Premium
SEASONAL VARIATION IN METABOLIC FUNCTIONS OF BRAMBLINGS
Author(s) -
Pohl Hermann
Publication year - 1971
Publication title -
ibis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.933
H-Index - 80
eISSN - 1474-919X
pISSN - 0019-1019
DOI - 10.1111/j.1474-919x.1971.tb05143.x
Subject(s) - respiratory quotient , zoology , oxygen , metabolic rate , body weight , biology , seasonality , basal metabolic rate , energy expenditure , ecology , chemistry , endocrinology , organic chemistry
SUMMARY Seasonal variation in the rate of oxygen consumption during rest at different test temperatures and in the respiratory quotient (RQ) was observed in male Bramblings Fringilla montifringilla which had been caught as immature birds during autumn migration and kept under outdoor conditions for one year. Resting oxygen consumption measured from +31 o to – 4 o C during one night was significantly lower in late April and October (migratory seasons) as compared to the preceding and the following December. Because of marked seasonal changes in body weight, the significance of differences in metabolic rate between different seasons was largely dependent on the manner of expressing the rate of oxygen consumption, either per bird or as the 0–67 power of body weight (“surface coefficient”). The lower resting rate of oxygen consumption during the migratory seasons was interpreted as one possible factor responsible for allowing fat deposition by reducing total energy expenditure. This modification occurred only in birds kept under quasi‐natural conditions outdoors and not in birds which were kept in cages under constant conditions of light and temperature in the laboratory.