PT  - JOURNAL ARTICLE
AU  - Pedro Américo D. Dias
AU  - Alejandro Coyohua-Fuentes
AU  - David Roberto Chavira-Ramírez
AU  - Domingo Canales-Espinosa
AU  - Ariadna Rangel-Negrín
TI  - A preliminary assessment of allostatic load in male mantled howler monkeys
AID  - 10.1101/2021.02.22.432350
DP  - 2021 Jan 01
TA  - bioRxiv
PG  - 2021.02.22.432350
4099  - http://biorxiv.org/content/early/2021/02/23/2021.02.22.432350.short
4100  - http://biorxiv.org/content/early/2021/02/23/2021.02.22.432350.full
AB  - Allostatic load refers to the wear and tear of the organism associated with the repeated activation of mechanisms that allow for homeostasis. Although allostasis (i.e., maintaining stability through change) is achieved through the orchestration of multiple systems, assessments of allostatic load in wildlife have usually relied on the measurement of single or few physiological mediators. In the present study, we aimed at constructing an allostatic load index (ALI) for male mantled howler monkeys (Alouatta palliata) based on seven physiological mediators (C-peptide, triiodothyronine, glucocorticoids, testosterone, amount of activity, foraging effort, and participation in agonistic interactions). We then examined if variation in this ALI was associated with social, ecological, and abiotic challenges. For five years, we studied ten adult males belonging to two groups. We assessed physiological mediators via behavioral observations (3,364 hours of samplings), and both urine (1,500 assayed samples) and fecal (1,500 assayed samples) sampling. We calculated an ALI based on mediator specific risk scores. Seasonality, encounters with extragroup males, mating, and centrality were positively related with male allostatic load, though only the first two had significant effects on ALI. ALI reflected the physiological and behavioral responses of males to social, ecological, and abiotic challenges. It remains for future research to determine if the observed trends correspond to normal fluctuations in mechanisms that allow male mantled howler monkeys to cope with their environment.Competing Interest StatementThe authors have declared no competing interest.