Seed dispersal by monk sakis (Pithecia monachus)

Area of Science:

• Ecology
• Primatology
• Botany

Background:

• Animal-seed interactions are complex, challenging a simple antagonistic vs. mutualistic classification.
• Pitheciine primates are typically viewed as seed predators due to their feeding habits, but may also disperse seeds.

Purpose of the Study:

• To investigate the role of monk sakis (Pithecia monachus) in seed dispersal.
• To determine if monk sakis contribute to endozoochorous seed dispersal despite their seed-predating reputation.

Main Methods:

• Analysis of 92 fecal samples from monk sakis over one year in western Amazonia.
• Quantification and identification of intact seeds within fecal samples.

Main Results:

• 54% of fecal samples contained intact seeds, with up to 17 seeds and 3 morphospecies per sample.
• 165 intact seeds from 20 morphospecies were recovered, all from small-seeded plants (<1 cm).
• Floating fecal pellets suggest potential interaction with hydrochorous (water) dispersal.

Conclusions:

• Monk sakis contribute to seed dispersal via gut passage, occupying a position on the seed dispersal-predation spectrum.
• Further research is needed on the dispersal potential and ecological significance of seed-predating primates.