CHAMPAIGN, Ill., 10/5/21: Prescribed fires used to improve the health of forests influence where wild turkeys choose to nest and roam, according to recent research at the Illinois Natural History Survey (INHS). It turns out that turkeys prefer a variety of forest conditions, from non-burned plots to forests burned each year.
Since turkey hunting is so popular in Illinois, understanding turkey behavior and the types of habitat they need will help with conservation decisions serving to maintain adequate populations.
Prescribed fires are commonly used in state-managed forests, particularly since the oak hickory overstory is dwindling in many forests in Illinois, and the understory is becoming predominantly maples and other shade-tolerant trees. Fires help the oaks to regenerate by providing favorable conditions on the forest floor and understory for oak seedlings and saplings to thrive.
“The goal of forest management is to manage the vegetation for the desired tree species composition and vegetation structure, and our turkey research is piggybacking on that to see what we can do to help or make suggestions to managers,” said Jeff Hoover, INHS avian ecologist. “In other words, if you’re going to use prescribed burns to benefit the forest, maybe some of these practices benefit turkey populations as well.”
In the recent study, Hoover and his research team examined the behavior of 47 turkey hens from two sites in Illinois during three years. They captured, tagged, and released hens during each late-winter and used GPS technology to log several of the turkeys’ locations daily and accelerometers to record their activity levels based on their amount of movement. This gave them detailed location and activity data throughout the turkeys’ annual cycle including the all-important reproductive period of egg-laying, incubation, and poult-rearing.
Turkeys can use 500 acres of habitat in a year, roaming in flocks much of the time. They prefer mature forests where they eat acorns, grains, seeds, and some insects. In late winter and early spring, they spend some time in open areas where the hens can assess males who are displaying and competing to mate with females. In spring the hens wander off into parts of the forest alone to lay their eggs in a nest on the ground and incubate the eggs.
In a general comparison of annual habitat use, hens used burned vs. non-burned forests similar to how much of each type of forest was available. When using burned forests during the reproductive season, however, hens showed some preferences for forests based on how recently and how frequently prescribed fire had occurred.
For example, during the egg-laying period, hens preferred burned forests that were one to two years post-fire, and during the post-nesting period they preferred forests burned just one time in the previous four years over those burned more frequently.
In core incubation areas, hens exhibited greater use of areas that were burned two or three times over those burned once. Another important finding was that hens almost always placed their nests in areas of the forest that had not been burned.
“It’s like they use the Goldilocks principle when choosing where to nest,” Hoover said. “They lay their eggs on the ground in shallow depressions. They want some vegetation for cover around the nest to be concealed from predators, but not so much that they can’t see a predator that might be coming toward them. So, just the right amount of cover–not too little and not too much. It seems areas of non-burned forest fit the bill.”
Turkey hens sometimes nested near previously burned areas so that when they left the nest for incubation recesses, they were close to areas that provided decent foraging opportunities. Once hatched, the poults are particularly vulnerable to predators, so hens tended to stay in the non-managed areas or areas infrequently burned where there is dense vegetation in the forest understory.
For those managing forested landscapes for wild turkeys, Hoover recommended developing a burn prescription in which some plots are burned more frequently than others and some of the non-burned forest is retained for turkey nesting. “Pyrodiversity” is a term used for this approach to varying the use of prescribed fire when managing forests.
“A management scheme that promotes a mosaic of forest habitats and structures seems to be the most beneficial to turkeys to give them all the habitat elements they need throughout the annual cycle,” Hoover said.
This research was funded by the U.S. Fish and Wildlife Service and was published in Forest Ecology and Management.
Christine Parker, the lead author of the study, described her experiences with capturing and studying wild turkeys in University of Illinois News Bureau Behind the Scenes features in 2017 and 2018.
Media contact: Jeff Hoover, 217-244-2922, firstname.lastname@example.org