Didelphis virginiana
Virginia opossum
Physical Description
Adult opossums can range in size from 24 to 33 inches (63-83 cm) and they
weigh between 6 and 15 pounds (2.5-7.5 kg) with the males generally being slightly
larger than the females. Opossums have short legs relative to their body size. Opossums
are covered with long grey to black hairs with white tips. This variation in color gives
the opossum a dark to grayish-silver coloration. They have long tapered muzzle and their
face, neck and underbelly are a white to yellowish-white color. The ears and tail of an
opossum are naked. The tail is black for the first few inches and then fades to a white or
a cream skin color. The typical dental formula for the opossum is as follows:
5  5 11
33 44
i
c
pm
m
 50 (Lyon 1936).
4  4 11
33 44
Distribution
The Virginia opossum ranges north and south from New York to Florida. They
range east and west from the Atlantic coast to the Midwest and down through Texas and
into Mexico (Lyon 1936). The only place in the U.S. where the opossum is not found is
in the upper northwest. All of Wisconsin is considered prime habitat for the opossum.
Ontogeny and Reproduction
Opossums have dentition that suggests omnivory, which is the case for the species.
Opossums can survive on a wide-ranging diet. They consume flesh in the form of dead
animals, birds and their eggs, frogs, worms, snails, etc. They also eat berries and fruits
when present. In agricultural areas they feed on corn. In areas where opossums have
urbanized they subside on refuse and waste from neighborhood garbage cans. This
ability to adapt to a wide variety of foods is part of the reason why opossums are so far
ranging. Most foraging is done at night throughout their home range. Males typically
have a home range of about 105 ha. Females’ home range is much smaller averaging
approximately 51 ha. (Gillette 1980)
The opossum is North America’s only marsupial. One important character of
marsupials is that they have an epipubic bone attached to the pelvis (Lyon 1936). The
female has a posterior opening pouch which contains 13 teets for nourishing young.
Following a brief gestation of only 12 to 13 days the young are born and immediately
crawl to the pouch and begin nursing. A typical litter consists of 12 to 22 offspring.
Those that are not able to locate and attach to a teet die of starvation.
Ecology and Behavior
Opossums prefer to live near a constant source of water such as a river or stream.
They nest in standing snags as well as fallen trees and the abandoned burrows of other
animals. Opossums prefer edge habitat over large expansive forests. Many times they are
found near agricultural fields that produce corn. In urban environments they have been
found to nest in tool sheds and barns. Their ability to adapt and use a variety of nest sites
is another reason why the opossum is so far ranging.
Opossums are usually not social unless they are actively looking to mate. Males
remain ready to mate throughout the year and must wait for the female to come into
estrous to breed (Winegarner 1982).They are slow moving and quiet animals. Opossums
are mostly nocturnal or diurnal. They are not aggressive except for females immediately
before and after estrous. One interesting character of the opossum is their defensive
behavior. When confronted an opossum will roll over and remain motionless as if
feigning death. This curious behavior has coined the phrase “playing possum”
(McManus 1970).
Remarks
Opossums were at one time valued for their fur, which was used to make cuffs
and collars for jackets and coats. They are still trapped by some and eaten although they
are not regarded as a prime source of nutrition. They are hunted primarily in the southern
U.S. at night with the aide of hounds and spotlights (Lyon 1936).
Literature Cited
1. Behavior of Captive Opossums, Didelphis marsupialis virginiana
John J. McManus
American Midland Naturalist, Vol. 84, No. 1. (Jul., 1970), pp. 144-169.
1. Mammals of Indiana
Marcus Ward Lyon, Jr.
American Midland Naturalist, Vol. 17, No. 1. (Jan., 1936), pp. 1-373.
2. Behavior of Escape Virginia Opossums
Troy A. Ladine; Robert E. Kissell, Jr.
American Midland Naturalist, Vol. 132, No. 2. (Oct., 1994), pp. 234-238.
3. Movement, Habitat Use and Denning of Opossums in the Georgia
Piedmont (in Notes and Discussion)
Carroll H. Allen; R. Larry Marchinton; W. Mac Lentz
American Midland Naturalist, Vol. 113, No. 2. (Apr., 1985), pp. 408-412.
4. Movement Patterns of Radio-Tagged Opossums in Wisconsin
Laurence N. Gillette
American Midland Naturalist, Vol. 104, No. 1. (Jul., 1980), pp. 1-12.
5. Seasonal Changes in the Reproductive Tract of the Male Opossum
Didelphis virginiana Kerr in Florida
Marsha Siegler Winegarner
American Midland Naturalist, Vol. 107, No. 2. (Apr., 1982), pp. 258-261.
Reference written by Michael Hawley, Biol 378: Edited by Christopher Yahnke.
Page last updated February 23, 2004.