The relationship between direct predation and antipredator responses: a test with multiple predators and multiple...

Area of Science:

• Ecology
• Behavioral Ecology
• Wildlife Biology

Background:

• Antipredator responses incur energetic costs, influencing prey growth, survival, and reproduction.
• The total cost of predation involves a trade-off between direct predation and risk effects.
• Field studies linking direct predation and antipredator response strength are scarce, especially for entire predator-prey guilds.

Purpose of the Study:

• To investigate the relationship between direct predation patterns and antipredator behavioral responses in a complete antelope guild.
• To assess how different large carnivore species influence prey vigilance and foraging behavior.
• To determine if the strength of antipredator responses aligns with the per-capita risk of predation.

Main Methods:

• Utilized scan sampling over a four-year field study in Liuwa Plains National Park, Zambia.
• Observed behavioral responses of antelopes (wildebeest, zebra, oribi) to lions, spotted hyenas, cheetahs, and African wild dogs.
• Quantified predator-prey kill proportions, prey abundance using distance sampling, and calculated per-capita predation risk.

Main Results:

• Antelopes increased vigilance by an average factor of 2.4 in the presence of predators.
• Vigilance varied significantly among prey species but showed weak responses to different predator types.
• Increased vigilance correlated with reduced foraging across all prey species.
• The strength of antipredator responses was not detectably related to direct predation patterns for 15 predator-prey combinations.

Conclusions:

• Antipredator behavioral responses, like vigilance, may not directly correlate with the actual risk of predation.
• The findings challenge the assumption that risk effects consistently mirror direct predation impacts.
• Further research is needed to understand the implications of this disconnect for predator-prey dynamics and population regulation.