Multilevel social structure and diet shape the gut microbiota of the gelada monkey, the only grazing primate.

Background: The gelada monkey (Theropithecus gelada), endemic to the Ethiopian highlands, is the only graminivorous primate, i.e., it feeds mainly on grasses and sedges.

Comparative primate obstetrics: Observations of 15 diurnal births in wild gelada monkeys (Theropithecus gelada) and their implications for understanding human and nonhuman primate birth evolution.

Objectives: The birth process has been studied extensively in many human societies, yet little is known about this essential life history event in other primates. Here, we provide the most detailed account of behaviors surrounding birth for any wild nonhuman primate to date.

Materials And Methods: Over a recent ∼10-year period, we directly observed 15 diurnal births (13 live births and 2 stillbirths) among geladas (Theropithecus gelada) at Guassa, Ethiopia.