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Another hand-raised zoo baby: It's a sloth!

The sloth, the slowest-moving mammal in the world, is one of the weirder zoo animals to be recently raised by humans.

When Erin Lewter was thrown into motherhood, she wasn’t sure what to do with her baby — a two-toed sloth.

She and fellow handlers at the Central Florida Zoo in Sanford had saved the infant, born in May, which turned dangerously weak after failing to feed properly with its mother at the zoo.

It was the facility’s first time raising a sloth — ever. Problem was: Nobody knew how to do it. The night of the rescue, zookeepers reached out to colleagues across the country. Finally, a veterinarian at the University of Florida scanned and e-mailed a chapter on sloths from a book about hand-rearing mammals.

“Only a few other [U.S.] zoos have ever hand-reared two-toed sloths,” Lewter said.

The sloth, the slowest-moving mammal in the world, is one of the weirder human-raised zoo animals in recent memory. Hand-raising, though, seems to be more common these days since German polar bear cub Knut, who was rejected by his mother and brought up by zookeepers, became an international celebrity.

His stardom paved the way for other zoo babies, including a neglected tiger cub and forgotten penguin chick. But Steve Feldman, a spokesman for the Association of Zoos and Aquariums, said the media attention doesn’t coincide with an upsurge in hand-rearing.

“There’s more attention being paid to that aspect because of the high-profile nature of Knut,” he said.

Will baby know it’s a sloth?
Plucking animal babies from mothers does, however, raise a red flag for Lisa Wathne, a spokeswoman for animal-rights organization PETA. She fears it could be a “promotional gimmick” to increase foot traffic and funds for zoos.

But, Wathne acknowledges that zoos have moved away from hand-rearing since the 1980s. Before that, she said, zookeepers had failed to see that baby animals with a natural upbringing fare better.

“As the zoo community started being comprised of people who’re educated and had degrees in animal behavior, attitudes changed,” said Wathne, who has a degree in biology and has worked in animal protection for 14 years.

Bonnie Breitbeil, the curator of the Central Florida Zoo, said hand-raised animals can lose their fear of humans, making them more dangerous because wild animals may be more likely to approach their zookeepers, rather than keep away.

Animals who grow up among their own kind may socialize better — and not get confused about what they are. “They know they’re a sloth or a lion,” Breitbeil said.

Central Florida Zoo staff attempted three times to return the sloth infant to its mother. The baby had a normal birth. But for unknown reasons, the creature just didn’t nurse, perhaps because its suckling reflex was not strong enough, Lewter said.

The sloth mom, who's called J.J., initially appeared to be a good mother, despite it being her first offspring. With her body, J.J. formed a near-basket around her little one for cradling. Quickly, the dehydration got the best of the newborn, which apparently lost grip of its mother, who normally hangs from tree props, because it was later found in an elevated food dish.

“At our facility, we don’t intervene unless it’s absolutely necessary,” said Breitbeil.

Baby sloth becomes an exception
As the baby sloth became weaker, its mother made little effort to keep it on her, possibly because her instinct to ignore a weakling had taken over. Soon, the baby’s eyes sunk in and its footpads deflated. 

“After we got fluid in him, he looked healthier,” said Lewter, who calls the baby “he” although its gender is undecipherable so far. “His pads on his paws were plump. His eyes were better.”

Image: Baby sloth

Lewter and five other zookeepers have become the baby’s surrogate mothers. It’s a 24-hour job: Guided by the hand-rearing book, the baby sloth got fed goat’s milk every two hours at first — and about a month later, the feeding schedule changed to every four hours.

Lewter, who gets custody about four to five days a week, said this baby is unlike any animal she has ever brought home. Compared to the adorable bird chicks and stray kittens she’s raised, the sloth newborn is “strange looking,” she said.

“He has incredibly long arms and legs. He moves in a very different way, in slow movements,” she said. “My mom said he looked like a kind of alien.”

That may explain why people largely misunderstand them. A new study published in Biology Letters challenged what scientists always believed: That sloths deserve their namesake. Researchers, however, had previously made their findings based on captive sloths, which get a whopping 16 hours of shuteye a day. The study found wild three-toed sloths sleep six hours less than they do in zoos.

How will baby sloth be reintegrated?
Two-toed sloths, which have three toes like all sloths but only two fingers, move faster than their three-toed cousins, which have three fingers. (Perhaps the inventor of the sloth nomenclature mixed up toes and fingers.)

Despite the baby sloth’s strange appearance, Lewter said the infant does cute things like climb on her back, squirm around — and latch onto things.

Sloths hang upside down in canopies most of their lives. They have less success on the ground, where they're susceptible to predator attacks. All sloths became tree-dwellers after their forefathers, who lived on the ground, became extinct about 10,000 years ago.

In the temperature-controlled cooler where the baby spends most of its time, it instinctively clings onto towels and stuffed animals.

“He likes to chew on your fingers and lick them,” Lewter said. “Baby sloths’ eyesight is not very good, so they ‘see’ through their tongue. He’s exploring the environment with his tongue."

Zookeepers haven't determined how to reintegrate the newborn with its kind — if at all. For now, they’re concentrating on a more imminent problem.

"I'm wondering how long until he starts trying to climb out of the cooler," Lewter said.