With increasing concerns over population declines in Ohio, the Ohio Department of Natural Resources and Ohio State University are conducting the first broad-scale study of hen survival in the state in almost two decades. Findings will help researchers and wildlife managers understand how survival rates, harvest rates and reproduction have changed in the last 17 years and what factors may be causing those changes.
In the early 2000s, researchers determined May 1 to be the median date for which hens begin incubating; however, it’s clear today that incubation start dates vary in different regions of the state. Changing weather and habitat conditions, too, may be impacting the initiation of nest incubation from the median date established in the early 2000s.
“There are growing concerns about the potential impacts regarding the timing of the removal of males during the hunting season, and therefore it is important to know as precisely as possible when hens begin incubating nests,” said Ryan Boyer, NWTF district biologist for Michigan, Indiana and Ohio. “In many cases, state agencies set their season open dates to coincide closely with the median date for nest incubation initiation, allowing time for hens to be bred and for nesting to begin. Ensuring that season start dates align with nesting chronology greatly reduces the chance of negatively impacting populations by removing males too early.
“Just like the world around us, wild turkey ecology is dynamic. We are proud to partner with the ODNR and Ohio State University to provide support for this research project and continue to ensure the best-available science is being used in informing management and regulatory decisions.”
Mark Wiley, ODNR game bird biologist, notes that it is not just timing that can have an effect nesting success, but also changes in habitat.
“Afforestation (establishment of a forest or stand of trees in an area where there was no previous tree cover) and forest maturation affect habitat quality, which in turn can affect nesting productivity and hen survival,” he said. “A more thorough understanding of hen demographics in relation to changing habitat conditions will improve our ability to successfully manage a dynamic wild turkey population.”
Beginning in early January and through March, ODNR staff will capture birds using rocket nets. Once captured, researchers and ODNR staff will quickly work to attach leg bands as well as GPS transmitters. The information from the transmitters will be invaluable to researchers.
“Researchers from OSU will download and monitor turkey location and activity data two to three times per week,” Wiley said. “They will use turkey location and activity data to detect nesting activity, movements and mortality events.”
The researchers will confirm nesting activity by locating the birds on the ground, and after the incubation period, the team will be able to determine nest fate, hatching rates and causes of nest failure, if it fails.
Three weeks after a successful hatch, the research team will locate and count the number of poults with each hen. They will also establish an annual survival rate of hens from transmitter data. That data will allow researchers to determine the sources of mortality and investigate the seasonal movements of hens.
Results of the study will be shared with nearby states that are conducting similar wild turkey research projects, including New Jersey, Pennsylvania and Maryland, and data will be aggregated to provide a larger representation of how climate and habitat changes impact nesting on a landscape scale.
“The research project is important to all hunters, experienced or new,” said Bill Sulicks, NWTF Ohio State Chapter president. “We are all eager to see the turkey population begin to thrive again as in earlier years. We believe this study can guide us, in a way, to approach the recent decline, and so in saying this: ‘Once you are aware of a problem, you need to understand how it works, before you can fix it.’”
Field work, including turkey trapping and telemetry monitoring, will occur throughout this year and 2024 and may continue into 2025. The final project report, thesis and scientific manuscript will be available at the end of the project in 2025.