Why Opossums Eat Ticks

Opossums Eat Ticks and Help Humans

Baby opossums (Photo: Flicker Sharinng,by Cryptozoo)

Why Opossums Get Ticked-off

Let's face it, ticks are one of those creatures that everyone hates. Even I, the biggest nature nugget of them all, hate ticks. They're flat and creepy and they invade the private moist areas of the human body that only my doctor and I should have access to. As if that's not enough, they bury their mouth parts in our skin, latch on, and suck our life-blood all while possibly transferring diseases. This creates a real ick factor that keeps many people out of the woods altogether.  However, there is some hope, namely because there is a cadre of creatures that eat ticks. There are the usual suspects of beetles, ants, centipedes, and other generalist eaters that wipe out ticks, but this list also includes chickens and ground fowl such as guinea birds and bobwhites. There's even an African bird called an oxpecker, which lives in sub-Saharan Africa that eats ticks off water buffalo and other hoofed animals (and who doesn't love that name!?). Well, since we're short on oxpeckers here in the Eastern US we have to rely on another creature to help us out, namely the Virginia opossum (Didelphis virginiana).

OPOSSUM VS. POSSUM

The name opossum comes from the Virginia Algonquain (Powhatan) word for "white" and "dog." The North American opossum is not the same thing as a possum (without an "O"). Both are marsupials, and opportunistic feeders, but that's about where the differences end. The North American opossum has a naked tail and long pointed face, as well as more teeth than any other mammal in North America. The possum (or common brush tail possum) is native to Australia. It's silvery-grey  and looks like the love child of a kangaroo and chinchilla (now you have that image in your mind there are comparison pictures below). You can read more about the etymology and differences by clicking here.

North American opossum (Photo: Flicker Sharing, Dawn Huczek)

Australia possum (Photo: Wiki Commons)

Australian brushtail possum (Photo: Wiki Commons)

A STRANGE SIDEBAR 

The Latin name of the opossum is Didelphis virginiana. The first part of the name, "Di" means two in Greek and "Delphi" means womb. Female opossums have two uteruses and the male has a forked penis for fertilizing them. There are some crazy myths that the male has a forked penis because he fertilizes the female through the nose and then the female "sneezes" her young into her pouch.   (now that's an interesting way to procreate!)  Some confusion may have arisen early on  because the pink baby opossums, when they are born, have to crawl out and around the mother's birth canal and into her pouch. The blind and lost little wee pink babies may crawl on the female's face for a time while looking for her pouch, which may have added to the confusion. Regardless, their biology is almost as weird as the myth.

BACK TO THE TOPIC AT HAND

Remember that bit I mentioned earlier about opossums having a lot of teeth (50 total) and being opportunistic feeders? Opossums are not picky eaters, they're omnivores. They eat anything they can find and this includes mice, baby rabbits, birds, eggs, lizards, slugs, snails, garden pests, worms, beetles, all sorts of insects, crayfish, acorns, cherries, fruit, garbage, and carrion (dead stuff).   Scientists are even studying opossums because they have acid proteins in their blood that make them immune to the hemorrhagic (swelling) and neurotoxin effects of snake venom. This includes snakes such as diamondback rattle snakes and cottonmouths, which if they are small enough, could make a tasty snack for an opossum!  (which would you rather have around your house, a cute marsupial or venomous snakes?). Interestingly opossums are mostly immune to rabies too, which makes them a superhero in the mammal world.

North American opossum (Photo: Flicker Sharing, Cryptozoo)

It turns out that opossums are fastidious groomers too. They like to be clean and are constantly cleaning their fur. They use their hind feet, and opposable thumbs to groom their body, and they lick their front paws and groom their face like a cat. It is this grooming practice that makes them good tick eaters. As they groom they ingest the ticks that they groom off. Opossums aren't going around hunting for ticks to eat. They are little furry low-riders that waddle around in grasses, brush, leaves, and such, which means that they're constantly getting ticks on their fur. They also get ticks from the carrion that they eat. The little blood suckers and parasites hop from the dead and cold host to the warm and furry consumer while it eats.

Juvenile American opossum (Photo: Flicker Sharing, Foreversouls)

Researchers from the Carey Institute of Ecosystem Studies in New York studied several of the best wee vectors (movers) of ticks, including white footed mice, chipmunks, squirrels and two species of birds to see how good they were at removing or getting rid of 100 ticks each. It turns out that the opossums, because of their fastidious grooming habits, were the best at removing the ticks, and that they ingested (ate/removed) 90-95% of the ticks they were exposed to.

Now don't get the wrong idea, opossums eat ticks mostly through grooming. They aren't going around hoovering up ticks like a vacuum, they're just exposed to a lot of them, and then they eat them off. This sort of makes them nature's ultimate fuzzy lint-brush remover. It's estimated that they could eat or remove 4,000-5,000 ticks in a season. This is pretty significant if you think about how many potential little blood suckers may be wiped out before getting the chance to transfer Lyme disease to humans.

Opossum playing dead (Photo: Flicker Sharing, Tobyotter)

Let's face it, opossums aren't on the top of anyone's "cute list" (except maybe mine). They have a lot of teeth, a rat-like tail, and they fall over, drool, and exude a stinky smell to play dead when excited (we've all dated or worked with people like this at one time or another I'm sure). Regardless of their appearances opossums eat ticks and other pests that affect humans. You don't have to love their looks, just respect their ecological role and give them berth to do their jobs in nature.

If you're really into opossums after reading this article you can join the Opossum Society of the United States. Their website is full of fun facts and even a shop where you can get an opossum tote or shirt!

American Opossum Society Logo (Photo: American Opossum Society).

 

 
Posted in Mammals, Parasites, Pest management and tagged on by .

About Infinite Spider

My name is Karen and I am currently the Education Program Coordinator at the Smithsonian Environmental Research Center, working with students K-gray and doing outdoor science education based on Smithsonian research. I have also been a curriculum developer for the Smithsonian Science Education Center and a contract curriculum writer for the Discovery Channel. In my spare time I love to explore nature topics that I want to know more about, which has lead me to blogging here on "The Infinite Spider" (Infinitespider.com). I've designed it to be a science and nature blog for every-day people, naturalists, and outdoor educators. Currently I live in Annapolis, MD. If you have questions you can reach me at greathornedowl76@gmail.com. Let me know if you enjoy the blog or if you would like to see a particular topic covered. Thanks for reading!