Thermal Windows on Brazilian Free-tailed Bats Facilitate Thermoregulation during Prolonged Flight

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 Brazilia...

Full description

Saved in:
Bibliographic Details
Published in:Integrative and Comparative Biology 2010-09, Vol.50 (3), p.358-370
Main Authors: Reichard, Jonathan D., Prajapati, Suresh I., Austad, Steven N., Keller, Charles, Kunz, Thomas H.
Format: Article
Language:English
Subjects:
Aerial locomotion
Altitude
Animal communication
Animal migration
Animal Migration - physiology
Animal wings
Animals
Bats
Biological taxonomies
Blood
Blood vessels
Body Temperature Regulation - physiology
Brazil
Cardiovascular system
Caves
Chiroptera - physiology
Energy Metabolism
Flight, Animal - physiology
Hair
Integrative Migration Biology
Intergative Migration Biology
Phylogeny
Radiators
Regional Blood Flow - physiology
Temperature
Texas
Wings, Animal - blood supply
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary: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.
ISSN:1540-7063
1557-7023
DOI:10.1093/icb/icq033