Effects of waterhole closures, fire, and rainfall on vegetation structure and small mammal communities

The issue of waterholes is a critical one for Kruger Park management. Though initially constructed to boost numbers of antelope and other animal species, many studies have demonstrated the negative effects of artificial waterholes, which create a zone of decreased biodiversity known as a piosphere (Gaylard et al.). One year prior to our study, students from the Organization of Tropical Studies did a rodent trapping study to examine the effects of artificial waterholes on rodent diversity by comparing rodent communities at an open waterhole and one that had been inactive for two years. We used similar live-trapping methods to examine the effects of one more year of inactivity at the closed waterhole, as well as the effects of a burn that had occurred at the closed waterhole within the past year. Similar to the previous study, we found significantly greater rodent and grass diversity at the closed waterhole. The overall rodent abundance was lower for our study than the previous study, likely due to the decreased grass cover at both sites. We also found dramatically increased numbers of the bushveld gerbil, Tatera leucogaster, at the burned site, supporting the notion that burning has an effect on rodent species composition.