Format

Send to

Choose Destination
J Comp Physiol A Neuroethol Sens Neural Behav Physiol. 2009 Oct;195(10):923-34. doi: 10.1007/s00359-009-0468-x. Epub 2009 Aug 12.

Context-dependent effects of noise on echolocation pulse characteristics in free-tailed bats.

Author information

1
Department of Biology, Texas A&M University, College Station, TX, 77843-3258, USA. jtressler@mail.bio.tamu.edu

Abstract

Background noise evokes a similar suite of adaptations in the acoustic structure of communication calls across a diverse range of vertebrates. Echolocating bats may have evolved specialized vocal strategies for echolocating in noise, but also seem to exhibit generic vertebrate responses such as the ubiquitous Lombard response. We wondered how bats balance generic and echolocation-specific vocal responses to noise. To address this question, we first characterized the vocal responses of flying free-tailed bats (Tadarida brasiliensis) to broadband noises varying in amplitude. Secondly, we measured the bats' responses to band-limited noises that varied in the extent of overlap with their echolocation pulse bandwidth. We hypothesized that the bats' generic responses to noise would be graded proportionally with noise amplitude, total bandwidth and frequency content, and consequently that more selective responses to band-limited noise such as the jamming avoidance response could be explained by a linear decomposition of the response to broadband noise. Instead, the results showed that both the nature and the magnitude of the vocal responses varied with the acoustic structure of the outgoing pulse as well as non-linearly with noise parameters. We conclude that free-tailed bats utilize separate generic and specialized vocal responses to noise in a context-dependent fashion.

PMID:
19672604
PMCID:
PMC2825556
DOI:
10.1007/s00359-009-0468-x
[Indexed for MEDLINE]
Free PMC Article

Supplemental Content

Full text links

Icon for Springer Icon for PubMed Central
Loading ...
Support Center