The use of IR thermography to measure the radiative temperature and heat loss of a barn owl (Tyto alba)
Publication Type: |
Journal Article |
Year of Publication: |
1998 |
Authors: |
D. J. Mccafferty, J. B. Moncrieff, I. R. Taylor, G. F. Boddie |
Publication/Journal: |
Journal of Thermal Biology |
Keywords: |
barn owl, heat loss, ir thermography, metabolic rate, tyto alba |
Abstract:
Infrared (IR) thermography was used to identify the major sites of heat loss from a female barn owl at an air temperature of 17.6°C. When perched, the mean radiative temperature of the owl was 21.1°C (SD=3.5). The facial disc averaged 23.9°C (SD=9.1) and the temperature of the eyes was greater than 33°C. Images showed an area on the lower abdomen that was warmer than 27°C. During flight, the temperature of plumage overlying wing muscles was more than 30°C.
The metabolic heat production of the barn owl was estimated to be 42 W m−2 (1.68 W) at 17.6°C which agreed with previous measurements of metabolism. Heat loss from the head was almost double that from the body as a whole, indicating the importance of reducing exposure of the head during roosting.
The metabolic rate during flight was calculated to be 13×BMR (Pennycuick, 1989). This suggested that barn owls lose considerable amounts of heat during prolonged periods of flight. It is hypothesised that by being active in cool nocturnal conditions, barn owls may exploit waste metabolic heat for thermoregulation.