Florida Panther

Puma concolor coryi

Description

The Florida panther (Puma [=Felis] concolor coryi ) is a medium-sized subspecies of puma or mountain lion. It is unspotted and relatively dark tawny in color, with short, stiff hair. It has relatively longer legs, smaller feet, and a more slender tail than other subspecies. Adult males reach a length of 85 in (2.15 m) from their nose to the tip of their tail and may exceed 150 lb (68 kg) in weight, but typically average around 120 lb (54.5 kg). They stand about 24-28 in (60-70 cm) at the shoulder. Females are considerably smaller, with an average weight of 75 lb (34 kg) and length of 70 in (1.85 m). The skull of the Florida panther has been described as having a broad, flat, frontal region, and broad, high-arched or upward-expanded nasals.

Florida panther kittens are gray with dark brown or blackish spots and five bands around the tail. The spots gradually fade as the kittens grow older and are almost unnoticeable by the time they are six months old. At this age, their bright blue eyes slowly turn to the light-brown straw color of the eyes of adults.

Three external characters are often observed in Florida panthers in southwest Florida which are not found in combination in other subspecies of P. con-color. These characters are: a right angle crook at the terminal end of the tail; a whorl of hair in the middle of the back; and irregular, light flecking on the head, nape, and shoulders. The light flecking may be a result of scarring from tick bites. The kinked tail and cowlicks are considered manifestations of inbreeding.

Behavior

Panthers are essentially solitary animals. Interactions between panthers were infrequent during a study ranging from 1985 through 1990. Most interactions occurred between adult females and their kittens. Interactions between adult male and female panthers were second in frequency. Interactions between males and females lasted from one to seven days and usually resulted in pregnancy. Documented interactions between males were not uncommon and sometimes resulted in serious injury or death. Between 1981 and 1996, intraspecific aggression was the second greatest cause of panther mortality. Aggressive encounters between females have not been documented.

The pattern of distribution involves several males maintaining large, mutually exclusive home ranges containing several adult females and their dependent offspring. This spatial arrangement seems to be a prerequisite for successful reproduction.

Males are polygynous. Breeding activity peaks in fall and winter. Parturition is distributed throughout the year with 81% of births occurring between March and July. Litter sizes range from one to four kittens, with a mean of 2.2 kittens per successful litter. Intervals between litters range from 16 to 37 months.

Den sites are usually located in dense, understory vegetation, typically of saw palmetto. Den sites are used for up to two months by female panthers and their litters (from parturition to weaning). Female panthers that lose their litter generally produce a replacement one. Five of seven females whose kittens were taken into the captive-breeding program successfully reproduced an average of 10.4 months after the removal of the litter.

Age at first reproduction has been documented to be 18 months for females. The first sexual encounters for males has occurred at approximately three years of age, although a male in Everglades National Park bred at 18 months. Dispersal of young typically occurs around 1.5 to 2 years of age, but may occur as early as one year of age.

The kitten survival rate between age six months and one year has been estimated at 0.9. This is based on a sample of 15 radio-instrumented kittens monitored from six months to one year of age. Young panthers are considered recruited into the population when they have successfully reproduced. Of 21 dependent kittens radio-instrumented and followed beyond independence, 71% of females and 29% of males have been recruited into the population. The longevity of resident male panthers and subsequent infrequent home range vacancies makes the likelihood of male recruitment low.

Females are readily recruited into the population as soon as they are capable of breeding. Males appear to have more difficulty being recruited. Without large areas of suitable habitat to accommodate dispersal, young males have few opportunities for recruitment as residents. As a result, the ability of the Florida panther to increase and outbreed is severely restricted. Successful male recruitment appears to depend on the death or home range shift of a resident adult male.

