area components (odor/ taste) and has been used extensively in western conifer plantations and reported in field studies to be 85% to 100% effective. It is registered for use on fruit trees prior to flowering, as well as ornamental and Christmas trees. Apply it to all susceptible new growth and leaders. Applications weather well and are effective for 2 to 6 months. A gallon (3.81) of liquid or 1lb (0.45kg) of powder costs about $24 and covers 400 3-in (7.6-cm) saplings or 75 4-ft (1.2-m) evergreens. Note: The odor may make this product impractical for many urban applications.

Hinder® (15% ammonium soaps of higher fatty acids). This area repellent is one of the few registered for use on edible crops. You can apply it directly to vegetable and field crops, forages, ornamentals, and fruit trees. Its effectiveness is usually limited to 2 to 4 weeks but varies because of weather and application technique. Reapplication may be necessary after heavy rains or continued irrigation. For small fields and orchards, you can treat the entire area. For larger areas, apply an 8- to 15-ft (2.4- to 4.6-m) band around the perimeter of the field. Apply at temperatures above 32F (0C). Four gallons (15.2l) of liquid cost about $96, and when mixed with 100gal (380l) of water will cover one acre (0.4ha). Hinder® can be used with most pesticides.

Thiram (7% to 42% tetramethylthiuram disulfide). Thiram is a fungicide that acts as a contact (taste) deer repellent, is sold under several trade names-Bonide Rabbit-Deer Repellent®, Nott's Chew-Not, and Gustafson 42-S1® among others. It is most often used on dormant trees and shrubs. A liquid formulation is sprayed or painted on individual trees. Although Thiram itself does not weather well, adhesives such as Vapor Card® can be added to increase its resistance to weathering. Thiram-based repellents also protect trees against rabbit and mouse damage. Two gallons (7.61) of 42% Thirarn cost about $50 and when mixed with 100g (3801) of water will cover an acre (0.4ha). Cost varies with the concentration of Thiram in the product.

Miller's Hot Sauce® Animal Repellent (2.5% capsaicin). This contact (taste) repellent is registered for use on ornamentals, Christmas trees, and fruit trees.Apply the repellent with a backpack or trigger sprayer to all susceptible new growth, such as leaders and young leaves. Do not apply to fruit-bearing plants after fruit set. Vegetable crops also can be protected if sprayed prior to the development of edible parts. Weatherability can be improved by adding an antitranspirant such as Wilt-Pruf® or Vapor Gard®. Hot Sauce and Vapor Gard® cost about $80 and $30/gal (3.81) respectively. Eight ounces (240ml) of Hot Sauce and two quarts (0.91) of anti-transpirant mixed with 100g (3801) of water cover 1acre (0.4 ha).

Tankage (putrefied meat scraps). Tankage is a slaughterhouse byproduct traditionally used as a deer repellent in orchards. It repels deer by smell, as will be readily apparent. To prepare containers for tankage, remove the tops from aluminum beverage cans, puncture the sides in the middle of the cans to allow for drainage and attach the cans to the ends of 4-ft (1.2-m) stakes. Drive the stakes into the ground, 1ft (0.3 in) from every tree you want to protect or at 6-ft (1.8-m) intervals around the perimeter of a block. Use 1 cup (225 gm) of tankage/can. Use mesh or cloth bags instead of cans if you prefer.. You may have to replace containers periodically because foxes or other animals pull them down occasionally. Tankage comes in bulk ($335/ton [$302/mt]) or bag ($20 per 50lb [22.5kg]).

Ropel® (benzyldiethyl [(2,6 xylylcarbamoyl) methyl ammonium saccharide (0.065%), thymol (0.035%). Ropel® is reported to repel deer with its extremely bitter taste. Apply Ropel® once each year to new growth. It isnot recommended for use on edible crops. Spray at full strength on nursery and Christmas trees, ornamentals, and flowers. One gallon (3.81) costs $40 and covers about an acre.(0.4 ha) of 8- to 10-ft (2.4- to 3.0-m) trees.

Hair Bags (human hair). Human hair is an odor (area) repellent that costs very little but has not consistently repelled deer. Place two handfuls of hair in fine-mesh bags (onion bags, nylon stockings). Where severe damage occurs, hang hair bags on the outer branches of individual trees with no more than 3ft (0.9in) between individual bags. For larger areas, hang several bags, 3ft (0.9m) apart, from a fence or cord around the perimeter of the area to be protected. Attach the bags early in spring and replace them monthly through the growing season. You can get hair at barber shops or salons.

Bar Soap. Recent studies and numerous testimonials have shown that ordinary bars of soap applied in the same manner as hair bags can reduce deer damage. Drill a hole in each bar and suspend it with a twist tie or soft cord. Each bar appears to protect a radius of about 1yd (Im). Any inexpensive brand of bar soap will work. Ready-to-use bars cost about $0.50 each.

