The stoichiometric approach in determining total evaporative water loss and the relationship between evaporative and non-evaporative heat loss in two resting bird species: passerine and non-passerine

Table 1 Thermoregulation energetics at rest at night in Budgerigar and European Greenfinch in summer (S) and in winter (W)

Species	N	M	Season	SMR	H _l	H _u	T _lc	T _uc	BMR	Q upon T _A
Melopsittacus undulatus	18	25.2 ± 0.6	Summer	80.0 ± 2.3	2.00	8.65	27.0	39.0	26.0 ± 0.7	q = 30.5 − 0.65T _A
Melopsittacus undulatus	18	33.6 ± 0.5	Winter	76.2 ± 1.9	1.83	8.13	26.0	38.5	28.5 ± 1.2	q = 30.0 − 0.68T _A
Chloris chloris	17	28.2 ± 0.4	Summer	81.2 ± 2.7	2.03	6.84	20.0	36.0	41.0 ± 1.3	q = 23.1 − 0.51T _A
Chloris chloris	17	29.0 ± 0.3	Winter	80.4 ± 2.1	2.15	8.03	16.0	36.0	48.1 ± 0.9	q = 24.0 − 0.55T _A

Abbreviations: n number of measured birds, m average body mass (g), SMR energy expenditure at rest at night at T _A = 0 °C or standard metabolic rate at T _A = 0 °C (kJ/bird day), h _l thermal conductance at rest (night) at low temperatures (kJ/bird day °C), h _u thermal conductance at rest (night) at upper critical temperature (h _u = BMR/(T _B − T _uc) (kJ/bird day °C) T _lc, lower critical temperature (^oC), T _uc, upper critical temperature (^oC), T _B body temperature, °C, BMR basal metabolic rate (kJ/bird day), q energetic equivalent of loss body mass at rest (kJ/g)
Differences are significant (p < 0.05) between the summer and winter values in Chloris chloris and are not significant between summer and winter values in Melopsittacus undulatus

ISSN: 2053-7166