This review investigates the ontogeny of the genus Alouatta, with the goal of determining whether howler monkey development follows a "fast-slow" continuum or whether individual life history features are dissociable from one another. Data indicate that while many aspects of howler life history are relatively accelerated compared to other atelines, a consideration of only the end parameters (e.g., age at weaning) obscures important variation within each trait. Moreover, sexual dimorphism in the pace and timing of Alouatta developmental events (e.g., somatic and craniodental maturation) provides support for a framework of life history dissociability. Based on these results, we propose a life history model for Alouatta ontogeny that recognizes that within the context of an overall rapid development, dissociabilities occur both among and within individual life history parameters.
Raguet-Schofield, M., & Pavé, R. (2015). An ontogenetic framework for Alouatta: Infant development and evaluating models of life history. In Howler Monkeys: Adaptive Radiation, Systematics, and Morphology (pp. 289–316). Springer New York. https://doi.org/10.1007/978-1-4939-1957-4_11