Acoustically eavesdropping bat predators take longer to capture katydid prey signalling in aggregation.

Area of Science:

• Ecology
• Behavioral Ecology
• Bioacoustics

Background:

• Prey aggregation can increase conspicuousness to predators but may offer safety in numbers.
• Previous research focused on visual predators; anti-predatory benefits in auditory contexts remain less understood.
• Katydids (Mecopoda) use acoustic signals for mating, potentially attracting bat predators.

Purpose of the Study:

• To investigate if katydids calling in aggregations gain anti-predatory benefits against acoustically eavesdropping bats (Megaderma spasma).
• To determine if aggregation influences predator foraging efficiency and prey survival in an auditory predation context.

Main Methods:

• A choice experiment was conducted where bats could approach either aggregated or solitary calling katydids.
• Prey capture tasks assessed bat foraging efficiency by measuring time to capture and number of passes.
• The effect of vegetation cover on capture success for solitary and aggregated prey was also examined.

Main Results:

• Bats were more attracted to aggregated katydid calls, suggesting higher initial risk.
• However, bats took significantly longer to capture katydids from aggregations, indicating reduced predation risk.
• Vegetation cover aided solitary prey but did not further benefit aggregated prey.

Conclusions:

• Acoustic prey signaling in aggregations gain anti-predatory benefits due to reduced predator foraging efficiency.
• The increased detectability of prey aggregations is offset by lower capture success for bats.
• This trade-off may influence predator foraging strategies in natural environments.