Plant secondary metabolites and primate food choices: A meta‐analysis and future directions

• Published in: American journal of primatology 2022-08, Vol.84 (8), p.e23397-n/a
• Main Authors: Windley, Hannah R., Starrs, Danswell, Stalenberg, Eleanor, Rothman, Jessica M., Ganzhorn, Joerg U., Foley, William J.
• Format: Article
• Language: English
• Subjects: Aversion; Breeding success; Diet; Ecology; Evolution; Feeding behavior; Food; Foregut; Meta-analysis; Metabolites; Metabolomics; Multilevel analysis; Nutrition; Phenols; Phylogeny; plant secondary metabolites; Primates; Reproduction; Secondary metabolites; Subgroups; Suitability; Tannins; Understanding
• ISSN: 0275-2565; 1098-2345
• DOI: 10.1002/ajp.23397

The role of plant secondary metabolites (PSMs) in shaping the feeding decisions, habitat suitability, and reproductive success of herbivorous mammals has been a major theme in ecology for decades. Although primatologists were among the first to test these ideas, studies of PSMs in the feeding ecology of non‐human primates have lagged in recent years, leading to a recent call for primatologists to reconnect with phytochemists to advance our understanding of the primate nutrition. To further this case, we present a formal meta‐analysis of diet choice in response to PSMs based on field studies on wild primates. Our analysis of 155 measurements of primate feeding response to PSMs is drawn from 53 studies across 43 primate species which focussed primarily on the effect of three classes of PSMs tannins, phenolics, and alkaloids. We found a small but significant effect of PSMs on the diet choice of wild primates, which was largely driven by the finding that colobine primates showed a moderate aversion to condensed tannins. Conversely, there was no evidence that PSMs had a significant deterrent effect on food choices of non‐colobine primates when all were combined into a single group. Furthermore, within the colobine primates, no other PSMs influenced feeding choices and we found no evidence that foregut anatomy significantly affected food choice with respect to PSMs. We suggest that methodological improvements related to experimental approaches and the adoption of new techniques including metabolomics are needed to advance our understanding of primate diet choice. Research Highlights • Both a random‐effects meta‐analysis and a second, multilevel analysis that corrected for phylogeny revealed a small but significant negative effect of plant secondary metabolites on primate feeding preferences. • The most important factor contributing to this finding was the significant effect of condensed tannins on feeding by colobine monkeys. • The available data are uneven and of variable quality and insufficient to specifically test for effects in other subgroups of primates. • New methods and experimental approaches for measuring plant secondary metabolites are needed to advance the understanding of primate feeding behavior.