Reproductive Energetics of Female Mantled Howlers (Alouatta palliata) Beatriz Cano-Huertes 1 & Ariadna Rangel-Negrín 1 & Alejandro Coyohua-Fuentes 1 & David Roberto Chavira-Ramírez 2 & Domingo Canales-Espinosa 1 & Pedro Américo D. Dias 1 Received: 28 December 2016 /Accepted: 30 July 2017 # Springer Science+Business Media, LLC 2017 Abstract The energetic costs of reproduction have an important influence on the life histories of female primates. At present, however, the interplay of female reproductive state, food availability, and strategies aimed at maintaining energy balance has been described for only a few species, limiting our ability to understand intra- and interspe- cific variation in female life histories. We assessed how female mantled howlers (Alouatta palliata) are affected by reproductive seasonality, and whether they alter their behavior to cope with the energetic demands of reproduction. From August 2013 to July 2015 we measured the reproductive state, behavior (1100 h of focal animal observations), and energetic condition (312 urine samples collected for C-peptide analysis) of 7 adult females, and assessed food availability (weekly phenological sampling of 397 food trees). Female behavior did not vary with reproductive state or reproductive seasonality. There were, however, differences in how females responded to variation in food availability according to reproductive state. Cycling and gestating females spent more time feeding than lactating females, and cycling females less time resting than females in other reproductive states, when food was more available. C- peptide concentrations were unaffected by either individual or overall variation in Int J Primatol DOI 10.1007/s10764-017-9990-9 Handling Editor: Joanna M. Setchell Electronic supplementary material The online version of this article (https://doi.org/10.1007/s10764-017- 9990-9) contains supplementary material, which is available to authorized users. * Pedro Américo D. Dias paddias@hotmail.com 1 Primate Behavioral Ecology Laboratory, Instituto de Neuroetología, Universidad Veracruzana, 91190 Xalapa, Mexico 2 Departamento de Biología de la Reproducción, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, 14080 Ciudad de México, Mexico