Mortality from various sources is a concern for the panthers. Forty panther deaths were detected and recorded between January 1986 and December 1996. Roadkills claimed 14 of these panthers. These numbers reflect all known panther mortality and are biased toward roadkills since the only documented deaths of non-instrumented individuals are the result of collisions. Of the 31 deaths of radio-instrumented panthers for the same time frame, only 16% were roadkills. Infant mortality was thought to be relatively high, with fewer than one-half of all pregnancies resulting in offspring that survived beyond six months of age. Turnover in the breeding population is low, with documented mortality in radio-collared panthers being greatest in subadult and non-resident males.

Food-habit studies of Florida panthers indicated that the feral hog was the most commonly taken prey followed by white-tailed deer, raccoon, and nine-banded armadillo. No seasonal variation in diet was detected; however, panthers inhabiting an area of better soils north of Interstate 75 consumed more large prey. In addition, deer abundance was up to eight-fold greater north of Interstate 75. Domestic livestock were found infrequently in scats or kills, although cattle were readily available.

Habitat

Native landscapes within the Big Cypress Swamp region are dominated by pine, cypress, and freshwater marshes, interspersed with mixed-swamp forests, hammock forests, and prairie. Private lands represent about 50% of occupied panther range in south Florida. The largest contiguous tract of panther habitat is the Big Cypress National Preserve/Everglades ecosystem. Poorer-quality soils prevalent south of Interstate 75 do not produce the quality or volume of forage required to support large herds of deer and other prey items. Therefore, habitat in Big Cypress National Preserve and Everglades National Park is not as productive as that in northern and western Collier County in terms of panther health, reproduction, and density. Private lands contain some of the most productive panther habitat, but better soils and drainage also make this land more suitable for intensive agriculture and urban growth than public lands.

Native, upland forests are preferred by panthers in southwest Florida. Highly preferred habitat types are relatively limited in availability but are sought by panthers as daytime resting cover. Understory thickets of tall, almost impenetrable, saw palmetto have been identified as the most important resting and denning cover for panthers. Early radio-telemetry investigations indicated that panther use of mixed swamp forests and hammock forests was greater than expected in relation to their availability within the home range. As investigations expanded onto private lands between 1985 and 1990, it was determined that panthers prefer native, upland forests, especially hardwood hammocks and pine flatwoods, over wetlands and disturbed habitats. Hardwood hammocks were consistently preferred by panthers, followed by pine flatwoods. This may be related to the fact that, among major vegetation types in south Florida, hammocks had the greatest potential for producing white-tailed deer, an important prey species.

Male panthers use more cover types and have larger home ranges than females. Dispersing males may wander widely through non-forested and disturbed areas. Habitats avoided by panthers include agricultural, barren land, shrub and brush, and dry prairie. Panthers have not been found in pastures during daytime but may travel through them at night.

Distribution

Historically, the Florida panther was distributed from eastern Texas or western Louisiana and the lower Mississippi River valley east through the Southeastern States in general, integrating to the north with F. c. couguar, and to the west and northwest with F. c. stanleyana and F. c. hippolestes. The Florida panther historically ranged through Arkansas, Louisiana, Mississippi, Alabama, Georgia, Florida, and parts of South Carolina and Tennessee.

The only remaining population is centered in and around the Big Cypress Swamp/Everglades physiographic region of South Florida. Data on radio-instrumented members of this population indicate that it is centered in Collier and Hendry counties of southwestern Florida. Instrumented panthers have also been documented in Broward, Dade, Glades, Hardee, Highlands, Lee, Monroe, and Palm Beach counties. There are still large areas of privately owned land in Charlotte, Collier, Hendry, Lee, and Glades counties where uncollared individuals may reside.

Private lands account for about half the occupied panther range in south Florida. This estimate is supported by over 16 years of telemetry data. The greatest concentration of unprotected, occupied panther habitat is found on private land in eastern Collier County and southern Hendry County. In general, these private lands are located north of the most important panther habitat on key publicly owned lands. For the most part, privately owned lands are higher in elevation, better drained, have a higher percentage of hardwood hammocks and pine flat-woods, and are higher in natural fertility/productivity than public lands south of Interstate 75. A difference in soils and drainage patterns is reflected in greater upland vegetation and more abundant prey in lands above Interstate 75. These factors, in combination with some management practices, tend to make the area more attractive to, and increase carrying capacities for, white-tailed deer and feral hogs. This results in panthers that are in better physical condition and more productive than individuals utilizing habitat only on public lands.

