More than 30 years ago, on December 28, 1973, President Richard Nixon signed into law the Endangered Species one of the most comprehensive and ambitious wildlife conservation measures ever enacted.

As part of our series on the impact of that law, VOA's Rosanne Skirble takes us to Florida's West Coast, where sprawling development threatens the future of the endangered panther.

Three times a week biologist Mark Lotz, the Florida Wildlife Conservation Commission attaches a radio antenna to a small CESNA aircraft and sets out to track radio-collared panthers. He directs the pilot to fly over large tracts of pine forest, hardwood hammocks and wetlands to pick up signals that correspond to dots on a map where cats have been spotted.

On this day he locates 29 cats. Other state and federal wildlife agencies monitor 70 more. Florida Panthers were on the brink of extinction 10 years ago. At that time, eight Texas cougar females were introduced to boost the population and prevent inbreeding among the cats.

Panthers are solitary animals and need a lot of space - 195 square kilometers for a female and 518 square kilometers for a male. When they stray too far from protected lands, and start venturing across asphalt highways, they can, and often do, end up as roadkill.

"Actually we have got some panther tracks right here," says Mark Lotz. "This is panther. It's a female."

Mark Lotz inspects an underpass that links panther habitat under Interstate Highway 75, also known as Alligator Alley. Chain-link fences and 36 wildlife corridors like this one extend along a 50-mile stretch of the road.

"Those underpasses were put in to prevent the panthers from getting hit," says Mr. Lotz. "It has been a great success. Since the underpasses have gone in we haven't had one cat killed on the Alley."

And before that?

"It was I think was eight or 10 that were hit on the Alley," he said.

The greatest threat to the Florida panther is loss of habitat. Naples on the Florida West Coast is the second fastest growing city in the United States. The city of 400,000 added 120,000 new homes in 2003. Even more are expected to be built in 2004. This is bad news for the panther.

Nancy Payton is a field representative for the Florida Wildlife Federation. We drive with her along Alico Road about 32 kilometers from Naples where we join a steady stream of dump trucks. She says all day, every day this caravan transports limerock from mines to construction sites in the region.

"The mining area is huge," she says. "The mine that we are in front of now. It is dusty. It is hot, and I haven't seen any wildlife, not even a bird. And, this is only one mine. There are many mines in the area that we are standing in and every mine is like this, and there are applications for more mines. And, of course when you mine land there is nothing left except to build houses so that there are waterfront homes."

The mines were tapped to build Florida Gulf Coast University, immediately to the east of where we stand. Opened on rural lands in 1997, it set into motion new homes, shopping malls and golf courses - all in panther country. Heading west we stop at the construction site of "Bella Terra" or "Beautiful Earth."

Payton: Correct, Bella Terra. The previous name was The Habitat. It is a new development in prime panther habitat, and what we are looking at is a totally denuded habitat with mounts of dirt and recently dug lakes and new homes are going in that are about five feet apart. It is very intense development with not much wildlife value left, if any.

Skirble: And this isn't the only development you see up and down these roads.

Payton: There are developments that are popping up everywhere, continually [such that] one of the busiest buildings in Southwest Florida is the Community Development Building where you get your [building] permits!

Skirble: What is it going to take to change?

Payton: I am sure that it is going to take litigation. That is what made the difference in Collier County.

Naples is located in Collier County. The Florida Wildlife Federation took Collier County to court for its failure to protect wildlife habitat. The result was a state-imposed, three-year moratorium on development in rural areas. The County was directed to create a plan that would both protect wildlife and promote economic development. Church bells usher in a new era for Collier County. They come from a housing complex, the temporary home for Ave Maria University and Town. The new development is the first test of the Rural Lands Stewardship initiative, a plan adopted by Collier County after the building moratorium was lifted in 2002.

Under the plan, rural Collier County was extensively mapped. All land was ranked according to its importance for species protection, with some areas placed off-limits to development

The plan also required that before a potential client, like Ave Maria University and Town, could develop any property, it would first have to pay for environmental credits. This would place sensitive lands off-limits to development. Ave Maria University and Town could then purchase and build on land designated in the plan for development.

Tom Jones manages the Barron Collier Company farmlands where Ave Maria University and Town will put its church, academic buildings, library, and athletic fields.

He says the plan gives landowners an opportunity to profit from property identified as environmentally sensitive.

"For the first time in the United States landowners have finally been able to derive some economic benefit from environmental resources," he says. "We don't have to develop those environmental resources. We don't have to try to develop those environmental resources to get a value from them. These are lands that society deems to be very valuable. They need to be protected and there has not been a fair way to compensate landowners for their loss for use of that property until this process evolved to where I now have value because I have environmentally significant land."

Nancy Payton with Florida Wildlife Federation says environmental groups also support Rural Lands Stewardship because it joins development with environmental protection. She says it is an incentive model, which can slow down the impact of sprawl and help protect the endangered panther.