FORT LAUDERDALE, Fla. -- "Cloudless sulphur," says Hal Wiedemann pointing at a flapping leaf in the air.
"Palamedes," someone else shouts out, motioning in the opposite direction.
These early morning stalkers are in pursuit of a small and vibrant prey. Hither and yon it flits, with the entourage futilely trying to follow.
Eyes, some boosted with binoculars, scan the trees, the underbrush, the low-lying vegetation round their feet. "Up there," says a self-appointed scout, directing attention with a walking stick.
This small knot of nature lovers is the vanguard of a new outdoor pastime -- butterfly watching. They've gathered at Loxahatchee National Wildlife Refuge in Florida in hopes of glimpsing what some believe to be the most delicate, graceful and beautiful creatures on the planet.
The group won't see great clouds of lepidopterans this morning, but they will spot more than a dozen different species.
Where bird-watching was in the 1940s and '50s, butterfly watching is today, says Jeff Glassberg, founder of the North American Butterfly Association and author of the first netless butterflying field guide.
"It's set to take off in the same way birding has," says Mr. Glassberg, speaking from his office in Chappaqua, N.Y. But the trajectory will be a lot steeper, he contends, "and it has the potential to ultimately involve more people."
Already, like birders, butterfly watchers are trekking the world in search of ever more exotic species.
Hal Wiedemann, the volunteer who leads Loxahatchee's butterfly expeditions, discovered the joys of butterflying about 11 years ago, while on an unsuccessful birding outing. The leader, having no birds to talk about, "started hitting on butterflies," Mr. Wiedemann recalls. Mr. Wiedemann became hooked. Obsessed, perhaps.
Now he reels off stats on butterflies as easily as a baseball-capped youngster spouts batting averages.
"There are 20,000 known butterfly species," he says. "Seven hundred sixty in North America, north of Mexico, and 165 species in Florida alone." One hundred six of those species are in South Florida and the Keys.
What this amiable fellow doesn't know about his colorful pursuit probably is of little consequence. What he does know, he shares with glee.
AThe fine powder on the wings of butterflies? Scales, he explains, "that overlap like shingles on a roof. A monarch butterfly may have as many as 500,000 scales. If you took all the scales off a butterfly's wings, it would affect its flight only about 15 percent."
And those wings, they're not just for flight, but for maintaining body temperature as well. Butterflies, you see, are cold-blooded. In fact, let their body temperature drop below 61 degrees Fahrenheit and they're as grounded as the plant they light upon, he says.
Know the No. 1 activity of butterflies? (This is the sexy part.)
"Reproduction," Mr. Wiedemann says. "They spend quite a good part of the day just looking for mates."
And how far will a butterfly go for a date? Try 2,000 miles or more, from Canada to Mexico, California and Florida. Well, maybe not for a date. But that's the stretch of the monarch's migration.
All that said, most butterflies aren't into marathon migrations. Just as well, Mr. Wiedemann says, since their existence is relatively brief, ranging from scant weeks to several years.
Out here on the trail, Mr. Wiedemann's experienced eyes spot the tell-tale signs of aging -- fading colors, wings nipped ragged by predatory birds and lizards.
"Until recently," says Mr. Glassman, "the people who have gone out looking for butterflies have been essentially collectors. That's a very different thing."
They've gone with nets to kill the very thing they admire. Through his organizations and books, Mr. Glassman is trying to popularize netless butterflying. He's trying to lay the groundwork for butterflying, much as Roger Tory Peterson did for birding.
Mr. Peterson proved, Mr. Glassman says, that you could identify birds with binoculars -- that you didn't have to shoot them out of the sky to put a name on them.
"You can do the same thing," Mr. Glassman says, "with butterflies."