Gareth Coombs

Predation risk may be high in small snakes and most small snakes are thought to avoid certain behaviours, such as basking in open areas to reduce predation risk. The extent to which this concealment limits predation during basking is not known, but available data suggests that such concealment may significantly reduce predation attempts. Using model snakes placed in the field, predation rates on small model snakes were tested, specifically whether attack rates differ between partially concealed model snakes and model snakes placed in open unconcealed positions. Results from the current study support previous studies that predation pressure was high (average = 22.15%), but was not significantly reduced by semi-sheltered basking. An important new finding of this study was the high number of model snakes that experience trampling by wild ungulates (average = 12.72%.) This suggests that snakes basking in open and sheltered areas are also at risk of being killed or injured through trampling by larger animals. This study makes an important contribution to understanding predation pressure in African snakes and highlights other threats that snakes are exposed to during basking and thermoregulation.

Botanical work since 2008 on the Sleeping Giant section of the Kamdebooberge (Sneeuberg mountain complex, Eastern Cape, South Africa) has indicated that these mountains may be of significant conservation value. Accordingly, a precursory, rapid multi-disciplinary biodiversity assessment was undertaken in January 2011, focusing on plants, tetrapod vertebrates and leafhoppers. The botanical results confirm the Kamdebooberge as being of high botanical conservation value, hosting three strict endemics, healthy populations of five other Sneeuberg endemics, and fynbos communities comprising species not found elsewhere in the Sneeuberg. The Kamdebooberge are important for herpetofauna (excluding serpentoids) and mammals, hosting several range-restricted and regional endemics. The expedition uncovered three new leafhopper species, together with several species previously only known from the Cape Floristic Region. Further detailed faunal work may provide further interesting results from these mountains, which show a high conservation value unique to the southern Escarpment.

Successful invasive plants such as Araujia sericifera usually either are capable of automatic self-pollination or maintain pollinator services by having generalized pollination systems to make use of local pollinators in the invaded range. Alternatively, plants must co-opt new pollinators with similar morphology to native pollinators or reproduce asexually. We aimed to document the pollination biology of A. sericifera in South Africa. Given the success of this species as an invader, we predicted that sexual reproduction occurs either through self-pollination or because A. sericifera has successfully co-opted native insect pollinators. We examined the pollination biology of the South American A. sericifera in South Africa. We documented the effective pollinators including a comparison of the efficacy of nocturnal versus diurnal pollinators as well as the breeding system and long-term natural levels of the pollination success of this species. We found that native honeybees (Apis mellifera) were the main pollinators of A. sericifera in South Africa. Visiting moths are unimportant pollinators despite being attracted by the pale colour and nocturnal scent of the flowers. Plants from the Grahamstown population were incapable of autonomous self-pollination but pollinator-mediated self-pollination does occur. However, the highest fruit initiation resulted from out-crossed pollination treatments. The high pollen transfer efficiency of this species was comparable to other hymenopteran-pollinated exotic and native milkweeds, suggesting that A. sericifera maintains pollinator services at levels experienced by indigenous asclepiad species. Araujia sericifera reproduces successfully in South Africa due to a combined ability of this species to attract and exploit native honeybees as its pollinators and of individual plants to set fruit from pollinator-mediated self-pollination.