The barn owl as a control agent for rat populations in semi-urban habitats
ABSTRACT The project to release barn owls in semi-urban areas within Sebokeng was initiated when the Gauteng Department of Health received complaints from Sebokeng residents about the increase in black house rats Rattus rattus. This project was designed to investigate the efficacy of using owls as biological control agents of rats at three schools in Sebokeng, and to inform learners at these schools about barn owls, in light of the learners’ strong sense of their culture and the associated beliefs and superstitions. There were two aims to the project. Firstly, to assess whether and how released barn owls impact on rat populations in the vicinity of the schools. Secondly, to provide environmental education to previously disadvantaged communities, and to assess how experiential group work using Outcomes Based Education (OBE) teaching changes the attitudes of learners towards owls. Owl boxes with two owlets each were established at two schools (SPS 1and SPS 3); another school (SPS 2) had a resident breeding barn owl pair. A fourth school, SPS 4, was used as a control and no owls were released here. Snap trapping of rats took place at these schools and SPS 4 to assess the impact of owls on rat populations. Trapping took place before owls were present and after they were released at the release sites. At SPS 1 and SPS 3, the percentage of rats caught per trap night decreased by 41 and 51% respectively after owls were released. At SPS 4, 34% more rats per trap night were caught than at SPS 2 (owls always present). In addition, the rats caught were smaller and showed a distinct male bias, potentially indicating a shift in behaviour and/or changes in demography. The environmental education part assessed the change in knowledge and perception of selected learners. Questionnaires were completed by the learners before the start of the environmental education as well as after the owl release programme started, where applicable. Learners at SPS 1 and SPS 3, who were required to feed and monitor the owlets before their release, showed significant changes in their perception, beliefs and enthusiasm for the owls. Learners at SPS 2 were well informed about owls, while those at SPS 4 harboured misgivings for and a lack of knowledge about owls. This study indicated that barn owls are suitable biological control agents for rats in the semi-rural areas. The success of the release programme was achieved by active participation of learners and environmental education, highlighting the benefits of a multidisciplinary approach in the programme.