A Meager Nectar Offering by an Epiphytic Orchid is Better than Nothing

Abstract

When a nectar reward is relatively low in quality and quantity, is it an effective pollinator attractant? In Puerto Rico, Comparettia falcata, a hummingbird-pollinated epiphytic orchid, produces an average one-time secretion of 3.3-4.0 μl of nectar (composed of 12.9-15.1 % sugar) per flower. In contrast, nectar sugar concentrations of other hummingbird flowers on Caribbean islands are 17-37 percent, and those of Puerto Rico visited by the C. falcata pollinator have standing crops averaging 2.0-6.2 μl and daily secretion rates of 3.1-10.6 μl. In 1989 and 1990, we monitored pollinator abundance, effective flower visitation, pollinarium removals (male success), pollinations, and fruit production (female success) at two sites in the Toro Negro Forest Reserve (...)