title: Using the stable carbon and nitrogen isotope compositions of vervet monkeys (Chlorocebus pygerythrus) to examine questions in ethnoprimatology.
abstract: This study seeks to understand how humans impact the dietary patterns of eight free-ranging vervet monkey (Chlorocebus pygerythrus) groups in South Africa using stable isotope analysis. Vervets are omnivores that exploit a wide range of habitats including those that have been anthropogenically-disturbed. As humans encroach upon nonhuman primate landscapes, human-nonhuman primate interconnections become increasingly common, which has led to the rise of the field of ethnoprimatology. To date, many ethnoprimatological studies have examined human-nonhuman primate associations largely in qualitative terms. By using stable carbon (δ13C) and nitrogen (δ15N) isotope analysis, we use quantitative data to understand the degree to which humans impact vervet monkey dietary patterns. Based on initial behavioral observations we placed the eight groups into three categories of anthropogenic disturbance (low, mid, and high). Using δ13C and δ15N values we estimated the degree to which each group and each anthropogenically-disturbed category was consuming C4 plants (primarily sugar cane, corn, or processed foods incorporating these crops). δ13C values were significantly different between groups and categories of anthropogenic-disturbance. δ15N values were significantly different at the group level. The two vervet groups with the highest consumption of C4 plants inhabited small nature reserves, appeared to interact with humans only sporadically, and were initially placed in the mid level of anthropogenic-disturbance. However, further behavioral observations revealed that the high δ13C values exhibited by these groups were linked to previously unseen raiding of C4 crops. By revealing these cryptic feeding patterns, this study illustrates the utility of stable isotopes analysis for some ethnoprimatological questions.
authors.affiliation: Department of Anthropology, East Carolina University, Greenville, North Carolina, United States of America; Department of Anthropology, University of Colorado, Boulder, Boulder, Colorado, United States of America.
authors.forename: James E
authors.initials: JE
authors.lastname: Loudon
authors.affiliation: Department of Genetics, University of the Free State, Bloemfontein, South Africa.
authors.forename: J Paul
authors.initials: JP
authors.lastname: Grobler
authors.affiliation: Department of Anthropology, University of Colorado, Boulder, Boulder, Colorado, United States of America.
authors.forename: Matt
authors.initials: M
authors.lastname: Sponheimer
authors.affiliation: University of Colorado, Denver, Denver, Colorado, United States of America.
authors.forename: Kimberly
authors.initials: K
authors.lastname: Moyer
authors.affiliation: Department of Anthropology, Central Washington University, Ellensburg, Wisconsin, United States of America.
authors.forename: Joseph G
authors.initials: JG
authors.lastname: Lorenz
authors.affiliation: Department of Genetics, University of the Free State, Bloemfontein, South Africa; Department of Anthropology, University of Wisconsin-Milwaukee, Milwaukee, Wisconisn, United States of America.
authors.forename: Trudy R
authors.initials: TR
authors.lastname: Turner
mesh_terms: D000818:Animals; D002247:Carbon Isotopes / Q000032:analysis; D016663:Cercopithecinae; D018556:Crops, Agricultural / Q000737:chemistry; D017753:Ecosystem; D005247:Feeding Behavior; D005308:Fertilizers / Q000032:analysis; D006197:Hair / Q000737:chemistry; D006801:Humans; D009587:Nitrogen Isotopes / Q000032:analysis
chemical_list: D002247:Carbon Isotopes; D005308:Fertilizers; D009587:Nitrogen Isotopes