TY - JOUR
T1 - Noise as an informational cue for decision-making
T2 - The sound of rain delays bat emergence
AU - Geipel, Inga
AU - Smeekes, Marcus J.
AU - Halfwerk, Wouter
AU - Page, Rachel A.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - 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.
AB - 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.
KW - Acoustic signals
KW - Echolocation
KW - Environmental conditions
KW - Foraging
KW - Micronycteris microtis
KW - Molossus molossus
KW - Roost emergence
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U2 - 10.1242/jeb.192005
DO - 10.1242/jeb.192005
M3 - Article
C2 - 30665972
AN - SCOPUS:85060945572
VL - 222
SP - 1
EP - 6
JO - Journal of Experimental Biology
JF - Journal of Experimental Biology
SN - 0022-0949
IS - 3
M1 - jeb192005
ER -