Nebraskaland Magazine
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Photo by Jeff Kurrus
By Monica Macoubrie, Wildlife Education Specialist
With a nearly hairless, scaly tail, a mouth full of teeth, the ability to “play dead” and its overall I-don’t-give-a-dang attitude, the opossum might be one of the most unique mammals to be waddling around Nebraska. I guarantee by the time you are done reading this article, you will, at the very least, have a little more respect and love for this remarkable marsupial.
Opossums are Marsupials
The Virginia oppossum is a marsupial. When most of us humans think of marsupials, you probably picture a kangaroo jumping with a joey in the front pouch. Well, yes, that’s correct. However, there are quite a few other species that bear the name marsupial. Others include wombats, koalas and opossums. Being a marsupial simply means that females have a pouch, and the underdeveloped young must spend time in this pouch to complete its development.
Once born, the offspring exits the birth canal and immediately seeks the mother’s pouch. When compared to a kangaroo, the pouch of an opossum is quite small, so small that it would be difficult for the casual observer to spot on a female. Young will not leave the pouch until they reach maturity. When siblings grow too large to fit in the mother’s pouch, you may notice the babies clinging to the mother’s back, where she will carry her young until they are able to go off on their own.
Playing Opossum
One characteristic that everyone seems to know about opossums is that they play dead, but there has been a lot of misinformation on how and why they do this. The myth is that opossums do this when they feel threatened. Turns out, this isn’t true. When an opossum plays dead, it is actually in an involuntary catatonic state. When threatened, opossums are more likely to bare their teeth, growl or run away – they’re little threat to most predators.
These animals typically “play opossum” in situations when they are caught unaware or suddenly attacked. The animal drops to the ground in an instant and closes its eyes or stares off into space. Its body goes limp, its breathing slows down drastically, it discharges its bowels, and it sticks out its tongue and drools. By all means, it appears to be dead. This defense tactic is supposed to confuse predators and allow the animal to escape.
Many would think an Oscar should be awarded to these animals, however, it’s not an act. These animals are going through a process called thanatosis: when the body enters a catatonic state in response to fear, and it’s all involuntary. During this time, the animal doesn’t feel any pain and has no reflexes. The animal will not respond no matter what the predator does.
Fortunately for opossums, many wild animals are completely turned off by dead prey. Scientists believe this is an evolutionary adaption among carnivores to prevent the consumption of diseased meat. Most predators will give up on an opossum once they believe it has died. So, what happens to the opossum? Well, it can take anywhere from a few minutes to several hours for the opossum to become mobile again.
Prehensile Tails, Sort of
A Virginia opossum is around the size of a large house cat. It has a triangular-shaped head, a long-pointed nose, is mostly covered in grayish fur, and it has a tail, which is prehensile. A prehensile tail is adapted for grasping and wrapping around things like tree limbs. Although it is a myth that opossums hang by their tails to sleep, they can grasp a branch with their tails for short periods of time. Their tails simply aren’t strong enough to hold them for longer than a few minutes.
Opossum Feet
Have you ever seen opossum tracks in the snow or mud? If you have, you might have thought an alien left them. These animals have what’s called an opposable hallux. Hallux are clawless, big toes that work like thumbs. The hallux helps this creature grab branches when they climb. So, when they leave tracks in the snow, it looks like a miniature child, or an alien, was walking around the prairie.
They’re Intelligent
If you consider the brain size of an opossum, you might not think it’s not the sharpest tool in the shed. Their brains are only around 1/6th the size of a raccoon and 1/5th the size of a domestic house cat, giving them one of the lowest brain-to-body ratios of any mammal. They also have a very smooth brain, lacking the network of folds and grooves seen in more “intelligent species.” They also lack a structure known as the corpus callosum, which connects the two halves of the brain and is largest in more intelligent animals. In humans, this would be considered a serious birth defect and is associated with a high rate of learning disabilities.
Despite all this, opossums excel at intelligence tests. In one study, scientists hid food for opossums to find, and their ability to remember was higher than cats, rats, dogs and rabbits. In another study, opossums demonstrated they can solve maze puzzles faster than cats and rats. Scientists have also documented the opossum’s ability to recall specific smells a full year after being exposed to them.
Rare for Rabies
Any mammal can get rabies, but it is extremely rare for an opossum to contract this disease. Compared to other mammals, some scientists think the opossum’s slightly lower body temperature makes it hard for viruses to survive in its host. An opossum’s normal temperature is around 95° Fahrenheit compared to a dog’s, which is around 101°-102.5° F. Rabies is much more common in animals such as raccoons, foxes and skunks.
Opossum Teeth
The opossum has more teeth than any other land mammal – it has 50! In its mouth are four kinds of teeth: incisors for gripping and tearing, canines, molars to crush their food and pre-molars for slicing. Opossums are considered omnivores, which means they will eat other animals and also plant material. Their teeth help them do everything from tearing apart prey to crushing tough nuts and seeds, and they have to be strong enough to handle different textures and hardness. Opossums also use their front incisors to pick up small insects accurately and precisely.
Their teeth can also be used as a defense against predators. On average, the opossum’s bite force is around 45 pounds per square inch, in comparison to a raccoon, which has a bite force of around 100 pounds per square inch.
Opossums are extremely misunderstood and misrepresented in discussion. Many people believe these animals are ugly, strange, stupid and useless, but just like every other animal in the ecosystem, opossums have a place. So, the next time you see these waddling marsupials, give them a wave and remember all this cool information.
