Growth trajectories in wild geladas (Theropithecus gelada)

Gelada females in Simien National Park, Ethiopia, reach adult body size by 7.72 years, with 97.2% of their shoulder-rump growth completed by first reproduction, contrary to expectations given their graminivorous diet and high infant mortality. Unlike other polygynous primates, male geladas surpass females in size not due to faster growth but because they grow for a longer period, reaching 96% of adult size at estimated first birth. The study employed a noninvasive photogrammetric method using parallel lasers to measure shoulder-rump growth in wild populations, providing novel insights into life history patterns in primates. This approach offers a promising tool for constructing comprehensive life history perspectives that were previously inaccessible.

Lu, A., Bergman, T. J., McCann, C., Stinespring‐Harris, A., & Beehner, J. C. (2016). Growth trajectories in wild geladas (Theropithecus gelada). American Journal of Primatology, 78(7), 707–719. Portico. https://doi.org/10.1002/ajp.22535