Variation in abundance and body condition of the Meletse bat assemblage, Limpopo Province, South Africa

Abstract

More studies are needed to understand how bat assemblages vary temporally in conjunction with environmental factors. This study investigated the temporal variations in relative abundance and body condition of a bat species assemblage in relation to with temperature and rainfall variations. Bats were captured and recorded using passive (echolocation recordings) and active monitoring (mist net and harp trap captures). The temporal variation in relative abundance, activity and body condition as temperatures and rainfall changed. Temperature was the main factor that correlated with variations in relative abundance and activity for Rhinolophus blasii, Miniopterus natalensis, Scotophilus dinganii and Neoromicia zuluensis. Relative activity peaked from spring to summer and reduced from autumn to winter. Body condition was positively correlated with both temperature and rainfall for Hipposideros caffer, R. simulator, R. smithersi, Nycteris thebaica, Min. natalensis and S. dinganii. These results indicate that Forearm Mass Index (FMI) changes in autumn to winter for H. caffer, Min. natalensis and N. capensis, and in spring to summer for R. blasii, Ny. thebaica, Min natalensis, Myotis tricolor, S. dinganii, N. capensis, N. zuluensis and Pipistrellus rusticus. These variations are important when developing management systems in the Meletse mountains to monitor important seasonal changes. Monitoring should consider breeding seasons and key species such as Min. natalensis, R. blasii and R. simulator which were strongly correlated with temperature and rainfall variations. This study can serve as a baseline for long-term monitoring programmes to assess high-risk species and develop early warning systems for conservation. This information is also critical for national and international reporting programmes and illustrates the importance of incorporating multiple monitoring techniques in developing temporal monitoring programmes to accurately assess bat assemblages.