A whole, diverse world squirms and swims all around us, and most of us have no idea.

Georgia, as it turns out, has the most diverse population of amphibians in North America and is third in biodiversity of freshwater fish, according to scientists with the state's Department of Natural Resources.

"Georgia has the most diverse (population), amphibian species-wise, than any state in the country," said John Jensen, senior wildlife biologist for Georgia DNR. "We just passed North Carolina in salamander diversity."

That's thanks in part to the recent discovery of one of the world's smallest kinds of salamanders, discovered in a creek in Stephens County. The patch-nosed salamander, orange with a yellow spot on its nose, is barely 2 inches long when fully grown.

The team that discovered it had to create a new genus to describe it, and it was later identified by a Piedmont College team led by Carlos Camp, a biology professor there.

Why so much diversity in the animal kingdom? In a sense, it's a case of form following function.

"We have five different physiographic regions in the state, and each of those has unique habitats," said Jensen, who edited "Amphibians and Reptiles of Georgia," released last year by University of Georgia Press. "We have some salamander that specialize in caves; just all the different habitats, different amphibians that have evolved to exploit them."

In the air

About five years ago, DNR and U.S. Forest Service workers cut down trees in some 20 areas across the Chattahoochee National forest, as an experiment in creating new habitats for cerulean warblers.

Listed as rare in Georgia, the sky blue-colored birds are the fastest-declining species of warblers in North America, and the only known populations in Georgia are in two sites in the Chattahoochee National Forest.

So, said Nathan Klaus, a senior wildlife biologist with DNR, the idea was to mimic their habitat in other places in the forest. Over time, he said, hopefully the cerulean warblers would be attracted to the new habitats, forming new populations.

"We have this tiny population that could eventually get snuffed out," Klaus said. "So, we're thinking, let's try to bolster that population. Their idea is, let's try to get a second population or a third population somewhere so we don't have all our eggs in one basket."

This spring, scientists documented warblers at 10 of the new habitats where none had been seen before. This not only means the experiment worked, but it also didn't take as long as previously thought.

"That's something you see more and more - the species that are endangered these days are specialists, the species that specialize in a particular niche," Klaus said. "They're the ones that are suffering, whether it's the way we suppress forest fires, everything is acting differently. We have to figure out what makes them tick, and it seems we might have figured that out with the cerulean warblers."

While the cerulean warblers like a canopy similar to an old-growth forest, the golden-winged warbler, found only on Brawley Mountain north of Suches, likes a low, scrubby, grassy habitat, similar to a place that has been burned.

"You sometimes find it in places where there was such a severe fire that everything's dead, and it's just starting to get going - and, as you might imagine, very rare today," Klaus said. "We're working there to work with the Forest Service to create some habitat for them. And we've been burning it a bunch and been trying to do some logging that would simulate a high-intensity fire."

In the water

Brett Albanese, senior aquatic zoologist with Georgia DNR, said there are so many fish species in Georgia that they're still discovering new ones.

"We really do live in a rainforest for freshwater species here," said Albanese, who helped compile the Fishes of Georgia Atlas, an online searchable database. "It's the most diverse area of the country, and Georgia is third in the nation for freshwater fishes."

Again, the state's different regions are credited with creating the biodiversity. One fish to look for in some North Georgia streams is a Halloween darter.

"It's a beautiful little darter, just described last year," Albanese said. "It's been overlooked for far too long. The reason is ‘cryptic biodiversity' (the difficulty of identifying species because there is so much diversity) ... we're still discovering new species because of this phenomenon."

Plus each river system - like the Chattahoochee, Savannah, Coosa, Tennessee and Mobile systems - have their own group of fish. "Some of them, like the Tennessee and the Mobile, are the two most diverse river basins in the Southeast."

The sicklefin redhorse, a type of sucker fish, is only found in Brasstown Creek, and was just discovered in the 1990s. It's about 20 inches long and is notable for its shark-like dorsal fin.

"Suckers, as a family, they have these fleshy lips that are open on the bottom of their body," Albanese said. "A lot of people don't show them respect. They say they're a bottom feeder, but that's not true - they have discriminating taste buds."

Some straddle both worlds

Don't be alarmed if you run across an Eastern hellbender on your next expedition for trout - they're one of the more unique species found in North Georgia. Even if they are a little scary.

The salamander can live both in water and on land, and thrives in clear rocky streams that are part of the Tennessee River drainage system.

"They're awesome. They're very bizarre looking," Jensen said. "I think most people aren't going to see them unless you make an effort to search for them, but they're more nocturnal, not usually active during the day.

"But occasionally a fisherman using bait, using worms, if their hook gets down under a rock that shelters a hellbender, one will catch on it."

Georgia is also home to the bog turtle. They are found in boggy environments but nest on land; they are the smallest turtle in North America - their shell is usually no more than 3 to 3 1/2 inches long.

Not too many frogs, lizards or salamanders in the state are listed as endangered, Jensen added. He credits that to the wide swath of North Georgia taken up by the Chattahoochee National forest. But, even so, there are lots of pockets of land inhabited by people, and it's a constant struggle to keep the balance.

"Habitat loss ... is far and away the biggest threat to amphibians and reptiles in Georgia," he said. "Without the habitats they don't survive or do well, but most of the species' habitat there is in place."