Threats

Of the 27 recognized subspecies of P. concolor, the Florida panther is the sole remaining subspecies in the eastern United States. The population of this large cat may have numbered as many as 500 at the start of the twentieth century. Hunting, habitat loss through residential and agricultural development, loss of the prey base, and other stressors have led to the decline of this species since that time. In 1950, the Florida panther was declared a game species in the State of Florida. This action resulted in the first regulation of panther harvest. By 1958 it was listed under state law as an endangered species. The population was estimated at 100 to 300 statewide in 1966. The federal government followed suit, and listed the species as endangered in 1967. The U.S. Fish and Wildlife Service cited heavy hunting and trapping pressures, the inability of the species to adapt to changes in the environment, and developmental pressures as the reasons for the decline of the Florida panther. The current population numbers between 30 and 80 individuals.

In a population with such low numbers, any form of mortality is a concern. Annual panther mortality averaged 3.5 per year between 1986 and 1996, with 35% of that attributable to human influences. The geographic isolation of the Florida panther, the small population size, and associated inbreeding have resulted in a significant loss of genetic variability and health of the population. Data suggest that the panther is experiencing inbreeding depression, resulting in decreased semen quality, lowered fertility and neonatal survival, congenital heart defects, and susceptibility to diseases (such as feline immunodeficiency virus).

Many panthers die from collisions with motor vehicles. This source of mortality accounted for 47% of documented deaths between 1979 and 1991. However, an unbiased study based on deaths of radio-instrumented panthers found a 16% loss to roadkills between 1986 and 1996. Although the relative significance of highway deaths to other sources of mortality is not entirely known, it has been the most frequently documented cause of mortality. Wildlife underpasses have been used as a tool to reduce risks in some problem areas. However, highways may also affect panthers through fragmentation of suitable habitat. Because of their wide-ranging movements and extensive spatial requirements, panthers are particularly sensitive to habitat fragmentation.

The expansion of transportation infrastructure in southwestern Florida threatens the long-term persistence of the Florida panther in the wild. Rapidly increasing human populations and expanding agriculture are compromising the ability of natural habitats to support a self-sustaining panther population. Continued expansion of Florida's urbanized east coast, increasing growth on the west coast, and the spread of agricultural development in the interior have placed increasing pressures on forested tracts in Collier, Glades, Highlands, and Hendry Counties. Tracts of private land must be targeted for conservation in support of long-term panther management. Where current uses on these lands are compatible with panthers, owners must be economically encouraged to continue these practices.

Conservation and Recovery

Early conservation and management efforts benefitting the Florida panther involved land acquisition and conservation. After nearly a decade of planning, Everglades National Park was established in 1947. The Corkscrew Swamp Sanctuary was established in 1954 when the National Audubon Society and The Nature Conservancy purchased a tract of old growth cypress from the Lee Tidewater Cypress Company. The Florida panther was designated as endangered by the State of Florida in 1958, and by the FWS in 1967. The Fakahatchee Strand State Preserve was established in 1974, and the National Parks Service began acquiring the Big Cypress National Preserve in 1978. Under an Act enacted in Florida in 1978, the deliberate killing of a panther is a felony. Speed limits were reduced at night on S.R. 84 and S.R. 29 in 1984 in an effort to decrease the number of vehicle/panther collisions. The NWR acquisition was initiated in 1989, the same year that panthers were first noted using underpasses installed when S.R. 84 was converted to Interstate 75.

