Seed dispersal of a neotropical cloud forest palm by a scatter-hoarding rodent
摘要
Wettinia praemorsa is a common understorey palm in the mountain cloud forests of Venezuela and part of Colombia. However, many aspects of its reproductive biology are unknown, including the process of seed dispersal. Even though W. praemorsa has fleshy fruits, frugivory has not been reported for this species or any of the other 26 species in the genus, suggesting that other dispersal mechanisms, such as scatter-hoarder granivores, may be involved in the seed dispersal of this group of palms. To obtain evidence of seed removal by scatter-hoarders, camera traps were placed at 27 experimental feeding stations on the forest floor, where seeds and fruits of W. praemorsa were offered. At five of these stations, seeds were individually tagged to track them in caches. In addition, camera traps were placed on the infructescences of five plants of this palm to check for possible fruit consumption by frugivores. The scatter-hoarding rodent Heteromys catopterius was recorded removing tagged seeds from experimental offering stations and storing them half-buried in caches on the forest floor. Seeds were stored without visible damage in separate caches at 6–9 m from the offering stations, and some were moved to different caches several times. At least 15% of the stored seeds persisted in the caches for eight weeks, a time that would allow some seeds to germinate. Moreover, no vertebrates were observed handling the fruits while they were still on the tree, and apart from H. catopterius, not even after they fell to the forest floor. All the data obtained indicate that H. catopterius can act as a primary seed disperser of W. praemorsa in the study area and probably in the entire geographical distribution of the palm.