This year’s IUCN Red List has updated its assessment of the Kihansi spray toad, moving the species from Critically Endangered to Extinct in the Wild. With that another amphibian species has been lost to a combination of habitat loss and the devastating amphibian disease, the chytrid fungus.
The Kihansi spray toad Nectophrynoides asperginis, which still survives in a number of zoos in the United States, had lived on just two hectares along the Kihansi gorge in Tanzania. The toad was specially adapted to the spray region of the Kihansi waterfall, which kept its small environment at a constant temperature and humidity.
The construction of a dam, funded by the World Bank, upset the flow of the waterfall and devastated the species. The toad was only discovered a year into construction of the dam, along with two plants, which were endemic to the microenvironment like the toad.
The Kihansi spray toad. Photo by: Tim Herman.
Several attempts were made to save the toad, including a sprinkler system set up to mimic the natural spray of the water that had been diverted for the dam, however the species continued to decline. In July 2003 after some recovery, the species was struck down by the chytrid fungus. A few individuals were found to be lingering on as late as 2004, but they couldn’t sustain the species and they too soon vanished.
In the midst of this crisis, 500 individuals of the Kihansi spray toad were taken to American zoos to start a breeding program. The program had numerous setbacks in the beginning, but as of 2007 the breeding program had retained around 460 individual frogs.
The Kihansi spray toad is a dwarf toad, no more than three quarters of an inch long.
Kihansi Spray Toad faces extinction
(07/07/2005) The number “52” is written on a white board and boxed with black pen like the long-sought solution to a math problem. The concern is this number is the result of a massive subtraction problem; one that leaves a small yellow toad teetering on the edge of oblivion.
Toad on brink of extinction, scientists race to study for bioactive compounds
(06/29/2005) Following the construction of a dam in Tanzania, the Kihansi Spray Toad sits on the brink of extinction. Scientists are racing to study the amphibian for bioactive compounds with potential medical applications.