Fine-scale habitat requirements of the Heidelberg Opal Butterfly (<i>Chrysoritis aureus</i>) in Gauteng and Mpumalanga, South Africa

Abstract

Background: This study quantified the fine-scale habitat requirements of Chrysoritis aureus, at 11 known habitats in Gauteng and Mpumalanga, South Africa, in order to make habitat management recommendations for this endangered species.Objectives: The habitats were quantified in terms of plant species composition and structure with reference to their environmental characteristics.Method: A modified area-based phytosociological approach was used to collect floristic data along with environmental characteristics of habitats occurring on the Witwatersrand and Ventersdorp Geological Systems.Results: Species recorded were predominantly forbs and graminoids with a slightly higher number of plant species in the habitats of the Ventersdorp Geological System. Few dwarf shrubs and shrubs and very few trees were recorded. A higher number of plant species were recorded during the late growing season on both geological systems. The butterfly food plant Clutia pulchella var. pulchella L. (Euphorbiaceae) was recorded in all the habitats and was dominant in habitats in both geological systems. The occurrence of the food plant is essential for the survival of the butterfly at these habitats.Conclusion: Monitoring of the C. aureus butterfly populations and of the vegetation structure, species composition and growth forms to determine trends in the vegetation condition after planned fires; regular burning of the habitats in order to maintain suitable vegetation composition and structure; and the monitoring and eradication of alien invader plants are very important management activities to ensure the conservation of C. aureus.