Can a Non-Native Primate Be a Potential Seed Disperser? A Case Study on Saimiri sciureus in Pernambuco State, Brazil.

The interaction between native fleshy-fruit plants and introduced fruit consumers contributes to the dynamics of highly fragmented environments. Such interactions can occur through pollination and seed dispersal. Here, we investigated the potential of seed dispersing by a non-native primate, the squirrel monkey (Saimiri sciureus), in an urban Atlantic forest fragment in north-eastern Brazil. Fleshy fruits from non-native plants were preferentially exploited by the squirrel monkeys. We measured 147 seeds (width and length) from 20 of 106 faecal samples. The dispersed seeds were from five plant species (four families). We found a positive correlation between the size of seeds found in faecal samples with their availability in the habitat. Only one seed was found visually damaged after passage through the squirrel monkeys' guts. The defecated seeds were uniformly distributed (variance to mean ratio index) in the home range of squirrel monkeys, and there was a lack of specific latrines (i.e., habitat preference for defecation). Our data provide evidence that non-native S. sciureus may in be (i) acting as a potential seed disperser of native plants in the Atlantic forest fragment, (ii) contributing to the ecological role of native frugivores, and (iii) potentially contributing to the regeneration process of the highly degraded study site.