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Species of the Week: Mazumbai Warty Frog

By on August 6, 2012 in Amphibians, EDGE Updates, Species of the Week

The Mazumbai warty frog (Callulina kisiwamsitu) has a very interesting lineage. Its family (Brevicipitidae) is a group of 26 unique frogs from Africa that usually have burrowing lifestyles and very bulbous bodies. The warty frogs diverged 40 million years ago within the Brevicipitids – about 5 million years before the origin of monkeys. For nearly 100 years since the discovery of the first warty frog (Callulina kreffti), this genus was presumed to only contain one species. However, in 2004 scientists distinguished two species by extensive DNA analysis and their subtly different call frequencies: Callulina kreffti was endemic to the East Usambara Mountains in Tanzania and a new species, the Mazumbai warty frog, was restricted to the West Usambara Mountains.

Callulina kreffti - the Mazumbai warty frog's closest relative


The Mazumbai warty frog is absolutely covered in small, prominent warts, which make its skin extremely bumpy. It grows to lengths of 30-40 mm and has a stout, rounded body with short, slender limbs and moderately long hands and feet. It has sticky discs on its feet and some opposable toes which help the frog grip whilst climbing trees, however it can also live on the ground. Through examination of the stomach contents, the Mazumbai warty frog is known to feed on bugs, crickets, and some roundworms.

The Mazumbai warty frog is also known to be very sticky and males actually glue themselves to females when mating! Eggs are often laid in dark and damp underground chambers, and the tadpoles don’t have to live in water – they go through what is called ‘direct development’: growth takes place inside eggs and they eventually hatch as froglets.

The species is found in damp mountain forests with dense undergrowth, and is known to occur in four remnant forest patches: Mazumbai Forest Reserve; Ambangula Forest Reserve; Shume-Mugambo Forest Reserve; and Lushoto.

There is no information on the abundance of this species but it is listed as Endangered because it is found in a total area of less than 500 km sq., within which remaining habitat is severely fragmented and is subject to continual degradation by logging and firewood extraction. Smallholder agriculture can also contribute to habitat loss in unprotected forests.

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