Diet disparity and diversity predict extinction risk in primates

Abstract

Species vary in their vulnerability to extinction according to their biology, ecology, environmental factors and threats to which they are exposed. Diet is an important ecological trait that affects many aspects of a species' biology, including its vulnerability to extinction. Despite the importance of diet as a species' trait, its influence on extinction risk has only been studied in a coarse way, in part due to a lack of detailed diet data covering a large breadth of species or geographic areas. We examined the association between diet and extinction risk in primates, using a high-resolution dataset covering all major primate lineages and habitats on a global scale. The resolution of the dataset allowed us to calculate multiple biologically informative metrics for diet composition and diversity, allowing us to tease apart what aspects of diet were most important for predicting the risk of extinction, whilst accounting for phylogeny, body mass and geographic range size. Our results showed that both diet disparity and diet diversity predict primate extinction risk, showing that primates that are able to consume more types of items, and items that are more disparate from one another, are less prone to extinction. Furthermore, we found that although closely related species tend to have similar dietary diversity and disparity, these metrics vary widely amongst primate families. Primates with a high diet diversity and disparity may be able to cope better with fluctuations in food availability than species with homogeneous diet items, through a portfolio effect. Understanding the degree of dietary specialization of the species may help guide new studies relating to extinction risk and threats and be useful in future species assessments.

Explaining the primate extinction crisis: predictors of extinction risk and active threats

“…Previous studies have included geographic range size as a covariate in similar analyses (e.g. [3,28]). However, a species' geographic range size is one of the main criteria used by the IUCN to assign threat status: species with small population sizes that have small or restricted geographical ranges are considered to be more imperiled [29] (i.e.…”

“…Primates have been especially important in studies assessing predictors of extinction risk [3,8,19,28]. Primates are crucial components of tropical biodiversity, core players in the function of ecosystems, and central to many cultures and religions [17].…”

Explaining the primate extinction crisis: predictors of extinction risk and active threats

“…Table 1 summarizes how we expected each trait to be associated with primate extinction risk. Previous studies have included geographic range size as a covariate in similar analyses (e.g., Purvis et al, 2000; Machado et al, 2022). However, a species’ geographic range size is one of the main criteria used by the IUCN to assign threat status: species with small population sizes that have small or restricted geographic ranges are considered to be more imperiled (IUCN, 2021) (i.e., threatened species have small geographic ranges by definition).…”

“…Primates have been especially important in studies assessing predictors of extinction risk (Purvis et al, 2000; Purvis et al, 2005; Matthews et al, 2011; Machado et al, 2022). Primates are one of the most threatened animal clades, with ∼65% of species at risk of extinction (IUCN, 2021).…”

Human‐modified landscapes driving the global primate extinction crisis

“…Due to their diversity and richness, primate species maintain various ecological niches, thus their ability to cope with anthropogenic pressures is equally diverse (Galán‐Acedo, Arroyo‐Rodríguez, Andresen, et al, 2019; Galán‐Acedo, Arroyo‐Rodríguez, Cudney‐Valenzuela, et al, 2019; Machado et al, 2022; Mittermeier et al, 2013). Whereas some primates might have little tolerance for anthropogenic pressures and cannot persist in modified habitats, others may be more ecologically flexible, allowing them to persist in anthropogenic landscapes (Eppley et al, 2020; Galán‐Acedo et al, 2021; Hoffman & O'Riain, 2012; Siljander et al, 2020).…”