THE FLORIDA
EVERGLADES
The Florida Panther
From: FICUS
Network - USF University of South Florida
The
Florida panther, our official state mammal, is
one the most endangered animals on Earth and a federally
listed endangered species. Between 30 and 50 individuals
are believed to remain in the wild-mainly south of Lake
Okeechobee. Unless its historic habitat and food supply
can be preserved and restored, the panther will probably
become extinct in less than 20 years. More than half the
remaining cats inhabit privately owned lands that are
rapidly being converted to agricultural production.
About a dozen live in a complex of public lands managed
by several state and federal agencies.
Panthers are elusive,
well-camouflaged, usually solitary animals that seem to
prefer the dense cover of cypress and hardwood hammock
habitats. Because they are predators that stalk their
prey (mainly deer and wild hogs), they can move silently
and stealthily, and are most active at night. Only
recently have we begun to understand that predators such
as panthers are an important part of native ecosystems
and that the interrelationships between prey and
predators are extremely complex.
Because panthers are so rarely seen,
researchers usually rely on signs that the animals
leave-such as droppings (scat), small mounds of leaves
or debris (scrapes), and tracks-to verify their
presence. In addition to the animal's confirmed presence
in southwestern Florida, evidence has been found between
Seminole and Indian River Counties in Central Florida,
but no established population has been confirmed.
Hunting
Panthers may have survived in Florida
because even until recently, areas existed that were so
inaccessible few people could penetrate them. While
legal hunting has been banned, illegal hunting may never
be completely eliminated and has accounted for about
one-fourth of known panther deaths. Hunting restrictions
are extremely hard to enforce; in a recent
reintroduction experiment with Texas pumas in northern
Florida, two cats were killed and their radio collars
removed and thrown into ponds.
Habitat Loss
Panthers need large, contiguous areas
of habitat. They may range over as much as 500 square
miles and can travel as much as 20 miles a night. Much
of their historic habitat has been lost to development,
and the remainder continues to be fragmented by roads,
agricultural activities, and isolated development.
Habitat loss in South Florida has been especially
severe. I-75, built across the southern part of the
state in the 1960s, brought people right into the
animal's last stronghold. Smaller roads were built for
other human activities, and off-road vehicles have
increased human intrusions.
Reduced Food Supply
Some Florida panthers have become
emaciated from food shortages. As a result, they are
more susceptible to disease, and females are less able
to raise their young. Competition for deer from
thousands of hunters is often cited as part of the
problem. In theory, there is no reason that panther
survival should be incompatible with deer hunting. For
example, in some western states both deer and panther
are hunted. In portions of Florida's Big Cypress
National Preserve, however, few deer are found. These
areas could be artificially managed for more deer. In
other parts of Big Cypress, where deer are more
plentiful, panthers often leave during hunting
season-possibly because of the presence of so many
humans.
Road Kills
Road kills have accounted for almost
two-thirds of known panther deaths. By building fences
and 36 underpasses to allow panthers to pass under I-75,
traffic-related deaths may be reduced. The panthers are
confirmed to be using the underpasses.
Health Problems and Inbreeding
Calcivirus, an upper respiratory
disease, was recently found in half of 14 panthers
tested, and the cats can also be infected by the hardy,
lethal distemper virus. The remaining panthers also have
many genetic problems that probably stem from
inbreeding. Genetic diversity in the species has dropped
70 percent. Most male Florida panthers have low sperm
counts, and as many as 90 percent of sperm are abnormal.
Seventy percent of the remaining males have only one
testicle-a genetic characteristic linked to
inbreeding-compared with 15 percent in the early 1980s.
Heart-valve defects and other problems have begun to
appear.
Mercury Poisoning
Mercury, a toxic heavy metal, is a
contaminant in fish, raccoons, otters, and alligators in
a number of areas in the Everglades. Because panthers
are at the top of their food chain, the metal
bioaccumulates in their organs and central nervous
systems. One dead panther discovered to have 110 parts
per million of mercury in its liver (35 parts per
million is considered lethal) is presumed to have died
of mercury poisoning, and the metal is suspected in at
least two other panther deaths since 1989. (See
Chapter 11 on Florida's Surface Waters for more
information on the problem of mercury contamination.)
Preserving the Remaining Cats
A comprehensive strategy to ensure
that Florida has panthers in its future must address
three major issues. First, the large area of public land
at the tip of the peninsula where panthers live might
accommodate more panthers, except that it is currently
poor deer habitat. Most of the land is controlled by the
National Park Service, which currently does not manage
for the benefit of a single species-even those that are
threatened or endangered.
Second, any and all measures could be
attempted to conserve the private lands north of Big
Cypress Swamp that still provide habitat but are rapidly
being converted to agriculture. Although the 1985
Florida Panther Recovery Plan calls for the Florida Game
and Fresh Water Fish Commission and the U.S. Fish and
Wildlife Service to prepare a plan to protect these
private lands, this has not yet been done.
Third, Florida's many isolated refuges
could be developed into a habitat system linked by
corridors. Unless forestalled by planning, habitat
fragmentation will doom the chances of reintroducing the
cats into regions where they historically occurred, such
as the northern part of the state. Little has been done
statewide, however, to promote the idea.
Captive Breeding
A limited panther captive-breeding
program began in 1991, and the current goal is to
produce a population of about 500 animals by the year
2010. All remaining Florida panthers may someday be
taken from the wild as a last hope for preservation.
Captive breeding must be part of an intensive approach
that at the same time restores habitat, and should not
be used to obscure the issue of habitat restoration,
which is the long-term key to the panther's survival. (See
Chapter 3 on Preserving Florida's Biodiversity for more
information on the controversy surrounding captive
breeding.)
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For information on the
Everglades and the Florida panther, contact the
following agencies (see the listing of governmental
agencies in the back of the guide):
