Anthropogenic food enhancement alters the timing of maturational landmarks among wild savanna monkeys ( Chlorocebus pygerythrus )

Anthropogenic landscapes are rapidly replacing natural nonhuman primate habitats. Yet, the access to anthropogenic resources on primate biology, health, and fitness remain poorly studied. Given their ubiquity across a range of human impacted landscapes, from cities to national parks, savanna monkeys ( spp.) provide an excellent study system in which to test these effects. We compared body condition and reproductive maturation in vervets () inhabiting a private farm in !Gariep Dam, with ample access to anthropogenic foods, and wild-foraging vervets in Soetdoring Nature Reserve, South Africa. Overall, vervets in !Gariep show significantly thicker skin folds, and higher BMI and body mass, than those in Soetdoring, suggesting increased fat deposition. Males in !Gariep have larger relative testis volumes at peri-pubescent ages compared to those in Soetdoring, suggesting early reproductive maturation associated with age-specific increases in body mass. Females from !Gariep showed evidence of an earlier onset of reproduction than those in Soetdoring, based on parity status as assessed by nipple length and evidence of lactation. Parity status at sub-adult dental ages was also strongly associated with body mass. These results are consistent with a positive effect of anthropogenic food-enhancement on body fat deposition, potentially linked to an earlier onset of reproductive maturation. Further investigation into primate responses to cultivated resources will inform our understanding of the broader effects of food enhancement on developmental plasticity.