HAWA NDIO VYURA WA KIHANZI/KIHANZI TOADS

Kihansi toads lived in the spray of a single waterfall before a major hydropower dam was built, But the Kihansi toad lives on thanks to the efforts of Tanzania and two American zoos. One hundred extremely rare Kihansi spray toads, a species last seen in Tanzania in 2004 after their habitat was destroyed by a new hydroelectric dam, have been flown home from the Bronx and Toledo zoos in the US.

Kihansi toads

A newborn Kihansi spray toad clings to the back of an adult female at the Bronx Zoo in New York.

They were taken to a "state-of the-art propagation centre" in Dar es Salaam where staff, presumably detecting a lot of tiny smiles, described the toads as "cheerful".Well they might be. If all goes well they will soon be returned to their parents' old hopping grounds, cooled by an artificial sprinkler system to mimic their original misty home.

Kihansi toad

The species was first discovered in 1996 during an environmental impact study for a large new hydroelectric dam in the Udzungwa mountains, in southern Tanzania. The toads lived exclusively in a five-acre zone under the spray of a waterfall.

Three years later construction of the hydroelectric dam drastically reduced the waterfall's flow, and the blanket of mist that gave the Kihansi spray toads their name disappeared. Soon, so too did the amphibians. With no sightings for five years, the toad was declared to be extinct in the wild by the International Union for the Conservation of Nature. 

Fortunately the World Bank, which part funded the dam, and the Tanzanian government had agreed on a plan in 1999 to try to ensure the species lived on. A colony of 499 toads were taken from the gorge to the US zoos, where they were bred in laboratories. They are now about 6,500 at the zoos. Unusually among toads, the females do not lay eggs that hatch into tadpoles, instead giving birth to fully formed young.Scientists who worked on the project suspect that a combination of habitat loss, exposure to pesticide, and the emergence of infective chytrid fungus led to the toad's original demise in the wild.