Viability of small seeds found in feces of the Central American tapir on Barro Colorado Island, Panama

Tapirs are known as effective dispersers of large-seeded tree species, but their role in dispersing small-seeded plant species has yet to be established. Tapir feces have been reported to contain large numbers of small seeds, but whether these are viable has rarely been evaluated. We determined the abundance and viability of small seeds in feces of Central American tapir (Tapirus bairdii) on Barro Colorado Island, Panama. A total of 72 fecal samples were collected opportunistically from 4 tapir latrine sites. Seeds were manually extracted from feces and classified by size. Seed viability was estimated by opening each seed and examining for the presence of at least 1 intact firm white endosperm. In total, we obtained 8166 seeds of at least 16 plant species. Small-seeded species dominated, with 96% of all seeds found measuring <5 mm. The canopy tree Laetia procera was the most abundant species in the samples. Of all small seeds found, 69% contained an intact endosperm and appeared viable. This suggests that small seeds, like large seeds, often pass through the digestive tract of T. bairdii intact. Thus, tapirs potentially serve as effective dispersers of a wide range of small-seeded plant species.