Wild bats briefly decouple sound production from wingbeats to increase sensory flow during prey captures

Summary

Active sensing animals such as echolocating bats produce the energy with which they probe their environment. The intense echolocation calls of bats are energetically expensive, but their cost can be reduced by synchronizing the exhalations needed to vocalize to wingbeats. Here, we use sound-and-movement recording tags to investigate how wild bats balance efficient sound production with information needs during foraging and navigation. We show that wild bats prioritize energy efficiency over sensory flow when periodic snapshots of the acoustic scene are sufficient during travel and search. Rapid calls during tracking and interception of close prey are decoupled from the wingbeat but are weaker and comprise <2% of all calls during a night of hunting. The limited use of fast sonar sampling provides bats with high information update rates during critical hunting moments but adds little to their overall costs of sound production despite the inefficiency of decoupling calls from wingbeats.

Graphical abstract

Highlights

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  Wild bats decouple wingbeats and call emission in short critical phases of hunting

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  These rapid capture calls are more than 30 dB weaker than most other calls

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  Fast sonar calls are vital for hunting but comprise just 2% of all emitted calls

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  High sensory flow when hunting therefore adds little to the cost of sound production

Abstract

Biological sciences; Ecology; Environmental science; Ethology; Zoology.