Among geladas (Theropithecus gelada), a band is a higher-level social grouping composed of multiple reproductive units that share a common ranging area. It represents one tier in their complex, multilevel society.

🌍 Gelada Social Organization

Geladas, primates living in the Ethiopian highlands, have one of the most intricate social systems among nonhuman primates. Their society is structured in nested levels:

• One-Male Unit (OMU): The basic group, consisting of a single dominant male, several reproductive females (up to 12), and their dependent offspring. Sometimes additional “follower” males are present.
• Band: Several OMUs that forage and travel together within the same range. Bands are relatively closed social units, meaning members interact more frequently with each other than with outsiders.
• Herd: Temporary aggregations of multiple bands, often formed around rich feeding areas.
• Community: The largest level, encompassing all geladas that share a broader home range.

🔑 Characteristics of Bands

• Size: Bands can include dozens to hundreds of individuals, depending on the number of OMUs.
• Function: Bands provide protection against predators, facilitate social interaction, and stabilize group dynamics.
• Social Bonds: While OMUs are the core reproductive units, bands allow for broader alliances and social buffering.
• Closed Nature: Bands are more stable than herds, with consistent membership over time.

📚 Anthropological & Evolutionary Significance

• Comparative Insight: Gelada bands resemble human bands in anthropology (small kin-based groups), but scaled up into a multilevel primate society.
• Evolutionary Models: Their nested social system is often studied as a model for the evolution of complex human social structures.
• Kinship & Genetics: Female relatedness patterns often mirror band-level associations, reinforcing cohesion.

In short: A band among geladas is a grouping of multiple reproductive units that share a range, forming a stable, higher-level social structure within their multilevel society.