Virginia Opossums

Virginia Opossums (Didelphis virginiana)

A female Virgina opossum with her joeys
A female Virginia opossum with her joeys.

Introduction

New Yorkers have a reputation for being brash and outspoken. But the reality is that most of us are masters at avoiding confrontation. As any daily commuter will tell you, something truly absurd has to happen in our vicinity to muster much of a reaction. And more often than not, that reaction is simply to move far, far away from the disturbance.

In that sense, Virginia opossums (Didelphis virginiana) are perfectly suited for life in the city. They avoid unwanted attention by foraging primarily at night. And they often prefer to “play possum” in stressful situations and hope the problem goes away, rather than confront it head-on. So how did such a reserved wildlife species find its way to the bustling streets of New York City in the first place?

Though the name “Virginia opossum” suggests they are confined to a very specific area, they can be found along the east coast and in some areas of Mexico, Central America, and southeastern Canada. They are native to New York, and the expansion of their range into the Northeast is believed to have occurred mostly during this century, especially from 1950 onward. One likely reason for this expansion was the increased availability of food in the region, brought on by the development of local farmland and cities. As an opportunistic omnivore, opossums appreciate the wide variety of easily accessible food sources that New York City provides.  And they’re more than happy to put up with the hustle and bustle of the urban environment in exchange for a tasty meal.

An adult opossum on a fence
An adult opossum on a fence.

General Information

Background

Opossums are mostly solitary during their lifetimes. They are also one of the few mammals that does not occupy a permanent living area as an adult. Like most New Yorkers, they’re usually on the move, setting up temporary dens from time to time as they search for water and food sources. When opossums do set up dens, they often do so in tree hollows, logs, sewers, buildings, and dens abandoned by other animals. Opossums usually occupy dens alone or with their young. However, groups of up to eight opossums will sometimes share a den in winter months.

They are skilled climbers thanks to the thumb-like toes on their back feet and their sharp claws. They will often climb trees or other structures to look for food or escape predators. Once in a tree, opossums can use their long tails for balance. They can even grip a tree limb with their tails and hang upside down to free their hands for eating. 

Speaking of eating, opossums love the culinary options that New York City provides. They will feed on a wide variety of foods, including dead animals, fruits, seeds, insects, birds, eggs, and reptiles. Urban opossums will also take full advantage of the conveniences of city living by raiding garbage cans, dumpsters, bird feeding stations, and food left out for pets.

Appearance

Opossums are most easily distinguished by their long, cone-shaped head and black, beady eyes. They are covered in a coarse fur, which is generally gray around their outer torso, black or brown around their legs, and white on their face and underparts. Their long, nearly hairless tail measures between 9 and 13 inches long. An average opossum measures about 28 inches long, and weighs around 8 pounds. Males are larger than females, and may weigh as much as 15 pounds. 

Behavior

Opossums have two breeding seasons. The first runs from January through late March. The second begins in mid-May and lasts until early July. The average litter size is between six and nine babies. 

Opossums hold the distinction of being the only marsupials in North America. As a marsupial, they carry and nurse their young in a pouch after birth—just like kangaroos and koalas! Newborn opossums crawl into their mother’s pouch and attach to one of her 13 nipples to feed. They remain attached and continue to feed for 60 to 65 days. At 70 days they leave the pouch, but continue to cling to their mother’s fur. When they are approximately 100 days old, young opossums become independent and head out on their own.  

Communication occurs mostly through chemical, vocal, and visual signals. A threatened opossum may hiss, growl, or make a distinctive clicking sound. They may also flash their teeth and arch their back. Opossums that are threatened by a predator will sometimes secrete a foul-smelling greenish fluid from their anal glands. They may also “play possum.” This involuntary response involves falling over and becoming unresponsive for up to six hours. These behaviors are meant to discourage predators from pursuing them.

A joey using its tail to hang from a tree
A joey using its tail to hang from a tree.

Fast Facts

Virginia opossums are the only native marsupial found in North America.

A study at the Cary Institute for Ecosystem Studies found that opossums are very efficient tick-eaters, and can consume up to 5,000 ticks in a season.

Opossums are very resilient. They are immune to several varieties of snake venom, and their naturally low body temperature makes it very difficult for them to contract rabies.

Baby opossums, like baby kangaroos, are referred to as “joeys.” 


Tips for Coexistence

Opossums can be seen day or night. Opossums are nocturnal, and often come out late at night. However, in urban environments, where there is plenty of food and few predators, they can be spotted looking for meals during the day. This does not mean they are sick.

Store all food and garbage in animal-proof containers. Trash and pet food are attractive meal options for urban opossums. Make sure pet food is not left unattended, and garbage bins are firmly secured.

Observe and appreciate opossums from a distance. Approaching opossums can cause them a great deal of stress. For your safety and the safety of the animal, always observe opossums from a distance.

Protect your pets. Though it is very unlikely, opossums are capable of carrying rabies. Walking dogs on a leash and keeping cats inside is best for the safety of both opossums and pets.



References