The Kihansi spray toad was first discovered in 1996, living in a five-acre micro-habitat created by the spray of nearby waterfalls in the Kihansi Gorge. In 1999, the construction of a hydroelectric dam was predicted to dramatically change the Kihansi spray toad’s habitat. The micro-habitat where the toad lived was dependent on the mist created by the waterfalls in the gorge. The dam, generating nearly one-fourth of Tanzania’s electrical supply, reduced the flow of the Kihansi falls by 90 percent, drastically lessening the mist zone.

The toad was last seen in the wild in 2005, and in 2009, it was declared extinct in the wild by the IUCN. Although the ultimate cause for extinction is still debated, it is likely a combination of habitat change and the emergence of chytrid fungus, a virulent pathogen which is responsible for alarming population crashes and extinctions of amphibian species across the world.

As the spray toad population rapidly declined, an agreement between WCS and the Tanzanian government was reached. Bronx Zoo scientists and Tanzanian officials collected an assurance colony of 499 Kihansi spray toads from the gorge. The small colony was brought back to the U.S. to initiate the off-site conservation program. Special microhabitats meeting all the environmental parameters necessary for the toads to survive were replicated in bio-secure facilities at the Bronx Zoo and later the Toledo Zoo. Both zoos were successful in breeding the toads and increasing their numbers so reintroduction efforts could commence.

Said Dr. Cristián Samper, WCS President and CEO: “The reintroduction of the Kihansi spray toad to the Kihansi Gorge is a momentous achievement in conservation. It clearly shows how zoos can play an important role in conservation. This has been a truly global effort to save a species. This project proves that through partnership and science – wildlife can prevail.”

In 2010, 100 Kihansi spray toads were returned to Tanzania, where a propagation center at the University of Dar es Salaam allowed for the establishment of a third assurance population and  preparations for the species’ eventual repatriation.

The Bronx and the Toledo zoos will continue to maintain an assurance population of the spray toads and have them on exhibit for visitors to see. The released toads and habitat will be closely monitored to ensure that environmental conditions remain favorable and to evaluate the progress of the animals. Additional releases may occur periodically to bolster the number of toads with the hope of having a viable, self-sustaining population.

Photo Credits:  Julie Larsen Maher (first, second, and fifth photos), Alyssa Borek (third and fourth photos)