For Endangered Butterfly, Golf Courses To Provide Essential Habitat

November 30, 1999

GAINESVILLE — University of Florida researchers have found an unusual ally in their efforts to re-create rare native habitat for an endangered butterfly in the Florida Keys: golf courses.

The UF zoology and entomology researchers are working with two large private golf courses to re-create large areas of tropical hardwood hammock in the course roughs to provide a corridor between breeding colonies for rare Schaus Swallowtail butterflies. The work, already showing signs of success, represents one more chapter in the ongoing comeback of the butterfly from the brink of extinction less than two decades ago.

“We realized that to really get the butterfly in a self-sufficient state, it has to be able to move back and forth between colonies as it could 20, 30 or 50 years ago,” said Tom Emmel, a UF professor of zoology and nematology. “Private golf courses own some of the largest tracts of land in the Keys, so they were the obvious choice.”

The project is funded in part through a three-year $55,000 grant from the U.S. Golf Association Foundation as part of a program called “Wildlife Links.” Operated jointly with the National Fish and Wildlife Foundation, a nonprofit conservation organization, the program seeks to establish corridors for a range of wildlife on the nation’s golf courses.

“We strongly believe there’s a good compromise between having a golf course and protecting a lot of the wildlife habitat that’s out there,” said Michael Kenna, research director for the U.S. Golf Association’s Green Section. “Existing golf courses have a lot of open space, and if something can be done for the Schaus or other species, why not do it?”

The habitat improvement will help many other species in the Keys besides the butterflies, including migrating birds, according to Emmel and wildlife officials. Songbirds flying south to the tropics for the winter use the Keys as a “staging area” to store up on nutrients for the long flight across open water, while birds returning north in the spring to breed rely on the Keys to recuperate, Emmel said. The butterfly project will help ensure the birds have the natural habitat they need, he said.

The Schaus was nearly extinct in 1984, when Emmel counted just 70 adults. His findings prompted the U.S. Fish and Wildlife Service to list the butterfly as endangered. Emmel spent much of the 1980s tracing the butterfly’s plight to two pesticides, Baytex and Dibron, used to combat mosquitos, findings that spurred a moratorium on Baytex and tight regulation of Dibron. The population began recovering, only to undergo a nearly catastrophic collapse because of Hurricane Andrew in 1992. Fortunately, a UF captive breeding program launched before Andrew augmented the 17 post-hurricane male butterflies left in the wild.

Today, following the introduction of 2,000 butterflies, the annual wild population consists of 1,000 to 1,200 adults located in 13 sites stretching from southern Dade County to the middle keys in Monroe County. Urban developments and a lack of habitat, however, separate these sites, preventing the butterflies from reaching each other to mate. Because the butterflies stem from a small population of ancestors, the separation could result in a dangerous lack of genetic diversity, Emmel said. The isolation of the butterflies also makes them more vulnerable to hurricanes or other disasters, he said.

Researchers decided the solution was to connect several of the colonies using re-created hardwood hammock habitat on two major golf courses as well as adjacent public lands. The golf courses, Sombrero Country Club on Marathon Key and Cheeca Lodge on Islamorada Key, agreed to the project, and researchers began transforming the roughs into native habitat in September. So far, they’ve planted 300 fire bush plants and 630 pentas plants to serve as adult nectar sources, and 1,500 wild lime trees currently are being grown for the project, Emmel said. The wild limes are particularly important because they are the natural host of the butterfly’s caterpillars, he said.

Emmel said the researchers are coupling the habitat improvements on the golf courses with similar improvements on public lands, including planting 500 wild lime trees on an old federal military site in Key Largo during the past two years. Last spring, researchers were overjoyed to discover dozens of Schaus eggs on the trees, he said.

“The Schaus Swallowtail is a flagship species for the whole idea of restoring the Keys to something like they once were,” Emmel said.