By their nature, South Florida’s tropical butterflies have always been ephemeral creatures, coming and going with the rhythms of the life cycle and season. Now they’re just gone.
In what may be an unprecedented die-off, at least five varieties of rare butterflies have vanished from the pine forests and seaside jungles of the Florida Keys and southern Miami-Dade County, the only places some were known to exist.
Marc Minno, a Gainesville entomologist commissioned by the U.S. Fish and Wildlife Service to perform a major survey of South Florida’s butterfly population, filed reports late last year recommending that the Zestos skipper and rockland Meske’s skipper — both unseen for a decade or more — be declared extinct. He believes the same fate has befallen a third, a Keys subspecies called the Zarucco duskywing, and that two more, the nickerbean blue and Bahamian swallowtail, also have disappeared from their only North American niche.
Considering that there have been only four previous presumed extinctions of North American butterflies — the last in California more than 50 years ago — Minno finds the government response to such an alarming wave frustrating.
“There are three butterflies here that have just winked out and no one did a thing about it,’’ Minno said. “I don’t know what has happened with our agencies that are supposed to protect wildlife. They’re just kind of sitting on their hands and watching them go extinct.’’
And the list of the lost could easily grow. South Florida has one of the world’s highest concentrations of rare butterflies. At least 18 others are considered imperiled, reduced to small, isolated populations vulnerable to a host of threats from exotic ants that eat their larvae to a single tropical storm that could blow a colony into oblivion.
Federal wildlife managers insist they are doing all they can do in a state with one of the longest lists of endangered and threatened species in the nation.
“It basically comes down to resources, what we have in terms of money, staffing and those kinds of things that we aren’t always in control of,” said Ken Warren, spokesman for the Fish and Wildlife Service’s South Florida field office in Vero Beach. “We are trying to be as responsive as we can.”
State and federal agencies haven’t ignored the decline. They formed a joint group in 2007 to develop recovery strategies and have supported laboratory breeding programs for signature species like the Schaus’ swallowtail and Miami blue. The service even put a biologist full-time on butterfly problems, Warren said, a level of attention otherwise reserved for high-profile species like the manatee and Florida panther.
But so far, it hasn’t been enough to reverse troubling trends. Experts acknowledge that reviving the rich array of butterflies that once ranged along much of the coast poses significant, possibly insurmountable challenges.
“It’s hard to see for some of the species what really can be done,’’ said Jaret Daniels, assistant curator of Lepidoptera for the Florida Museum of Natural History in Gainesville, who has directed captive breeding efforts for the two others on the brink, Miami blue and Schaus’ swallowtail.