On Friday the 3rd of February, Lorna Watt gave a most interesting talk on the Brenton Blue Butterfly in Hilary Haarhoff’s lovely garden. Lorna highlighted the plight of the endangered species and the sterling work done by the management committee who are custodians of the THE BRENTON BLUE BUTTERFLY RESERVE, home of one of the rarest butterflies in the world. The site extends over approximately 2ha of mixed coastal fynbos and coastal forest. The Brenton Blue shares its home with a wide variety of other insects, as well as mammal and bird species. The Brenton Blue Butterfly Reserve (BBBR), is marked by a single signpost, access is only by appointment.
The Brenton Blue Butterfly, Orachrysops niobe, was re-discovered by Ernest Pringle in 1991 at Brenton on Sea at the site of a new development. After serious campaigning by variousenvironmental organisations the State purchased the property, about 1.5 ha in extent.
The Brenton Blue Butterfly Special Nature Reserve was established in 2003 with a Management Committee and then also a Trust to ensure the survival of thisendangered butterfly which is found nowhere else in the world. This reserve is under the control of CapeNature.
The Knysna Municipality has now agreed to an extension to the reserve which will bring the size up to 15ha, in the hope that the space will give the butterfly a larger protected area to breed in. Dr Dave Edge has led the scientific investigation into the ecology and requirements of the butterfly on the site.
Habitat needed for the butterfly’s survival: south-facing coastal slopes and fynbos vegetation, the host plant being the small pea-flowered Indigofera erecta, on the leaves of which the female lays about 200 eggs, and on the rootstock of which the larvae feed. Also assisting is an ant, Camponotus baynei, which makes its nest in the dead fallen branches of the Candlewood tree. Pathways are kept open for the butterfly’s flight path, since it is a low-flying insect. Management interventions are necessary to ensure the continued survival of this butterfly but fire is considered to be a threat. No alien vegetation is present. No insecticides can be used for any reason.
The butterfly has three emergences a season, at the end of October, again at the end of February and in April. The highest number recorded was 170 in 2003. Numbers vary for various reasons, but the hope is for it to flourish in future. Already this reserve has been a success story, thanks to the dedication of many individuals.
The Brenton Blue Trust raises money for the management of the reserve but also for protection of the 14 butterflies and one moth considered endangered throughout South Africa. Other butterflies of concern in the Knysna area are the Brenton Copper and the Knysna Skolly near Pezula. Custodians have been appointed for each one and funding assists with travel costs to each site.
Butterflies are a good indicator of the health of an ecosystem and we need to treasure all our natural assets particularly by not polluting them in any way.