Biotope selection by adult male dragonflies (Odonata) at an artificial lake created for insect conservation in South Africa

Abstract

A large pond at the National Botanical Gardens, Pietermaritzburg, South Africa was created as part of an ecological landscaping urban project for plant and insect conservation. Biotope preference by resident adult male dragonflies was used to determine the conservation value of the created conditions. Various biotopes were created to cater for the apparent preferences of adult male dragonflies. Stenotopic species were highly sensitive to a number of factors such as sunlight or shade, to still or flowing water, and to vegetation structure. The provision of a wide range of appropriate biotopes was shown to increase local species richness more than two-fold, but with loss of one riverine species that was formerly present. Most of the colonisers were eurytopic and vagile, but some were more local, stenotopic species.