B-1

BEAVERS

James E. Miller

Program Leader, Fish and Wildlife

USDA — Extension Service

Natural Resources and Rural

Development Unit

Washington, DC 20250

Greg K. Yarrow

Extension Wildlife Specialist

Department of Aquaculture, Fisheries,

and Wildlife

Clemson University

Clemson, South Carolina 29634-0362

Fig. 1. Beaver, Castor canadensis

Damage Prevention and

Control Methods

Exclusion

Fence small critical areas such as

culverts, drains, or other structures.

Install barriers around important trees

in urban settings.

Cultural Methods and Habitat

Modification

Eliminate foods, trees, and woody

vegetation where feasible.

Continually destroy dams and

materials used to build dams.

Install a Clemson beaver pond leveler,

three-log drain, or other structural

device to maintain a lower pond

level and avoid further pond

expansion.

Frightening

Shooting of individuals or dynamiting

or other continued destruction of

lodges, bank dens, and dams,

where legal, will occasionally move

young colonies out of an area.

Repellents

None are registered; however, there is

some evidence that repellents may

be useful.

Toxicants

None are registered.

Trapping

No. 330 Conibear® traps.

Leghold traps No. 3 or larger

(including coil-sp ring types with

equivalent jaw spread and impact).

Basket/suitcase type traps are

primarily used for live trapping.

Snares can be useful, particularly in

dive sets and slides where legal.

Shooting

Rarely effective (where legal) for

complete control efforts and can be

dangerous to humans.

Other Methods

Other methods rarely solve a beaver

damage problem and may increase

risks to humans and nontarget

species.

PREVENTION AND CONTROL OF WILDLIFE DAMAGE — 1994

Coop erat ive Extension Division

Institute of Agriculture and Natural Resources

University of Nebraska - Lincoln

United States Department of Agriculture

Animal and Plant Health Inspection Service

Animal Damage Control

Great Plains Agricultural Council

Wildlife Committee

B-2

Hind foo t

Marks of webs not always distinct

Walking

3" to 6"

Tail mark

Fig. 2. Beaver tracks

Front foot

6"

Fig. 3. A beaver uses its tail as a prop in order to

sit upright.

Details of beaver cuttings.

Fig. 4. Range of the beaver in North America.

Identification

The beaver (Castor ca nadensis, Fig. 1) is

the largest North American rodent.

Most adults weigh from 35 to 50

pounds (15.8 to 22.5 kg), with some

occasionally reaching 70 to 85 pounds

(31.5 to 38.3 kg). Individuals have been

known to reach over 100 pounds (45

kg). The beaver is a stocky rodent

adapted for aquatic environments.

Many of the beaver’s features enable it

to remain submerged for long periods

of time. It has a valvular nose and ears,

and lips that close behind the four

large incisor teeth. Each of the four feet

have five digits, with the hind feet

webbed between digits and a split

second claw on each hind foot. The

front feet are small in comparison to

the hind feet (Fig. 2). The underfur is

dense and generally gray in color,

whereas the guard hair is long, coarse

and ranging in color from yellowish

brown to black, with reddish brown

the most common coloration. The

prominent tail is flattened dorso-

ventrally, scaled, and almost hairless.

It is used as a prop while the beaver is

sitting upright (Fig. 3) and for a rudder

when swimming. Beavers also u se

their tail to warn others of danger by

abruptly slapping the surface of the

water.The beaver’s large front (incisor)

teeth, bright orange on the front, grow

continuously throughout its life. These

incisors are beveled so that they are

continuously sharpened as the beaver

gnaws and chews while feeding,

girdling, and cutting trees. The only

way to externally distinguish the sex of

a beaver, unless the female is lactating,

is to feel for the presence of a baculum

(a bone in the penis) in males and its

absence in females.

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Range

Beavers are found throughout North

America, ex cept for the arctic tundra,

most of peninsular Florida, and the

southwestern desert areas (Fig. 4).

The species may be locally abundant

wherever aquatic habitats are found.

