Talking Turkey- Interview With VDGIF Conservationist Gary Norman – Part 3
In my conversation with Gary Norman, game bird conservationist for the Virginia Department of Game and Inland Fisheries, he explained how data on turkey and ruffed grouse population and mortality was collected, and now he talks about how that data was used to help rejuvenate the area’s wild turkey population.
“One of my first research responsibilities was with a wild turkey study where we looked at the parameters that we just mentioned, survival and reproduction harvest rates. And we found back in 1987, when population was starting to decline that harvest rates were high. That’s when, as you mentioned, there was a very liberal fall season in Highland County, and other counties west of the Blue Ridge. It was eight weeks long and included the first two weeks of the firearms deer season. And almost a third of the birds that were being harvested then were being taken during that first week of the firearms deer season.”
“And we did a study looking at this, and we were able to work with West Virginia, and they were also concerned about survival rates, we were able to pair our data with theirs. That was over 1,000 radios we put out on birds in both states over a five year period of time, so it was a significant study. And from that, we determined that our harvest rates were indeed much higher than West Virginia, as they had a four week season. And what we determined from that was that our additional harvest mortality was being additive, rather than being compensatory.”
He explained, “Those two terms are really important when you’re talking about population management, because the whole concept of wildlife management and hunting is that hunting is compensatory. Compensatory means that the number of birds, or number of animals that hunters takes, is simply replacing natural mortality in the population. And a scenario, for example, where you would have a population of 100 animals, and you would have 50 that survived, at the end of the year, and were ready to reproduce, you would have a survival rate of 50%, and a mortality rate at 50%. That 50% mortality rate could be composed of natural mortality, be it predators, weather influences, accidents, diseases, poaching – a number of factors that could contribute to those losses. In the mix, though, would be hunting. And the whole idea was that in any given year, there might be highs and lows, but the core population was still stay at 50. You would have that number at the end of the year to go in and and reproduce and keep the population going.”
“So that’s the desirable and ideal scenario for hunting. But with additive mortality, what happens is there might be one parameter that is consistently higher than others. And it’s consistent over time such that it puts the population from 50 down to 40. And we can directly account for that parameter alone being the cause of the survival rate declining.”
“And that’s what we were able to do with that study. And we determined that our higher harvest rates were the cause of that. So we reduced the season, we took it out of the first two weeks of the firearm seasons. What we found since then, is that the population still hasn’t done what we want in terms of building a density that we think the county can sustain. So we shortened the season again, and it’s been about eight years now that it’s been at this very short timeframe, just two weeks in length. And turkey numbers are responding nicely in the county. They’re not at a level yet where I want to see a longer season immediately, but I think in the next two to four years will be at a point where we can begin to lengthen the season. No promises, but I know that the county is moving from a stable situation to one where the population is increasing and that’s been a significant step.”
So, the next time you see a flock of turkeys alongside the road during your travels, or hear this on a cold spring morning …(turkey gobbling)…you might have Gary Norman to thank.