TY - JOUR TI - Brazilian free-tailed bats (Tadarida brasiliensis: Molossidae Chiroptera) at high altitude: links to migratory insect populations AU - McCracken, G AU - Gillam, E AU - Westbrook, J AU - Lee, Y AU - Jensen, M AU - Balsley, B T2 - Integrative and Comparative Biology AB - Existing information on the activity of bats in the aerosphere is restricted almost exclusively to altitudes that are within a few tens of meters above the ground. We report a total of 50.2 h of ultrasonic recordings made using radio microphonic bat detectors suspended from free-floating helium balloons and from kites. The data include a total of 22 353 echolocative calls from ground-level to 1118 m above ground level (AGL). These calls are attributed to Brazilian free-tailed bats based on acoustic features and the large numbers and high-altitude aerial dispersion of these bats over the local landscape. Bat activity varied significantly throughout the air column and was greatest at 400–500 m AGL and near ground level. Feeding buzzes, indicating feeding on aerial prey, were most abundant near ground level and at 400–500 m, and were detected to altitudes of ∼ 900 m AGL. The peak activity of bats at 400–500 m AGL is concordant with the altitude of the atmospheric boundary layer and the seasonal formation of the low-elevation southerly wind jet that has been identified as a major aeroecological corridor for the nocturnal dispersal of noctuid moths and other insects. DA - 2008/07// PY - 2008 VL - 48 IS - 1 SP - 107 EP - 118 UR - https://academic.oup.com/icb/article-lookup/doi/10.1093/icb/icn033 DO - 10.1093/icb/icn033 LA - English KW - Bats ER -