The Virginia opossum ( Didelphis virginiana) is the only marsupial native to North America. Opossums are highly adaptable and range throughout Kansas, but are most common in the eastern part of the state where deciduous forest, wooded riparian zones, and water sources are most common. Like some of the other furbearers, the opossum thrives in and around towns and cities, taking advantage of abundant food and shelter inadvertently provided by people.
The opossum is identified by its long snout, typically grayish fur, and long, scaly, prehensile tail. Opossums also have 50 teeth, more than any other Kansas mammal. About cat-sized, they typically weigh six to 13 pounds, with males being somewhat larger than females. As a marsupial, the reproductive process of the opossum is unique among Kansas furbearers. Females have a fur-lined abdominal pouch called a marsupium in which young develop. After a gestation period of less than two weeks, up to 17 tiny, naked, and blind young are born. Developed just enough to survive outside the uterus, only those able to crawl into the marsupium and attach to one of 13 or so nipples may survive. They remain attached to a nipple in the pouch for the next two months, undergoing most of their basic development. An average of seven young make it out of the pouch, and they are fully weaned and on their own by about 100 days of age. Within a short time after the first litter has become independent, another litter is born.
The opossum finds daytime shelter and refuge for extended periods of cold in rock, wood, or junk piles, hollow trees or logs, burrows of other animals, or various other crevices. Densities of eight to 10 opossums per square mile are probably common in Kansas, but phenomenally high densities of 259 per square mile have been recorded in prime waterfowl nesting habitat. The diet of the opossum is extremely diverse, but primarily consists of plant matter including fruits, berries, and grains, and invertebrates including beetles, grasshoppers, crayfish, and snails. Small mammals, birds and their eggs, and all types of carrion are also consumed opportunistically.
Though highly prolific, opossums experience extremely high mortality and rapid turnover rates within the population. In fact, few survive past one year, and virtually none past two. Populations are drastically reduced by periods or drought or extreme cold, and are very susceptible to human-induced mortality, especially roadkill. The opossum is a good swimmer and climber, but lacks in speed and intelligence. A common predator evasion technique is “playing dead,” which is effective only on those predators that choose not to kill. The great horned owl is the opossum’s primary predator, though coyotes, bobcats, and other carnivores will sometimes kill them. Opossums are resistant to rabies, but may be severely impacted by a variety of parasites.
The opossum is a significant furbearer in Kansas in terms of the number harvested, usually ranking third behind raccoons and coyotes. However, individual pelt value is very low, so that most are caught either in damage control situations or incidental to the pursuit of other species. Most opossums are trapped, but some are also taken by houndsmen. Over the past five seasons, annual harvest has averaged almost 27,000.