The opossum, a distinctive marsupial native to the Americas, possesses a unique appearance and set of behaviors. It is the only marsupial species found north of Mexico, making it a subject of curiosity regarding its geographical spread. Its nocturnal habits and defense mechanisms contribute to its presence across various landscapes.
Opossum Presence in Idaho
Opossums are found in Idaho, though they are not native to the state. The Virginia opossum (Didelphis virginiana) is classified as an introduced species, regularly occurring within its boundaries. Their presence in the Western United States, including Idaho, indicates a significant expansion of their range beyond their historical distribution. Historically, their range was primarily limited to the eastern and southern United States, but over the last century, they have steadily moved northward and westward.
This expansion into areas like Idaho is influenced by several factors, including climate change and human activities. Opossums are highly adaptable and can thrive in diverse environments, including rural, suburban, and urban settings. Agricultural land development and urbanization can facilitate their spread by offering new habitats and food sources. Their ability to adapt to varying conditions has been key to their successful colonization of new territories.
Identifying Opossums
These cat-sized mammals have a pointed snout, grayish fur, small, hairless ears, and a long, scaly, hairless tail. Their body length ranges from about 15 to 21 inches, not including their tail, and they can weigh between 4 and 12 pounds. A notable feature is their feet, which have an opposable “thumb” on their hind feet, aiding them in climbing.
Opossums are nocturnal. One of their most widely recognized behaviors is “playing ‘possum,” a defense mechanism where they feign death when threatened. This involves the animal becoming motionless, drawing back its lips to bare teeth, foaming at the mouth, and sometimes secreting a foul-smelling fluid from their anal glands. This state of shock can last from a few minutes to several hours.
Coexisting with Opossums
Opossums are opportunistic omnivores. Their varied diet encompasses insects, fruits, small animals, eggs, and carrion. They also consume pests like rodents, cockroaches, ticks, slugs, and snails, contributing to pest control. This adaptability allows them to utilize diverse food sources, from natural resources to human food scraps in urban environments.
Managing food sources helps coexist with opossums. Securing trash cans with locking lids, bringing pet food indoors at night, and picking up fallen fruit can discourage their presence. Opossums do not build their own dens, often seeking shelter in existing spaces like hollow trees, abandoned burrows, or under human structures such as decks or sheds. While generally non-aggressive, they may hiss or bare their 50 teeth if cornered. Opossums have a low risk of carrying rabies.