They're elusive and sightings are rare, but nearly three times as many Florida panthers now roam the wilds of South Florida than 20 years ago.

Efforts to bring the panther back from the brink of extinction produced dramatic success. Breeding and genetic restoration projects were accomplished. Vast tracts of habitat were saved. From an estimated 30 panthers, officials say the population now numbers at least 87, not including kittens.

The birth rate has outpaced the number of panthers that die in auto collisions, but biologists say territorial fights are a bigger and just as lethal threat.

Savvy and smart, panthers are efficient at prowling their territories for prey and water. But that prowess can't always help when they're attacked by disease, other panthers or even mosquitoes. It leaves them powerless in the face of the sprawling growth that threatens their habitat and competes for vacant land. The Florida panther is still endangered.

And, during the past year, simmering squabbles over panther protection have bubbled into very public debate among scientists, the state and federal agencies they work for, environmental groups and developers.

The crux of the dispute is over panther habitat -- chiefly, how the U.S. Fish and Wildlife Service evaluates panther habitat and recommends what developers should do to make up for damage.

The wildlife service oversees panther protection and recovery in Florida. The service works with the Florida Fish and Wildlife Conservation Commission, which also oversees panther protection and monitors the panther population. Both agencies work on restoration projects and conduct and support scientific research.

The federal agency's panther plans put priority on preserving forested land, saying it's the cat's favored habitat. Others say different types of habitat, such as grassland and farmland, are just as important and that faulty science has prevented the federal agency from adopting that principle in permitting.

A federal complaint filed May 3 is the latest in a series of disputes and allegations.

Andrew Eller, a biologist with the federal wildlife service for 17 years, alleges in the complaint that his employer knowingly uses flawed science, which creates poor permitting decisions that allow crucial panther habitat to be destroyed.

A scientific panel, commissioned by the wildlife service, drew similar conclusions in December after reviewing research used by the state and federal agencies to set policy. The panel issued a report, scathing in some sections, saying the service should immediately stop using its modeling method that puts priority on forested habitat.

The panel of four experts from outside Florida also recommended the appointment of an independent scientific steering committee and a re-analysis of existing data. It chided the agencies for allowing panther research to lag.

The wildlife service also is embroiled in at least two lawsuits raising similar concerns brought against it by the National Wildlife Federation and the Florida Panther Society.

PANTHER PROGRESS

Officials at the state and federal level have been taken aback by the fervor of their critics.

"We are the catalyst that has helped to understand how to protect the panther and its habitat," said Jay Slack, field supervisor for the federal wildlife service in Vero Beach. "We are really serious about protecting the Florida panther. It's the right thing to do and we are bringing all of our knowledge and resources to bear on doing just that."

Both the state and federal agencies point to the huge volume of information collected, hundreds of thousands of protected acres and wildlife underpasses built under South Florida highways.

"If you look at where cats are today compared to where they were 20 years ago, it's been an incredible effort with significant results to further the conservation of the species," said Thomas Eason, bureau chief of the state wildlife commission's bureau of wildlife diversity and conservation.

"It's been at great effort and cost to a lot of people," Eason said, including all the Floridians who bought the 1.4 million panther license plates sold since 1993. "We've thrown a lot of money and resources at it and I think it's paid off for the panther."

The commission has monitored 132 panthers during the past 23 years, officials said.

Darrell Land, panther coordinator for the wildlife commission, has worked in the panther program for 20 years.

"I feel pretty good about it but we shouldn't dust off our hands and act like the job is done," he said. "We've still got a long way to go before having a population we don't have to manage."

The cats "will always be in danger but we're at a point where we can keep panthers here into the foreseeable future," Land said.

The Florida panther, a genetically distinct part of the puma family, was placed on the federal Endangered Species List in 1967 because of its dramatically declining numbers. Cats that once roamed the entire Eastern seaboard were confined to a shrinking population in the lower half of Florida.

In 1979, the state wildlife commission began capturing panthers and putting radio collars on them to track their movements. They learned where the panthers were, where they traveled and how they interacted with each other and their environment.

When the panthers still ranged throughout the Southeast, experts say they periodically crossbred with Texas pumas. When that ended, the genetic variation that sustains a healthy population gradually gave way to genetic problems that come with inbreeding.

In 1995, the state and federal governments began a genetic restoration project. Eight Texas females were released in South Florida and produced 17 kittens. The last of those females were removed last fall and retired to a private wildlife conservation center.

Genetic intervention will have to continue as long as there are fewer than 100 panthers, because the cats won't be able to find mates they're not related to, Land said. But the next phase won't start until more studies are completed on the long-term results of the last effort.

