Phantom rivers filter birds and bats by acoustic niche

Author

D. G. E. Gomes
C. A. Toth
H. J. Cole
C. D. Francis
J. R. Barber

Files

Publication Date

5-24-2021

Publication Title

Nature Communications

Volume Number

12

Abstract

Natural sensory environments, despite strong potential for structuring systems, have been neglected in ecological theory. Here, we test the hypothesis that intense natural acoustic environments shape animal distributions and behavior by broadcasting whitewater river noise in montane riparian zones for two summers. Additionally, we use spectrally-altered river noise to explicitly test the effects of masking as a mechanism driving patterns. Using data from abundance and activity surveys across 60 locations, over two full breeding seasons, we find that both birds and bats avoid areas with high sound levels, while birds avoid frequencies that overlap with birdsong, and bats avoid higher frequencies more generally. We place 720 clay caterpillars in willows, and find that intense sound levels decrease foraging behavior in birds. For bats, we deploy foraging tests across 144 nights, consisting of robotic insect-wing mimics, and speakers broadcasting bat prey sounds, and find that bats appear to switch hunting strategies from passive listening to aerial hawking as sound levels increase. Natural acoustic environments are an underappreciated niche axis, a conclusion that serves to escalate the urgency of mitigating human-created noise.

Document Type

Article

Digital Object Identifier (DOI)

https://doi.org/10.1038/s41467-021-22390-y

Language

English

Recommended Citation

Gomes, D. G. E.; Toth, C. A.; Cole, H. J.; Francis, C. D.; and Barber, J. R., "Phantom rivers filter birds and bats by acoustic niche" (2021). KIP Articles. 9860.
https://digitalcommons.usf.edu/kip_articles/9860