Community ecology of small-mammal pollinated proteas

The floral characteristics of small-mammal pollinated (SMP) Protea species have been assessed in a number of previous studies. This study aimed to determine whether the inflorescences of Protea canaliculata, Protea sulphurea and Protea humiflora possess these traits and are pollinated by small mammal species. An additional aim of this study was to determine whether there is a variation in pollinator efficiency of different animal species. Floral characteristics that may influence plantpollinator interactions were measured, including floral dimensions, nectar production and spectral reflectance. Live-trapping was conducted using Sherman traps and mean facial and faecal pollen load was determined for the different species caught. Furthermore pollinators were observed through footage from motion sensor cameras placed facing the inflorescences of SMP proteas. The results of this study confirmed that Protea canaliculata, Protea sulphurea and Protea humiflora are pollinated by small mammal pollinators. The evidence supporting this is that the afore-mentioned species have traits that correspond to those possessed by known small-mammal pollinated proteas including: bowlshaped inflorescences, high nectar concentrations (ranging between 24.1-42.9%), sucrose-rich nectar composition, a "yeasty" scent, floral colours that are visible to small mammals, and a winter flowering season. These proteas were found to have separated peak flowering times, providing a nectar source throughout winter for small mammals at this site. Fifty-eight small mammals of seven different species, were trapped in P. canaliculata and P. sulphurea stands over 98 hours. The average nighttrapping success was 22.7% and day-trapping success was 5.7%, indicating a relatively abundant nocturnal small-mammal population. A separation in pollinator efficiency was observed for different small mammal species, with Elephantulus edwardii identified as the most effective pollinator as it showed the greatest pollen removal (highest faecal pollen load) and spent the longest time foraging on inflorescences (±28 seconds per inflorescence). Another important pollinator was Aethomys namaquensis because it visited flowers 75% more frequently than any of the other pollinators. Camera trapping was shown to be a superior method than conventional trapping for assessing pollination by providing insight into pollinator behaviour, identifying new pollinators of 'trap-shy' species and also due to its more animal-friendly disposition.

Grantor dc:publisher.institution

Department of Biological Sciences

Year dc:date.issued

2013

Author dc:creator

• Kuhn, Nicola

Advisors dc:contributor.advisor

• Midgley, Jeremy
• Steenhuisen, Sandy-Lynn

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/14252

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/14252