Monday, August 2, 2010

PS 18-145: Unexpected generalized pollination system in a tropical island herb, Heliconia caribaea

Stephanie Cruz Maysonet, University of Puerto Rico in Bayamón, Elvia Meléndez-Ackerman, University of Puerto Rico, Rio Piedras and Center for Applied Tropical Ecology and Conservation (CREST-CATEC), and Silvana Martén-Rodríguez, National Museum of Natural History - Smithsonian Institution.

Background/Question/Methods

Insular and mainland Heliconia species exhibit specialization toward hummingbird pollination. In Puerto Rico, Heliconia caribaea shows long, tubular, nectar producing flowers hold by bright colored bracts: morphological features in accordance to the hummingbird pollination syndrome. The two components of pollination effectiveness (visitation rate and pollinator efficiency) were analyzed for the floral visitors of H. caribaea to test the hypothesis that this species is mostly pollinated by hummingbirds given its flower characteristics. Pollinator observations and analyses of pollen loads of virgin stigmas were performed for ten plants distributed in four patches. Stigmas of virgin
flowers were collected for each potential pollinator species after a single visit.

Results/Conclusions

In 116 h of observations, two hummingbird species (Anthracothorax viridis and Chlorostilbon maugaeus) and a bananaquit species (Coereba flaveola) were recorded as visitors. Low visitation rates and meager pollen loads resulted in low pollination effectiveness indices with no significant differences (P= 0.2616) among the three visitors. These results suggest a generalized pollination system.