Habitat

Beaver habitat is almost anywhere

there is a year-round source of water,

such as streams, lakes, farm ponds,

swamps, wetland areas, roadside

ditches, drainage ditches, canals, mine

pits, oxbows, railroad rights-of-way,

drains from sewage disposal ponds,

and below natural springs or artesian

wells. Beavers build dams to modify

the environment more to their liking.

Dam building is often stimulated by

running water. The length or height of

a dam generally depends upon what is

necessary to slow the flow of water

and create a pond. In areas of flat to-

pography, the dam may not be over 36

inches (0.9 m) high but as much as 1/4

miles (0.4 km) long. In hilly or moun-

tainous country, the dam may be 10

feet (3 m) high and only 50 feet (15 m)

long. Beavers are adaptable and will

use whatever materials are available to

construct dams — fencing materials,

bridge planking, crossties, rocks, wire,

and other metal, wood, and fiber

materials. Therefore, about the only

available aquatic habitat beavers avoid

are those systems lacking acceptable

foods, lodge or denning sites, or a su it-

able dam site. Some of the surround-

ing timber is cut down or girdled by

beavers to form dams. Subsequent

flooding of growing tim ber causes it to

die, and aquatic vegetation soon be-

gins growing. Other p ioneer species

(for example, willow, sweetgum, and

buttonbush) soon grow around the

edges of the flooded area, adding to

the available food supply. The beaver

thus helps create its own habitat.

Food Habits

Beavers prefer certain trees and

woody species, such as aspen, cotton-

wood, willow, sweetgum, blackgum,

black cherry, tulip poplar, and pine,

depending on availability. However,

they can and will eat the leaves, twigs,

and bark of most species of woody

plants that grow near the water, as

well as a wide variety of herbaceous

and aquatic plants. Beavers often

travel 100 yards (90 m) or more from a

pond or stream to get to corn fields,

soybean fields, and other growing

crops, where they cut the plants off at

ground level and drag them back to

the water. They eat parts of these

plants and often use the remainder as

construction material in the dam.

General Biology,

Reproduction, and

Behavior

Beavers are active for approximately

12 hours each night except on the

coldest of winter nights. The phrase

“busy as a beaver” is appropriate. It is

not uncommon, however, to see

beavers during daylight hours, par-

ticularly in larger reservoirs.

Beavers are generally monogamous;

copulation may take place either in the

water or in the lodge or bank den.

After a gestation period of about 128

days, the female beaver generally gives

birth to 3 or 4 kittens between March

and June, and nurses them for 6

weeks to 3 months. The kittens are

born fully furred with their eyes par-

tially opened and incisors erupted

through the gums. They generally

become sexually mature by the age of

1 1/2 years.

Beaver communicate by vocalizations,

posture, tail slapping, and scent posts

or mud mounds placed around the

bank and dam. The beaver’s castor

glands secrete a substance that is

deposited on mud mounds to mark

territorial boundaries. These scent

posts are found more frequently at

certain seasons, but are found year-

round in active ponds.

Fig. 5. Cross section o f a beaver lo dge.

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Beavers have a relatively long life

span, with individuals known to have

lived to 21 years. Most, however, do

not live beyond 10 years. The beaver is

unparalleled at dam building and can

build dams on fast-moving streams as

well as slow-moving ones. They also

build lodges and bank dens, depend-

ing on the available habitat. All lodges

and bank dens have at least two en-

trances and may have four or more.

The lodge or bank den is used prima-

rily for raising young, sleeping, and

food storage during severe weather

(Fig. 5).

The size and species of trees the beaver

cuts is highly variable — from a 1-inch

(2.5-cm) diameter at breast height

(DBH) softwood to a 6-foot (1.8-m)

DBH hardwood. In some areas bea-

vers usually cut down trees up to

about 10 inches (25 cm) DBH and

merely girdle or partially cut larger

ones, although they often cut down

much larger trees. S ome beavers seem

to like to girdle large pines and sweet-

gums. They like the gum or storax that

seeps out of the girdled area of sweet-

gum and other species.

An important factor about beavers is

their territoriality. A colony generally

consists of four to eight related bea-

vers, who resist additions or outsiders

to the colony or the pond. Young bea-

vers are commonly displaced from the

colony shortly after they become sexu-

ally mature, at about 2 years old. They

often move to another area to begin a

new pond and colony. However, some

become solitary hermits inhabiting old

abandoned ponds or farm ponds if

available.

