We examined the relationship between body temperature (T(b)) of free flying pigeons and ambient water vapor pressure and temperature. Core or near core T(b) of pigeons were measured using thermistors inserted into the cloaca and connected to small transmitters mounted on the tail feathers of free flying tippler pigeons (Columba livia). Wet and dry bulb temperatures were measured using modified transmitters mounted onto free-flying pigeons. These allowed calculation of relative humidity and hence water vapor pressure at flight altitudes. Mean T(b) during flight was 42.0 ± 1.3 °C (n = 16). Paired comparisons of a subset of this data indicated that average in-flight T(b) increased significantly by 1.2 ± 0.7 °C (n = 7) over that of birds at rest (t = -4.22, P < 0.05, n = 7) within the first 15 min of takeoff. In addition, there was a small but significant increase in T(b) with increasing ambient air (T(a)) when individuals on replicate flights (n = 35) were considered. Inclusion of water vapor pressure into the regression model did not improve the correlation between body temperature and ambient conditions. Flight T(b) also increased a small (0.5 °C) but significant amount (t = 2.827, P < 0.05, n = 8) from the beginning to the end of a flight. The small response of T(b) to changing flight conditions presumably reflects the efficiency of convection as a heat loss mechanism during sustained regular flight. The increase in T(b) on landing that occurred in some birds was a probable consequence of a sudden reduction in convective heat loss.
|Number of pages||5|
|Journal||Journal of Comparative Physiology B: Biochemical, Systemic, and Environmental Physiology|
|State||Published - 1 Apr 1999|
- Body temperature
- Columbia livia