a1 Centre for Research in Evolutionary and Environmental Anthropology, Roehampton University, London SW15 4JD, UK
a2 Coordenação de Bioiversidade, Caixa Postal 478, Instituto Nacional de Pesquisas da Amazônia, Manaus 69060-001, Amazonas, Brazil
a3 Department of Biology, Rhodes College, Memphis 38112-1690, Tennessee, USA
a4 Biological Dynamics of Forest Fragments Project, Instituto Nacional de Pesquisas da Amazônia and Smithsonian Tropical Research Institute, Manaus 69011-970, Amazonas, Brazil
a5 Centro Nacional de Pesquisa e Conservação da Biodiversidade Amazônica, Instituto Chico Mendes de Conservação da Biodiversidade – I, Manaus, 69041-10, Amazonas, Brazil, and Curso de Pós-Graduação em Ecologia, Instituto de Biologia, Universidade Estadual de Campinas, Campinas, São Paulo 13083-970, Brazil
a6 Laboratório de Herpetologia, Universidade Federal do Mato Grosso, Av. Fernando Correa da Costa, 2367, Boa Esperança 78060-900, Mato Grosso, Brazil
a7 Instituto de Ciências Exatas e Tecnologia, Universidade Federal do Amazonas, Rua N. Sra. Rosário, 3868, Itacoatiara 69100-000, Amazonas, Brazil
a8 Coordenação de Pesquisas em Entomologia, Instituto Nacional de Pesquisas da Amazônia, Manaus 69060-000, Amazonas, Brazil
a9 Departamento de Zoologia, Universidade Federal de Pernambuco. Av. Prof. Moraes Rego, 1235 - Cidade Universitária, Recife - PE - CEP: 50670-901, Brazil
The Neotropics house two guilds of large arboreal vertebrate seed predators: parrots and the pitheciin primates. Both have diets dominated by immature fruits. The possibility of members of the Pitheciinae (genera Cacajao, Chiropotes and Pithecia) acting as occasional seed dispersers has been mooted, but not experimentally shown. We combined primate behavioural data and seed germination data from three separate field studies in the Brazilian states of Amazonas and Pará to analyse patterns of post-consumption seed survivorship for seeds discarded by three pitheciin species (Cacajao melanocephalus ouakary, Chiropotes chiropotes and Chiropotes albinasus). We then calculated the frequency of dispersal events for four species eaten by C. m. ouakary. All three primate species dropped intact seeds while feeding, and 30.7% of 674 dropped seeds germinated ex situ. Undamaged seeds from unripe and ripe samples germinated (29.3% and 42.7%, respectively), and all three primate species carried some fruits up to 20 m from the parent tree before consuming them. Potential seed-dispersal events varied from 1 (Macrolobium acaciifolium) per fruiting cycle to more than 6500 (Duroia velutina), suggesting that there are differences in dispersal potential. In summary, although they are highly specialized seed predators, these primates may also act as important dispersers for some plant species, and effective dispersal is not restricted to ripe fruits, as immature fruits removed from a tree may continue to mature and the seeds later germinate, a much-neglected aspect of dispersal ecology. The possibility that similar events occur in parrots should be experimentally investigated.
(Accepted September 08 2012)
2 Co-lead authors, by virtue of equal contribution.