Beavers have only a few natural preda-

tors aside from humans, including

coyotes, bobcats, river otters, and

mink, who prey on young kittens. In

other areas, bears, mountain lions,

wolves, and wolverines may prey on

beavers. Beavers are hosts for several

ectoparasites and internal parasites in-

cluding nematodes, trematodes, and

coccidians. Giardia lamblia is a patho-

genic intestinal parasite transmitted by

beavers, which has caused human

health problems in water supply sys-

Fig. 6. Pine plantation in Arkansas killed in flooding caused by beavers.

tems. The Centers for Disease Control

have recorded at least 41 outbreaks of

waterborne Giardiasis, affecting more

than 15,000 people. For more informa-

tion about Giardiasis, see von

Oettingen (1982).

Damage and Damage

Identification

The habitat modification by beavers,

caused primarily by dam building, is

often beneficial to fish, furbearers,

reptiles, amphibians, waterfowl, and

shorebirds. However, when this modi-

fication comes in conflict with human

objectives, the impact of damage may

far outweigh the benefits.

Most of the damage caused by beavers

is a result of dam building, bank bur-

rowing, tree c utting, or flooding. Some

southeastern states where beaver dam-

age is extensive have estimated the

cost at $3 million to $5 million dollars

annually for timber loss; crop losses;

roads, dwellings, and flooded prop-

erty; and other damage. In some

states, tracts of bottomland hardwood

timber up to several thousand acres

(ha) in size may be lost because of bea-

ver. Some unusual cases observed

include state highways flooded

because of beaver ponds, reservoir

dams destroyed by bank den burrows

collapsing, and train derailments

caused by continued flooding and bur-

rowing. Housing developments have

been threatened by beaver dam flood-

ing, and thousands of acres (ha) of

cropland and young pine plantations

have been flooded by beaver dams

(Fig. 6). Road ditches, drain pipes, and

culverts have been stopped up so

badly that they had to be dynamited

out and replaced. Some bridges have

been destroyed because of beaver

dam-building activity. In addition,

beavers threaten human health by

contaminating water supplies with

Giardia.

Identifying beaver damage generally is

not difficult. Signs include dams;

dammed-up culverts, bridges, or drain

pipes resulting in flooded lands, tim-

ber, roads, and crops; cut-down or

girdled trees and crops; lodges and

burrows in ponds, reservoir levees,

and dams. In large watersheds, it may

be difficult to locate bank dens. How-

ever, the limbs, cuttings, and debris

around such areas as well as dams

along tributaries usually help pinpoint

the area.

B-5

Legal Status

The legal status of beavers varies from

state to state. In some states the beaver

is protected except during furbearer

seasons; in others it is classified as a

pest and may be taken year-round

when causing damage. Because of its

fur value, dam building, and resulting

water conservation, it is generally not

considered a pest until economic

losses become extensive. Fur prices for

beaver in some states, particularly in

the Southeast, make it hardly worth

the skinning and stretching. In some

northern states, trap ping is prohibited

near lodges or bank dens to protect

and perpetuate beaver colonies. Fur

prices for beaver pelts are usually

much higher in these areas.

Damage Prevention and

Control Methods

Exclusion

It is almost impossible as well as cost-

prohibitive to exclude beavers from

ponds, lakes, or impoundments. If the

primary reason for fencing is to

exclude beavers, fencing of large areas

is not practical. Fencing of culverts,

drain pipes, or other structures can

sometimes prevent damage, but fenc-

ing can also promote damage, since it

provides beavers with construction

material for dams. Protect valuable

trees adjacent to waterways by encir-

cling them with hardware cloth,

woven wire, or other metal barriers.

Construction of concrete spillways or

other p ermanent structu res may

reduce the impact of beavers.

Cultural Methods

Because beavers usually alter or

modify their aquatic habitat so exten-

sively over a period of time, most

practices generally thought of as cul-

tural have little impact on beavers.

Where feasible, eliminate food, trees,

and woody vegetation that is adjacent

to beaver habitat. Continual destruc-

tion of dams and removal of dam

construction materials daily will

(depending on availability of construc-

tion materials) sometimes cause a

colony or individual beavers to move

to another site. They might, however,

be even more troublesome at the new

location.

