Pennsylvania is tracking wild turkeys by GPS to find out why populations are declining
Pennsylvania's wild turkey population has been going down, after peaking in 2001, so to help find out why the state Game Commission has outfitted about 100 hens with GPS transmitters as part of its largest turkey research project.
"The whole idea for this turkey study is to determine what are the limiting factors, at this point, of the turkey population. And what we, as a wildlife agency, can do to help improve the turkey population in areas where it's declining, which is a lot of the state," said Mary Jo Casalena, wild turkey biologist with the Pennsylvania Game Commission.
Turkeys were more successful reproducing in some parts of the state last year. But, Casalena noted, one year does not make a trend.
“You know, the turkey population has been declining," Casalena said. "And so, I mean, one year of really good reproduction is fantastic. But it's not going to be enough to give us the huge boost that we need.”
Possible factors in the decline include loss of habitat, weather patterns, predators and disease.
To better understand why, the Commission is using GPS transmitters to track hens — female turkeys — in four parts of Pennsylvania that have different geographies, turkey populations and hunting patterns. Those areas are in the central, southeastern, northeastern, and westcentral parts of the state. The research also includes taking blood samples from the hens.
Casalena said they’re working with researchers at Penn State and the University of Pennsylvania's Wildlife Futures Program to analyze the data. They’ll be using the transmitters through 2025.
“So we're comparing all those areas and getting an idea of what predation rates are, what nesting rates are, poult production is, and weather patterns are, and how that may be affecting turkeys in all of the different types of habitats," Casalena said.
Only about half of the 100 hens originally outfitted with GPS devices are still alive. Casalena said that's not necessarily surprising, but they'll have more information at the end of nesting season.
Next year, researchers from Maryland, New Jersey and Ohio will be part of the project.
And as it does every year, the Commission is asking the public for help counting turkeys — hens, male gobblers and baby poults. That survey, which helps with population estimates and management, runs through the end of August.
"It's really nice to have the public involved," Casalena said. "Because, with any kind of data, the more data you have, the tighter your confidence intervals are going to be, and the more confidence you can have in the estimates."
Pennsylvania's work is part of a national survey. Turkeys, Casalena noted, don't know state borders.
In 2021, the state had approximately 159,000 turkeys. That's down from the high point of 280,000 in 2001. The state had been trapping and transferring turkeys to restore turkey populations.
"So their populations can fluctuate tremendously from year to year, depending on their productivity," she said. "So it's important for the state for state wildlife agencies — since it's a game species — to get an idea of the annual production to help us to manage our hunting populations accordingly."
It can be easier to see wild turkeys in the summer — after farmers cut their hay fields and the birds are looking for insects and berries to eat.
“They’re seeking water. They’re seeking, of course, trees to roost in at night. They’re seeking open areas for bugging, for feeding during the day," Casalena said. "Then when the berries are ripe, they’re seeking the berries to eat. I’ve seen turkeys eating blueberries and their beaks are dark blue-black.”
To find out more about the survey and to report sightings, go to the Game Commission's website.