More recent conservation efforts include accelerating and completing state acquisition of the Save Our Everglades Project, including Fakahatchee Strand State Preserve and Picayune Strand State Forest (formerly South Golden Gate Estates and Belle Meade) with matching federal funds. The Okaloacoochee Slough, the first publicly owned land in Hendry County, was purchased by the State of Florida and the FWS in 1996. Lands were added to the Big Cypress National Preserve and National Wildlife Reserve when the Collier-Phoenix land exchange was finalized late in 1996. The U.S. Department of Agriculture is investigating the use of landowner incentive programs to protect panther habitat. Some private landowners in southwest Florida have initiated a grassroots effort to link Federal estate tax reform with protection of endangered species habitat.

Public opinion necessitates that state and federal agencies make every effort to prevent extinction of the Florida panther. An interagency committee, the Interagency Committee, was established in 1986 to provide a cooperative, coordinated recovery program for the panther.

Recovery efforts are placing emphasis on three major areas: protection and enhancement of the remaining wild population, associated habitats, and prey resources; improving genetic health and population viability; and reestablishing populations within the panther's historic range.

The protection and enhancement of the wild population, its associated habitat, and prey resources is critical to maintaining a self-sustaining population of panthers in South Florida. This action needs to be accomplished through appropriate management of existing public lands and the preservation of key private lands, especially well-drained and productive forested uplands. A Habitat Preservation Plan for panther habitat in South Florida was developed in 1993. This plan identifies occupied and potential panther habitat, threats to these habitats, and options available to maintain sufficient habitat for a self-sustaining population of panthers in South Florida. Implementation of the Habitat Preservation Plan, however, has been somewhat difficult. Certain private landowners fear losing land-use opportunities and oppose research and conservation efforts.

Managers of public lands occupied by panthers must be encouraged to maintain habitat quality where panther density is high, and to improve habitat conditions where panther density is low in order to accommodate dispersal of subadults. Although panther density may be limited by environmental conditions on some public lands, their importance as panther range in light of decreasing habitat on private lands is a compelling reason for improving conditions for panthers on these preserves.

The second area being emphasized in the panther recovery effort is genetic health and population viability. The persistence of the population appears dependent upon successful restoration of genetic health and viability. A genetic management program was implemented with the release of eight female Texas cougars into south Florida in the spring and summer of 1995. This program should restore the depressed genetic pool through the replacement of variability from this formerly contiguous sub-species without significant alteration in the basic genetic makeup of the Florida panther, or swamping the existing gene pool which may be adapted to local environmental conditions. Six litters of kittens had been born as of January 1998, and three kittens from two litters have potentially dispersed and are no longer with their mothers. One goal of the program is to radio-instrument all offspring so that the progress of genetic restoration may be closely monitored. It may be some time before we are able to determine if these offspring are successfully recruited into the population.

Population reestablishment is the third major recovery task under investigation and is the third, essential link to prevention of extinction for the Florida panther. The recovery objective identified in the 1987 Recovery Plan is to achieve at least three viable, self-sustaining populations within the historic range of the Florida panther. To achieve this objective, at least two additional populations will have to be reestablished. The feasibility of reintroducing the panther into a north Florida site has been studied and evaluated in two experiments. This process involved site selection, evaluation, and surrogate population establishment and monitoring. During a two-phase study, 26 mountain lions were released in the north Florida/south Georgia study area as surrogate panthers. Six of the released mountain lions were born and raised in captivity. The remaining 20 were captured in the wild in western Texas and translocated to Florida. Of the translocated mountain lions, all but three were released into the wild shortly after arriving in Florida. The other three were part of an early study to develop captive-breeding techniques and technology for the Florida panther, and had been held in captive breeding facilities in Florida for two to eight years prior to release.

The reestablishment of panther populations into portions of the historical range is biologically feasible. Habitat and prey available in northern Florida and southern Georgia is sufficient to support a viable, self-sustaining population of Florida panthers. The risk of extinction for the panther can only be significantly reduced through the reestablishment of additional populations. However, complex social issues identified during the reintroduction studies would have to be satisfactorily addressed prior to reestablishing a population of panthers.