The use of a three-log drain or a struc-

tural device such as wire mesh cul-

verts (Roblee 1983) or T-culvert guards

(Roblee 1987) will oc casionally cause

beavers to move to other areas. They

all prevent beavers from controlling

water levels. However, once beavers

have become abundant in a watershed

or in a large contiguou s area, periodic

reinvasions of suitable habitat can be

expected to occur. Three-log drains

have had varying degrees of success in

controlling water levels in beaver im-

poundments, especially if the beaver

can detect the sound of falling water or

current flow. All of these devices will

stimulate the beavers to quickly plug

the source of water drainage.

A new device for controlling beaver

impoundments and keeping blocked

culverts open is the Clemson beaver

pond leveler. It has proven effective in

allowing continual water flow in previ-

ously blocked culverts/drains and

facilitating the manipulation of water

levels in beaver ponds for moist-soil

management for waterfowl (Wood

and Woodward 1992) and other envi-

ronmental or aesthetic purposes. The

device (Fig. 7) consists of a perforated

PVC pipe that is encased in heavy-

gauge hog wire. This part is placed

upstream of the dam or blocked cul-

vert, in the main run or deepest part of

the stream. It is connected to nonper-

forated sections of PVC pipe which are

run through the dam or culvert to a

water control structure downstream. It

is effective because the beavers cannot

detect the sound of falling or flowing

water as the pond or culvert drains;

therefore, they do not try to plug the

pipe. The Clemson beaver pond lev-

eler works best in relatively flat terrain

where large volumes of water from

watersheds in steep terrain are not a

problem.

Repellents

There are no chemical repellents regis-

tered for beavers. Past research efforts

have tried to determine the effective-

ness of potential repellent materials;

however, none were found to be effec-

tive, environmentally safe, or practical.

One study in Georgia (Hicks 1978)

indicated that a deer repellent had

some potential benefit. Other studies

have used a combination of dam blow-

ing and repellent soaked (Thiram 80

and/or paradichlorobenzene) rags to

discourage beavers with varying

degrees of success (Dyer and Rowell

1985).

Additional research is needed on

repellents for beaver damage preven-

tion.

Toxicants

None are registered. Research efforts

have been conducted, however, to find

effective, environmentally safe and

practical toxicants. Currently there are

none that meet these criteria.

Fumigants

None are registered.

Trapping

The use of traps in most situations

where beavers are causing damage is

the most effective, practical, and envi-

ronmentally safe method of control.

The effectiveness of any type of trap

for beaver control is dependent on the

trapper’s knowledge of beaver habits,

food preferences, ability to read beaver

signs, use of the proper trap, and trap

placement. A good trapper with a

dozen traps can generally trap all the

beavers in a given pond (behind one

dam) in a week of trap nights. Obvi-

ously in a large watershed with several

colonies, more trapping effort will be

required. Most anyone with trapping

experience and some outdoor “savvy”

can become an effective beaver trapper

in a short time. In an area where bea-

vers are common and have not been

exposed to trapping, anyone experi-

enced in trapping can expect good suc-

cess. Additional expertise and

improved techniques will be gained

through experience.

A variety of trapping methods and

types of traps are effective for beavers,

depending on the situation. Fish and

wildlife agency regulations vary from

B-6

Elbow and stand pipe are optional.

Needed only to manage water level if

maintaining pond is an objective.

1" re-bar

6' long

8" diameter 40 PVC pipe

T - jo int tilted with a drain plug

may replace elbow.

Pond side

20'

Table 1. List of materials for the Clemson Beaver Pond Leveler.

