Bats aloft: Variability in echolocation call structure at high altitudes

Erin H. Gillam, Gary F. McCracken, John K. Westbrook, Ya Fu Lee, Michael L. Jensen, Ben B. Balsley

Research output: Contribution to journalArticlepeer-review

37 Citations (Scopus)


Bats alter their echolocation in response to changes in ecological and behavioral conditions, but little is known about how they adjust call structure in response to changes in altitude. We examined altitudinal variation in the echolocation of Brazilian free-tailed bats, Tadarida brasiliensis, a species known to fly to altitudes of 3,000 m above the ground. From 50. 2 h of recordings, we analyzed 113 high-quality echolocation call sequences recorded from 0 to 862 m above ground level. Bats flying near the ground used shorter, higher-frequency, broader-bandwidth calls compared to bats at higher altitudes, an effect likely due to the greater levels of echo-producing clutter (i. e., vegetation, buildings) found near the ground. When ground-level recordings are excluded, bats continue to shift towards the use of longer-duration, lower-frequency, narrower-bandwidth calls with increasing altitude. We propose that the observed high-altitude changes in call structure are a response to changing acoustic attenuation rates and/or decreasing insect densities at higher altitudes.

Original languageEnglish
Pages (from-to)69-79
Number of pages11
JournalBehavioral Ecology and Sociobiology
Issue number1
Publication statusPublished - 2009 Nov

All Science Journal Classification (ASJC) codes

  • Ecology, Evolution, Behavior and Systematics
  • Animal Science and Zoology


Dive into the research topics of 'Bats aloft: Variability in echolocation call structure at high altitudes'. Together they form a unique fingerprint.

Cite this