Wild robust capuchin monkey interactions with sympatric primates

Area of Science:

• Primate behavioral ecology
• Interspecific interactions
• Primate social behavior

Background:

• Sympatric primate interactions offer insights into competition, cooperation, and avoidance dynamics.
• Capuchin monkeys (Cebus and Sapajus spp.) interact with various primate species, with documented differences in interaction types for gracile capuchins (Cebus).
• Limited information exists on the interspecific interactions of robust capuchins (Sapajus spp.).

Purpose of the Study:

• To describe and classify interspecific encounters involving robust capuchins (Sapajus libidinosus and S. nigritus).
• To compare interaction patterns among different sites, environments (Cerrado, Caatinga, Atlantic forest), and capuchin group sizes.
• To investigate the influence of interacting species' body size on capuchin behavior.

Main Methods:

• Observation of Sapajus libidinosus and S. nigritus interactions with Alouatta caraya, A. guariba, Brachyteles arachnoides, and Callithrix jacchus.
• Data collection across three distinct environmental sites over 8421 hours.
• Classification of interactions based on type (neutral, positive, negative) and frequency, considering group size and environmental factors.

Main Results:

• Capuchins in larger groups exhibited more frequent aggressive interactions with other primates.
• Smaller primates tended to avoid capuchins, while interactions with larger muriquis (Brachyteles arachnoides) were mostly neutral for capuchins.
• Robust capuchins displayed aggression towards primates larger than themselves, with aggressive behavior being most common in larger groups and drier habitats.

Conclusions:

• Robust capuchins demonstrate a capacity for aggression towards a range of sympatric primate species, irrespective of relative body size.
• Group size and environmental aridity are significant factors influencing the frequency and type of aggressive interspecific interactions in robust capuchins.
• Interspecific interaction patterns of robust capuchins are complex and influenced by ecological and social variables, highlighting the need for further research.