Lethal Methods

Herd management through harvest is an important tool to reduce damage from deer to agricultural crops. Deer may be legally shot in Florida only during designated hunting seasons and in areas where the use of firearms is allowed by law. Sport hunting regulations are readily available at all sporting goods outlets and also can be viewed on the Florida Fish and Wildlife Conservation Commission (FWCC, formerly Florida Fresh Water Fish and Game Commission) Web site http://www.myflorida.com/.

In some cases, FWCC may issue depredation permits to farmers allowing them to kill deer out of season to reduce severe or persistent damage to valuable crops. Inquiries for obtaining depredation permits should be directed to the regional biologist serving your area, who may be contacted through the FWC Regional Wildlife Office serving your area (Table 4).

Note: Although some states provide technical assistance or direct compensation for damage by deer, there are no compensation programs available in Florida.

Other Methods and Methods Prohibited by Law in Florida

Contraception. The use of contraceptive devices have been attempted to control deer populations in some urban settings. This approach has only limited success, must be repeated on an annual basis, and is prohibitively expensive. Although research continues on delivery and effectiveness of chemosterilants and immunocontraception for urban deer, this currently is not a viable option.

Live capture and relocation. It is illegal to trap deer in Florida and FWCC will not capture deer and relocate deer from urban settings in response to damage complaints. Capturing deer is expensive, plus it poses risks of killing the animal due to stress, and transmitting diseases and parasites to wild populations.

Poisons. It is illegal to use poisons to attempt to control deer or other wildlife in Florida. Florida Administrative code (Chapter 39-12.009) allows the killing of destructive mammals except deer, fox, or bear on your property by means other than gun and light, steel traps or poison, provided that the destructive mammals are killed only within the immediate locality where damage is occurring. Killing destructive deer or bear, and using a gun and light at night, poison, steel traps, or other traps for the purpose of killing damaging birds or mammals may be authorized by the Commission (FWCC).

Economics of Damage and Control

A national survey conducted by USDA's National Agricultural Statistics Service in 1992 identified deer damage as the most widespread form of wildlife damage. No estimate exists of nationwide annual crop losses to deer, but damage estimates have been made for some states. In Wisconsin, a 1984 survey of farmers suggested minimum statewide deer damage of $36.7 million annually. A similar study in Pennsylvania estimated the annual crop loss at $16 to $30 million. There are no documented estimates of costs associated with damage to crops or fruit trees in Florida, but damage to ornamental plantings, young citrus, and a variety of vegetable crops is known to occur. Although deer sometimes cause damage, they are still a highly valuable public resource and contribute in important ways to ecosystem processes. State-funded subsidies for damage control materials or direct compensation for crop losses are costly. As an example, the Wisconsin Wildlife Damage Program expended $2.25 million in 1992 for abatement materials, claims, and administration. One reason why no such programs exist in Florida at this writing. Finally, habitat modification is not recommended as a solution to deer damage. Destruction of wooded or brushy cover in hopes of reducing deer use would destroy valuable habitat for other wildlife, reduce the availability of native forages to deer, and might ultimately increase damage to crops from deer that have been deprived of adequate native forage.

Additional Information

Andelt, W. F., K. P. Burnham, and J.A. Manning. 1991. Relative effectiveness of repellents for reducing mule deer damage. J. Wildl. Manage. 55:341-347.

Bucklin, R. A., W.E. Kunkle, and R. S. Sand. 1992. Construction of High Tensile Wire Fences. Florida Coop. Ext. Serv., IFAS, Univ. Florida, Gainesville, 32611. AE017.

Burt, W. H., and R.P. Grossenheider. 1976. A field guide to the mammals, 3rd ed. Houghton Mifflin, Boston. 289 pp.

Cummings, C., and G.K. Yarrow. 1996. Reducing deer damage at home and on the farm. Clemson Univ. Ext. Wildl. Prog. and Integrated Pest Manage. Prog.. AFW 6.

Craven, S.R., and S.E. Hygnstrom. 1994. Deer. Pp. D25-D40 In: Hygnstrom, S.E. , R.M. Timm, and G.E. Larson, (eds.). Prevention and control of wildlife damage. Univ. Nebraska Coop. Ext., USDA, Animal and Plant Health Insepection Service, Animal Damage Control.

Conover, M. R. 1984. Effectiveness of repellents in reducing deer damage in nurseries. Wildl. Soc. Bull. 12:399-404.

Cummings, M. W., M. H. Kimball, and W. M. Longhurst. 1980. Deer-resistant plants for ornamental use. Leaflet 2167. Div. Agnc. Sci., Univ. California. Oakland. 7 pp.

