An adult Schaus Swallowtail, raised in captivity at the University of Florida/NPS

The rapidity with which butterflies can reproduce has played a huge role in the ongoing recovery of endangered Schaus swallowtail butterflies at Biscayne National Park in Florida, where the species once thought to be teetering on the lip of extinction has grown by more than 1,000 individuals.

It was just two years ago that biologists were only able to find five of the butterflies on Elliot Key in the park, which is one of its last habitats. That led the U.S. Fish and Wildlife Service to authorize the capture of up to four adult butterflies for a captive-breeding program. Now officials say that program has led to more than 1,000 butterfly larvae being produced at the University of Florida. Larvae and adult butterflies are now being released into their natural habitat.

Among the increased population, 11 adult females, four males and 308 larvae were recently released on Elliott Key. Nearly two dozen adults are staying at UF in order to raise more butterflies. Thirty-five pupae are housed on Elliott Key and will be released upon emergence.

'œAll of this is great news, considering where this species was two years ago,' said Jaret Daniels, lead UF researcher. 'œThe initial success of the captive breeding program kindles hope for the recovery of the species.'

The Schaus'™ swallowtail was listed under the Endangered Species Act as "threatened" in 1976. Along with the Bahamian swallowtail, it was the first insect added to the endangered species list. In 1984 its status was changed to "endangered.' The Schaus is limited to tropical hardwood hammock habitat in Biscayne National Park and on northern portions of Key Largo.

Only 75 butterflies were recorded over the past three years combined. The butterflies are dark brown with yellow markings and a broad rusty patch underneath the hind wing. Adults have a wingspan of 3.25-3.75 inches. Butterfly recovery is hindered by habitat destruction, insecticide use, droughts, hurricanes and illegal collection. As pollinators, butterflies are important members of any ecosystem. They are key components of the food chain, particularly as larvae. They are also good indicators of the ecological quality of a habitat.

'œEnsuring that the Schaus'™ swallowtail survives helps to keep this ecosystem intact,' said Biscayne Superintendent Brian Carlstrom. "National parks like Biscayne protect each and every species, for the benefit of all."

Conservation and monitoring efforts for the Schaus'™ swallowtail butterfly are being coordinated by cooperating agencies including USFWS, UF, the Florida Fish and Wildlife Conservation Commission, the National Park Service, the Florida Natural Areas Inventory, and the Florida Department of Environmental Protection.