LABELLE

In the Darwinian world of the Florida panther, the strong kill the weak to win the right to mate. In Southwest Florida, there is no surplus of wild land for young males. It's taken. If they stick around, they may get their tawny brown butts whipped or worse.

So they wander north looking for new territory and romance. They pad through the Big Cypress, the Fakahatchee Strand and the Florida Panther Refuge. They skulk through farmlands, orange groves and ranches. If they don't lose heart and turn back, they encounter the Okaloacoochee Slough State Forest, which buys them a few more days of safe passage. Finally — and this is no sure thing — the young male sprints over busy State Road 80, bounds a fence and slinks onto a cattle rancher's latest acquisition.

It contains hammock and wetlands. Some of it, scarred from a long-ago dredging project, resembles moonscape. The whole parcel is somewhat unremarkable except for one thing.

It is critical to the Florida panther's future. It's where panthers coming from the south tend to end up. Like a funnel, the modest piece delivers curious cats to one of the last known places where they can cross the Caloosahatchee River.

If Florida panthers are going to repopulate stomping grounds that once stretched beyond the Mississippi River, and scientists are praying that they do, they're going to swim from that spot.

Recently, the environmental organization known as the Nature Conservancy and a cattle rancher, Dwayne House, brokered a deal to protect the crossing, ensuring that this crucial gateway to the north would never close.

In a sense, scientists are holding open the door and waiting for the panther to walk through. Males have swum the 80 yards plenty of times. All they need now is for a female to follow.

• • •

What we call the Florida panther once ranged all the way to Arkansas. But hunting and development and the 20th century wiped them out everywhere but the Everglades.

By 1980, the low point, the panther population was down to two dozen bedraggled, inbred animals that seemed destined for extinction. Since then they have been nursed back to relative stability by land purchases and science. Biologists catch panthers and fit them with radio collars to reveal where they hunt, sleep and travel. A breeding program in 1995, using the genes of the panther's closest relative, the western cougar, invigorated the failing bloodline.

In the wilderness between Miami and Naples about 160 adults and perhaps half as many young panthers hold their own today.

That hardly means they're safe, experts say. A catastrophic hurricane, a feline virus, global warming or the wrong kind of development could sink them again.

Folks who think professionally about panthers say two things need to happen.

One, do everything to sustain the current population south of the Caloosahatchee River. That means limit development. That means take steps to reduce the number of panthers killed crossing roads. Thirteen have perished this year.

The second objective is even more challenging.

Do everything possible to encourage panthers in Southwest Florida to reach the gateway, to cross the Caloosahatchee River and start families in other parts of Florida and beyond.

"We need to establish at least two other panther populations to keep them safe," says Darrell Land, head panther biologist for the Florida Fish and Wildlife Conservation Commission. It's also the goal of the U.S. Fish and Wildlife Service's thick Panther Recovery Plan.

Three panther populations of 240 animals each by mid-century would be ideal, according to the recovery plan. In such a scenario, scientists would expect amorous males to wander back and forth between populations, sharing their genes and preventing inbreeding.

Thanks to the ongoing radio collar program, scientists know that young male panthers are already doing their best. They're swimming the river and looking for love.

But it usually ends the same way. The sexually frustrated tomcat loops back to Southwest Florida where the girls are.

It's been decades since a scientist documented a female panther north of the river.

The Caloosahatchee, development and the female panther's own biology are the barriers.

Female panthers are homebodies. They tend to stay close to where they are born. Generally, that means well south of the river, nearer Naples than to LaBelle.

A male requires about 200 square miles to feel comfortable — an area just a little smaller than Pinellas County. A female can make do with about 80 square miles. If this were the 18th century, and Pinellas were still all pines and palmettos, the peninsula might be able to support a single male panther, a couple of females and their kittens. That's it.

They're even more conservative when they have kittens or cubs. For a few years females keep their cubs close, teaching them how to hunt and hide from dangers that even include male panthers.

Yes, a male panther will kill a cub sired by a competitor. Why? The female who loses her cub may go back into heat, giving Don Juan a chance to mate with her and pass on his genes.

It's a jungle out there.

• • •

Modern Florida can be just as unfriendly. Cars run over the panthers. There are no reliable accounts of 7-foot Florida panthers attacking people, but some folks are sure children eventually will end up on the menu. Ranchers, meanwhile, worry panthers will develop a taste for prime rib. They're anxious, too, about government seizing their land and handing it over to welfare panthers.

Dwayne House, 76, is different. He grew up in the dairy business in Maryland, got rich selling diesel engines in Miami and two decades ago began buying land near LaBelle. He acquired the sprawling Goodno Ranch on the river and crossed Brahman and Angus to create Brangus cattle.

On the back of his battered Toyota is one of those "Protect the Panther'' license plates.

A few years ago, he got a call from a real estate buyer from the Nature Conservancy, an environmental group that raises money to buy wild land threatened by development. Once the conservancy buys the land, it typically sells it to someone friendly to environmental causes.

The conservancy buyer was looking for a sympathetic rancher and wanted to know if House might be interested in owning a little more of Glades County. Biologists through the radio telemetry program had determined the importance of the land years ago. Now the conservancy was trying to save it from development.

