Ecological characteristics in habitats of two African mole-rat species with different social systems in an area of sympatry: implications for the mole-rat social evolution



Jan Šklíba, University of South Bohemia, Faculty of Sciences, Branišovská 31, České Budějovice, 370 05, Czech Republic. Tel: +42 038 777 2257; Fax: +42 038 531 0366



African mole-rats (Bathyergidae) are subterranean rodents with diverse social systems, which range from solitary to highly cooperative. The social systems are thought to reflect ecological conditions. We examined ecological characteristics in habitats occupied by two mole-rat species with different social systems in an area of sympatry in the Nyika Plateau, Malawi. Whereas the solitary silvery mole-rat Heliophobius argenteocinereus occurs there in the afromontane grasslands, the social Whyte's mole-rat Fukomys whytei is bound to the Miombo woodlands. The habitat of F. whytei was characterized by a lower food supply and harder soil. We suppose that the niche segregation of the two species in the Nyika Plateau is due to the inability of the solitary species to survive under the harsh ecological conditions. Absence of F. whytei in higher altitudes may be due to its less effective thermoregulation, competitive exclusion by H. argenteocinereus, or other unknown factors. Analysis of available data on food supply and precipitation from different mole-rat localities revealed that there is no clear separation of the localities inhabited by solitary, social and so-called eusocial species.