Noise as an informational cue for decision-making: The sound of rain delays bat emergence

Inga Geipel*, Marcus J. Smeekes, Wouter Halfwerk, Rachel A. Page

*Corresponding author for this work

    Research output: Contribution to JournalArticleAcademicpeer-review


    Background noise can have strong negative consequences for animals, reducing individual fitness by masking communication signals, impeding prey detection and increasing predation risk. While the negative impacts of noise across taxa have been well documented, the use of noise as an informational cue, providing animals with reliable information on environmental conditions, has been less well studied. In the tropical rainforest, downpours can be intense and frequent. Strong rainfall may impede efficient orientation and foraging for bats that need echolocation to both navigate and detect prey, and can result in higher flight costs due to increased metabolic rates. Using playback experiments at natural roosts, we tested whether two bat species, differing in their hunting strategies and foraging habitats, use rain noise as a cue to delay emergence from their roosts. We found that both species significantly delayed their emergence time during rain noise playbacks versus silence and ambient noise controls. We conclude that bats can use background noise, here the acoustic component of rainfall, as a reliable informational cue to make informed decisions, in this case about whether to initiate foraging trips or remain in the shelter of their roosts. Our findings suggest that environmental background noise can sometimes be beneficial to animals, in particular in situations where other sensory cues may be absent.

    Original languageEnglish
    Article numberjeb192005
    Pages (from-to)1-6
    Number of pages6
    JournalJournal of Experimental Biology
    Issue number3
    Publication statusPublished - 1 Feb 2019


    I.G. was funded by a Smithsonian Tropical Research Institute Tupper Postdoctoral Fellowship and the Wissenschaftskolleg zu Berlin, Germany. M.J.S. was supported by a Smithsonian Tropical Research Institute internship. R.A.P. and I.G. were funded both by the Smithsonian Tropical Research Institute and by the Human Frontier Science Program (RGP0040/2013).

    FundersFunder number
    Smithsonian Tropical Research Institute
    Human Frontier Science ProgramRGP0040/2013
    Wissenschaftskolleg zu Berlin


      • Acoustic signals
      • Echolocation
      • Environmental conditions
      • Foraging
      • Micronycteris microtis
      • Molossus molossus
      • Roost emergence


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