Avoidance of simultaneous patch use in Japanese large-footed bats.

Area of Science:

• Behavioral Ecology
• Animal Behavior
• Ecology

Background:

• Group foraging can improve prey detection but may lead to conflicts over resources.
• Evaluating foraging performance alongside inter-individual interactions is crucial for understanding this balance.
• Quantifying both simultaneously under natural conditions presents significant challenges.

Purpose of the Study:

• To investigate how individual foraging efficiency and pairwise interactions are affected by simultaneous exploitation of a foraging patch.
• To use the Japanese large-footed bat (Myotis macrodactylus) as a model system to study these dynamics.
• To link individual behavior and foraging performance non-invasively.

Main Methods:

• Monitoring an entire pond foraging patch using two thermal cameras and an eight-channel microphone array.
• Reconstructing individual bat arrival, prey-attack, and exit times.
• Employing a Poisson generalized linear mixed model (GLMM) and a null model for statistical analysis.

Main Results:

• Prey-attack rates were approximately 25% lower during paired flights compared to solitary flights.
• Bats significantly shortened the duration of shared patch use compared to predictions from a null model.
• No evidence of a prior residence advantage was found; exit order did not depend on arrival order.

Conclusions:

• Japanese large-footed bats limit the duration of shared patch use, suggesting a strategy to mitigate costs associated with conspecific interactions.
• Reduced prey-attack rates during simultaneous patch use indicate a trade-off between foraging benefits and social costs.
• Bats serve as an effective model for studying foraging dynamics and sensory interference in the wild without invasive methods.