Large-bodied seed dispersers like long-wattled umbrellabirds (Cephalopterus penduliger) feed on infructescences of the tropical palm O. bataua as they appear intermittently across the canopy. Umbrellabirds are a lekking species, with males leaving leks only to forage, while females visit leks solely for mating. The distribution of these infructescences may have implications for the dispersal of O. bataua seeds by umbrellabirds, and the subsequent survival and recruitment of these seeds. Here, I examined the relationship between umbrellabird foraging patterns and resource distributions of O. bataua fruits and their association with seed dispersal using remote logging stations. These stations were mounted on infructescences and recorded a visit when transmitters mounted on umbrellabirds approached within 3 meters of the logging station. Movement of birds were modeled in relation to presences of infructescences, and potential seed dispersal locations were plotted based on gut retention times. Distance and density matrices were derived from the resulting data to predict negative density-dependence effects and genetic structure of dispersed seeds.
Results/Conclusions
Resource distribution had a significant relationship with both male and female umbrellabird movement, resulting in discrete foraging patterns. The degree of resource patchiness was significantly related to local genetic structure of seedlings. These results call for a long term assessment of seedling recruitment and survival with respect to resource distribution.