Fargione, M.J., P.D. Curtis, and M. E. Richmond. 1991. Resistance of woody ornamental plants to deer damage. Cornell Coop. Ext. Fact Sheet. Ithaca, NY. 4 pp.

Gallagher, B. 1992. 9th international power fence manual. Gallagher Power Fence, Inc., San Antonio, TX. 45 pp.

Halls, L.K. 1978. White-tailed deer. Pp. 43-65 In: Schmidt, J.L. and D.L. Gilbert, (eds.). Big game of North America: ecology and management. Stackpole Books, Harrisburg, PA.

Halls, L.K, (ed.). 1984. White-tailed deer: ecology and management. Stackpole Books, Harrisburg, PA. 870 pp.

Harris M.T., W.L Palmer, and J.L. George. 1983. Preliminary screening of white-tailed deer repellents. J. Wildl. Manage. 47:516-519.

Hesselton, W.T., and R.A.M. Hesselton. 1982. White-tailed deer. Pp. 878-901.In: Chapman, J.A. and G.A. Feldhamer, (eds.). Wild mammals of North America: biology, management and economics. Johns Hopkins Univ. Pr., Baltimore. 000 pp.

Gerlach, D., S. Atwater, and J. Schnell (eds.). 1994. Deer. Stackpole Books, Harrisburg, PA. 000 pp.

Mackie, R.J., K.L. Hamlin, and D.F. Pac 1982 Mule deer. Pp. 862-877. In: Chapman, J. A, and G. A. Feldhamer, (eds.). Wild mammals of North America: biology, management and economics. Johns Hopkins Univ. Pr., Baltimore.

Palmer, W.L., R.G. Wingard, and J.L. George. 1983. Evaluation of white-tailed deer repellents. Wildl. Soc. Bull. 11:164-166.

Pomerantz, G.A., C. Ng, and D.J. Decker. 1986. Summary of research on human tolerance of wildlife damage. Nat. Resour. Res. Ext. Ser. No. 25. Dep. Nat. Resour., Cornell Univ., Ithaca, NY. 42 pp.

Schaefer, J.M. and M.B. Main. Florida's White-Tailed Deer. Florida Coop. Ext. Serv., IFAS, Univ. Florida, Gainesville, 32611. Formerly SS-WEC-11. WEC-133

Selders, A.W., J.B. McAnninch, and R.J. Winchcombe. 1981. High-tensile wire fencing. Northeast Regional Agric. Eng. Serv. Bull. 11. Cornell Univ., Ithaca, NY. 14 pp.

Siemer, W. F, and D. J. Decker. 1991. Human tolerance of wildlife damage: synthesis of research and management implications. Human Dimensions Res. Unit, Ser. No. 91-7. Dep. Nat. Resour., Cornell Univ., Ithaca, NY. 24 pp.

Stapells, R.D.H. 1983. Everything you should know about electric fences and fence controllers. J.C. Hallman Mfg. Co., Ltd. Kitchaner, Ontario. 30 pp.

Swihart, R.K., and M.R. Conover. 1990. Reducing deer damage to yews and apple trees: testing Big Game Repellent40 Ropel®, and soap as repellents. Wildl. Soc Bull. 18:156-162.

US Steel Corporation. 1980. How to build fences with USS Max-Ten 200 high-tensile fence wire. No. T-11 1575 US Steel Corp. Pittsburgh, PA. 75 pp.

Wallmo, O.C. 1978. Mule and black-tailed deer. Pp. 32-42. In: J.L. Schmidt and D.L. Gilbert, (eds.). Big game of North America: ecology and management. Stackpole Books, Harrisburg, PA.

Acknowledgments

Figure 1 adapted from Schwartz and Scwartz. (1981) Figure 2 adapted from Cabrera (2000) Animal Tracks of Humboldt County, http://www.humboldt.net/~tracker/ Figures 3 through 12 adapted from Craven and Hygnstrorn (1993), "Controlling Deer Damage in Wisconsin," University of Wisconsin Extension publication G3083.

The Institute of Food and Agricultural Sciences (IFAS) is an Equal Opportunity Institution authorized to provide research, educational information and other services only to individuals and institutions that function with non-discrimination with respect to race, creed, color, religion, age, disability, sex, sexual orientation, marital status, national origin, political opinions or affiliations. For more information on obtaining other extension publications, contact your county Cooperative Extension service.

U.S. Department of Agriculture, Cooperative Extension Service, University of Florida, IFAS, Florida A. & M. University Cooperative Extension Program, and Boards of County Commissioners Cooperating. Millie Ferrer, Interim Dean.

• Copyright 2009 |
• Site Feedback |
• About This Site