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4 Animals That Change in Captivity

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Put a wild animal in a cage, and it’s bound to act differently. Zoologists and vets have many strategies to help an animal get settled and normalize its behavior in captivity. Psychological changes can be overcome with animal enrichment programs that keep creatures entertained and mentally stimulated—but some of the internal and physical changes in these four animals are more difficult to tackle.

1. Koalas

Image courtesy of jsteel's Flickr stream.

While some animals eagerly engage in free love (deep sea squid, bonobos, and penguins have all been found to have bisexual tendencies), koalas are a more conservative bunch. These eucalyptus-munching marsupials are strictly heterosexual—at least in the wild. Once in captivity, female koalas participate in lesbian orgies. According to scientists at the University of Queensland, who monitored 130 koalas using digital cameras, female koalas in captivity engage in homosexual acts three times as often as they participate in heterosexual activities. The orgies often include up to five females at a time. (They don’t count the males out, though: The females' heterosexual activities lasted twice as long as their homosexual encounters.)

Scientists remain uncertain about the cause of these encounters. Some believe that female koalas use the orgies as a method of attracting males, while others think it’s a hormonal behavior. Still others believe it serves to release stress.

2. Komodo Dragons

Image courtesy of vsellis' Flickr stream.

Don’t get bitten by a wild Komodo dragon: Their mouths contain 57 septic pathogens including e. coli and Staphylococcus which, according to some scientists, cause horrible infections in the creatures’ victims. (Lucky for the dragons, they’re immune to all the bacteria.) Once in captivity, however, Komodo dragons lose their filthy mouths thanks to cleaner diets and antibiotics which kill the pathogens.

Why give Komodos antibiotics when they’re immune to the bacteria? Once taken from the wild, the dragons are highly susceptible to infection and disease. This may be because the animals have a lower core temperature in captivity, but no one knows for certain.

3. Poison Dart Frogs

Image courtesy of e_monk's Flickr stream.

The bright color of a poison dart frog’s skin is a loud warning: Don’t touch me! The poison secreted by these paper-clip-sized amphibians is so deadly that indigenous tribes in South America coat their hunting darts with it. (According to National Geographic, the Golden poison dart frog has enough venom to take out 10 men.) But the frogs generally stop being poisonous once removed from the wild .

As with the Komodo dragon, this change comes down to diet. Poison dart frogs derive toxins from what they eat: Some get their poison from ants, others from beetles, a few from spiders. The toxins are collected in glands in the frogs’ skins and secreted through it, which is what makes them poisonous to the touch. It’s practically impossible for zookeepers and others who take care of the animals to obtain these toxic food sources.

Frogs taken from the wild can hold on to their poison for a long time, sometimes years. But eventually they lose their toxicity, and captive bred frogs will never become poisonous (unless, of course, they’re fed the specific insects that result in that species’ toxicity).

There is one exception to this no-toxin rule: Australia’s corroboree frog, the only species known to produce its own poison rather than deriving it through diet. These creatures maintain their poison no matter how many generations are raised in captivity—a very good thing because captive breeding and eventual release into the wild is the only hope of survival for the critically endangered frogs.

4. Japanese Fire Belly Newts

Image courtesy of Eric Michon's Flickr stream.

Like poison dart frogs, these newts are highly toxic in the wild; they secrete Tetrodotoxin, a neurotoxin for which there is no antidote. But in captivity, the animals may lose their toxicity. The key word here is “may”: Some newts born in captivity actually hold on to their poison instead of losing it. While scientists are unclear about the reason for this occasional biological change, many speculate that the animal’s toxicity is formed through contact with an environmental bacteria that is sometimes, but not always, passed to the next generation.

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9 Wild Facts About the Bronx Zoo
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Even if you’ve never set foot in New York, you almost certainly know of the Bronx Zoo. Opening its doors for the first time in 1899, this sprawling 250-acre wildlife reservation has over 4000 different animals and 650 species. Take a look at a few things you might not have known about one of the world’s most famous zoological retreats.

1. IT WAS CO-CREATED BY A TAXIDERMIST.

William Temple Hornaday was working as a taxidermist for the Smithsonian Institution when he noticed that the nation’s population of bison was shrinking. Eager to promote conservation efforts, Hornaday used his voice with the Smithsonian to spread the word about the threatened species. After a spat with the Institution, he was approached by the New York Zoological Society in 1896 to serve as director of the Bronx Zoo. In doing so, Hornaday helped bring the bison back from the brink of extinction by sending several of the Zoo's bison back out west in 1906. He remained with the zoo for 30 years.

2. IT ONCE HOUSED TASMANIAN TIGERS.

Thylacines, or Tasmanian tigers, were nearing extinction in the early 1900s, but the Bronx Zoo was able to acquire several for exhibition beginning in 1902. The first lived for six years; the next two, arriving in 1912 and 1916, lived only a short time in captivity before perishing. The zoo's last thylacine was secured in 1917. The species was thought to have died out in 1936, but in early 2017, several eyewitness accounts of the distinctive animals were reported in Australia. Zoologists are working to determine if the thylacine might still be alive.

