Tannins, a type of plant secondary metabolite, are well-known for their ability to precipitate proteins and thereby reduce the protein available to consumers. Most primate studies have focused on condensed tannins (CTs) as they were thought to be the most effective type of tannin at preventing protein acquisition, but there is Développement Durable) for research facilitation and collaboration, and to local communities and research assistants based at Tsinjoarivo. They thank Bruno Ramorasata for field support and guidance, and Amanda Hamrick, Chazal Vololontsoa and Zo Rijamanalina for field collaborations. They would also like to thank J. Rothman for invaluable methodological advice and W. Foley for valuable conversations on pollen.