Antoine, an alligator that went on display Sunday at the Shedd Aquarium, probably has set an all-time world record for living longer than any other alligator of his kind.
Normally, that would be quite a feat. Alligators belong to the crocodilian family, reptiles that have been around for 250 million years and once hunted and ate dinosaurs.
Normal, however, is not a word that fits Antoine and 16 of his brothers. Now ranging from 6 to 8 feet long, the 8-year-old alligators are as white as pure sculpted ivory, devoid of color save for their striking blue, reptilian eyes.
A fisherman found them in August 1987, right after they had hatched from the clutch of eggs their mother had left in a nest in a remote Louisiana swamp. They are leucistic (pronounced loo-SIS-tic), an extremely unusual mutant occurance making them even rarer than almost-never-seen, pink-eyed albino alligators.
Antoine and his brothers are the first leucistic alligators confirmed by science. Experts thought their birth was a one-in-a-million, once-in-a-lifetime event. That theory was shot down last year when another surviving leucistic hatchling was discovered in a nest 100 miles from Antoine’s.
New Orlean’s Audubon Zoo lent 6-foot-long Antoine to the Shedd for a special exhibition, “White Alligator: Secret of the Swamp,” that will run through Sept. 13. The aquarium has built an elaborate re-creation of Louisiana bayou country to show him off.
Antoine’s odyssey of personal survival is due to the luck of the fisherman finding him in his infancy.
Being a snowy white infant devoid of camouflage and left otherwise defenseless in a swamp is tantamount to hanging a sandwich board on the animal with a simple message to all predators: “Here I am. Eat me.”
“Antoine and his brothers wouldn’t have remained alive for long if the fisherman hadn’t stumbled across them,” says Heather Parker, alligator keeper at the Audubon Zoo.
Only 2 percent of all normal alligator hatchlings manage to survive to adulthood in nature, she said.
An alligator infant’s only defense is its black and yellow striping, camouflaging it in swamp water and foliage. A white one can’t hide.
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The rich folklore of the bayous has no mention of white alligators.
Not much is known or written about “leucism” in scientific annals. Shedd researchers rely on Georgia researcher Bernard Bechtel to explain the differences between albino and leucistic animals.
Albino animals, he says, suffer from non-functioning pigment cells. They have no pigment in their bodies at all. The red in their eyes is simply the blood vessels showing through transparent tissue. They often suffer poor hearing and eyesight and weakened immune systems, which, in nature, often condemns them to a short life.
Besides Antoine, the Shedd exhibit also uses a display of live, specially-bred snakes to illustrate leucistic, albino, partly albino and normally colored animals.
“I wanted to make sure that the white alligator wasn’t exhibited just as a freak,” said Judith Bacal, the exhibit’s design chief. “They do occur naturally, and I wanted to tell their story biologically.”
It starts with a re-creation of an alligator nest, telling how the sex of the hatchlings is determined by the heat in the nest during the first two weeks after the eggs are laid. If the heat rises and remains above 93 degrees in the nest during that early critical stage, all the embryos become males, as in Antoine’s egg clutch.
The heat comes from the composting of plant matter in the muddy nest. If the alligator mother properly regulates the heat by regularly rearranging nesting material, both male and female alligators eventually will emerge.
Since they were collected, two of the 19 white alligators have died. Owned by the land company that owns the swamp, five of them are on permanent loan to Audubon Zoo, the rest are scattered in public and private collections.
Thirty years ago, naturalists feared all alligators were on the verge of disappearing.
Through much of this century, alligator swamps have been disappearing under shovels of developers. Prized for their hide and meat, alligators themselves were hunted close to extinction by the 1950s.
But the alligators happily became one of the great success stories of environmental protection. When Congress passed the 1973 Environmental Protection Act, alligators were one of the first species to go on the protected list, stopping hunting and habitat destruction.
Its provisions were so effective that within a few years alligator populations roared back to old levels.
Ironically, today the protection legislation itself is on the endangered list, as the Republican-dominated Congress is considering drastically reducing the powers of the 1973 law.
Survivability of the leucistic white alligators seems assured, with prospects of most of them gracefully growing old in captivity, into their 50s and 60s. Indeed, there is worry about an explosion of captive white alligators if experts conducting breeding experiments between leucistic males and normal females succeed.
The Audubon Zoo is not trying to breed them. It has Antoine and four of his brothers, plus the baby brought in last year. They are among the zoo’s most popular attractions, but zoo officials say six white alligators are definitely enough.
Chief curator Rick Atkinson is in no hurry to see them reach full sexual maturity, keeping them on a diet designed to keep their growth down-a pound and a half of frozen rats twice a week.
“As they get older, they become solitary and want very little to do with each other,” he said. “When they get to be 8 or 9 feet long, they are very sexually active and aggressive about their territory, with a lot of limb biting and tail chewing.
“We have to build habitats that mimic the dams they build in the wild, structures where they retreat to so they don’t have to look at each other.”
Having five brothers together seemed to make breeding among the leucistic animals a non-issue for the zoo. But when the new-found leucistic hatchling was added to the equation last year, it may well have changed the equation. Recently the zoo got tentative results on tests trying to determine its sex.
“It looks like it’s a female,” Parker said.