D-59

OPOSSUMS

Jeffrey J. Jackson

Extension Wildlife Specialist

Warnell School of Forest Resources

University of Georgia

Athens, Georgia 30602

Fig. 1. Opossum, Didelphis virginiana

Damage Prevention and

Control Methods

Exclusion

Practical where opossums are entering

structures.

Habitat Modification

Remove cover and plug burrows to

reduce frequency of visits by

opossums.

Frightening

Generally not practical.

Repellents

None are registered.

Toxicants

None are registered.

Fumigants

None are registered.

Trapping

Leghold trap s.

Box traps.

Cage traps.

Body-gripping (kill) traps.

Shooting

Effective where firearms are permit-

ted. Use a shotgun with No. 6 shot

or a .22-caliber rifle.

Identification

An opossum (Didelphis virginiana) is a

whitish or grayish mammal about the

size of a house cat (Fig. 1). Underfur is

dense with sparse guard hairs. Its face

is long and pointed, its ears rounded

and hairless. Maximum length is 40

inches (102 c m); the ratlike tail is

slightly less than half the total length.

The tail may be unusually short in

northern opossums due to loss by

frostbite. Opossums may weigh as

much as 14 pounds (6.3 kg); males av-

erage 6 to 7 pounds (2.7 to 3.2 kg) and

females average 4 pounds (6.3 kg). The

skull is usually 3 to 4 inches (8 to 10

cm) long and contains 50 teeth — more

than are found in any other North

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

D-60

General Biology,

Reproduction, and

Behavior

Opossum s usually live alone, having a

home range of 10 to 50 acres (4 to 20

ha). Young ap pear to roam randomly

until they find a suitable home range.

Usually they are active only at night.

The mating season is January to July in

warmer parts of the range but may

start a month later and end a month

earlier in northern areas. Opossums

may raise 2, rarely 3, litters per year.

The opossum is the only marsupial in

North America. Like other marsupials,

the blind, helpless young develop in a

pouch. They are born 13 days after

mating. The young, only 1/2 inch (1.3

cm) long, find their way into the

female’s pouch where they each attach

to one of 13 teats. An average of 7

young are born. They remain in the

pouch for 7 to 8 weeks. The young

remain with the mother another 6 to 7

weeks until weaned.

Most young die during their first year.

Those surviving until spring will breed

in that first year. The maximum age in

the wild is about 7 years.

Although op ossums have a top run-

ning speed of only 7 miles per hour

(11.3 km/hr), they are well equipped

to escape enemies. They readily enter

burrows and climb trees. When threat-

ened, an opossum may bare its teeth,

growl, hiss, bite, screech, and exude a

smelly, greenish fluid from its anal

glands. If these defenses are not suc-

cessful, an opossum may play dead.

When captured or surprised during

daylight, opossums appear stupid and

inhibited. They are surprisingly

Walking

2"

6"

Opossum tracks

a

b

c

Fig. 2. Opossum sign and characteristics: (a) tracks, (b) droppings, and (c) skull.

Fig. 3. Range of the opossum in North America.

American mammal. Canine teeth

(fangs) are prominent. Tracks of both

front and hind feet look as if they were

made by little hands with widely

spread fingers (Fig. 2). They may be

distinguished from raccoon trac ks, in

which hind prints appear to be made

by little feet. The hind foot of an opos-

sum looks like a distorted hand.

Range

Opossums are found in eastern,

central, and west coast states. Since

1900 they have expanded their range

northward in the eastern United

States. They are absent from the

Rockies, most western plains states,

and parts of the northern United

States (Fig. 3).

Habitat

Habitats are diverse, ranging from

arid to moist, wooded to open fields.

Opossums prefer environments near

streams or swamps. They take shelter

in burrows of other animals, tree

cavities, brush piles, and other cover.

They sometimes den in attics and

garages where they may make a

messy nest.

Food Habits

Foods preferred by opossums are ani-

mal matter, mainly insects or carrion.

Opossums also eat considerable

amounts of vegetable matter, espe-

cially fruits and grains. Opossums liv-

ing near people may visit compost

piles, garbage cans, or food dishes

intended for dogs, cats, and other pets.

D-61

intelligent, however. They rank above

dogs in some learning and discrimina-

tion tests.

Damage

Although op ossums may be consid-

ered desirable as game animals, certain

individuals may be a nuisanc e near

homes where they may get into gar-

bage, bird feeders, or pet food. They

may also destroy poultry, game birds,

and their nests.

Legal Status

Laws p rotecting opossums vary from

state to state. Usually there are open

seasons for hunting or trapping opos-

sums. It is advisable to contact local

wildlife authorities before removing

nuisance animals.

Damage Prevention and

Control Methods

Exclusion

Prevent nuisance animals from enter-

ing structures by closing openings to

cages and pens that house poultry.

Opossums can be prevented from

climbing over wire mesh fences by

installing a tightly stretched electric

fence wire near the top of the fence 3

inches (8 cm) out from the mesh. Fas-

ten garbage can lids with a rubber

strap.

