8 min read

The 10 Reptile And Amphibian Species Deemed ‘Most Reliant On Zoos’

<p><a class="checked-link" href="https://www.flickr.com/photos/rachdian/5418187901/in/photolist-9fMCuM-arD7K-96of8S-9UkVkL-6zYBZd-6zUudz-6zUts6-bATsxM-aLNyia-6zUsb6-6zUuDZ-6zYyKu-9qug71-6zUsZM-6BsgFA-5hVeoG-6zYyqJ-6zYzvm-7CYWe5-oABGsK" style="text-decoration: none;">Adhi Rachdian</a></p>

Ten threatened species, from the massive komodo dragon to the rare mountain chicken frog, have recently been deemed "most reliant on zoos." But not all conservationists believe that captivity holds the answer.

The British Association of Zoos and Aquariums (BIAZA) recently released a list of the "Top ten reptiles and amphibians benefitting from zoos": the axolotl; the golden mantella; the komodo dragon; the lemur leaf frog; the Morelet's leaf frog; the mountain chicken; the orange-tailed skink; the ploughshare tortoise; the Round Island boa; and the sand lizard. The International Union for the Conservation of Nature lists six of the species as critically endangered and one as endangered. All face human-made threats.

A golden mantella (Photo: The Deep)
Despite evolutionarily parting ways 300 million years ago, scaled reptiles and slippery-skinned amphibians - what with their cold blood and (generally) four legs - are often lumped together in zoos and museums. And though they might use their habitats differently, the animals frequently share similar surroundings around the world.

As ecological roommates, reptiles and amphibians are "equally vulnerable to habitat degradation," herpetologists at the University of Georgia and the Center for Biological Diversity pointed out in a 2000 paper. Fourteen years later, the "global threats of deforestation, draining of wetlands, and pollution from agricultural runoff" still pose a risk - if not increasingly so - to animals from both of these classes.

Zoos help these reptiles and amphibians by maintaining a healthy stock of rare animals, says Andrew Marshall to The Dodo. Marshall, a conservationist at the University of York and the zoological park Flamingo Land, helped curate the list. For species that have little chance of surviving in the wild, Marshall says, "there's a real need for a captive breeding program." (Biologists are aware that sounds a bit like Noah saving animals from the flood, calling it the "ark concept.") By tracking the genetics of animals in captivity across the globe, zoos aim to avoid the loss of diversity associated with a population bottleneck.

Sand lizard (Photo: Chester Zoo)

But there are drawbacks. Contributions to conservation "cannot be considered without balancing against the losses imposed on those individual animals who have been denied so much by the same industry," Liz Tyson, the director of the Captive Animals' Protection Society, says in an email to The Dodo. "If you are concerned about the conservation of species, please do not support zoos."

Breeding programs can also be hampered by international legislation meant to stop wildlife trafficking, which prevents potential mates from crossing country borders. These laws are "a seriously huge barrier to developing breeding programs of endangered animals," said Dalia Conde, a University of Denmark biologist, in a statement last year.

Zoo experts agree that some of the most important work is done in animals' home countries. Ferrying animals across the world poses "a risk that new diseases could be introduced," says Benjamin Tapley, a herpetologist at the Zoological Society of London who works with mountain chickens. "It's better to breed the animals in the country of origin."

The population of mountain chicken frogs has been in freefall since 2002, following an outbreak of the deadly chytrid fungus. On the frog's home island of Dominica, the Zoological Society of London helped establish a mountain chicken breeding program. "It's not possible at this stage to treat the environment," Tapley says. Other frogs on the island carry the disease - but don't appear to have any problems - acting as a reservoir of the fungus.

A mountain chicken. (Photo: Gerardo Garcia, Chester Zoo)

Hundreds of miles away from home, however, it's tougher to raise species for conservation. "Husbandry is always going to be challenging," says Iri Gill, a herpetologist at Zoological Society of London, to The Dodo. Zoo experts are at "the forefront of collecting microhabitat data," he says; changing the levels of ultraviolet light, for example, can mimic the environmental fluctuations in a native country, with the goal of improving an animal's captive surroundings.

But zoos, by their very nature, won't ever be able to perfectly represent an animal's habitat. Captive animals "will be denied their freedom and their ability to carry out some, if not most, of their natural behaviors," Tyson says. "Instead, seek out those projects working hard within the animals' natural home territory and support them directly."