Species co-occurrence patterns and dietary resource competition in primates

Area of Science:

• Ecology
• Community Ecology
• Evolutionary Biology

Background:

• Diamond's assembly rules propose that interspecific competition leads to nonrandom species distributions.
• Competitive exclusion can prevent certain species pairs from co-occurring in the same community.
• Previous studies show mixed support for Diamond's rules, with notable exceptions.

Purpose of the Study:

• To investigate co-occurrence patterns of primate species globally.
• To assess the role of interspecific competition in structuring primate communities.
• To compare competitive exclusion effects across different primate dietary guilds.

Main Methods:

• Analyzed primate species co-occurrence in 109 global communities.
• Utilized EcoSim software to calculate checkerboard (C) scores for each region.
• Conducted analyses including all species and by dietary guilds (frugivores, folivores, insectivores, frugivore-insectivores).

Main Results:

• Significantly high C scores, indicating nonrandom distributions, were found in 9 of 10 regions when considering all primate species.
• Over 50% of regions showed significantly high C scores for frugivores, suggesting strong competitive exclusion.
• Only 23% of regions exhibited significantly high C scores for folivores, indicating weaker competitive exclusion.

Conclusions:

• Primate communities exhibit nonrandom structure, likely driven by interspecific competition.
• Frugivorous primates experience greater interspecific competition and competitive exclusion than folivorous primates.
• Dietary guilds play a significant role in mediating competitive interactions and community assembly patterns.