Traps

Opossu ms are not wary of traps and

may be easily caught with suitable-

sized box or cage traps (Fig. 4). No. 1

or 1 1/2 leghold traps also are effec-

tive. Set traps along fences or trail-

ways. Dirt hole sets or cubby sets are

effective (Fig. 5). A dirt hole is about 3

inches (8 cm) in diameter and 8 inches

(20 cm) deep. It extends into the earth

at a 45

o

angle. The trap should be set at

the entrance to the hole. A cubby is a

small enclosure made of rocks, logs, or

a box. The trap is set at the entrance to

the cubby. The purpose of the dirt hole

or cubby is to position the animal so

Fig. 4. Cage trap (set position).

Fig. 5. Leghold trap and sets for opossum.

Cubby sets

Dirt hole set

Spring levers

Pan adjustment screw

Coil springs

Extra swivel

Leghold trap (coilspring type in set position)

Bait

D-62

that it will place its foot on the trap.

Place bait such as cheese, or slightly

spoiled meat, fish, or fruit in the dirt

hole or c ubby to attract the animal.

Using fruit instead of meat will reduce

the chance of catching cats, dogs, or

skunks.

A medium-sized body-gripping (kill

type) trap will catch and kill opos-

sums. Place bait behind the trap in

such a way that the animal must pass

through the trap to get it. Body-

gripping traps kill the captured animal

quickly. To reduce chances of catching

pets, set the trap above ground on a

running pole (Fig. 6).

Shooting

A rifle of almost any caliber or a shot-

gun loaded with No. 6 shot or larger

will effectively kill opossums. Use a

light to look for opossums after dark.

If an opossum has not been alarmed, it

will usually pause in the light long

enough to allow an easy shot. Once

alarmed, opossu ms do not run rap-

idly. They will usually climb a nearby

tree where they can be located with a

light. Chase running opossums on foot

or with a dog. If you lose track, run to

the last place where you saw the ani-

mal. Stop and listen for the sound of

claws on bark to locate the tree the ani-

mal is climbing.

Sometimes opossums can be

approached quietly and killed by a

strong blow with a club, but they can

be surprisingly hard to kill in this man-

ner. They can be taken alive by firmly

grasping the end of the tail. If the ani-

mal begins to “climb its tail” to reach

your hand, lower the animal until it

touches the ground. This will distract

the opossum and cause it to try to

escape by crawling. Opossums can

carry rabies, so wear heavy gloves

and be wary of bites.

Euthanize unwanted animals

humanely with carbon dioxide gas, or

release them several miles from the

point of capture.

Fig. 6. Body-gripping trap and running pole set.

Dog

Jaws

Spring

Trigger

Body-gripping trap (set positio n)

Running pole set

D-63

Economics of Damage

and Control

No data are available; however, it is

usually worthwhile to remove a par-

ticular animal that is causing damage.

Acknowledgments

Much of the information o n habitat, food habits,

and general biolo gy comes from J. J.

McManus (1974) and A. L. Gardner (1982).

The manuscript was read and improved by

Jim Byford and Ro bert Timm.

Figures 1, 2a, 2c, and 3 from Schwartz and

Schwartz (1981).

Figure 2b by Jill Sack Johnso n.

Figures 4, 5, and 6 by Michael D. Stickney, from

the New York Department of Environmental

Conservation publication “Trapping

Furbearers, Student Manual” (1980), by R.

Howard, L. Berchielli, C. Parsons, and M.

Brown. The figures are copyrighted and are

used with permission.

For Additional

Information

Fitch, H. S., and L. L. Sandidge. 1953. Ecology of

the opossum on a natural area in

northeastern Kansas. Univ. Kansas Publ.

Museum Nat. Hist. 7:305-338.

Gardner, A. L. 1982. Virginia opossum. Pages

3-36 in J. A. Chapman and G. A. Feldhamer,

eds. Wild mammals of No rth America:

biology, management, and economics. The

Johns Ho pkins Univ. Press, Baltimore,

Maryland.

Hall, E. R., and K. R. Kelson. 1959. The

mammals of North America, Vol. 1. Ronald

Press Co ., New York. 546 pp.

Hamilton, W. J., Jr. 1958. Life history and

economic relations of the opossum (Didelphis

marsupialis virginiana) in New York State.

Cornell Univ. Agric. Exp. Sta. Memoirs

354:1-48.

Ho ward, R., L. Berchielli, C. Parsons, and M.

Brown. 1980. Trapping furbearers, student

manual. State of New York, Dep. Environ.

Conserv. 59 pp.

Lay, D. W. 1942. Ecology of the opossum in

eastern Texas. J. Mammal. 23:147-159.

McManus, J. J. 1974. Didelphis virginiana.

Mammal. Species 40:1-6.

Reynolds, H. C. 1945. Some aspects of the life

history and ecology of the opossum in

central Missouri. J. Mammal. 26:361-379.

Schwartz, C. W., and E. R. Schwartz. 1981. The

wild mammals of Missouri, rev. ed. Univ.

Missouri Press, Columbia, 356 pp.

Seidensticker, J., M. A. O’ Connell, and A. J. T.

Johnsingh. 1987. Virginia opossum. Pages

246-263 in M. Novak, J. A. Baker, M. E.

Obbard, and B. Malloch, eds. Wild furbearer

management and co nservatio n in North

America. Ontario Ministry Nat. Resour.

Toronto.

Editors

Scott E. Hygnstrom

Robert M. Timm

Gary E. Larson

D-64