Assessing blue wildebeests' vigilance, grouping and foraging responses to perceived predation risk using playback...

Area of Science:

• Behavioral Ecology
• Animal Behavior
• Wildlife Science

Background:

• Understanding ungulate antipredator behavior is crucial for conservation.
• Key questions remain regarding how prey balance vigilance and social learning under threat.
• The influence of group dynamics and environmental context on antipredator responses needs further investigation.

Purpose of the Study:

• To investigate how wildebeest balance antipredator and social vigilance when exposed to predation threats.
• To determine how environmental factors and social context affect wildebeest antipredator responses.
• To analyze the impact of predator cues on wildebeest vigilance and group behavior.

Main Methods:

• Playback experiments using lion roars and car noises were conducted on 101 wildebeest groups in Etosha National Park, Namibia.
• Vigilance behaviors (antipredator and social) and within-group density were quantified.
• The influence of playback type, proximity to cover, and presence of other prey species on vigilance were analyzed.

Main Results:

• Wildebeest increased antipredator vigilance, but not social vigilance, in response to lion roars, indicating reliance on individual assessment.
• Antipredator vigilance was higher when individuals were farther from cover and in mixed-species groups, suggesting heightened risk perception.
• Wildebeest exhibited increased 'bunching' behavior and decreased feeding rates following lion roars compared to car noises.

Conclusions:

• Wildebeest primarily use individual vigilance to assess direct predation threats rather than relying on social information.
• Environmental factors like cover availability and interspecific interactions significantly modulate antipredator vigilance.
• The use of social information in antipredator strategies is context-dependent in ungulates.