The Nimba Mountains are a small mountain chain in the transboundary region of Guinea, Côte d’Ivoire and Liberia, West Africa. They consist of a mosaic of habitats combining lowland evergreen and higher altitude forests and high and low altitude grasslands. The known herpetofauna of the Nimba Mountains is the richest in terms of biodiversity and endemism within West Africa. Because of this high biodiversity and high endemism for many faunal and floral taxa the larger part of the Guinean and all of the Ivorian Nimba Mountains were declared a World Heritage Site in 1981/1982. Due to mining concessions, and additional threats, the Nimba Mountains are listed since 1992 as "in danger".
The main goal of this project is to give the scientific basis for a potent management plan, protecting this very high biodiversity. This goal we want to achieve in monitoring the herpetofauna, in determining key environmental parameters necessary for the persistence of this exceptionally high herpetodiversity and to develop scientifically based recommendations for its effective conservation. The research focuses on the one hand on the viviparous Nimba toad (Nimbaphrynoides occidentalis) and on the other hand on the riparian forest amphibian assemblages. The Nimba toad is (eu-) viviparous, occurs exclusively in the high altitude grasslands of the Nimba Mountains, and their life- and reproductive cycle is tightly linked to the mountains’ seasonality. The riparian forest assemblages are very divers and contain threatened species, of which most are assumed to be very sensitive to environmental changes. By determining the key determinants of the current herpetofauna we aim to help keeping these key parameters constant in the future and with this protect this exceptionally rich herpetofauna and possibly other animal and plant taxa with it.
The Nimba project started in 2007 at the University of Würzburg and since 2008 is based at the Museum für Naturkunde. It is financed by grand agreements with the Société de Mines de Fer Guinée (SMFG).
The viviparous Nimba toad (Nimbaphrynoides occidentalis) is a small and inconspicuous, toad endemic to the high altitude grasslands of the Nimba Mountains. It’s very restricted (< 4km²) and patchy distribution; enforced by the fact that the Nimba Mountains are now considered to be a World Heritage in danger, lead to the declaration of the Nimba toad as critically endangered by the IUCN. The most exciting characteristic is nevertheless its viviparous reproduction. Mothers nourish their young during the gestation by oviductal secretions and give birth to fully developed juveniles after nine months. This makes the Nimba toad the only truly viviparous anuran (frogs and toads) on Earth!
The main goals of this Nimba toad project are to determine the key environmental variables for the toad’s distribution and temporal distribution changes, the toad’s abundances and the temporal variance in its abundance and the variables important for the toad’s population structure. Together these results should enable us to develop potent recommendations for the protection of this very special toad.
Laura Sandberger-Loua prepared her PhD thesis within this part of the Nimba Project.