Frugivory of Persea lingue (Lauraceae) and its effect on seed germination in southern Chile

Abstract

Frugivory is a common interaction mechanism between plants and animals in the temperate rainforest of southern
South America. In this study, we examined primary dispersal and predation stages of Persea lingue (Ruiz et Pav.) Nees
(Lauraceae), an endemic large-seeded tree of these forests. The main goal was to determine the identity of vertebrate seed
dispersers of P. lingue, to distinguish legitimate seed dispersers, pulp consumers and seed predators, and their influence
on seed germination. In order to know which birds and small mammals were feeding P. lingue seeds, we observed 20
P. lingue canopies, and live traps baited with P. lingue seeds were installed in fragment forests in south-central Chile.
To determine whether birds could be legitimate dispersers of P. lingue, we collected regurgitated and fecal samples. We
examined whether rodents removed the fruit pulp, the seeds, or the whole fruit. Additionally, we studied if seeds placed
on the forest floor were removed by rodents. In a final experiment we conducted germination trials to establish whether
pulp removal (by birds, rodents, or artificially-removed) influenced germination rates. We found six bird species feeding
on P. lingue seeds. None of them defecated intact seeds, but, Turdus falcklandii Quoy & Gaimard (Turdinae) and Xolmis
pyrope (Kittlitz) (Tyrannidae) regurgitated intact seeds. We captured five species of rodents in Sherman traps. Four of them
left intact seeds. We did not find any effect of the seed handling types (pulp consumption vs. seed regurgitation) in seed
germination rates. However, pulp removal was an important factor for germination success. We conclude that T. falcklandii
and X. pyrope are legitimate seed dispersers of P. lingue, since they swallow the whole fruit and regurgitate the intact
seed. Abrothrix olivaceus (Waterhouse) (Cricetidae) and probably Oligoryzomys longicaudatus (Bennett) (Cricetidae) are
potential secondary dispersers of P. lingue seeds, as they prefer to eat the fruit pulp rather than the seeds.