Schaus Swallowtail Butterfly

Above: Florida's rarest butterfly, the Schaus Swallowtail (Heraclides aristodemus ponceanus).

A few butterflies are returning as September dampens. . .but nothing like what one would expect in a normal year. The most rare butterfly in Florida -- The Schaus Swallowtail -- is virtually extinct for the same reasons that more common butterflies are missing this year: Overpopulation, habitat-destruction, pesticide use, and pervasive drought.

Read more about the Schaus Swallowtail below. . .

SEARCHING FOR THE LAST REMAINING SCHAUS SWALLOWTAIL BUTTERFLY

An overgrown trail on northern Key Largo is not where you want to be on a muggy day in Florida. The mosquitoes are horrifying, generating a constant whine and forming a cloud around each person's head. Susan Kolterman, a bartender at the local seafood restaurant Snapper's, and Jeffrey Bach, a biologist with the Florida Department of Environmental Protection, step over tree trunks and pick their way past thorn-covered branches along this miserable path for a single reason: The recent sighting there of a Schaus swallowtail butterfly (Heraclides aristodemus ponceanus).

They are part of a group of two dozen or so butterfly enthusiasts, park volunteers and environmental professionals who are scouring Key Largo and the islands of southern Biscayne Bay to collect sightings of one of the rarest butterflies in the United States. The survey is intended to give a rough picture of where the Schaus can be found and in what numbers to help wildlife managers devise a plan to save it from extinction.

The Schaus, boldly patterned in dark brown and pale yellow, is not the sort of butterfly likely to show up in a suburban garden. It is a creature of a wilder Florida, an insect of the deep forest, inhabiting tropical hardwood hammocks. It was featured on a 32-cent stamp in a 1996 series on endangered species. It displays an acrobatic style of flight that suits its surroundings.

"Its behavior is so unusual that it's really restricted to the confines of the hardwood hammock," said Jaret Daniels, assistant professor of entomology at the University of Florida.

"This is a butterfly that really flies well with shady forested areas. The understory is very dense and hard to even walk in, and it can maneuver well within that maze of vegetation."

Unfortunately the butterfly's habitat — dry, easily cleared land — turned out to be the ideal habitat for houses, schools and condominium towers.

Below: The larve of the Schaus Swallowtail



Habitat destruction caused the species' initial decline, but the Schaus continued to grow scarce even within the confines of its forested home, and scientists aren't sure whether the cause is anti-mosquito spraying pesticides, the impact of Hurricane Andrew or something else.

Coordinating the search is the Florida Fish and Wildlife Conservation Commission, with volunteers from the North American Butterfly Association and the Florida Natural Areas Inventory. The butterfly hunters work in teams of at least two, the idea being that, like a hole in one, a credible Schaus sighting requires a witness. Kolterman is a volunteer at Dagny Johnson Key Largo Hammock Botanical State Park, the scene of Sunday's search, which encompasses one of the biggest stands of tropical hardwood hammock left in North America. She has learned to identify the park's trees, plants and wildlife, and she can quickly identify the butterflies that show up along the way.

"Zebra longwing!" she said, pointing to a yellow-and-black striped butterfly high above the trail.

"I love the zebra. They're my favorite, they're just so beautiful."

In weeks of searching, she found only one piece of evidence of the Schaus' persistence on Key Largo: A single egg laid on a torchwood tree.

"Two weeks later it was gone," she said. "Just a little bit of shell left. So we don't know whether it was eaten by something or hatched."

They walked through forests of wild tamarind, Jamaican caper, hog plum, ironwood and other trees. On several of the trees were rare white tree snails. A black racer, a snake common to the hammocks, slithered from one branch to another as intruders approached. After three hours of searching and mosquito swatting, they had seen zebra longwings, gulf fritillaries and a couple of other butterflies. But they saw no Schaus swallowtails. The other team out that day on the islands of Biscayne Bay also came up empty. These were typical days in a search that has yielded disappointing results since it began on May 14. Although final tally sheets still need to be assembled, it appears the number of Schaus sightings will be somewhere between 15 and 20, said Ricardo Zambrano, biologist and project coordinator for the Florida Fish and Wildlife Conservation Commission. This figure is lower than expected, even given the species' difficulties, and he said one possible reason is the drought, which weakened both the host plants on which the Schaus lays eggs and the flowering plants from which it obtains nectar.

Once the results are assembled and analyzed, the commission will decide what steps to take next, Zambrano said. These could include further surveys, the planting of more torchwood and wild lime plants on which the Schaus lays eggs, or eventually a captive-breeding program.

About 190 species of butterfly live in Florida, and of these, several are unique to the state, said Daniels of UF.

"Species have always gone extinct, but nowadays we're losing species at an alarming rate," he said. "It's on our shoulders to not let it go extinct on our watch."

"They're part of our natural heritage and part of what makes Florida Florida."

VISIT THE FLORIDA NATURAL AREAS INVENTORY http://www.fnai.org/

READ MORE ON THE SCHAUS SWALLOWTAIL BUTTERFLY at this LINK