Ideas: Spring 2008

Henry Doorly Zoo: Making a World of Difference

Omaha’s Henry Doorly Zoo has taken a lead role in amphibian conservation, working with others around the world to prevent hundreds of endangered species from the threat of extinction. In a modest setting unseen by the zoo’s 1.3 million annual visitors, zoo personnel are using energy to simulate various habitats, making the treasured amphibians feel right at home.

In a semiarid region of Puerto Rico, a Puerto Rican crested toad blends into its surroundings. With hues of olive green, gold and brown, the toad’s textured, bumpy skin mirrors the vegetation and rocky terrain around it. The camouflage may trick predators, but the small amphibian – and about 2,000 other species worldwide – is on an endangered list, with the threat of becoming extinct.

“Half of the amphibians on our planet are threatened with extinction,” said Jessi Krebs, supervisor of reptiles and amphibians at Henry Doorly Zoo.

Omaha's Henry Doorly Zoo, together with other zoos and organizations, has launched the Amphibian Conservation Initiative to address this issue on a global scale. This initiative includes the establishment of facilities and the training of staff capable of quarantining amphibians and carrying out captive breeding programs. Once threats have been lowered or resolved, offspring of the amphibians will be released back into the wild. 

According to Krebs, declines in amphibian populations are due to many factors, including loss of suitable habitat, logging, urbanization, pollution and some agricultural practices. In addition, diseases – particularly the chytrid fungus – are spreading rapidly through worldwide amphibian habitats, killing entire populations at alarming rates.
“Not since the dinosaurs has the planet experienced such a loss of biomass,” said Krebs, who came to Henry Doorly 12 years ago from the Denver Zoo.

That’s a scary thought since amphibians are vital to the ecosystem and research. Frogs and toads act as exterminators, controlling populations of insects such as mosquitoes, which may carry the deadly West Nile Virus and malaria. Currently, skin secretions from some amphibians are being used in the pharmaceutical industry to help treat specific conditions including cancer, and other amphibians are aiding in medical research.

Back to Nature
There’s a good chance the Puerto Rican crested toad spotted in the wild was bred at Omaha’s Henry Doorly Zoo, which established its amphibian conservation area three years ago. The Puerto Rican crested toad, the first amphibian to receive species survival plan status, was among the first the zoo took in. With only 150 known in captivity and only a few hundred estimated in the wild, zoo personnel released about 800 back into a pool that they helped build in an area of Puerto Rico that had not seen these frogs in 30 years.

In southeast Wyoming, the zoo released 7,000 Wyoming toads back to their native habitat, thanks to the project. Once the most abundant animal in that area, it was thought the species had been reduced to about 10.

There are many more species that the Amphibian Conservation Initiative is helping.

“We had been watching the decline of amphibians since the 1980s, but this decade, we committed to doing our part to help,” Krebs said.

When Director Dr. Lee Simmons, Assistant Director Danny Morris, Krebs and others at Henry Doorly Zoo made that commitment, they did so knowing that there was no specific funding for the project, and that the project wasn’t a money-maker.

“Having the opportunity to affect all of these species is a natural for us,” said Morris. “We don’t know what the impact of their extinction would be – short term or long term – to the balance of nature.”

Two full-time keepers and one part-time keeper care for the amphibians while at the zoo, but several other experts there play an integral role in the project. They deal with genetics and reproduction, physiology and hormone regiments, nutrition and proper diet, and education.

Imitating Nature
Tucked away in an unused corridor, the zoo currently has seven climate-controlled rooms, each of which houses a specific species of endangered amphibians from the southeast United States, Wyoming, Mississippi, Panama or Puerto Rico. Three additional rooms are under construction, and there is room for another five or 10.

Each environmentally controlled chamber is heated and cooled in a manner that replicates the animals’ natural habitats, and thermal gradient lights allow them to create hot spots up to 100 degrees Fahrenheit to warm them. A pumping system in each tank helps humidify the setting, showering mist at varying integrals to raise the humidity level. This and other sensitive areas at the zoo are covered by backup generators, which would kick on in the event of a power outage.

Zoo personnel take great care to provide suitable water for the amphibians. Each day, a reverse-osmosis system purifies 300 gallons of water for use in the aquariums. The water also goes through mechanical filtration and ultraviolet treatment before it becomes reconstituted “frog water.” Once the frogs are done with it, the wastewater goes through a treatment process before it leaves the zoo grounds.

“The keepers scrub in and gown up before they go in each room, just like doctors,” said Krebs. “Nothing goes in or out without being sterilized. When they go from room to room, they change boots and lab coats.

“The simple, sterile environment meets all the requirements of the animals,” said Krebs. “We are doing everything ourselves, and we are doing it frugally, which shows our level of dedication to the effort.”

Nurturing Nature
 More than 20 zoos have visited Henry Doorly’s facility, working alongside the keepers, and other zoos are coming on line with the project. Zoo personnel also are working with local governments around the world, giving them the tools to save their own frogs. They also have “frog loggers” monitoring endangered species.

“They go out at night with headlamps and listen to the calls of the frogs,” Morris said. “If they hear five or six, and the year before they heard 30, it’s an indication that there’s a problem.”

To further increase awareness, the zoo has deemed this the Year of the Frog. The zoo’s Butterfly Pavilion, which opens this spring, will include a display about the amphibian conservation project.

“This effort goes beyond amphibians,” said Morris, the assistant zoo director. “People need to feel stewardship, and be careful and responsible with the environment.

“We hope by giving them a peek, they will appreciate our level of commitment and see how serious we are,” Morris said. “We want to inspire them to make a difference at home.”

Going Green at the Henry Doorly Zoo
While the amphibian conservation area at the zoo is a tremendous environmental effort, there’s plenty more. Among the zoo’s “green” efforts:

• composting a tremendous amount of waste (animal and biological waste, leaves, hay) for use on grounds
• recycling
• using more green products
• installing occupancy sensors in all new buildings and in remodeled areas
• using ice to help cool facilities
• testing waterless toilets