The panthers, meanwhile, have problems all on their own, even without human impacts.

NATURE TAKES ITS TOLL

In 2002, 30 kittens were born from radio-collared females.

"That was really an amazing year," said Layne Hamilton, manager of the Florida Panther National Wildlife Refuge. But, fewer than half that year's kittens survived.

"It's a hard life. Sometimes the mothers aren't real experienced at raising kittens," Hamilton said. "There are a lot of things coming at the population that are challenging us in trying to manage it and allow it to grow."

Biologists think two of the 2002 kittens may have died from anemia from mosquito bites. Hamilton said one biologist working that summer said the mosquitoes were so thick he could hardly breathe.

Predators, road kills and feline leukemia are among the other dangers, but biologists say the biggest cause of death is territorial aggression. Hamilton said most male panthers don't live past 18 months because they're killed by other males, Hamilton said.

Last August biologists released two panther siblings, a male and a female, orphaned about a year earlier when an uncollared male killed their mother. Three months later, the young male was killed, apparently by the male that killed his mother. Meanwhile, the female may be pregnant by that same male.

"It's kind of a soap opera out there," Hamilton said. "It's survival of the fittest."

DEVELOPMENT VS. PANTHERS

The lack of agreement among experts about precisely what makes up ideal habitat creates confusion and conflict among developers, their consultants, environmental groups and the agencies involved in panther protection.

Generally, the U.S. Army Corps of Engineers is responsible for permitting development projects. If the Corps decides the project may impact an endangered species, the Fish and Wildlife Service is called in.

The service, for example, consults on projects that may affect panthers within a designated priority area in Southwest Florida that includes Big Cypress Swamp, the Everglades and several preservation areas.

The permitting guidelines say the agencies are to use the best available science to evaluate direct and indirect impacts and minimize impacts where possible.

Environmental groups argue that 13,000 acres of habitat have been destroyed by development in South Florida. But the wildlife service says not all of the permitted development destroys habitat. The habitat may be disturbed and then later used again by panthers.

They say of 11,263 acres of development permitted since January 2002, 6,496 acres have been permanently preserved or improved by developers through such projects as removing exotic species and restoring native landscapes.

Since 2000, the wildlife service has been working on new guidelines to "ensure the survival and recovery of the panther." A new panther habitat conservation plan and a landscape conservation plan to help guide property owners, agencies and permitters are expected to be released later this year, said Bert Byers, spokesman for the wildlife service's Vero Beach regional office. The habitat plan also will include a new priority area map that will increase the area within which permit applications require federal review.

The wildlife service also is working on a revised recovery plan. The plans, required for all endangered species, spell out how the service hopes to bring the animals back to the point they can be removed from the endangered list.

The current recovery panther plan, developed in conjunction with the state and other interested parties, was last revised in 1995. Initially the service said the new plan would be ready this fall, but now reports it probably won't be ready until 2005.

It frustrates environmental groups that the federal government moves so slowly, said Karen Hill, vice president of the Florida Panther Society.

"They keep saying they're going to do something but we have yet to see anything," Hill said. "The new conservation strategy for panther habitat has been dragging for years."

The environmental groups' lawsuit mentions that delay, stating the federal government has failed to produce "a meaningful plan" to guide development and uses bad science to issue permits.

"Developers are rapidly mining, bulldozing, clearing and paving the natural landscapes needed for the panther to survive," the suit states.

In one suit, the environmental group wants to stop the federal permit for a 3,212-acre limerock-mining pit in Fort Myers. The groups say the buffers and other trade-offs proposed for the Florida Rock mine will not make up for the isolation of panther territories and the damage to more than 5,000 acres.

"If this rate of habitat loss keeps up over the next five to 10 years, the panthers would be facing extinction," said the panther society's Hill.

Both lawsuits were filed in the District Court in Washington, D.C.

In the other suit, the groups allege the service has failed to protect the panther by ignoring the concerns of its own biologists and other scientists and by putting too much emphasis on protecting forested lands and not enough on other kinds of habitat that panthers also use.

John Kostyack, attorney for the National Wildlife Federation, said the wildlife groups don't disagree with "every aspect of federal policy."

"We praise them for the acquisitions and the wildlife crossing," Kostyack said. "And the restoration was a big success."

However, Kostyack said the results of the recent reviews mean "we're going to have to change the way they develop in South Florida."

The success of the genetic restoration program could serve as a model for a similar effort to preserve habitat, said Hill.

"The panthers were facing genetic crisis and all the agencies and conservation groups came together and did what needed to be done to save the panthers," she said. "That's what needs to happen again."