DNR working to improve accuracy of turkey-brood data
CHARLESTON, W.Va. -- Turkey hunters are curious about a lot of things, but they're particularly curious about the number of turkeys hatched two years before the spring season.
That number, which wildlife officials call the "brood index," gives hunters an idea how many 2-year-old gobblers will be strutting their stuff when springtime rolls around. For the past couple of years, though, a change in the way West Virginia Division of Natural Resources employees report brood sightings has made the index less reliable, at least temporarily.
Before 2009, DNR officials accepted reports of turkey sightings from several sources: wildlife employees, law enforcement employees, forestry employees and the general public.
In some years, the agency received lots of reports; in other years, not so many. Biologists ultimately realized that the old reporting method resulted in inconsistent data.
"We decided to standardize who would be [brood] observers, and when those observers actually observed," said Chris Ryan, the DNR's supervisor of game management services. "We wanted to make the process as scientific as possible."
The first change, which went into effect in 2010, was to cease taking reports from the public. The second, instituted in 2011, mandated that DNR Wildlife Resources personnel be the only recognized observers. The third, for 2012, restricted observations only to DNR employees' on-the-clock hours.
Paul Johansen, the agency's assistant wildlife chief, said the changes were made "to standardize the reporting system."
"We want to have a core group [of employees] responsible for reporting brood sightings," he added. "We want the index to be more consistent from one year to the next."
Johansen and Ryan acknowledged that the numbers from 2010 and 2011 weren't consistent because the reporters were different. The 2011 and 2012 figures were more consistent, but not perfectly so.
This year's numbers should match up pretty well with last year's. The number of involved wildlife employees should be roughly the same as it was in 2012, and the observations will be made only during observers' on-the-clock hours.
Johansen estimates, though, that it will take four to five years' worth of consistent reporting before the annual brood report can be considered wholly reliable.
"That's about how long it will take to develop reliable trend data based on the new system," he said. "But even this year, we should have a good idea what's going on. Our confidence [level] might not be as high [in the data], but we'll be able to tell whether turkey broods are trending up or down."
The danger, Johansen added, would be for hunters to compare brood-report data from before 2009 with reports generated afterward.
"We're dealing with different protocols, so it's almost impossible to determine a trend based on pre-2009 numbers," he said.
Why should hunters consider turkey brood reports important? Well, mainly because 2-year-old gobblers have a profound effect on spring gobbler season outcomes. They're old enough to be actively gobbling and interested in mating, yet they're inexperienced enough to be called in and ambushed relatively easily.
DNR officials have found that the number of turkey poults hatched in a given year has a direct effect on the spring season two years down the road. The higher the brood count, the higher the corresponding harvest tends to be.
"Right now, we're tightening up our methodology so we can have reliable numbers from year to year," Johansen said. "I think we're making good progress."
Reach John McCoy at firstname.lastname@example.org or 304-348-1231.