The dynamics of small mammal populations in Rocky Highveld Grassland, Telperion, South Africa

Abstract

The present study investigates trap success, species richness, community structure, capture-recapture ratios, sex, population estimates, climatic effects, diversity, age structure, signs of reproduction, and seasonal changes in the body biomass in seven broad vegetation communities in the Bankenveld Grasslands of Telperion in Mpumalanga Province, and Ezemvelo Nature Reserve in Gauteng Province, South Africa. This study focuses on the effect of past management influences on diversity and abundance. The mean trap success recorded for the study is 8.6%. The Rocky Open Shrub community had the highest trap success recorded (37.03%), followed by the Northern Slope Woodland community (20.09%), Sheltered Woodland Community (14.51%), Rocky Highveld Grassland (11.98%), Degraded Grassland (7.25%), Moist Degraded Grassland (4.73%) and the lowest traps success was recorded in the Burkea Eragrostis Clumps community (4.39%). The capture frequency differed between transformed sites (12.9%) and non-transformed sites (87.1%), although the untransformed Rocky Highveld Grassland had the highest species richness, followed by the transformed Degraded Grassland community. The population of small mammals investigated appears to be resident, however certain species were not recorded at certain times of the year, and local movements are expected. Telperion and Ezemvelo Nature Reserve are estimated to have a population estimate of 377 620 small mammals on the properties. Climate appears to have a direct impact on small mammal fauna, influencing food availability, abundance, home range size and breeding. The summer months had the highest species diversity, possibly due to the fact that animals are reproductively active and more readily recorded, while maximum temperature does not appear to impact species richness, possibly due to the fact that the majority of the species recorded are nocturnal in habits. The Rocky Highveld Grassland community had the highest diversity score (H = 1.89), and is considered the most diverse community with ten species recorded. The Moist Degraded Grassland community had the second highest diversity score (H = 1.87) with eight species recorded. Three species were recorded in the Rocky Open Shrub community with the lowest diversity score (H = 0.65). The study site has a diverse and abundant small mammal fauna, indicative of a balanced ecosystem.