Classified as Extinct in the Wild on The IUCN Red List of Threatened Species™, the Kihansi Spray Toad (Nectophrynoides asperginis) is the focus of conservation efforts involving the International Union for Conservation of Nature’s (IUCN) Species Survival Commission (SSC) Amphibian Specialist Group and the IUCN SSC Re-introduction Specialist Group. Together with a collaboration of a number of partners across the world they are reintroducing the Kihansi Spray Toad back to its original habitat.
Once abundant in a tiny area, a population of around 17,000 Kihansi Spray Toads lived in vegetation that was soaked by the spray of the Kihansi falls. A serious population decline occurred after a dam was built upstream on the Kihansi River which reduced the flow of water to the gorge by 90% and altered the habitat. A sprinkler system was constructed in 2000 which restored much of the vegetation and the population of the Kihansi Spray Toad recovered. However the toad population declined dramatically in 2003 and although chytrid fungus has been implicated as a potential factor given that it was confirmed in deceased toads, the contributions of each threat factor towards this species’ demise in the wild are still not fully understood.
In 2000, as part of an effort to stop the extinction of the Kihansi Spray Toad, the Tanzanian Government invited the Wildlife Conservation Society to collect some of these toads and take them to the USA where they were bred in captivity at both Bronx Zoo and Toledo Zoo. This population grew from an initial 499 toads to over 6,000 today. In 2010 a captive colony was established in Tanzania by the University of Dar Salaam and National Environmental Management Council researchers.
Also in 2010, a team of conservation experts including the IUCN SSC Amphibian Specialist Group and the IUCN SSC Re-introduction Specialist Group came together to develop a plan to reintroduce the Kihansi Spray Toad back into its natural habitat. By this time, the sprinkler system that had been installed in 2000 to recreate the spray of the river was working properly and had helped restore the habitat to conditions suitable for the Kihansi Spray Toad. Bridges and walkways were also built to allow long term monitoring of the reintroduced species without causing further disturbance to the habitat.
Following successful trials, the first release of the Kihansi Spray Toad back into the wild took place on 29 October 2012. A total of 2,500 toads had been flown from the USA to Tanzania four months before and acclimatized to their new surroundings before being released back into their native habitat. More releases are expected in the future as researchers work towards the goal of establishing a population that is able to sustain itself.
“The success story of the small Kihansi Spray Toad can teach us big lessons for the future of biodiversity conservation,” said Dr Claude Gascon, Co-Chair of the IUCN SSC Amphibian Specialist Group. “While amphibians and other species are incurring severe threats to their survival, it is never too late to use the best science and conservation action to save a species and its habitat. This success story has only been possible with the help and partnership of many organizations around the world and the leadership of the Government of Tanzania, and the belief that no species and no situation is too dire to try to save life on Earth. Extinction in the wild is not forever.”