A fawn predator study is slated
The Pennsylvania Game Commission is going to do another fawn-predator study.
Starting this year and continuing through the end of 2017, it will be collaring fawns and following them to figure out how they die, in what numbers and what’s taking them.
Of course, the commission has been down this road before. It conducted a fawn mortality study in 2000 and 2001. It determined that predators do take fawns, but not to the point of impacting populations.
Ongoing data collection has supported that since, commission biologists have said. In fact, a draft copy of the new study plan presented to commissioners at their recent work session in Harrisburg notes that “wildlife management unit data indicate that deer populations remain productive and are stable or increasing.”
But sportsmen’s groups and lawmakers, including some in key positions like the House and Senate game and fisheries committees, have been pushing for an update, concerned that increasing bear and coyote numbers in particular are driving deer populations down. Some members of the commission’s own board have been pushing the idea of doing a study for a while, too.
All are finally getting their wish.
“Whether there are management implications from it or not, I don’t know. I guess we’ll see in a couple of years,” said Commissioner Jay Delaney, of Luzerne County. “But it’s good to look at it.”
This latest study, as discussed at the work group session, will have six goals. They are: to estimate fawn survival; determine mortality causes; identify species, sex and individual identity of predators that consume fawns; estimate relative abundance of black bear, bobcat, coyote and fisher; compare relative predator abundance and observed predator mortalities; and effectively communicate activities and results to the public.
Total cost to do the work will be about $1.1 million.
John Dunn, acting director of the commission’s Bureau of Wildlife Management, said the study will be carried out on two sites, one in Susquehannock State Forest and another where Bald Eagle and Rothrock state forests meet. Those were chosen because the commission and Penn State University are already collaring deer for another research project. Piggybacking on that work will save money, Dunn said.
Wildlife technicians will be hired to find fawns – by following pregnant does implanted with vaginal transmitters and by walking fields and forests, as was done more than a decade ago – and outfit them with radio collars of their own. Those will be monitored daily from spring through August, and one to three times per week September through December.
When technicians get an indication a fawn has died, they’ll locate the scene and do an investigation to figure out if a predator caused the death and, if so, what kind it was. Bite wounds and hemorrhaging will be the clues to predators.
Dunn said the study will differ from the one done in the early 2000s in that it will also involve trying to figure out how many predators are on the landscape.
When it comes to bears, wildlife conservation officers and study technicians will try to capture a set number of bears, for example.
“Estimates of relative bear abundance will be compared between the two study areas and with estimates of fawn survival to determine how abundance influences predation activity,” reads a line in the study draft.
To get a handle on the relative abundance of coyotes, bobcats and fishers, the study calls for “using scent stations uniformly distributed throughout the study areas during summer/fall periods and winter track surveys following fresh snowfall events.”
Scent stations, as defined in the report, will be 1-meter diameter circles in the woods where all of the vegetation has been removed and the soil has been “pulverized” to a depth of 3 centimeters. It will be covered with “fine-textured soil” around a scent attractant to facilitate track identification.
Cameras will also be placed at each site to get visual confirmation of what shows up.
The search for tracks will occur within 24 hours of a fresh snow along existing trails and roads.
Commissioners had a few questions about the plan.
Commissioner Dave Putnam, of Centre County – one of those who sat in on an October scoping meeting to help develop the study – asked if there are any indications that bears in particular are impacting deer numbers. The commission has changed bear seasons several times in recent years, he noted. That’s included expanding the season in places, specifically to bring their numbers down.
Has that led to more fawns making it alive to fall? he wondered.
Chris Rosenberry, the commission’s chief deer biologist, said the answer is no. The commission looks at fawn-to-doe ratios annually, he said. However, there’s been “no measurable change” in those figures in areas where more bears are being taken.
Commissioner Ralph Martone, of Lawrence County, asked about information the study will provide. If it shows that predators aren’t impacting deer numbers in Susquehannock State Forest, will that mean they’re not impacting deer numbers everywhere.
Rosenberry said that won’t necessarily be the case. While the results may be somewhat applicable to the northcentral region of the state, which is “especially typical of where these complaints come from,” they’ll be more a glimpse of what’s going in a particular time in a particular location than anything broader.