Big acorn crop last fall has consequences for wildlife

One fox, two fox, red fox, another red fox.

One chipmunk, two chipmunks, 16 chipmunks. Well-fed red fox.

That may be the state’s story this spring. A combination of things — lots of acorns last fall, a mild, nearly snowless winter — has given us a plethora of things scurrying and stalking.

“It’s a chipmunk festival up here,” said Cathy Hagadorn, executive director of Deer Pond Farm, the nature center in Sherman owned by the Connecticut Audubon Society.

“I’ve never received so many chipmunk calls in my life,” said Dan Schwarzbeck, owner of Got Wildlife?, a New Milford wildlife control company.

“Everything,” said Joe Gray of Bats R. Us Wildlife, a Bethel wildlife control company, of the calls he’s gotten. “Chipmunks, squirrels, flying squirrels. They started breeding earlier this year. Even the skunks were breeding early.”

Add another factor or two. One is that because people are working from home, animals may be emboldened to wander into new spaces.

“Red foxes may be more willing to walk near an office because people aren’t there,” said urban wildlife expert Laura Simon.

Add this: People aren’t commuting, which could mean fewer road kills.

But they’re out walking around in the world or watching it from the kitchen window. It may be that animal numbers are the same, but people are noticing them more. Freed from the 9-to-5, they’re mixing coyote shots in with kid pics on their cell phone cameras.

“People are out at all times of the day,” said Jenny Dickson, director the state Department of Energy and Environmental Protection’s wildlife division. “A lot of people have seen foxes, a lot of people have seen coyotes. They’re seeing things they never saw before.”

The great driver of all this is the acorn crop. If it’s a mast year, with lots of nuts, a host of creatures — everything from mice and squirrels to blue jays, wild turkey and black bears — share the bounty. They get fat and healthy and have lots of offspring.

Likewise, the birds and beasts that eat rodents — foxes, coyotes, bobcats owls, hawks — do well if there’s more game to hunt.

If it’s a poor year, it’s the reverse — less food, hunger, fewer babies all around.

“We consider it the great engine,” said Rick Ostefeld, a disease ecologist at the Cary Institute of Ecosystems Studied in Millbrook, N.Y.

Ostfeld said 2018 was a poor year for acorns, while 2019 was a good one.

This means that ticks, which had fewer mice to feed on in the spring and summer of 2019, may have fared poorly. He’s predicting there will be fewer infected nymphal ticks in the region this summer. With plenty of scurriers this year, they’ll rebound in 2021, he said.

Like others, Ostfeld is worried that people going out in the world to get their mind off coronavirus, may forget about ticks and the diseases they spread. Tick repellent and vigilance is still required.

“The relatively low number of ticks could still translate to a high number of human cases,” he said.

Ostfeld, who has spent years studying these cycles, said mast years impact the natural world in other, surprising ways. If there are lots of mice after a big acorn crop, those mice will eat gypsy moth cocoons, reducing gypsy moth damage later in the year.

He also said mice and chipmunks will eat the eggs, and even the very young, of ground-nesting birds like veerys, ovenbirds and thrushes. The great acorn engine giveth and taketh away.

With lots of mice and squirrels and chipmunks around, the light winter made them easier to catch, Dickson said. There was no snow to hide under. Sharp-eyed hawks and owls, sharp-nosed foxes and coyotes may have fed well.

There is another factor. This a good time to see predators like red fox anyway. Foxy parents — dogs and vixens — mate for life and share the rearing of their kits. Generally nocturnal, they’re out in the daytime now, finding food to fill famished fox mouths.

Simon said if people should stumble on a fox den, with fox kits crying and mewling, they should leave it alone. They’re not abandoned, it’s just that the parents are out hunting.

Hagadorn of Deer Pond Farm also has this warning. A mild winter means there was no cold spell to kill off bugs. We may have a summer of DEET, deer flies and swatting ahead.

“I like to remind people we’re going to pay for this,” she said.