Interactions between aroids and arboreal mammals in the Brazilian Atlanticrainforest

The Brazilian Atlantic rainforest harbours at least 129 non-volant mammal s pecies. There is also a diverse and numerous epiphytic flora associated wit h this Neotropical rainforest, including several species of Araceae. Nevert heless, knowledge of the ecology of this group of plants and its interactio n with animals is poor. In this study we investigated the interactions betw een epiphytic aroids and arboreal mammals in the Atlantic forest. We carrie d out the field work between November 1995 and June 1997 in the Parque Esta dual Intervales, southeastern Brazil, a still well preserved forest area of approximately 490 km(2). We analysed faecal samples from primates (Cebus a pella and Brachyteles arachnoides), collected during observations in the fi eld, and marsupials (Didelphis aurita, Micoureus demerarae, Gracilinanus mi crotarsus), collected from animals captured monthly or bi-monthly in live-t raps. We recorded 17 species of Araceae in the study area. The seeds of eig ht species occurred in the faecal samples: Anthurium harrissi, Monstera ada nsonii, Philodendron corcovadense, P. appendiculatum, P. exymium, P. crassi nervium, P. obliquifolium, and Heteropsis oblongifolia. Aroids were present in faecal samples of the primates during most of the year, with a mean mon thly percentage of occurrence of about 56.2%. For marsupials, aroids also w ere a seasonally important food source, as between November and June the me an monthly percentage of occurrence in faecal samples was about 26.5%. Our data indicate that aroids are an important food source for arboreal and sem i-arboreal mammals and that these animals may play an important role as see d dispersers of this group. Aroids and arboreal mammals appear to interact more strongly in Atlantic forest than in other Neotropical forests.