Evidence for secondary seed dispersal by rodents in Panama

Abstract

The data presented show that Virola nobilis (Myristicaceae), a bird/mammal-dispersed tree species in Panama, may also be dispersed by a terrestrial rodent, the agouti (Dasyprocta punctata). Using a thread-marking method, we observed that agoutis scatterhoarded V. nobilis seeds that they found both singly or in clumps. Seed removal and seed burial rates were strongly affected by features of forest habitats, such as V. nobilis tree richness (rich vs poor) and/or forest age (old vs young), but not by seed dispersal treatment (scattered vs clumped). Predation (mostly post-dispersal) of unburied seeds by weevils was independent of habitat and dispersal treatment. Seeds artificially buried in a Virola-rich area were more likely to escape predation and become established than unburied seeds under natural conditions. The food reward for agoutis is in the germinating seedlings. The seed dispersal syndrome of V. nobilis involves long- and short-distance dispersers which both appear important for tree recruitment. © 1991 Springer-Verlag.