Quantity

Item

1 .................................. 10' section, 10" diameter PVC pipe (Schedule 40)

1 .................................. PVC cap for 10" diameter PVC pipe (Schedule 40)

1 .................................. 10" x 8" PVC pipe reducer coupling (Schedule 40)

4 .................................. 86" sections, 3/4" diameter plastic roll pipe (water pipe), 160 psi grade

4 .................................. 3/4" metal couplings for roll pipe

16 .................................. 1/4" x 2" galvanized eyebolts

16 .................................. 1/4" galvanized nuts

16 .................................. 1/4" galvanized washers

16 .................................. 16" sections, 8 gauge galvanized wire (medium hardness)

2 .................................. 96" sections, 2" x 4" 1/2 gauge galvanized welded wire

2 lbs .................................. Crab trap clamps (fasteners)

The above materials are required to assemble the intake device. The carrying pipe (flow pipe) may consist of 20 to 40 feet of

8-inch diameter PVC, Schedule 40 with coupling sleeves and elbows appropriate to the desired configuration.

Fig. 7. Clemson beaver pond leveler.

state to state. Some types of traps and

trapping methods, although effective

and legal in some states, may be

prohibited by law in other states.

Individual state regulations must be

reviewed annually before beginning a

trapping program

In some states where beavers have

become serious economic pests, special

regulations and exemptions have been

passed to allow for increased control

efforts. For example, some states allow

trapping and snaring of beavers and

other control measu res throughout the

year. Others, however, prohibit trap-

ping except during established fur

trapping seasons. Some states allow

exemptions for removal of beavers

only on lands owned or controlled by

persons who are suffering losses. In

some states a special permit is

required from the state fish and wild-

life agency.

Of the variety of traps commonly

allowed for use in beaver control, the

Conibear® type, No. 330, is one of the

most effective (Fig. 8). Not all trappers

will agree that this type of trap is the

most effective; however, it is the type

most comm only used by professional

trappers and others who are princi-

pally trapping beavers. This trap kills

beavers almost instantly. When prop-

erly set, the trap also prevents any

escape by a beaver, regardless of its

size. Designed primarily for water use,

it is equally effective in deep and shal-

low water. Only one trap per site is

generally necessary, thus reducing the

need for extra traps. The trap exerts

tremendous pressure and impact

when tripped. Appropriate care must

be exercised when setting and placing

Intake

device

Beaver

dam

B-7

the trap. Care should also be taken

when using the Conibear® type traps

in urban and rural areas where pets

(especially dogs) roam free. Use trap

sets where the trap is placed com-

pletely underwater.

Some additional equipment will be

useful: an axe, hatchet, or large cutting

tool; hip boots or waders; wire; and

wire cutters. With the Conibear®-type

trap, some individuals use a device or

tool called “setting tongs.” Others use

a piece of 3/8- or 1/2-inch (9- or 13-

mm) nylon rope. Most individuals

who are experienced with these traps

use only their hands. Regardless of the

techniques used to set the trap, care

should be exercised.

Earlier models of the Conibear® type

of trap came with round, heavy steel

coils which were dangerous to handle

unless properly used in setting the

trap. They are not necessary to safely

set the trap. However, the two safety

hooks, one on each spring, must be

carefully handled as each spring is

depressed, as well as during trap

placement. On newer models an addi-

tional safety catch (not attached to the

springs) is included for extra precau-

tion against inadvertent sp ring release.

The last step before leaving a set trap is

to lift the safety hook attached to each

spring and slide the safety hook back

from the trap toward the spring eye,

making sure to keep hands and feet

safely away from the center of the trap.

If the extra (unattached) safety catch is

used, it should be removed before the

safety hooks that are attached to the

springs to keep it from getting in the

way of the movement of the safety

hooks.

Conibear®-type traps are best set while

on solid ground with dry hands. Once

the springs are depressed and the

safety hooks in place, the trap or traps

can be carried into the water for

proper placement. Stakes are needed

to anchor the trap down. In most bea-

ver ponds and around beaver dams,

plenty of suitable stakes can be found.

At least two strong stakes, preferably

straight and without forks or snags,

should be chosen to place through

each spring eye (Fig. 8). Additional

stakes may be useful to put between

the spring arms and help hold the trap

in place. Do not place stakes on the

outside of spring arms. Aside from

serving to hold the trap in place, these

stakes also help to guide the beaver

into the trap. Where needed, they are

also useful in holding a dive stick at or

just beneath the water surface (Fig. 9).

If necessary, the chain and circle

attached to one spring eye can be

attached to another stake. In deep

water sets, a chain with an attached

wire should be tied to something at or

above the surface so the trapper can

retrieve the trap. Otherwise the trap

may be lost.