It was a complicated buy that took years of haggling between private donors, government bureaucracies and conservation organizations. In 2012 the conservancy closed the $6.65 million deal on the day the property was poised to be auctioned. Then it turned around and sold it to Dwayne House for $1.5 million. Last May, House acquired a little more adjacent land.

It was a good deal for everyone. The Nature Conservancy won praise from environmentalists who sometimes write big checks. House got 1,278 acres on which to run his cattle. The panthers got a place to cross the river without encountering a Starbucks.

"Some other ranchers think I'm crazy,'' House tells people. "They're suspicious of the government. They're nervous about having an endangered species on their land. They're nervous about panthers eating livestock — which, I don't kid myself, may turn out to be a problem. But I like the idea of doing something for panthers.''

He dreams of seeing a female and her cubs getting wet feet.

"I'll be watching,'' he says gazing at the river.

• • •

So why not just catch a few fertile female panthers and move them across the river?

Kevin Godsea hears the question often. He's the Florida Panther Project leader for the U.S. Fish and Wildlife Service.

Why not indeed? It might be cheaper and quicker.

Experts who want to save the panther have debated the idea for years. But then rejected it.

"We want range expansion to happen as naturally as possible,'' Godsea says in an email.

One, panthers of both sexes have historically been found on both sides of the Caloosahatchee. It might take them longer than what scientists would like, but panthers may accomplish the goal of population expansion on their own timetable provided habitat continues to be protected.

Two, moving panthers artificially might confuse them and even slow down the process. Nobody wants to end up with three isolated panther populations and the possible inbreeding that can lead to birth defects, experts say. Purchase a few wildlife-friendly corridors between state parks and national forests, experts advise, then let them figure out the birds and the bees on their own.

Three, if panther expansion happens organically, no anti-government folks will be able to claim credibly that panthers were forced down the throats of unwilling citizens. The panthers simply did what came naturally, crossed the river.

Godsea says: "Bottom line is we are being cautious as to not create more problems.''

In Naples, maps in the Florida Fish and Wildlife Conservation Commission office show what has happened naturally. Young male panthers have been documented north of the Caloosahatchee River on a ranch in Hillsborough County, in the pine lands of Myakka River State Park near Sarasota and in Highlands Hammock State Park outside of Sebring.

Traveling fools, they have crossed Interstate 4 and crept around Orlando. They've ambled through swamps along the St. Johns River. They've disappeared into Georgia.

The nearest female to the Caloosahatchee is 10 miles south.

At least that's what the experts thought.

• • •

Cliff Coleman is one of those Florida men who grew up in the woods and on the water. He hunts hogs in the Big Cypress and catches bass in Lake Okeechobee. He can identify animal tracks at a glance.

He's 47 now and has the perfect job for his talents. For nearly two decades he has managed the Black Boar Ranch near Dwayne House's property outside of LaBelle. Black Boar caters to wealthy hunters who visit during the cooler months.

The ranch, about 7,000 acres, is home to native wildlife and game animals from foreign lands. As pretty as a state park, Black Boar Ranch boasts swamps, hammocks, pine lands and wide prairies.

Coleman never suspected panthers were hunting on the ranch until five years ago. When he saw tracks, he called state biologists who sent a team to capture and attach a radio collar to the wandering male.

Sometimes Coleman found a dead animal, killed by a bite on the neck. The deer usually was disemboweled and its heart, lungs and liver devoured. Sometimes Coleman found the rest of the carcass, buried under leaves and sand. A panther's pantry.

A talented photographer, he began hunting panthers with his camera. He snapped pictures of them ambling down roads and hunting deer from the tall grass.

Last year he discovered the most interesting tracks of all. One set clearly had been left by an adult panther. Two other sets of cat tracks, nearby, were much smaller. "It's a female with cubs,'' Coleman told state biologists.

They were skeptical. Nobody had seen a female, much less cubs, so close to the river in at least four decades. The biologists arrived at the ranch with motion-sensitive cameras and their doubts.

They spent the night. In the morning they checked the camera. A female panther with two cubs.

Now, a year later, Coleman is finding multiple tracks again. It could be the same female; he isn't sure. But it's less than a mile from Dwayne House's property on the river.

And Coleman is seeing the usual males.

One morning he witnessed a 7-footer jumping an intimidating fence.

"You wouldn't think something that big could jump an 8-foot fence like it isn't even there,'' he says. "But that's what they do.''

• • •

Across SR 80, at the Goodno Ranch, Dwayne House stays alert to the possibility of seeing another panther, male or female.

Sometimes, after a day on horseback, he steps out onto the porch and listens to the night sounds. Usually he hears owls. Screech owls warble. The big barred owls hoot.

One night, stepping out of the house, he heard something creeping along the chicken coop. When his eyes adjusted, he saw a panther looking at him. Male or female, he didn't know. Anyway, it ran off.

When a female panther is in heat, she loses her shyness. She rubs her bottom on the ground and leaves her scent for a male to follow.

Biologists describe the come-hither sound she makes as a caterwaul. She mews and chirps, purrs and yowls.

If she is receptive, he'll mount her. He may bite her enthusiastically on the neck. Together they will groan, whimper, grunt, growl, hiss. They will part and go at it again.

Dwayne House, like most of us on earth, has never heard the sound of panther sex.

One day he hopes to hear it on the breeze — coming from the far side of the Caloosahatchee River.

Jeff Klinkenberg can be reached at (727) 893-8727 and klink@tampabay.com.