4 Animals You Can Only Find in Zoos

filed under: zoos
Image credit: 

People go to zoos to see the animals from exotic locales we couldn’t get to on our own. But some of these animals can’t be seen anywhere except zoos. These are the animals that are extinct in the wild, dependent on the keepers and zoo breeding programs for their very survival. Here are a few animals that you can only find in zoos, and two that have been re-released into the wild.

1. New Guinea Singing Dog

While scientists argue about this adorable canid’s taxonomic status, some even classifying them with domestic dogs, they do have a distinct genetic code and are unique from all other existing canines.

The first of these dogs to be studied was taken from New Guinea in 1897, but because they were largely considered feral dogs, not a special breed or species, little research was performed on the animals until much later. This delayed any protection of the dogs in the wild, although their numbers drastically declined in the twentieth century until there were no more left. There have not been any sightings of the animals in the wild since 1970. There are a number of the dogs in captivity in zoos around the world but, unfortunately, they have been largely inbred from a small genetic pool so it is unclear if the population can ever be restored.

[Image courtesy of whatadqr's Flickr stream.]

2. Pinta Island Tortoise

If you’re a regular Mental Floss reader, there’s a good chance you’ve already heard of Lonesome George, but just in case, here’s a quick recap of the world’s most lonely tortoise. The Pinta Island tortoises are one of the many subspecies of Galapagos tortoises, but what makes this specific breed so special is the fact that there is only one known to be in existence. That would be poor Lonesome George.

George was discovered on Pinta Island on December 1, 1971, after the island’s vegetation was destroyed by feral goats. He was rescued from the island and brought to the Charles Darwin Research Station on Santa Cruz Island, where he would have plenty of food to munch on. George was penned with two females of other Galapagos subspecies, but while they have laid eggs, none have been fertile. George is estimated to be around 100 years old (reasonably young for a tortoise) and he’s very healthy, so he should be in his reproductive prime. Scientists are offering a reward of $10,000 for anyone who discovers a female Pinta Island tortoise who may help save the subspecies.

[Image courtesy of putneymark's Flickr stream.]

3. Kihansi Spray Toad

This toad’s natural habitat was limited to the spray zone of two waterfalls in Tanzania. The toads relied on the water spray to provide them with oxygen. After a dam was built upstream from the waterfalls, the spray was reduced by 90%, causing an immediate reduction in the toad population. To make matters worse, as conservationists tried to step in and help the toads by installing the world’s largest sprinkler system, they accidentally tracked in a deadly fungus, which decimated the toad population.

Fortunately, before the dam was built, some of the animals were put in captivity. Since the animals disappeared from the wild, the Toledo Zoo, the Bronx Zoo and the Chattanooga Zoo started captive breeding programs with their Kihansi spray toad populations. Until last year, these were the only places where the spray toads survived, but in 2010, 100 toads were flown from the Bronx and Toledo Zoos to Tanzania. While they are now back in their native land, there are still no plans to re-release them into their natural habitat, which is still impacted by the dam.

4. Micronesian Kingfisher

Like many island animals, the Micronesian kingfisher was perfectly adapted to its native habitat in Guam. But with one small change, its existence was suddenly changed forever. It all started in WWII, when brown tree snakes were introduced to the island. Guam never had any large native snakes and the birds had no defense mechanisms against the fast tree dweller.

As time wore on, the bird’s population began to drastically decline, but no one realized the snakes were to blame until 1983. By that time, it was too late to stop the snakes. Scientists captured the remaining 29 kingfishers on the island and put them in zoos with breeding programs. By 1988, there were no more wild kingfishers on Guam.

Since the animals were introduced to zoos, the population doubled to around 60. Unfortunately, the captive birds have showed aggression to one another, so the chicks have to be raised by zoo staff members to ensure their safety. Before scientists can hope to reintroduce the birds to the wild, they must better understand the bird’s nutritional needs and the reason for their aggression. All of these challenges mean it will probably be a long while before there are more Micronesian kingfishers in the wild.

[Image courtesy of coracii's Flickr stream.]

* * * * *

It’s not all doom and gloom for animals that have become extinct in the wild, though. While the term is often used interchangeably with “functionally extinct,” many of these animals do make a comeback thanks to captive breeding programs. Here are a few animals that were once extinct in the wild, but have since been reintroduced into their home territory.

Guam Rail

Like their islandmates the Micronesian kingfishers, the Guam rail evolved in the absence of any predatory snakes and were eradicated by the introduction of the brown tree snake. They were also removed from the wild around the same time as the kingfishers and entered into a breeding program. Unlike the kingfishers though, the rails did very well in their program. After 20 years, the population increased enough that the birds were able to be released back into the wild. Because the brown tree snakes made Guam unsuitable for the birds, they were instead released into the wild on the nearby island of Rota in the Northern Mariana Islands.

There are currently seventeen zoos participating in the Guam rail breeding program, working to further increase the viability of this highly endangered species.

California Condor

Condors naturally have a low birthing rate and a late age of sexual maturity, so when they started to fall victim to environmental hazards such as DDT and lead poisoning from eating animals killed with lead buckshot, they had a hard time building their numbers back up.  By 1987, there were only 22 condors left in the wild, all of which were captured for a captive breeding program.

Because the condors lay only one egg at a time and wait a long time between clutches, the zoologists involved took the first egg laid by the birds, incubated it, and raised the chick themselves. The birds would then lay a second fertile egg, meaning researchers could double the number of chicks born at the zoo.

The program was incredibly successful. Within only four years, researchers were able to release some of the birds back into the wild. The program has continued to produce birds in captivity, but the wild birds have started breeding on their own as well. Before being released, the birds are now trained to avoid power lines and wind turbines. California has also passed a law banning hunting with lead buckshot in the California condor's habitat to protect the birds from lead poisoning. There are currently 189 birds living in zoos and 192 in the wild—a far cry from the 22 individuals left when the breeding program began.

[Image courtesy of primatewrangler's Flickr stream.]

More from mental_floss...

May 31, 2011 - 9:58am
submit to reddit