Contact

U.S. Fish and Wildlife Service
117 Newins-Ziegler Hall
University of Florida
Gainesville, Florida 32611-0307
Telephone: (904) 392-1861

References

Belden, R.C. 1988. "The Florida Panther." W.J. Chandler, ed., Audubon Wildlife Report, 1988-1989, pp. 514-531. The National Audubon Society, New York.

U.S. Fish and Wildlife Service. 1993. Florida Panther (Felis concolor coryi ). Endangered and Threatened Species of the Southeastern United States (The Red Book) FWS Region 4. http://endangered.fws.gov/i/a/saa05.html

U.S. Fish and Wildlife Service. 1995. Florida Panther Recovery Plan. Second revision. Atlanta, Georgia.

Florida panther

The Florida panther (Felis concolor coryi ), a subspecies of the mountain lion, is a member of the cat family, Felidae, and is severely threatened with extinction . Listed as endangered, the Florida panther population currently numbers between 30 and 50 individuals. Its former range probably extended from western Louisiana and Arkansas eastward through Mississippi, Alabama, Georgia, and southwestern South Carolina to the southern tip of Florida. Today the Florida panther's range consists of the Everglades-Big Cypress Swamp area. The preferred habitat for this large cat is subtropical forests comprised of dense stands of trees, vines, and shrubs, typically in low, swampy areas.

Several factors have contributed to the decline of the Florida panther. Historically the most significant factors have been habitat loss and persecution by humans. Land use patterns have altered the environment throughout the former range of the Florida panther.

With shifts to cattle ranching and agriculture, lands were drained and developed, and with the altered vegetation patterns came a change in the prey base for this top carnivore. The main prey item of the Florida panther is white-tailed deer (Odocoileus virginianus ). Formerly, the spring and summer rains kept the area wet, and then, as it dried out, fires would renew the grassy meadows at the forest edges, creating an ideal habitat for the deer. With development and increased deer hunting by humans, the panther's prey base declined and so did the number of panthers. Prior to the 1950s, Florida had a bounty on Florida panthers because the animal was considered a "threat" to humans and livestock. During the 1950s, state law protected the dwindling population of panthers. In 1967 the Florida panther was listed by the U. S. Fish and Wildlife Service as an endangered species .

Land development is still moving southward in Florida. With the annual influx of new residents, fruit orchards being moved south due to recent freezes, and continued draining and clearing of land, panther habitat continues to be destroyed. The Florida panther is forced into areas that are not good habitat for white-tailed deer, and the panthers are catching armadillos and raccoons for food. The panthers then become underweight and anemic due to poor nutrition.

Development contributes to the Florida panther's decline in other ways, too. Its range is currently split in half by the east-west highway known as Alligator Alley. During peak seasons, over 30,000 vehicles traverse this stretch of highway daily, and, since 1972, 44 panthers have been killed by cars, the largest single cause of death for these cats in recent decades.

Biology is also working against the Florida panther. Because of the extremely small population size, inbreeding of panthers has yielded increased reproductive failures, due to deformed or infertile sperm. The spread of feline distemper virus also is a concern to wildlife biologists. All these factors have led officials to develop a recovery plan that includes a captive breeding program using a small number of injured animals, as well as a mark and recapture program, using radio collars, to inoculate against disease and track young panthers with hopes of saving this valuable part of the biota of south Florida's Everglades ecosystem .

[Eugene C. Beckham ]

RESOURCES

BOOKS

Belden, R. "The Florida Panther." Audubon Wildlife Report 1988/1989. San Diego: Academic Press, 1988.

Fergus, Charles. Swamp Screamer: At Large with the Florida Panther. New York: North Point Press, 1996.

Miller, S. D., and D. D. Everett, eds. Cats of the World: Biology, Conservation, and Management. Washington, DC: National Wildlife Federation, 1986.

OTHER

Florida Panther Net. [cited May 2002]. <http://www.panther.state.fl.us>.

Florida Panther Society. [cited May 2002]. <http://www.atlantic.net/~oldfla/panther/panther.html>.