Description: The Kihansi spray toad, Nectophrynoides asperginis, is endemic to only one specialized locality in the Udzungwa Mountains, Tanzania. When discovered in 1996, this toad was found in approximately 4 ha of waterfall spray wetland habitat on the Kihansi River. Day and night time searches of the nearby Udagaji gorge and other gorges in the area, by various groups from 1997 to 2002, has failed to find any of these toads.

This ovoviviparous toad is a smaller member of the Bufonidae family. Adult males are usually between ½" and ¾" in size, females are about ¼" larger, some even over 1" long. They can live for over three years and young toads can breed at about 9 months of age. Adults are normally yellow with various dark brown markings on the back. This can vary from a brighter yellow with dark stripes and a dark posterior spot during the wet breeding season to a dull brown overall during the dry season. Juveniles are purple with irregular light green stripes. Sub-adults are variable in color, changing from the purple background to yellow.

The hands and feet are webbed with friction pads but lack the expanded toe pads that other climbing species in this genus have. None the less, they easily climb wet vertical rock faces and overhangs where the waterfall spray collects and drains.

This thin-skinned toad is an extreme specialist, restricted to cooler, high humidity spray zone habitats. Its’ small size and excellent climbing ability allow it to live here. The very wet conditions in this high-wind zone creates a unique habitat where trees do not grow, but wetland plants, grasses and mosses thrive. The adults prefer to stay in the wet vegetation, roots and other moist places in the spray zone during the day. At night they forage up and down the rock faces. Young toads mostly stay on the ground where small insects can be hunted, sub-adults are found in the vegetation and seem to prefer the tangled mass near the ground. All are actively feeding night and day throughout the habitat. They may sit and wait until an insect comes near or actively hunt for them. During the dry season, large numbers will aggregate in the wettest spots available.

Reproduction: Calling increases during the rainy season, December to February. Choruses can be heard calling from the vegetation, mostly during the day. The prolonged amplexus also occurs in the vegetation, during the day. The male clasps the female under the arms and presses his cloaca closely to hers. This is how he deposits his sperm inside her to fertilize the eggs. The eggs hatch and the tadpoles remain inside her body until they develop into small toads and are born. Baby toads are most abundant from March to May. Clutch size is usually between 5 and 13.

Natural enemies: Predation is not common, crabs, snakes, the large torrent frog and safari ants are occasionally successful. The difficult terrain is undoubtedly a deterrent.

The endemic Chytrid fungus Batrachocytrium dendrobatidis has been known to infect and kill this toad in the wild. How widespread or serious this may be is unknown.

Saving a species: This gorge is deep and has a fairly stable water flow making it an excellent site for a hydropower dam. Environmental impact studies are not a high priority for countries with poor economies and a desperate need for electricity. The Kihansi spray toad was not discovered until after construction of the Lower Kihansi Hydropower Project had begun. Time was running out and action needed to be taken soon.

The river was diverted before emergency mitigation measures could be undertaken. The habitat was desiccating, many unique plants and animals had died off and some were in immediate danger of going extinct. As of March 2001, toad numbers had decreased to a low of 1250.

A sprinkler system was installed as an emergency measure to save these toads and various other species from extinction. This worked to avoid the initial disaster but it needs constant monitoring and up-keep and will be very difficult to maintain in the long run. In September 2002, over 17,000 toads were counted.

None of this is funded by the Tanzanian government and is generally frowned upon as a loss of electrical generating capacity. So far, it has been funded by the Norwegian Agency for Development Cooperation (Norad) and the Swedish International Development Agency (Sida).

Extinction? Large numbers of toads and insects were reportedly found dead in the Upper Spray Wetland in June 2003. Very few or no live toads had been found since then (as of early 2004). It has been suggested that the population crash was the result of high pesticide use upstream. In September 2003, some of the dead toads collected had Chytrid fungus. Safari ants are another possible cause but all of this is just speculation.

The artificial spray habitat is being maintained and if any survived, they should be able to multiply. If no more toads are found in this area it means that this toad is extinct in the wild.

Originally, 499 animals were shipped to various captive-breeding facilities in North America. That population number had declined to 142 as of April 2005.

ENJOY YOUR PET LIFE FORMS, Dave & Donna