The science behind afternoon spring gobbler hunting has little to do with gobblers. It's all about the hens.
Traditional conservation theory held that by mid-May, morning breeding activity was waning and after 12 p.m. hens were settled on their nests incubating eggs. Approaching hunters could frighten hens off the nests, leaving the unprotected eggs vulnerable to predation.
But in 34 of 49 wild turkey states, an emerging theory holds that the number of afternoon hunters during spring gobbler season is so low that few hens are being pushed off the nests, increased hunting opportunity does not result in a significantly higher kill and hens will renest if a clutch is destroyed.
"By the second half of the season, hunter participation decreases significantly and nesting hens are less prone to abandon nests," said Mary Jo Casalena, Pennsylvania Game Commission wild turkey biologist, in a written statement. "All-day hunting during this portion of the season has had minimal impact to nesting."
Since 2011 when late-day spring gobbler hunting in the second half of the season was legalized, afternoon and evening harvests totaled 6 percent of the total reported harvests and 22 percent of harvests during the all-day portion of the seasons, according to Game Commission hunter surveys. When gobbler hunting is permitted all day, 78 percent of the harvest occurs before noon.
There's little evidence the late-day hunts result in increased egg mortality, said Bob Eriksen, a New Jersey-based biologist for the National Wild Turkey Federation who spends a lot of time hunting Pennsylvania turkeys.
"First, it's a tougher time of day for hunters. There's less gobbling," he said. "Although it's probably more convenient for most hunters, they're generally not out there, so there's less interference with nesting hens. Not only that, hens can renest if they lose a clutch of eggs -- I've seen hens produce broods in August and early September."
While most eggs hatch in late May and early June, Eriksen said a secondary hatch could occur in late July, and in some cases hens can produce a third or fourth clutch.
"As for the gobblers, I've called them in as late as June 15," he said. "I suspect the only reason I haven't called in some later is I haven't tried."
Late-day spring gobbler hunting is best in the hour before dusk.
"If you know where they're roosting, you get there early and set up before they get there," he said. "Don't be very vocal, just call enough to get their attention. You might catch a tom coming in thinking he's rounding up a stray hen."