by Bill O'Donnell
Copyright 2000, All Rights Reserved.
Still
wet from the long trek through the marshy sawgrass of the Everglades,
my shoes squished on the dry soil of the hammock. My elusive quarry
waited somewhere in the dense tropical hardwood hammock ahead.
Sometimes crawling and sometimes climbing through mastic, tetrazygia,
and palmetto, I made my way through the dense ring of vegetation
to the open area in the center of the hammock. Suddenly, a treasure
more valuable than gold appeared. Flitting on iridescent black,
purple and blue wings, a tiny Florida Atala butterfly glistened
in the sun like a living jewel. I had never seen one alive in
the wild before, but there was no mistake. I was eye to eye with
one of Florida’s endangered butterflies. The atalas led me to a clump of coontie, the only plant the Atala caterpillars feed on. To my amazement, the plants held not only caterpillars, but eggs and chrysalises, allowing me to photograph the butterfly’s entire lifecycle in a single afternoon! Once upon a time, such an event would have been commonplace. Unfortunately today’s world has less room for butterflies and several of Florida’s are now endangered.
Florida’s butterflies are responding
to the same kinds of environmental problems that have been responsible
for the decline of such species as the Florida panther and the
West Indian manatee. The chief threat to most wildlife in much
of Florida is the area’s expansion of urban areas to accommodate
a skyrocketing human population and the inevitable loss of habitat.
For example, it is estimated that approximately nine hundred people
move to Dade, Broward, and Monroe Counties each day. They all
need housing, water, roads and jobs. This increasing human presence
adds up to a shrinking amount of natural areas in the state. Florida is an area with a wide variety of natural habitats, from deciduous forests to prairies to mangrove forests and, of course, the magnificent Everglades. Each of these different areas harbors plants and animals unique to it. As they are nibbled away at by development, they become less and less diverse, supporting fewer and fewer species.
One butterfly that used to be widespread on the mainland is the Schaus’ swallowtail (Papillio aristodemus ponceanus ). This large brown swallowtail with yellow markings was one of the very first insects to be placed on the United States Department of Interior’s Endangered Species List. Originally, it was found in large areas of the mainland. It bred in hammocks that contained torchwood and wild lime, the only plants the larvae feed on. Brickell Hammock, where this handsome butterfly was first discovered, is now one of Miami’s most affluent neighborhoods. Today it is found only on Elliott Key, which is protected within Biscayne National Park, and on the northern tip of Key Largo. Habitat destruction and mosquito control operations continue to threaten the population on Key Largo. The terrible risk we take by limiting species to such a small area was graphically illustrated when Hurricane Andrew all but obliterated the hardwood hammocks of Elliott Key in 1992. The population barely survived. It is fortunate that a small breeding population was being kept in captivity. Most species don’t have this kind of life insurance policy.
The attractive little Florida Atala (Eumaeus atala florida) is found in the coastal pinelands and in hardwood hammocks in the Everglades. It was always found near its larval foodplant, coontie, a native cycad. One major factor in this butterfly’s decline was the widespread destruction of its foodplant and habitat during urban and suburban development. The drier pinewoods between the wet Everglades and the sea were naturally the most attractive area for Florida’s pioneers to settle.
In the early part of this century, something dramatic and awful
happened to atala populations. A writer in 1898 was quoted in
Holland’s Butterfly Book (1916 edition) as saying "the
insect fairly swarms in the pinewoods between the shores of Biscayne
Bay and the Everglades." Unfortunately, by 1951, A.B. Klots
in the Peterson’s Field Guide to Butterflies said the species
was "probably extinct." Everglades National Park publications
report the atala "extirpated" in the 1940s.Widely believed to be extinct by the nineteen fifties, this little butterfly has been staging a comeback in South Florida. The federal government declined to list it on its Endangered Species List for reasons that aren’t exactly clear, although it was considered for inclusion at the same time as Schaus’ swallowtail. It is possible that many biologists thought it was already extinct. Federal inaction notwithstanding, it was local action that saved the atala. Concerned individuals, in a private effort, began captive breeding programs and cultivation of coontie. Atala larvae were reintroduced in suitable habitats in Dade County where natural populations of coontie were already established. Today there are several colonies of the atala in South Florida, the most accessible being at Fairchild Tropical Garden in Miami.
One of the most imperilled butterflies on the Florida Keys is the amethyst hairstreak (Chlorostromon maesites maesites). This tiny blue butterfly is found in small populations on several. Caribbean islands, but is rare in the United States. The only known populations in the U.S. are found on Key Largo and Stock Island. In the past it was found on the mainland in Dade County, but it is believed that the species was always rare. The Department of Interior lists it as "threatened", a category below "endangered". Although both Florida populations may be destroyed by development in the immediate future, the government decided that it didn’t warrant listing because the Caribbean populations aren’t immediately threatened. This species would be difficult to fully protect because very little is known of its life history. To properly protect a species it is important to understand its requirements in the way of foodplants and habitat.
One butterfly that finds protection within Everglades National Park is the Florida purplewing (Eunica tatila tatilata). This species is widely distributed in Central America and the Caribbean. In Florida it is found in hardwood hammocks in the Everglades and the Keys. Like the amethyst hairstreak, its foodplant requirements were a mystery. Recently however, Roger Hammer, a Dade County Parks naturalist, reared some unidentified larvae he found feeding on gumbo limbo trees and they proved to be of the Florida purplewing. While some populations on the Keys seem stable, the species seems to be declining in some areas of Dade County. This species is listed as a "species of special concern" by the Department of Interior.
Another declining mainland species is Bartram’s hairstreak (Strymon acis bartrami). This small butterfly is found throughout the Caribbean, but the Florida subspecies is unique and found nowhere else. It lives in slash pine habitats where its larvae feed on pineland croton. While there does seem to be ample habitat for this species in Everglades National Park, the mainland population seems to be declining. The only healthy population is on Big Pine Key in the lower Florida Keys, where development threatens it. It is listed as a "species of special concern", but would seem to warrant more protection.
Florida has been fortunate to have saved so much of its unique wildlife and natural areas in the face of tremendous development pressure over the past decades. There is still much to do if we are serious about creating a future for Florida where man, butterflies, and development can all exist together. If we become aware of the needs of our wildlife today, we can still save many species for tomorrow. If we wait until tomorrow, who knows what treasures may be lost?