Federal wildlife officials are reviewing a South Florida butterfly survey that concluded five rare species may be gone for good.
The U.S. Fish and Wildlife Service hired entomologist Marc Minno to perform the survey. In reports filed late last year, Minno concluded that the Zestos skipper, the rockland Meske's skipper, the Zarucco duskywing, the nickerbean blue and the Bahamian swallowtail had disappeared from the pine forests and seaside jungles of the Florida Keys and southern Miami-Dade County, the only places where some where known to exist.
Minno said he spent six years on a survey that was only supposed to take two. He said neither he nor other butterfly experts ever saw these species in any stage of life, from larvae to adult butterfly.
“I thought I was going to find some at some point so I just took a lot more time,” Minno told The Miami Herald. “They're just not there.”
Federal officials said it may be too early to declare the butterflies extinct or at least missing from their only known habitat in Florida. The wildlife service's lead butterfly biologist, Mark Salvato, said some butterfly species have vanished in the past but then made surprise reappearances years later.
For example, the Miami blue butterfly was generally considered extinct after Hurricane Andrew devastated South Florida in 1992 until a colony was discovered seven years later in Bahia Honda State Park. That colony disappeared in 2001 but another colony was later found in remote islands off Key West.
The rockland Meske's skipper also went missing for a decade once before, Salvato said.
“It's a very indistinct butterfly. It's not hard to overlook,” he said.
None of the species that concerned Minno were being considered for listing as endangered species.
“There is no requirement for us to do anything as far as a formal announcement that it's gone,” said Ken Warren, spokesman for wildlife service's South Florida field office in Vero Beach. “At this point, I would say the smart thing for us is to take the recommendation under consideration and give it a little time to see what happens.”
Federal officials said they are doing all they can to protect wildlife in a state with one of the longest lists of endangered and threatened species in the nation. They have supported laboratory breeding programs for species such as the Schaus' swallowtail and the Miami blue, and the agency hired Salvato to work on butterfly issues full-time, a position usually reserved for species such as the manatee or the Florida panther.
Salvato and other experts say butterflies face significant, possibly insurmountable challenges in Florida. Development has hastened their decline, and tropical storms and hurricanes can wipe out their remaining habitat. Exotic predators such as green iguanas can eat the plants that shelter their eggs and caterpillars. Pesticides may also be killing larvae.
Breeding programs have helped reinvigorate some butterfly populations in other states, but they haven't worked well in South Florida, and researchers aren't sure why.
“With a lot of these butterflies, we don't necessarily know the ins and outs of them,” Salvato said. “There are a whole bunch of factors that could be affecting them. It's hard to find a smoking gun.”
Information from: The Miami Herald, http://www.herald.com