MONITORING OF THE EGGS OF THE KARKLOOF BLUE BUTTERFLY, ORACHRYSOPS ARIADNE, FOR ITS CONSERVATION MANAGEMENT
Adrian Armstrong and Sharon Louw
Ezemvelo KZN Wildlife, 1Biodiversity Research and Assessment and 2Ecological Advice

 

Abstract
The Endangered Karkloof blue butterfly Orachrysops ariadne (Butler 1898) is extant at only four sites, all in the Endangered Moist Midlands Grassland of KwaZulu-Natal, South Africa. These sites differ with respect to land use. The aims of this study were to monitor the butterfly’s numbers and the effectiveness of management interventions through egg counts, and to devise an efficient monitoring method for the three unmonitored colonies. Monitoring of the Nkandla colony, situated in a grassland area that is frequently burnt to ensure palatable grass is available to livestock, has been carried out since 2002. Early count results suggested the implementation of management interventions at the butterfly’s breeding area in order to prevent its local extinction. These interventions included fencing to exclude domestic livestock and a firebreak to control the frequency of burning. The number of eggs laid at the monitoring site each year fluctuated after the interventions were initiated but by 2013 had nearly reached the target of 250. An index egg count method was developed for the other three colonies where the mapped areas of the butterfly’s host-plant ranged from 1.35 ha to 8.15 ha, ruling out total egg counts as too time-consuming. Sampling of the butterfly’s host-ant at one colony site indicated that the ant regularly occurred where the host-plant occurred, therefore eliminating the need for the host-ant distribution to be considered during monitoring. A test of the method at one colony was shown to be efficient in terms of time in relation to the number of eggs sampled. Alien invasive and indigenous encroacher plant control using herbicides at, and continued appropriate burning of, the habitat of Orachrysops ariadne should help in ensuring the survival of these colonies.
Presentation Topic

MONITORING OF THE EGGS OF THE KARKLOOF BLUE BUTTERFLY, ORACHRYSOPS ARIADNE, FOR ITS CONSERVATION MANAGEMENT
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