New Haven Register (Sunday) (New Haven, CT)
Connecticut wildlife to cope with shortage of acorns
The table for the autumnal feast will be short its main dish this year. Acorns are in short supply.
In turn, there will be a cascade of events that will affect dozens of species — those that scurry, those that stalk, those that browse, those that fly, those that suck blood.
It’s part of the natural cycle that’s been going on since the first acorns took root in Connecticut.
“We’ve known about it since people started studying oaks,” said Jeff Ward, forester for the Connecticut Agricultural Experiment Station in New Haven.
The agricultural experiment station monitors the acorn crop every year, looking at 12 deer and turkey management zones throughout the state. In total, there are 300 red oaks and 275 white oaks in those study areas.
The station’s staff surveyed the zones for two weeks in August. It found there was a widespread acorn crop failure throughout the state.
Joseph Barsky, lead forest researcher for the experiment station, said the failure wasn’t due primarily to the summer’s drought or insect infestations or diseases. It’s simply due to the oak’s survival strategy.
Every five to seven years, the state’s oaks absolutely blanket the ground with acorns. That happened in 2021, Barsky said.
It takes a lot of energy for the trees to produce that many acorns. They need a year off to regain their strength..
“This year, the trees are in recovery,” Barsky said.
Ward said oak trees have huge acorn mast years because so many creatures, from acorn weevils to black bears depend on them for food.
In normal years, those creatures eat most of the acorns. But in peak years, there are too many acorns that some are left over.
“It overwhelms the acorn predators,” Ward said.
Those surplus little acorns take root and into great oaks grow. As a result, oak trees have survived as a species.
Oaks are now the predominant tree in the state forests. As a single species, there are more red maples. But the oak family — red, white, black — reign sovereign. Connecticut’s state tree is the white oak, as thanks to the Charter Oak.
Oaks really took over the place around the turn of the last century. Oak seedlings need a lot of sunlight to thrive. At that time, a lot of the state’s forests had been cut over for charcoal production and the chestnut blight was felling the American chestnut — the previous forest boss. The oaks filled in the open spaces
Mature oaks can live for centuries and produce millions of acorns over their lifespan.
Mice, voles and chipmunks all depend on them as a food source. Blue jays and squirrels gather them up and cache them in select spots across the landscape, spreading the acorns around.
Wild turkeys eat them. So do white-tailed deer and black bears.
In turn, a host of predators — foxes, coyotes, bobcats, hawks, and owls — feed on those mice and squirrels.
If there are a lot of acorns around, the well-fed scurrying class produces more babies. That means the predators have more to eat and they, in turn, have more young.
In lean winters — like the one coming up — the process will be reversed. There will be fewer mice and voles and squirrels, and fewer owlets and foxy kits.
Barsky of the Agricultural Experiment Station said white-tailed deer — deprived of acorns — may wander more in search of food. That could mean more deer on the roads and more deer-car collisions.
In could also mean more deer in the shruburbs, munching on the azalea.
“Maybe that’s why we’ve seen a doe in our backyard,” Ward said.
Black bears are omnivores and can eat a lot of things. In the fall, when they need to fatten up before hibernation, acorns are a food source. Without them, garbage bags and bird feeders may be more tempting than ever.
But there is another, welcome, disruption in the cascade of changes, at least for humans.
In their two year cycle, black-legged ticks — as larvae, nymphs and adults — snatch a blood meal from any mammal moving by,
including white-footed mice.
These mice are one of the main reservoirs of Lyme disease.
So, if there are fewer acorns lying around, there will be less food for whitefooted mice.
“The mouse population will collapse,” Ward said
Next year, when the ticks come out to feed, fewer mice means fewer blood meals.
“In two years, there will be fewer ticks carrying Lyme disease,” Ward said.