As the weather begins to warm in March, some animals that have been relatively inactive all winter begin to make their presence known. One such creature is the opossum. Native to more southern regions, this cat-sized mammal is not well adapted to New England winters and was not seen here regularly until a few decades ago. Since it is more suited for the south, it survives the winter by remaining dormant in dens, except on warmer days.
Opossums (commonly just called possums) have a rat-like tail and naked ears, the tips of which sometimes get frostbite from the cold. Nonetheless, as their range has progressed north, they have become common, especially in urban areas.
Unfortunately the most frequent sightings of possums are when they are dead on the side of the road.
But are they really dead?
One of the myths about possums is that they "play possum" and act dead when threatened. These animals don't move fast, so they can't easily escape predators. In order to survive attacks, they "play dead."
Their initial response to a threat is to hiss and show their 50 sharp teeth. If this is not effective at deterring an aggressor, they go into a temporary paralysis, triggered by shock. This is an involuntary response and is not an act at all. Part of this response can lead to an excretion from scent glands that makes them even smell dead. They may remain in this comatose state for several hours.
Apparently this adaptation has served them well because, they are one of the oldest species of mammals -- with ancestors that date back at least 70 million years.
Another adaptation that has helped possums survive is their high reproductive rate. Females are sexually mature when they are only 6 months old and can give birth to 10 to 15 young at a time. These young, called joeys (like their cousins, the kangaroos), are born after only 13 days of gestation. They are the size of raisins, and a whole litter can fit into a tablespoon.
Though they are tiny at birth, as North America's only marsupial they crawl across their mother's belly and enter into her pouch, where they attach to one of 13 nipples.
They remain there for about two months, eating and growing in a soft, warm nursery. When they emerge from the pouch, they stay with their mother for another six weeks, learning to find food and fend for themselves.
Possums are quintessential omnivores, eating almost anything they encounter. Common foods include fruit, birds' eggs, mice, slugs, earthworms, nuts, snakes and carrion. Sometimes they are referred to as nature's garbage collectors because they eat things left behind by other creatures. Of course, not all of these things are available year round, which is another reason while they may stay in a den during colder months, living off stored fat.
They do not however, stay in one place for long. Possums tend to be rather nomadic. If you happen to have one in your neighborhood or yard, as I do, it may seem like it is a permanent resident. However as one moves on, another may come to occupy the niche left vacant.
You are not likely to see live possums, because they are nocturnal and come out when we are inside our well-lit homes. But the best way to tell if you have one of these unique creatures in your vicinity is to look for tracks in the snow.
Their footprints are very distinctive, thanks to an opposable thumb on their back feet. This is handy for climbing in trees as they grip branches and sometimes hang from their back feet, freeing their front paws for harvesting fruit or nuts.
Their prehensile tail is also good for gripping branches and acts as a third hand as they clamber among the branches.
They do not, however, hang from their tails, as often seen in cartoons. Representing opossums as tail-hanging characters may make them appealing to some people.
Others may find their rat-like tail, pointy nose and compost-raiding habits offensive.
But regardless of how you feel about possums, it can be fun to watch for their signs to see if you have one of these fascinating creatures as a wild neighbor.