Why cooperation between species is so common and how it can persist in the face of cheating is one of the great enigmas in biology. This project will explore how ecological conditions can cause a species to switch between benefiting and parasitizing another species, using one of the most important cases of cooperation, the pollination of plants by animals. This key type of mutually beneficial relationship between species can switch to a parasitic relationship when animal pollinators steal nectar from flowers without transferring pollen. The project will combine field observations, manipulative experiments, and a model of two bee species that switch between pollinating and cheating in the Rocky Mountains to determine (1) when and why bees cheat the plants they visit; (2) whether cheating or cooperation benefits the bees more under different circumstances; and (3) how nectar robbing affects the reproduction of the plants that the bees visit.
The broader impacts of this project include student training, outreach to the general public, and greater understanding of a major ecosystem service. The project will train undergraduate students, a graduate student, and a postdoctoral researcher. Public outreach is planned through museums, middle and high schools, and summer science camps. Results will increase understanding of pollination, a critical service for agriculture and conservation of biodiversity: identifying the conditions under which pollinators refrain from cheating could help increase crop yields and maintain native plant species.