Temporal variation of floral visitors in two sympatric co-flowering Salvia species with contrasting pollination syndromes

Abstract

Pollination systems in Salvia are specialized, and species have been mainly classified as melittophilic (visitedby bees) or ornithophilic, visited by birds. Both systems often occur in sympatry and species bloom simultaneously.This scenario allowed us to evaluate the correspondence between contrasting floral morphologies and functionalgroups of flower visitors, and their role in the coexistence of related plant species. We studied the degree of floweringoverlap and its consequences on the diversity of flower visitors in S. plurispicata, a melithophilic species, and S.elegans, an ornithophilic species. During the 3 years of study, both species flowered simultaneously and S. plurispicataconsistently produced from 3 to 7 times more flowers than S. elegans. Three hummingbird species and 3 bee speciescontributed to 93 and 6.7% of the visits to S. elegans, respectively. In S. plurispicata, 4 bee species contributedto 77.5% of the visits, while 22.5% of the visits were by hummingbirds. We found a strong association betweenflower pollination syndromes and functional groups of floral visitors to each plant species, which could explain thecoexistence and co-flowering of Salvia species.