Impala (Aepyceros melampus) habitat utilisation and activity patterns in Sourish Mixed Bushveld

Abstract

The habitat utilisation and daily activity patterns of Impala at Loskop Dam Nature (LDNR) Reserve were studied to provide an insight into the management of this species. We used the Braun-Blanquet and TWINSPAN methods to classify plant communities within the Impala home range. Movement data was collected using a GPS collar fitted onto an Impala ram (Aepyceros melampus), and field data about the animal’s home range and the behaviour of the breeding herd associated with him was collected through direct observations. Seasonal home ranges, habitat selection and utilisation, as well as seasonal daily activity patterns were determined. Vegetation maps were produced to illustrate available plant communities, and seasonal home range maps were created to show Impala movement patterns and home range sizes. Environmental variables considered in the analyses included rainfall, temperature, and photoperiod. The Impala home range comprised of a variety of plant communities and species forming various habitats that provided the necessary resources for the Impala to live and procreate. Impala utilised habitats with available quality and quantity of forage. The Euclea crispa Vachellia karroo closed woodland plant community was preferred by the Impala in both the wet and dry seasons. This community is the primary habitat for the Impala at LDNR. All environmental variables investigated had an impact on the daily activity patterns of Impala. The majority of Impala the activity patterns were influenced by seasonality for all social group types. Given that time is a limited and valuable resource for wildlife species in general, time partitioning affected the Impala’s daily activity patterns at the study site. Time partitioning resulted in reduced or compromised activities at the expense of priority activities like vigilance. Vigilance was higher in both the wet and dry seasons, and often led to reductions in feeding time.