TY - JOUR
T1 - Thermal windows on Brazilian free-tailed bats facilitate thermoregulation during prolonged flight
AU - Reichard, Jonathan D.
AU - Prajapati, Suresh I.
AU - Austad, Steven N.
AU - Keller, Charles
AU - Kunz, Thomas H.
N1 - Funding Information:
Funding was provided by Boston University’s Center for Ecology and Conservation Biology, the National Park Service (Grant No. H7170040002 to T.H.K., PI), and the National Science Foundation (Grant No. IIS-0326483 to T.H.K., P.I., and M.B., G.F.M., J.K.W., and P.M., Co-PIs) for supporting this research. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Park Service or the National Science Foundation. This study was also made possible, in part, by software available from the National Institute of Health/National Center for Research Resources Center for Integrative Biomedical Computing (Grant No. 5P41RR012553 to C.K.). Additional funding was made available by Sigma Xi Grants-in-Aid to J.D.R.
PY - 2010/9
Y1 - 2010/9
N2 - The Brazilian free-tailed bat (Tadarida brasiliensis) experiences challenging thermal conditions while roosting in hot caves, flying during warm daylight conditions, and foraging at cool high altitudes. Using thermal infrared cameras, we identified hot spots along the flanks of free-ranging Brazilian free-tailed bats, ventral to the extended wings. These hot spots are absent in syntopic cave myotis (Myotis velifer), a species that forages over relatively short distances, and does not engage in long-distance migration. We hypothesized that the hot spots, or "radiators," on Brazilian free-tailed bats may be adaptations for migration, particularly in this long-distance, high-flying species. We examined the vasculature of radiators on Brazilian free-tailed bats with transillumination to characterize the unique arrangements of arteries and veins that are positioned perpendicular to the body in the proximal region of the wing. We hypothesized that these radiators aid in maintaining heat balance by flushing the uninsulated thermal window with warm blood, thereby dissipating heat while bats are flying under warm conditions, but shunting blood away and conserving heat when they are flying in cooler air at high altitudes. We also examined fluid-preserved specimens representing 122 species from 15 of 18 chiropteran families and radiators appeared present only in species in the family Molossidae, including both sedentary and migratory species and subspecies. Thus, the radiator appears to be a unique trait that may facilitate energy balance and water balance during sustained dispersal, foraging, and long-distance migration.
AB - The Brazilian free-tailed bat (Tadarida brasiliensis) experiences challenging thermal conditions while roosting in hot caves, flying during warm daylight conditions, and foraging at cool high altitudes. Using thermal infrared cameras, we identified hot spots along the flanks of free-ranging Brazilian free-tailed bats, ventral to the extended wings. These hot spots are absent in syntopic cave myotis (Myotis velifer), a species that forages over relatively short distances, and does not engage in long-distance migration. We hypothesized that the hot spots, or "radiators," on Brazilian free-tailed bats may be adaptations for migration, particularly in this long-distance, high-flying species. We examined the vasculature of radiators on Brazilian free-tailed bats with transillumination to characterize the unique arrangements of arteries and veins that are positioned perpendicular to the body in the proximal region of the wing. We hypothesized that these radiators aid in maintaining heat balance by flushing the uninsulated thermal window with warm blood, thereby dissipating heat while bats are flying under warm conditions, but shunting blood away and conserving heat when they are flying in cooler air at high altitudes. We also examined fluid-preserved specimens representing 122 species from 15 of 18 chiropteran families and radiators appeared present only in species in the family Molossidae, including both sedentary and migratory species and subspecies. Thus, the radiator appears to be a unique trait that may facilitate energy balance and water balance during sustained dispersal, foraging, and long-distance migration.
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U2 - 10.1093/icb/icq033
DO - 10.1093/icb/icq033
M3 - Article
C2 - 20811514
AN - SCOPUS:77956269539
SN - 1540-7063
VL - 50
SP - 358
EP - 370
JO - Integrative and Comparative Biology
JF - Integrative and Comparative Biology
IS - 3
ER -