Warmer temperatures linked to climate change are contributing to an increase in the deer population in Athens County.
The Athens County deer population has grown by over 13.3% over the past three years, according to the Ohio Department of Natural Resources. Local sightings, including an unusual number of fawns on Ohio University’s campus this fall, reflect the trend.
The National Oceanic and Atmospheric Administration reported the August 2025 temperature was 4.6 degrees Fahrenheit above average, part of a pattern of rising seasonal temperatures.
Warmer conditions extend the rut, or mating cycle, of white-tailed deer, which typically is in the beginning of November, according to Ryan Donnelly, an ODNR wildlife officer assigned to Athens County.
“The fact that there are very young deer now suggests perhaps they have two cycles in a year, or their reproductive cycle is extending,” Glenn Matlack, professor of environmental and plant biology, said.
Matlack said increased temperatures and recent droughts reduce environmental stress on deer, encouraging more frequent reproduction.
The overabundance of deer can affect native vegetation and natural ecosystems. Deer feed heavily on young saplings, wildflowers and shrubs, often targeting oaks and maples. Overbrowsing limits forest regeneration and reduces plant diversity, according to the Ecological Society of America.
That loss of vegetation affects other species. Local birds rely on dense understory shrubs for nesting and cover. As deer strip away young growth, forests become more open, leaving birds with fewer safe places to feed and nest.
In addition to climate factors, deer behavior is also changing. Matlack said deer in Athens have adapted to human presence, allowing people to approach more closely than in rural areas.
“In town, they're acclimating to people,” Matlack said. “They've seen people. People aren't scary. They don't care. But the further out you go, the fewer people they're familiar with, and the more cautious they are.”
This acclimation, combined with warmer weather, is amplifying the presence of deer in Athens, raising concerns about the long-term balance of the region’s ecosystems.
“We have seen that the deer population is strong and still growing,” Donnelly said. “It's a gradual shift over time. It's not a thing that happens overnight.”