3. THEY EXHIBITED A MAN.

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In the most ignoble chapter in the zoo’s history, organizers opened an attraction in 1906 that featured a "Mbuti pygmy” or “bushman”—an African man named Ota Benga. Benga and other tribesmen had been brought to America by anthropologist Samuel Verner at the behest of organizers of the 1904 St. Louis World's Fair so visitors could gawk at them in mock-up villages. When the fair was over, Verner brought Benga and others back to Africa: the two struck up a friendship, and Benga reportedly asked to come back to the States. Verner approached the Bronx Zoo with the prospect of Benga becoming a fixture: Hornaday agreed to let him live on and roam the grounds. Public outrage followed, and Benga was released after just two weeks to the care of an orphanage. He committed suicide in 1916.

4. THE ZOOKEEPERS HAD TO BE TOLD NOT TO MAKE FRIENDS WITH THE BEARS.

Too much children’s literature about cuddly bears may have proven disastrous for early zookeepers at the park. In 1919, Hornaday told the New York Tribune that he had to constantly warn his employees not to try and befriend the mammoth bears housed on the property. Two keepers ignored his advice; both had to be pried from the clutches of the bear and suffered “severe” injuries.

5. IT’S HOME TO A REMNANT OF THE ICE AGE.

Not all of the Zoo’s attractions are feathered or furred. The Rocking Stone sits near the World of Darkness exhibit and packs 30 dense tons into a formation standing 7 feet tall and 10 feet wide. The boulder was carried by glaciers in the last Ice Age. The “rocking” label came from the fact that the stone was so perfectly balanced that it could be moved with slight pressure. The Zoo, fearing someone might one day push it too far, eventually shored up the base to keep it on firmer footing.

6. THEY ONCE SAVED A SPECIES OF TOAD THAT WAS DECLARED EXTINCT.

The kihansi spray toad was in dire circumstances in 2009: A hydroelectric dam in Tanzania had dried up mists showering a five-acre area near Kihansi Gorge, the toad's only known micro-habitat, and the species was officially declared extinct in the wild. Fortunately, Tanzanian authorities had seen the situation coming and allowed the Bronx Zoo to come in and obtain 499 toads to bring back to America. A portion went to the Toledo Zoo; both facilities spent nearly a decade breeding them in a captive assurance population. The Zoos replicated their habitat while Tanzania created a gravity-operated misting system that would restore water. Roughly 100 toads were returned in 2010 as test cases; a full-scale reintroduction followed in 2012.

7. A COBRA ONCE ESCAPED (AND SIGNED ONTO TWITTER).

A photograph of an Egyptian cobra
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Animal escapes have been few and far between at the Zoo. One of the most publicized was the the disappearance of a 20-inch venomous Egyptian cobra in 2011. Zoo officials weren’t certain how the reptile broke out of her habitat, but felt confident she would remain in the building. She did, and was found after a week’s search. In the interim, someone on Twitter engaged 203,000 followers with the freed snake’s fictional exploits. It’s still tweeting.

8. IT SET AN ORIGAMI ELEPHANT WORLD RECORD.

In 2016, the Zoo was recognized by Guinness World Records as having the largest displayed collection of origami elephants in the world: 78,564. The display, which was briefly open to the public, was intended to draw attention to the plight of the creatures and their poaching rivals through their 96 Elephants campaign meant to stop the trafficking of ivory. The Zoo is down to just three live elephants, and has vowed not to acquire any more once they pass. On August 3, 2017, Zoo organizers plan to crush two tons of ivory in Central Park as part of the awareness campaign.

9. IT HAS PLANS FOR YOUR POOP.

A shovel is stuck in a pile of fertilizer
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With thousands of daily visitors, the Bronx Zoo could probably make use of its own sewage system. Instead, the park unveiled an eco-friendly restroom on park grounds in 2006 that captures human waste and diverts it into compost. The system, which uses only six ounces of water per flush, is estimated to save a million gallons of water a year.

Want to learn more about the Bronx Zoo? Catch The Zoo, a documentary series now airing on Animal Planet. New episodes premiere in February.

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World’s Oldest Sloth Dies at 43
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Courtesy the Adelaide Zoo

The oldest sloth in the world has died, according to LiveScience. Miss C, a Hoffmann’s two-toed sloth that lived at the Adelaide Zoo in Australia, was 43 years old.

She was put to sleep after her keepers noticed her acting unwell on June 2. She had several age-related health issues, as might be expected from an animal thought to be the oldest of her kind. “The treatment Miss C required was very invasive and would likely only delay the inevitable so the hard decision was made to humanely euthanize her,” one of the zoo’s curators, Phil Ainsley, said in a statement. She had lived at the Adelaide Zoo since birth.

The average lifespan of a Hoffmann’s two-toed sloth in the wild is 12 years, and in captivity, 31 years. Miss C’s male counterpart at the zoo, Al G, died in 2015 at the age of 26. At the time of her death, she was the only remaining sloth in Australia.

Hoffmann’s two-toed sloths are native to the tropical environments of Central and South America. In the wild, two-toed sloths like Miss C largely live in tree canopies, only making their way down to the ground periodically to poop.

It has been a tough year for record-holding zoo animals. Elly, the oldest black rhino in the world at 46, died at the San Francisco Zoo in May.

[h/t LiveScience]

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