Turkey gobbler study will help guide management decisions

April 06, 2010

University Park, Pa. -- A recently completed, four-year Penn State study of male wild turkey harvest and survival rates in three northeastern states shows that game managers and hunters have a choice to make. Do they want more spring hunting opportunity at the risk of fewer adult gobblers available for harvest?

Over the past 20 years, turkey populations have increased, their range has expanded throughout eastern North America and month-long spring gobbler seasons have become very popular with hunters. Consequently, state wildlife-management agencies are being asked whether hunters can have more opportunities to harvest birds.

But results of this research -- which was supported by the National Wild Turkey Federation (NWTF), the Pennsylvania Game Commission, the New York Department of Environmental Conservation and the Ohio Department of Natural Resources -- indicate sportsmen face a dilemma with additional gobbler hunting.

"Because the gobblers have already bred the hens, it's a social decision more than a biological decision," said study author Duane Diefenbach, adjunct professor of wildlife ecology and leader of the Pennsylvania Cooperative Fish and Wildlife Research Unit in the university's College of Agricultural Sciences.

Ohio will be allowing spring gobbler hunters to hunt all day during the second half of the month-long season this spring (they are restricted to mornings, now). Pennsylvania recently instituted a second spring gobbler tag for hunters who want to purchase one and is considering allowing all-day hunting during the last two weeks of the season in spring 2011.

"Increasing hunting hours will boost harvest rates and result in fewer adult male turkeys in the population, possibly lowering hunter satisfaction," Diefenbach said. "So it's a trade-off -- more time to spend hunting but with the potential for perhaps reduced chances of harvesting a big gobbler. If hunters want more hunting opportunity, that may result in fewer older males in the population."

State agency personnel and NWTF volunteers banded more than 3,200 male birds across the three states. Diefenbach's research revealed that harvest rates on adult males two years and older -- gobblers -- varied from state to state in the spring turkey seasons, ranging from a high of 40 percent in Ohio to 38 percent in Pennsylvania and 36 percent in New York. The harvest rate for younger male turkeys -- often referred to as jakes -- was about half that of gobblers in all three states during the 2006-to-2009 study period.

The research project showed that in Ohio and New York, about 50 percent of the male turkey population is adults two years of age and older; in Pennsylvania, approximately 70 percent of male birds are adults.

"That information is valuable to game managers because we didn't have accurate estimates of the percentage of adult male turkeys in the population," Diefenbach said. "There are more juveniles out there than you would think. Because gobblers are more vulnerable to harvest than jakes -- and hunters prefer to take gobblers -- they comprise the majority of the spring harvest. And game managers lacked estimates of annual survival of gobblers."

Hunters, in the three states studied, harvest a lot of turkeys every year in the spring season. New York hunters take 27,000 to 35,000; in Ohio, hunters kill 18,000 to 20,000; and in Pennsylvania, 36,000 to 40,000.

Because of its broad scope, Diefenbach's research was unique.

"Typically, turkey-survival studies monitor birds with radio transmitters, so you learn a lot about what the birds die from, but by necessity fewer birds are studied over a smaller area. With help from field personnel from the wildlife-management agencies and National Wild Turkey Federation local chapter volunteers, we used rocket nets to trap turkeys at baited sites and banded 3,266 male birds," he said. "In every county where you find turkeys -- Ohio's turkey population is still expanding -- we captured and banded birds."

Diefenbach noted that half of the bands were inscribed with rewards offering hunters $100 if they turned them in, ensuring larger sample sizes and accurate estimates of the harvest rate. The NWTF paid out more than $75,000 to hunters who returned reward bands.

"We knew from previous studies that if we didn't offer rewards, we would underestimate harvest rates," he said. "Although more than 80 percent of hunters reported the harvest of a turkey banded without a reward band -- a higher reporting rate than for goose and duck hunters -- without rewards we would not have obtained accurate harvest and survival estimates."

It turns out that for male turkeys, becoming an adult means you don't have long to live, Diefenbach said.

"Once a male turkey becomes a gobbler, it has on average about one year to live. They are harvested at much higher rates than jakes by hunters and they are more likely to die from other causes, including predation."

Despite hunter harvest and predation, there are a lot of gobblers out there, the Penn State study confirmed. According to research estimates, there are between 60,000 and 80,000 in Ohio, and both Pennsylvania and New York have 100,000 to 120,000 gobblers each.

"The bottom line is, if we increase hunting pressure on gobblers, there will be fewer adult male birds in the population." Diefenbach said. "Studies have shown that seeing turkeys, hearing and calling gobblers, and harvesting adult birds contribute the most to hunter satisfaction. So hunters will have to help state agencies decide whether upcoming changes to spring hunting seasons adequately balance hunting opportunity with hunter satisfaction."

  • An adult Pennsylvania wild turkey male, or gobbler, will have approximately one year to live after reaching adulthood, according to a Penn State study.

    IMAGE: Penn State

(Media Contacts)

Last Updated November 18, 2010