From Correspondent Gary Strieker

MONTE CABANIGUAN WILDLIFE REFUGE, Cuba (CNN) -- Illegal hunting and declining habitat have caused the number of American crocodiles to decline from Florida to Peru.

But there is one place where the crocodiles are not endangered -- indeed, they are said to be thriving -- and that is along the Gulf of Guacanayabo in eastern Cuba.

They live along a remote coastline of marshes and lagoons that are not easy to reach, and they are protected by a wildlife refuge at the mouth of the Jobabo River.

They live, says Robert Rodriguez Soberon of the National Wildlife Program, in something rather like a tunnel. "It's a den made by a mother croc," he says, "and it goes about 25 or 30 feet (8 or 10 meters) underground."

Crocodiles function as de facto engineers, their tunnels and ditches helping to move water between lagoons and marshes, keeping the wetlands wet. A robust crocodile population means a healthy swamp.

In this refuge, there are at least 10 separate nesting areas, all of them monitored by a research team.

Sometimes crocodile mothers abandon their nests, and when it's time for the babies to hatch, they'll suffocate unless they are dug out from the sand.

The research teams weigh and measure the hatchlings, mark and identify their nest areas, and then release them.

The researchers will continue to record the histories of those that survive the first dangerous months when most baby crocodiles are eaten by birds, fish and other crocodiles.

And while crocodiles elsewhere are in decline, the crocodile population here is increasing.

"They have the necessary abundance of food and the non-disturbance they need to breed, to procreate and to thrive in this area," says Rodriguez.

They also have protection under wildlife conservation laws that are strictly enforced.

The crocodiles here at Monte Cabaniguan are laying eggs in more than 200 nest sites every year. There are more crocodile nests on one small stretch of beach here than in all of Florida.

And scientists from other countries come here to collaborate with Cubans, who are trying to raise the money they need to operate a biological field station. The hope is that others might learn what can be done to save their own crocodile populations before it's too late.