A comparison of fruit removal in Ficus colubrinae between birds and Ectophylla alba (Chiroptera: Phyllostomidae) in a Costa Rican rain forest

ABSTRACT

Ectophylla alba almost exclusively feeds on the fruits of Ficus colubrinae therefore significantly contributing to dispersal of its seeds. The objective of this research was to quantify the fruit removal of F. colubrinae by E. alba and compare it with that of birds in a F. colubrinae tree at the La Selva Biological Station, Costa Rica. We established seven quadrats randomly at different heights of the tree. We took photographs of each quadrat, quantified the fruits in each photograph, and compared the number of fruits removed during periods of high and low activity. The on-site persistence time of birds (9:05 min) was higher than that of E. alba (0.32 s). Birds removed more fruits (46) than E. alba (41). Birds defecated on site more times (13.08 feces per day) than E. alba (7.5 feces per day). Thus, E. alba is a more important seed disperser of F. colubrinae than are birds, because it persisted a short time at the feeding site, and consumed food beyond the individual trees’ canopies. Most importantly, by defecating during flight or away from the fruiting tree, E. alba disperse seeds some distance from the F. colubrinae tree, thereby contributes more effectively toward seed dispersal.

KEYWORDS:

• Activity peaks
• bats
• frugivory
• La Selva
• seed dispersal

Acknowledgments

We carried out this study during the course Vertebrate Population Ecology of the ICOMVIS, UNA, Costa Rica, taught by JMM. Lucia I. Lopez helped us with feces washing and seed weights. We appreciate the comments of the anonymous reviewers who made valuable suggestions to improve the manuscript. JMM acknowledges the time provided to work in this paper by Daniel Tobias of Unidad de Ceincias Básicas, Sede Atenas, and Emilce Rivera of Carrera de Gestión Ecoturística, Sede Central, Universidad Técnica Nacional.

Disclosure statement

No potential conflict of interest was reported by the authors.