Pa. grouse population reaches 50-year low with no relief in sight
There's a chance Pennsylvania's grouse will one day rise from the ashes where they reside now.
Just don't expect it this fall.
It looks as though things might get worse before they get better.
Lisa Williams, grouse biologist for the Pennsylvania Game Commission, said populations are at a 50-year low. That's a continuation of a troubling trend. Numbers have been depressed for several years.
“We're now kind of hitting record lows year after year,” she said.
Even in areas of good habitat, grouse are struggling.
It's not just here either.
“Most of our neighbors are at record lows or near record lows for grouse populations, too. This is not anything unique to Pennsylvania,” Williams said. “But it certainly is concerning.”
West Nile Virus is thought to be a large part of the problem. Birds bitten by mosquitoes carrying the disease suffer heart and brain damage, often leading to death.
And this year has been a bad one on that front.
Pennsylvania's Department of Environmental Protection monitors for the disease annually. It turned up in April this year, which was a “record early detection for the virus on the landscape,” Williams said.
“We know we are in an exceptionally bad year for the virus. And that leads to an exceptionally bad year for grouse,” she added.
Still, most of the Department of Environmental Protection's surveying goes on around human population centers. Grouse are not a focus.
So this summer, the commission collected mosquitoes on its own, on state game land 176 in Centre County. The idea was to see if infected mosquitoes are as troublesome in that kind of habitat as elsewhere.
The answer is yes.
Using two kinds of traps, the commission caught mosquitoes two days a week for 10 weeks. They collected 13,190 of 25 varieties.
“We did find eight species that I say fall into that Goldilocks zone. They're just right for what we want to look at,” Williams said.
“In other words, they are carrying the virus, and they bite birds.”
None of that is good news.
The problem is widespread, too.
The commission has examined hunter harvest birds for evidence of West Nile over the last two years. It's examined about 400. They have come from 41 of the state's 67 counties.
Everywhere, the disease has cropped up.
“Essentially what we have seen is that where we have grouse, we have West Nile affecting grouse,” Williams said.
The good news, “if there is any,” she added, is that some grouse can survive a West Nile infection.
“Once they get the disease and they recover, that protection probably lasts for their lifetime,” Williams said. “So that gives us some management opportunities.”
They come on three fronts, all of which must be tackled simultaneously, she added.
First, Williams said, the commission needs to figure out if it's possible to control the disease at all, perhaps by treating certain types of stagnant water bodies.
In natural wetlands, with dragonflies and other predatory insects, mosquitoes don't necessarily get out of control, Williams said. Smaller wet spots don't see that, though.
Perhaps, she said, there are opportunities there.
Second, it needs to “work smarter, not harder,” when it comes to habitat.
“If we can identify areas where the disease risk is lower, that's where we should be putting habitat,” Williams said.
The southeast region of the state, for example, has a lot of survivors among grouse, she said. The northwest and north central have the most and best habitat.
It might be wise to work in such places and allow survivors to disperse, or “build outward.”
Third, it needs to focus on harvest management. That means limiting take to increase the percentage of disease-resistant birds in the breeding population.
The commission closed the post-Christmas grouse season for 2017-18. Williams didn't say if that might have to remain closed or if other seasons might need to be shortened.
She won't make season recommendations for next year until January.
But the commission needs to increase virus-resistant birds as a percentage of the breeding population, she added.
If all that comes together, the birds could respond. But they need help now.
“The concern is that as these bad years come closer and closer together, if that's going to be a pattern, then we really have an urgent management situation,” she said, “even where we have good grouse populations.”