Trap Sets. There are many sets that can

be made with a Conibear®-type trap

(for example, dam sets, slide sets,

lodge sets, bank den sets, “run”/trail

sets, under log/dive sets, pole sets,

under ice sets, deep water sets, drain

Fig. 8. Basic method of setting and staking a

Conibear® 330 trap. Additional stakes are

normally used (see Fig. 9).

Dive stick

Fig. 9. Conibear trap in dive set.

Run

Levee

Entrance

Fig. 10. Runs or underwater entrances to lodges

are good places to set beaver traps.

B-8

pipe sets), depending on the trapper’s

capability and ingenuity. In many bea-

ver ponds, however, most beavers can

be trapped using dam sets, lodge or

bank den sets, sets in “runs”/trails,

dive sets or sets in slides entering the

water from places where beavers are

feeding. Beavers swim both at the sur-

face or along the bottom of ponds, de-

pending on the habitat and water

depth. Beavers also establish runs or

trails which they habitually use in trav-

eling from lodge or den to the dam or

to feeding areas, much like cow trails

in a pasture.

Place traps directly across these runs,

staked to the bottom (Fig. 10).

Use a good stake or “walking staff’

when wading in a beaver pond to

locate deep holes, runs, or trails. This

will prevent stepping off over waders

or hip boots in winter, and will help

ward off cottonmouth snakes in the

summer. The staff can also help locate

good dive holes under logs as you

walk out runs or trails. In older beaver

ponds, particularly in bottomland

swamps, it is not uncommon to find

runs and lodge or bank den entrances

where the run or hole is 2 to 3 feet (0.6

to 0.9 m) below the rest of the im-

poundment bottom.

To stimulate nighttime beaver move-

ment, tear a hole in a beaver dam and

get the water moving out of a pond.

Beavers quickly resp ond to the sound

of running water as well as to the cur-

rent flow. Timing is also important if

you plan to make dam sets. Open a

hole in the dam about 18 inches to 2

feet (46 to 60 cm) wide and 2 to 3 feet

(60 to 90 cm) below the water level on

the upper side of the dam in the morn-

ing. This will usually move a substan-

tial amount of water out of the pond

before evening (Fig. 11). S et traps in

front of the dam opening late that

same evening. Two problems can arise

if you set a trap in the morning as soon

as a hole is made: (1) by late evening,

when the beavers become active, the

trap may be out of the water and inef-

fective; or (2) a stick, branch, or other

debris in the moving water may trip

the trap, again rendering it ineffective.

Fig. 11. Dam set. Set the trap underwater in

front of the hole created in the dam. When the

beaver returns to patch the hole, it will be

caught in the trap.

Ho le torn through dam to release water.

Beaver dam

Fig. 12. Leghold trap (No. 3 o r No. 4, double

spring) attached to wire for drowning set.

Dig out slide under water to accept trap and

springs.

Slide wire fastened to

stake and weight.

Fig. 13. Leghold trap in slide set.

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The best dam sets are made about 12

to 18 inches (30.8 to 45.7 cm) in front of

the dam itself. Using stakes or debris

on either side of the trap springs,

create a funnel to make the beaver go

into the jaws of the trap. Always set

the trigger on the Conibear®-type trap

in the first notch to prevent debris

from tripping it before the beaver

swims into the trap . The two heavy-

gauge wire trippers can be bent out-

ward and the trigger can be set away

from the middle if necessary, to keep

debris from tripping the trap. This can

also keep small beaver or possibly fish

or turtles from springing the trap.

Double-spring leghold trap s have been

used for hundreds of years and are

still very effective when properly used

by skilled trappers. Use at least No. 3

double (long) sp ring or coil spring type

leghold traps or traps of equivalent

size jaw spread and strength. Use a

drowning set attachment with any

leghold trap (Fig. 12). As the traps are

tripped, the beaver will head for the

water. A weight is used to hold the

trapped beaver underwater so that it

ultimately drowns. Some trappers

stake the wire in deep water to accom-

plish drowning. If leghold traps are

not used in a manner to accomplish

drowning, there is a good likelihood

that legs or toes will be twisted off or

pulled loose, leaving an escaped, trap-

wise beaver.

