It’s been a banner year for the barred owl population in Massachusetts, but it seems they’ve had little to hoot about lately.
Wildlife experts and veterinarians say that with the abundance, they’re seeing higher numbers of owls being injured than in recent years.
And rodents are partially responsible.
As the populations of squirrels, mice, and other small mammals ballooned this year — paralleled by a noticeable uptick in roadkill — so too did the number of their natural predators, according to Greg Mertz, CEO for Weymouth’s New England Wildlife Center and the Cape Wildlife Center in Barnstable.
“The whole thing makes sense,” Mertz told Boston.com Tuesday. “It’s been a banner year. Populations of wildlife almost always have an up and down cycle.”
Barred owls are the most abundant owls in the Bay State and are drawn to woodlands, particularly wet forests, said Tom French, assistant director for the state’s Division of Fisheries and Wildlife.
They hunt everything from gray squirrels down to mice and songbirds, according to French, who said the state’s barred owl population increases during the winter when the birds from more northern states head down to Massachusetts to stay out of even colder territories.
“Frankly, the fact that there are a lot of injured ones reflects nothing other than there are a lot of barred owls out there,” he said.
Putting a number on how many owls that is, however, is rather difficult.
“I mean an owl is hard enough to find individually, and to monitor them…,” French said. “We have no idea.”
The seasonal increase this year coincides with the recent rise in population — an uptick that happens every three to five years as the prey population fluctuates, according to French.
An abundance of acorns last year is what triggered the latest ripple effect that’s still reverberating, he said. The availability of food fueled the rise of rodents, giving way to the large body of barred owls now getting hurt across the state.
In an average year, Mertz said each of his centers sees about two injured barred owls among their patients. But veterinarians have handled “three or four times that amount” in just the last month alone, he said.
Some owls are hit by passing cars as they swoop in to pluck rodents off roadways. Others, Mertz said, have flown into soccer goal nets or have gotten caught in glue traps all while they’re in pursuit of prey.
The owls are left with injured eyes and wings and broken bones.
“We see a lot of head trauma, almost like concussion-like signs … (and) trauma to their eyes because their eyes are just so big,” said Maureen Murray, assistant director of the Tufts Wildlife Clinic at Cummings Veterinary Medical Center at Tufts University.
As of Tuesday, Murray’s North Grafton clinic had treated 111 owls since Aug. 1. Usually, the center sees less than 100 in a given year, with 71 owls total last year, she said.
Mertz believes a now dwindling number of prey available to the over-abundant owls is playing a part.
With less options, owls may be taking more risks to find food, especially the wave of young owls born amid this year’s boom, he said.
“These are juvenile, younger animals and they probably getting into trouble more frequently than an older, wiser owl,” he said.
For motorists, it can be difficult to avoid hitting an owl since many swoop down and collide with vehicles on their own, according to Murray.
But she advises drivers remain aware of the possibility while driving in wooded areas and slow down.
“The more time you have to react, the more time they have to react to you,” Murray said.
In the event of finding an injured owl, she said contacting a local animal control officer is usually the best first step of action.
French said the spike in owl injuries usually comes in the late fall and lasts through mid-winter. There could be another, though, when this new generation has its own offspring.
But overall, he said, there’s no major need for concern.
“They’re doing very well,” French said. “Barred owls are as secure as any animal we have.”