Metabolic rate and evaporative water loss in the silky starling (Sturnus sericeus).

Abstract

To better understand the physiological characteristics of the silky starling (Sturnus sericeus), its body temperature (Tb), basal metabolic rate (BMR), evaporative water loss (EWL) and thermal conductance (C) elicited by different ambient temperatures (Ta) (5-30 ℃) were determined in the present study. Our results showed that they have a high Tb (41.6 ± 0.1 ℃), a wide thermal neutral zone (TNZ) (20-27.5℃) and a relatively low BMR within the TNZ (3.37 ± 0.17 mL O₂/g·h). The EWL was nearly stable below the TNZ (0.91 ± 0.07 mg H₂O/g·h) but increased remarkably within and above the TNZ. The C was constant below the TNZ, with a minimum value of 0.14 ± 0.01 mL O₂/g·h·℃. These findings indicate that the BMR, Tb and EWL of the silky starling were all affected by Ta, especially when Ta was below 20 ℃ and the EWL plays an important role in thermal regulation.