Alexander E. Primus
Department of Biology, Carleton College, Northfield, MN, USA, 55057
Abstract. Nectar robbers are floral visitors which obtain a nectar reward from a flower with effecting pollination. While nectar robbers are quite common in the neotropics and their effects on plant fitness has been a relatively hot topic of study within pollination ecology, very few investigations have documented the extent and relative frequency of this parasitism. In this study I examined the relative frequency of nectar robbery on a neotropical treelet, Hamelia patens, at La Selva Biological Research Station in Costa Rica. It was found that nectar robbery of H. patens is rather intense (nearly 50 % of flowers suffered from nectar robbery). It was also found that nectar robbery of H. patens is intraspecifically and temporally variable. Below follows a discussion on the numerous possible causal agents behind intraspecific variations in nectar robbery of H. patens which include variations in conspecific clumpedness, nectar availability, behavioral competition, floral defenses, or distance to nectar robber nests. Since nectar robbery appears to play an undeniable role in the reproductive biology of H. patens, examining these possibilities further would no doubt shed light on the ecology of H. patens as well as on the ecology of floral larceny.