Does a Social Introduction Alter Cortisol in Captive Bonobos (Pan paniscus)?

Area of Science:

• Primatology
• Animal Behavior
• Endocrinology

Background:

• Social animals often use group living to buffer against stressors.
• Changes in social dynamics can also be a significant stressor, impacting hormone levels.
• Glucocorticoids, like cortisol, are key hormones regulating homeostasis during stress.

Purpose of the Study:

• To investigate the impact of social environment changes on glucocorticoid levels in captive bonobos.
• To compare stress responses between established group members and a new individual during social integration.

Main Methods:

• Monitoring cortisol levels (corrected for creatinine) in urine samples from captive bonobos.
• Collecting samples before, during, and after the introduction of a new group member.
• Observing stress hormone fluctuations in both resident and emigrating individuals.

Main Results:

• Cortisol levels in established bonobos remained stable throughout the social integration process.
• The newly introduced bonobo exhibited elevated cortisol upon arrival, which decreased with gradual integration.
• These findings suggest the emigrating individual experienced greater stress compared to resident bonobos.

Conclusions:

• New social introductions can be a significant stressor, particularly for the incoming individual.
• Careful, gradual introductions and avoiding prolonged isolation are crucial for integrating new members into social groups.
• When human-mediated, social introductions should aim to mimic natural dispersal patterns to minimize stress in social animals.