Life Histories of Frogs in the Namib Desert

Abstract

Four anuran taxa inhabit the central Namib: Xenopua 1oel'ia, Tomoptema de1alande1 cryptotia, Phrynomerus annectens and Bu/o ilertebralis boeschi. Xenopus is confined to permanent pools in the Kuiseb river canyon. Tomoptema extends further into the Namib, but is restricted to the Kuiseb river bed. The Kuiseb is normally dry, receiving water only briefly (as floods) during the rainy season. Thesefloods are responsible for moving adults and larvae. Phrynomerua and Hulo occur on granite inselbergs. The inselbergs provide shelter mainly in the form of cracks under granite exfoliations. Large runoff surfaces collect the low rainfall (25 mm per year) in depressions in which the frogs breed. P/UYnomerus is only active at night; males are aggressive towards one another; oviposition takes place in deep pools and development takes at least eight weeks. Bu/o is active during the heat of the day; oviposition takes place in warm shallow pools; development takes about three weeks.