title: Sources of variation in hair cortisol in wild and captive non-human primates.
abstract: Hair cortisol analysis is a potentially powerful tool for evaluating adrenal function and chronic stress. However, the technique has only recently been applied widely to studies of wildlife, including primates, and there are numerous practical and technical factors that should be considered to ensure good quality data and the validity of results and conclusions. Here we report on various intrinsic and extrinsic sources of variation in hair cortisol measurements in wild and captive primates. Hair samples from both wild and captive primates revealed that age and sex can affect hair cortisol concentrations; these effects need to be controlled for when making comparisons between individual animals or populations. Hair growth rates also showed considerable inter-specific variation among a number of primate species. We describe technical limitations of hair analyses and variation in cortisol concentrations as a function of asynchronous hair growth, anatomical site of collection, and the amount and numbers of hair/s used for cortisol extraction. We discuss these sources of variation and their implications for proper study design and interpretation of results.
authors.affiliation: Department of Anthropology, Center for the Advanced Study of Hominid Paleobiology, The George Washington University, 2110 G Street NW, Washington, DC 20052, USA. Electronic address: fourienh@mail.nih.gov.
authors.forename: Nicolaas H
authors.initials: NH
authors.lastname: Fourie
authors.affiliation: Center for Species Survival, Smithsonian Conservation Biology Institute, Front Royal, VA 22630, USA.
authors.forename: Janine L
authors.initials: JL
authors.lastname: Brown
authors.affiliation: Department of Anthropology, New York University, Rufus D. Smith Hall, 25 Waverly Place, New York, NY 10003, USA.
authors.forename: Clifford J
authors.initials: CJ
authors.lastname: Jolly
authors.affiliation: Department of Anatomy and Neurobiology, Washington University School of Medicine, 660 South Euclid Avenue, Saint Louis, MO 63110, USA; Department of Anthropology, Washington University in St. Louis, McMillan Hall, Room 112, One Brookings Drive, St. Louis, MO 63130, USA.
authors.forename: Jane E
authors.initials: JE
authors.lastname: Phillips-Conroy
authors.affiliation: Human Genome Sequencing Center and Department of Molecular and Human Genetics, Baylor College of Medicine, 1 Baylor Plaza, Houston, TX 77030, USA.
authors.forename: Jeffrey
authors.initials: J
authors.lastname: Rogers
authors.affiliation: Department of Anthropology, Center for the Advanced Study of Hominid Paleobiology, The George Washington University, 2110 G Street NW, Washington, DC 20052, USA.
authors.forename: Robin M
authors.initials: RM
authors.lastname: Bernstein
mesh_terms: D000367:Age Factors; D000818:Animals; D000835:Animals, Wild; D000836:Animals, Zoo; D002623:Chemistry Techniques, Analytical; D005260:Female; D006197:Hair / Q000737:chemistry*; D006854:Hydrocortisone / Q000032:analysis*; D008297:Male; D011323:Primates / Q000033:anatomy & histology* / Q000502:physiology*; D012737:Sex Factors; D013010:Sonication
chemical_list: D006854:Hydrocortisone
keywords: Chronic stress; Cortisol; Hair cortisol analysis; Primates; Stress