Opossums in New Hampshire: A Resilient Marsupial

As temperatures moderate in New Hampshire, sightings of Virginia opossums are becoming increasingly common. Once a rare sight, these adaptable marsupials are now frequently observed in neighborhoods across the state, even north of the White Mountains. Their presence has sparked interest and, for some, a need for greater understanding of these often-misunderstood creatures.

A History of Northward Expansion

The northward expansion of opossums in New Hampshire has been observable since the 1980s, initially along railroad rights of way. Despite not being particularly well-adapted to harsh winters – they are susceptible to frostbite on their ears and tails – they have established a significant presence throughout the state and have even been named the official state marsupial through a legislative proposal with bipartisan support.

What is an Opossum?

Often mistakenly called “possums,” the North American variety is technically the Virginia opossum (Didelphis virginiana). True possums are tiny, brown marsupials native to Australia. Opossums are ancient animals, sharing the earth with dinosaurs over 70 million years ago. They are the only native marsupial in the United States.

Adaptability and Diet

Opossums are opportunistic eaters, readily adapting to human-provided food sources like bird feeders, trash, and pet food left outdoors. Like raccoons and skunks, they thrive in areas where food is readily available. They also play a beneficial role in the ecosystem by consuming ticks and even tackling venomous snakes. Some studies suggest their blood proteins may hold potential for developing rabies or snake venom antidotes for humans.

Unique Biological Traits

Opossums possess several unique biological characteristics. They have a low body temperature and a strong immune response, offering resistance to many diseases, including rabies and Lyme disease. They even have opposable thumbs on their feet, aiding in climbing and gripping branches, complemented by their prehensile tails. Despite excellent night vision, they are nearsighted and rely heavily on scent and touch for navigation.

Reproduction and Development

Opossums typically initiate having babies in February. Their offspring, called joeys, are born at a remarkably early stage of development – about the size of a bumblebee. These tiny joeys must immediately latch onto one of the mother’s 13 nipples to survive for the next eight weeks. Like kangaroos, they develop in the mother’s pouch for 8-10 weeks before riding on her back, clinging tightly to her fur.

Intelligence and Behavior

Contrary to common perceptions, opossums are surprisingly intelligent. Their brains are proportionately smaller than most mammals, but they exhibit excellent memory, particularly regarding food sources. Studies have shown they can outperform dogs in learning tasks and even solve mazes more effectively than rats.

If You Find a Deceased Opossum

If you encounter a dead opossum on the road, it’s crucial to check for joeys that may still be alive in the mother’s pouch. These young can survive for days. Contact a licensed wildlife rehabilitator for assistance.

Something Wild on NHPR

This information is brought to you by Something Wild, a program on New Hampshire Public Radio (NHPR) hosted by Dave Anderson and Grace McCulloch, and produced by Jessica Hunt. The program is a partnership between NH Audubon, the Forest Society, and NHPR.