4 July 2019
This is part of a series of posts from our own Shane Hanlon’s disease ecology class that he’s currently teaching at the University of Pittsburgh Pymatuning Laboratory of Ecology. Students were asked to write popular science posts about (mostly) wildlife diseases. Check out all the posts here.
By Linh Pham
It is a common misconception that possums are rabid, disease carrying animals with no good intentions. When someone says the word “possum” the one thought that will probably pop into most people’s head is rabies. People often find them scaling trashcans and scavenging for remnants of last night’s dinner. Most encounters with possums are described as unpleasant, especially when they hiss, bear their teeth, or play dead. However, this is not the case for Karen Brace of Stafford County. Brace serves as a wildlife rehabber who tends to a variety of animals, recently including possums.
Brace emphasizes the importance of possums to wildlife and the implications we face if they are no longer around. She also claims that they are the “most misunderstood animal in all of Virginia”. Possums will only act hostile when they feel cornered or threatened, and will escape when given the chance. When they show hostility by hissing and acting like they are diseased, it is usually just an extra protective measure to scare off whatever it feels threatened by. As an extreme, last resort, possums will also emit an odor or defecate. However, this only happens when it feels as if it has no other option.
Regarding rabies, there is actually a very low chance that a possum you will run into will carry the disease. According to Carolyn Wilder, who serves as the president of the Wildlife Rescue Club of Northern Virginia, the virus that causes rabies (lyssavirus) is not likely to be carried by possums because their body temperatures are too low for the virus to successfully replicate and spread. In fact, they are almost immune to rabies and are eight times less likely to carry it than dogs living in the wild.
From her experience with caring for possums and spreading positive awareness about them, Brace believes that possums serve a good purpose in the wild as well. Since they eat almost anything they come across (rotten fruits/vegetables, and many pests), they help keep things balanced and in check. Possums will even keep the balance between cockroaches and rats since they all compete for the same food and resources. Their impact is greater than we realize, as they can consume roughly 5,000 ticks per season. Because of this, tick borne diseases such as Lyme and Heartland Virus (HRTV) spread at a slower rate.
After reading more about possums and their common misconceptions, I think that they are just misunderstood animals who were given a bad image. It is important to shed light on the importance of possums to the food chain because they help maintain balance. Mice, roaches, slugs, and other pests can become problematic if their numbers become too high. Possums are one of the animals in this food chain that keep things in check by either eating pests, or competing with them for resources. To answer the question of the title, yes, possums are awesome! The next time you see a possum just let it do its own thing.Chances are, whatever it’s up to is nothing we should worry about.