Placement is even more critical with

leghold traps than with the Conibear®-

type. Place leghold traps just at the

water’s edge, slightly underwater,

with the pan, jaws, and springs cov-

ered lightly with leaves or debris or

pressed gently into the pond bottom in

soft mud. Make sure there is a cavity

under the pan so that when the

beaver’s foot hits the pan, it will trig-

ger the trap and allow the jaws to snap

closed. Place traps off-center of the

trail or run to prevent “belly pinching”

or missing the foot or leg. With some

experience, beaver trappers learn to

make sets that catch beavers by a hind

leg rather than a front leg. The front

leg is much smaller and easier to twist

off or pull out.

Sometimes it’s wise, when using

leghold traps, to make two sets in a

slide, run, dam, or feeding place to

increase trapping success and remove

beavers more quickly. In some situa-

tions, a combination of trapping

methods can shorten trapping time

and increase success.

Trappers have come up with unique

methods of making drown sets. One of

the simplest and most practical is a

slide wire with a heavy weight

attached to one end, or with an end

staked to the bottom in 3 or more feet

(>0.9 m) of water. The other end of the

wire is threaded through a hole in one

end of a small piece of angle iron. The

trap chain is attached to a hole in the

other end of the angle. The end of the

wire is then attached to a tree or stake

driven into the bank (Fig. 13). When

the beaver gets a foot or leg in the trap,

it immediately dives back into the

water. As the angle slides down the

wire, it prevents the beaver from

reaching the surface. The angle iron

piece will not slide back up the wire

and most often bends the wire as the

beaver struggles, thus preventing the

beaver from coming up for air. Trap-

pers should be prepared to quickly

and humanely dispatch a beaver that

is caught in a trap and has not

drowned.

The leghold trap set in lodges or bank

dens is also effective, especially for

trapping young beavers. Place the set

on the edge of the hole where the bea-

ver first turns upward to enter the

lodge or den, or place it near the bot-

tom of the dive hole. Keep the jaws

and pan off of the bottom by pulling

the springs backward so that a swim-

ming foot will trip the pan. Stake the

set close to the bottom or wire the trap

to a log or root on the bottom, to avoid

the need for drowning weights, wires,

and angle iron pieces. Generally, more

time and expertise is necessary to

make effective sets with leghold traps

and snares than is required with the

Conibear®-type trap.

Use scent or freshly cut cottonwood,

aspen, willow, or sweetgum limbs to

entice beaver to leghold trap sets. Bait

or scent is especially useful around

scent mounds and up slides along the

banks or dams. Most trapp ers who use

Conibear®-type traps do not employ

baits or scent, although they are occa-

sionally helpful. In some states it is ille-

gal to use bait or scent.

Several other types of traps can be

used, inc luding basket/suitcase type

live traps. These are rarely used, how-

ever, except by professionals in urban

areas where anti-trap sentiment or

other reasons prevent the killing of

beavers. These traps are difficult and

cumbersome to use, and will not be

further discussed here for use in bea-

ver damage control. Any type of traps

used for beavers or other animals

should be checked daily.

Snaring can be a very cost-effective

method for capturing beavers. Snaring

equipment costs far less than trapping

equipment and is more convenient to

use in many situations. In addition,

beavers can be captured alive by snar-

ing and released elsewhere if desired.

Snare placement is similar to trap

placement. First, look for runways and

fresh sign that indicate where beaver

activities are focused. Find a suitable

anchor such as a large tree, log, or root

within 10 feet (3 m) of the runway

where the snare will be set. If neces-

sary, anchor snares by rods driven into

the ground, but this is more time con-

suming and less secure. Attach three

14-gauge wires to the anchor so that

each can swivel freely. Cut each wire

to length so they reach about 1 foot (30

cm) past the runway. Twist the wires

together to form a strong braided

anchor cable. Drive a supporting stake

into the ground near the runway and

wrap the free end of the anchor cable

around it twice. Prepare a new, dyed,

No. 4 beaver or coyote snare, consist-

ing of 42 inches (107 cm) of 3/32-inch

(