Pollination
I work on all aspects of the interactions of bees and flowering plants, ranging from the physiology and behaviour of individual bees (foraging, courtship and sexual harrassment) through to the community impacts of shared pollinators (see the references and links below).
My first work on bees looked at their ability to raise their internal body temperatures, and to maintain a regulated body temperature during flight. This activity has long been known, but we know a lot less about what determines the difference in thermal physiology between species. My work focussed initially on solitary bees in the genus Anthophora (Stone 1993a, 1994a). This group includes the most 'warm-blooded' of all bees, and they are an important part of the bee fauna of Northern Hemisphere habitats ranging from sub-alpine meadows to deserts. Despite the severe physical constraints acting on small warm-blooded animals, bees still show significant adaptive variation in endothermic abilities between sexes and between species (Stone & Willmer 1989b; Stone & Purvis 1992;Stone 1993b; Stone 1994a). In general, females are more warm-blooded than males, and species active in cooler climates are better able to warm up than those flying in warmer environments. Cuckoo bees, which do not collect their own pollen and nectar but pirate the resources collected by other bees, are less influenced by the independence of ambient conditions that thermoregulation provides, and routinely are poorer thermoregulators and less warm-blooded than their provisioning relatives (Stone & Willmer 1989b).
Most recently, we have used our knowledge of Anthophora bees to tease apart the factors structuring activity in a very simple pollination system in the St Katherine Nature Protectorate, Sinai, Egypt (Stone et al. 1999). This work forms part of a long and ongoing research programme led by Dr. Francis Gilbert of Nottingham University in collaboration with Prof. Samy Zalat of Suez Canal University, and also involving Dr. Simon Potts of Reading University and Professor Pat Willmer of St. Andrew's University.
Most of my current pollination work is focussed on Acacias, with studies in Australia (with student Matthew Prescott), Mexico (with Dr. Nigel Raine) and eastern Africa (with Dr Sean Nee at Edinburgh University, Pat Willmer, and student Katherine Baldock).
Our initial acacia work in Africa was part of a joint programme run by the Royal Geographic Society, the Tanzanian Government's Department of Wildlife, and Oxford University, based at the Mkomazi Game Reserve in Tanzania. All of our current African work is based in Kenya, at the Mpala Research Centre north of Nanyuki, and is carried out in collaboration with National Museums of Kenya. We are particularly interested in the potential impacts of shared pollinators on competition for pollination between sympatric acacia species (Stone et al. 1996, 1998), and Katherine Baldock is currently using visitation webs (an approach developed primarily by Dr. Jane Memmott at Bristol University) to quantify the shared-pollinator interactions between Mpala acacias and other plants. I am about to start a new NSF-funded collaboration on gene flow in African acacias with Prof. Andrew Schnabel of Indiana University at South Bend. This will use microsatellite-based analysis of paternity in acacia seeds, and will provide direct evidence of how far pollinators carry acacia pollen.
