Buzz
Florida panthers, about the size of a large Golden Retriever, display various shades of tan, with pale bellies and tails nearly as long as their bodies. Also known as pumas, these endangered cats tend to live alone, rarely make sounds, and hunt primarily at dawn and dusk. It's no surprise that human encounters with them are rare—except when they cross roads.
After a century of paying bounties for dead panthers, Florida officially listed them as an endangered species in 1958, and the federal government followed suit in 1967. In the 1970s, wildlife officials, uncertain whether a viable population still existed, set up preserves and formed a panther recovery team. Today, the total population remains under 180, according to the Florida Wildlife Conservation Commission. As the population grows, the risk from roads becomes even greater. Vehicle collisions are now the leading cause of death for these cats: by June 25, 2014, at least 12 had been killed by vehicles. In 2013, 15 panthers died this way, and 18 in 2012.
Once spanning seven states, the panther's range has dwindled, and today, the entire breeding population resides south of Florida’s Caloosahatchee River. That region has likely reached its capacity, meaning some panthers will need to seek new territories. In doing so, they will almost certainly have to cross roads.
Road kill isn't an issue exclusive to panthers. In the U.S., an estimated one to two million collisions occur annually between vehicles and large animals like deer and moose. If you include smaller animals—such as raccoons, armadillos, and skunks—the total number climbs significantly. According to the Federal Highway Administration, vehicle collisions pose a major threat to at least 20 endangered or threatened species, in addition to the panther.
To protect panthers, Florida has installed warning signs and lowered speed limits in areas with heavy panther traffic. However, these measures have not been highly successful. As a result, biologists are now focusing on a more costly but also more promising solution: Specially designed underpasses that enable panthers to cross roads safely without coming into contact with vehicles.
Wildlife crossings—both underpasses and overpasses—are considered the most effective solution to this issue, according to Jon Beckmann, a biologist with the Wildlife Conservation Society. A study by Utah State University found that two wildlife crossings on state interstates reduced vehicle-animal collisions by up to 90%. Engineers from the Utah Department of Transportation estimated that the crossings paid for themselves within three years due to the reduced cost of vehicle repairs. In Canada, overpasses have cut mule deer and elk road kill by over 90%, and in Florida, four culverts along a mile of U.S. Highway 27, which cuts through Lake Jackson, save hundreds of turtles and other animals annually.
For these crossings to be effective, they need to be placed in the right locations, properly designed, and maintained, according to Beckmann. Typically, these crossings include fencing to guide animals and vegetation to help them feel secure when using them.
So far, 59 panther crossings have been established along about 40 miles of Florida highways, reports Darrell Land, the Florida panther team leader for the Florida Fish and Wildlife Conservation Commission. Based on collision data, these crossings have significantly reduced panther road kill in the affected areas. Land has also identified numerous other locations in need of crossings and monitors road maintenance or upgrade projects where additional crossings can be incorporated.
Florida is currently experimenting with roadside animal detection systems (RADs), which use light beams triggered by animals to activate flashing lights that alert drivers. The University of Central Florida’s biology department is in its second year of monitoring RADs along several miles of US 41 in the Big Cypress National Preserve. This marks the first time the system is being used for animals the size of panthers (RADs are typically designed for deer, elk, and moose). Researchers are eager to determine whether the system works for panthers and if drivers respond appropriately.
Despite the RADs, at least one panther-vehicle collision has occurred on US 41. "There are many challenges for a system like this to be effective," says Land. "It's a complex system with many components, unlike a wildlife crossing with a fence that can be easily monitored to ensure it's functioning. I don't think RADs will ever replace crossings."
If you spot a panther, please report it. This helps biologists identify the areas frequented by these large cats and, perhaps, prevent them from becoming victims of road kill.
