Fleeing hurricanes, Florida deer head into panther country

When hurricanes blow strongest, Florida deer evade danger by fleeing to higher, forested ground, but those areas may also be habitat for panthers.

“Clearly they’re not dumb — they respond to their environment,” said TWS member Heather Abernathy, a PhD Student at Virginia Tech and the lead author of a study published in Proceedings of the Royal Society B. “Animals have behavioral responses that can help promote survival during these events.”

Researchers had been monitoring Florida white-tailed deer (Odocoileus virginianus seminolus) — the primary panther (Puma concolor coryi) prey — in the Florida Panther National Wildlife Refuge and the northern management units of Big Cypress National Preserve, to better understand population dynamics when Hurricane Irma struck the area in September 2017.

As part of that research, many deer were equipped with GPS collars that tracked their movements. Abernathy and her colleagues took the opportunity to use this data to observe deer movement in the midst of the hurricane.

Some 59 deer wore collars that transmitted GPS data on the day the eye of the storm blew through the region, coming within 8 miles of the study area. The collars emitted location data every four hours, allowing researchers to track the deer’s responses.

Florida white-tailed deer show no preference for higher elevations, and typically use prairies and other areas that become periodically flooded in the wet season, both to forage where food is better and to avoid higher elevation forests that panthers prefer. But when Hurricane Irma moved in, the deer sought out the high ground, limiting their exposure to the storm but putting them at greater risk of predation. Researchers found that 53% of the tracked animals left their home ranges.

“On the day of the storm, they selected for higher elevation and pine forests,” Abernathy said.

Panther researchers haven’t yet studied whether the cats also change their behavior during storms, Abernathy said, but anecdotal reports suggest they hunker down, possibly posing less risk to deer during these periods.

GPS data also revealed that female deer “moved around like crazy” during Hurricane Irma, Abernathy said, increasing their movement rates by 46%, possibly trying to avoid falling trees or windblown vegetation. Male deer may have also moved around more, but that was harder to determine, since the storm struck shortly after the breeding season, a time when males are on the move in search of mating opportunities.

The deer’s response served them well. All of the collared deer survived the day of the storm and the next three days. The study shows that wildlife living in areas that periodically experience storms are likely adapted to dealing with them, Abernathy said.

Wildlife researchers may need to take behavioral responses like this into account when predicting impacts from increasing extreme weather conditions due to climate change, she said. Other research has shown that shorebirds can weather hurricanes. Sharks dive deep to avoid the worst water conditions. Anole lizards (Anolis scriptus) in the Turks and Caicos use their forelimbs to cling to trees during strong winds.

But not all animals can easily weather these types of problems. Ongoing research suggests that hurricanes can affect bat habitat for months and disrupt other wildlife.

“Deer adapted to living in a system that experiences frequent tropical storms have these behavioral responses, but that may not be the case for all animals,” Abernathy said.

Header Image: Two Florida white-tailed deer, a fawn on the left and a female fitted with a GPS collar on the right, observed during a helicopter aerial survey in Big Cypress National Preserve, Bear Island Unit.
©Elina Garrison, Deer Biologist, Florida Fish and Wildlife Conservation Commission