Are opossums homely? Maybe. But their fan base in Vermont and elsewhere is growing, partly because the critter is a champion at scarfing down ticks that carry Lyme disease.
Yet, North America’s only marsupial (it carries its young in a pouch, like a kangaroo) is too often misunderstood, undervalued and tormented, said Heidi Conant, founder of Winooski-based nonprofit Opossum Awareness and Advocacy.
“But they’re not nuisance animals,” she added. “We need more of them. Vermont has a serious Lyme disease problem. We need all the help we can get.”
How people show they care
Conant, a marketing consultant, started the group two years ago after determining that opossums deserve our help and respect. Its Facebook page now has more than 133,000 followers worldwide.
“I was blown away by how many people out there really like opossums,” Conant said this week. “They’re cool, and I want people to know that they’re cool.”
Her organization doesn’t gloss over the problems presented by opossums. They can harbor other diseases (one of them, EPM, is fatal to horses), and they occasionally feed on small, ground-dwelling birds (including chickens) as well as garden pests such as snails.
Opossum Awareness and Advocacy aims to motivate folks, as well as educate them.
Among the conversations it hosts is: How to provide winter shelter for opossums, which are poorly suited to cold weather, and don’t hibernate: Insulated picnic coolers, modified with an entrance hole and lined with blankets or straw, get high marks.
Carrie Storm of Brattleboro says her backyard opossum, whom she names Momma, needs no such coddling: The animal lives in a nearby architectural cavity that she won’t name for reasons of privacy.
“I’m never going to tell,” Storm said Wednesday. “She’s not hurting anyone.”
Momma dines nightly regularly on senior cat chow, taking turns with Storm’s three cats and a dog.
“Everybody gets along just fine,” Storm said.
The dangers of feeding opossums
There’s no law in Vermont against building shelters for wildlife — just think of bird houses and bat-boxes.
Getting better acquainted with native animals is almost always a positive thing, points out Kim Royar a wildlife management biologist at the Vermont Fish & Wildlife Department, and so is overcoming a revulsion or fear of creatures like bats, snakes and yes, opossums.
But Vermonters may not domesticate wild animals, and should be aware that humans might do so inadvertently, Royar warns.
Feeding wild mammals, for instance, “habituates them to humans, and increases the risk of conflict with humans,” she said.
Food left out for an opossum usually attracts more opossums to the neighborhood, as well as other, more aggressive (and rabies-prone) animals like raccoons, she said, which often leads to noisy, messy raids on back porches and garbage cans.
“Then the attitudes toward these animals change pretty quickly,” Royar continued, “and it usually ends badly for the animals. We usually say, ‘leave wildlife in the wild.'”
Opossums, though, don’t seem to get the message: They go where humans go.
Why is Lyme disease still spreading?
When Royar first began work as a biologist for the state in 1981, opossums were rare.
They steadily migrated north, she remembers, “through Vermont’s two banana belts — the Champlain and Connecticut River valleys.”
Thanks in part to gradually warming seasons, opossum sightings are now common. Many are recorded and mapped on the iNaturalist Vermont Atlas of Life, operated by the Norwich-based Vermont Center for Ecostudies.
But the advance of opossums into suburban North Country neighborhoods doesn’t translate into a slam-dunk defeat of Lyme disease.
That’s because more and more humans have moved into formerly forested areas, disrupting natural systems that typically keep the disease in check, says Rick Ostfeld, a senior scientist at the Cary Institute of Ecosystem Studies, based in Duchess County, New York.
White-footed mice and chipmunks — species that rapidly transmit Lyme disease via ticks — thrive when predators like hawks, owls, bobcats and foxes distance themselves from human society, said Ostfeld, who has studied the spread of Lyme disease for two decades.
“Chopping up forests into smaller bits tends to eliminate some of the species that protect us,” he said.
“By carving out homes where everyone has a half-acre lot of woods, we’re inadvertently creating a paradise for black-legged ticks,” Ostfeld continued. “We’re plunking our houses right in the middle of harm’s way.”
Less wary of human neighbors, opossums are apt to hang around.
But their legendary appetite for ticks isn’t enough to make up for their poor performance as mouse-catchers, Ostfeld said — and Lyme disease rates increase.
Opossums still need us, and vice-versa
Advocates for opossums like Ostfeld, Royar and Conant remind us to look at a big-picture view of the relationship; that we need to extend our concern for nature beyond a single species, and cultivate a greater diversity of plants and animals.
“Enjoy how opossum’s live in the landscape in the context of the greater forest community,” said Fish & Wildlife’s Kim Royar. “We’ll end up with healthier wildlife and healthier humans.”