Robert Miller: Acorns are a banquet for animals underfoot
Updated 11:17 pm, Friday, August 31, 2012
If you go out in the woods in the next few weeks -- or even walk under an oak tree near a sidewalk -- you may hear a crunch underfoot.
It's the sound of you crushing acorns.
We take them for granted, but those nuts -- scarce some years, omnipresent in others -- are central to the woods.
They're one of the most widely used and important food sources for animals in the Northeast. Species numbers rise and fall each year, depending on the acorn crop.
The rodents of the woods -- squirrels, mice, chipmunks -- depend on them. So do the fox and coyotes, hawks and owls that eat those rodents.
Blue jays store them in hidden depots so they have food for the winter.
Other birds eat them as well.
"I've seen crows eat acorns," Ward said.
Three great comeback species feed on acorns, too.
One is the wild turkey. One is the white-tailed deer. One is the black bear.
All of them were extirpated -- gone -- from Connecticut in the 19th century after European settlers cut down the great majority of the state's woodland and converted the land to farm fields.
When the farmers abandoned those fields and let them grow back to woods, the woodland creatures came back.
In the case of the wild turkey, the state helped, importing turkeys from other states until flocks got established here again.
All of the three feed on acorns. There have been studies that show when the acorn crop goes down, black bear mortality rises. Not from lack of food but by getting hit by cars.
"If there's not enough food in their territory, black bears disperse," said Ed Faison, ecologist at the Highstead Arboretum in Redding. "That gets them traveling and walking on the roads."
Because of the interconnection of everything, acorn crops have an effect on how many people get Lyme disease in Connecticut.
The great carrier, the reservoir of the Lyme bacteria, are the countless white-footed mice that scurry through the leaves on the forest floor, or, when they find a way in, across your pantry floor.
Black-legged ticks bite the mice, then bite humans, spreading the Lyme bacteria as they go.
White-footed mice depend on the acorn crop. When there are a lot of acorns, there are a lot of white-footed mice. When the crop crashes, so does the mouse population.
"When the white-footed mice population goes down, so do the number of Lyme disease cases," Faison said.
Oak trees have their own rhythm. Faison said they operate on a three- to five-year cycle, with huge masts of acorns one year, declining to slim pickings the next.
The 2010 acorn crop was huge. The 2011 crop was scanty.
This year, Ward said, he's seen lots of acorns under some species, like black oaks. But because of the hot, dry year, he said, he's also seen some oaks shedding their crops before the nuts are mature.
That means the acorn feeders and hoarders in the woods are going to have to hustle to get their fall meals in.
"I think it will be spotty," Ward said of the acorn crop. "I think it will be hit or miss."