The Heat Production of Goldfinches and Canaries
in Summer and Winter
S. GELINEO
Abstract
Investigations of heat production were carried out in July and January on
6 male goldfinches Carduelis carduelis and 6 male canaries Serinus canaria in a resting
16 hrs unfed state. By a number of previous experiments the birds were familiarized
with the investigator and the experimental technique. The experiments have shown
that both species have a lower heat production in summer compared with that in
winter at the neutral temperature and at 1 0c.
Whereas the results of several authors indicate that the basal metabolic
rate (BMR) does not depend on the season, there are many other papers
recording either an increase of BMR in winter and correspondingly a
decrease in summer, or the opposite [6, 8]. This means that the problem of
seasonal heat production in homoiotherms is still open.
Our present interest is focussed on the following point: how do BMR
and heat production (at about 1 0c) behave in two kinds of birds, whose
geographical distribution and, hence, average environmental temperatures
are different? One of them, the goldfinch Carduelis carduelis, is distributed
throughout Europe and even reaches the polar region [9], whereas the
other, the canary Serinus canaria, perfers warmer regions.
Methods
Both the summer and winter experiments on male C. canduelis and S. cararia
were done on the same individuals caged in open air and placed several times in the
respiratory apparatus prior to the experiment in order to adjust them to the
experimental conditions. Measurements of gas exchange (60-80 min) were done
according to [5] between 7 and 10 a.m. (relative humidity 52-70%) both in July
(2-3 months after nesting) and in January. The environmental temperature at
which the canaries lived was 23-28° C in summer 4 weeks prior to the experiment, for the goldfinches 22-28 °C; in winter the temperature was-6 to + 8 °C
for canaries and 0-10 °C for goldfinches. - Metabolism was calculated as
calories/m 2 /24 hr; the body surface was calculated by MEEH's formula (K = 10).
Results
1. General Remarks
Birds brought in summer to winter temperature (1°C) soon fell into
hypothermia of 3.3 °C (goldfinch) or 3.8 °C (canary). In C. carduelis panting
in Summer and Winter
S. GELINEO
Abstract
Investigations of heat production were carried out in July and January on
6 male goldfinches Carduelis carduelis and 6 male canaries Serinus canaria in a resting
16 hrs unfed state. By a number of previous experiments the birds were familiarized
with the investigator and the experimental technique. The experiments have shown
that both species have a lower heat production in summer compared with that in
winter at the neutral temperature and at 1 0c.
Whereas the results of several authors indicate that the basal metabolic
rate (BMR) does not depend on the season, there are many other papers
recording either an increase of BMR in winter and correspondingly a
decrease in summer, or the opposite [6, 8]. This means that the problem of
seasonal heat production in homoiotherms is still open.
Our present interest is focussed on the following point: how do BMR
and heat production (at about 1 0c) behave in two kinds of birds, whose
geographical distribution and, hence, average environmental temperatures
are different? One of them, the goldfinch Carduelis carduelis, is distributed
throughout Europe and even reaches the polar region [9], whereas the
other, the canary Serinus canaria, perfers warmer regions.
Methods
Both the summer and winter experiments on male C. canduelis and S. cararia
were done on the same individuals caged in open air and placed several times in the
respiratory apparatus prior to the experiment in order to adjust them to the
experimental conditions. Measurements of gas exchange (60-80 min) were done
according to [5] between 7 and 10 a.m. (relative humidity 52-70%) both in July
(2-3 months after nesting) and in January. The environmental temperature at
which the canaries lived was 23-28° C in summer 4 weeks prior to the experiment, for the goldfinches 22-28 °C; in winter the temperature was-6 to + 8 °C
for canaries and 0-10 °C for goldfinches. - Metabolism was calculated as
calories/m 2 /24 hr; the body surface was calculated by MEEH's formula (K = 10).
Results
1. General Remarks
Birds brought in summer to winter temperature (1°C) soon fell into
hypothermia of 3.3 °C (goldfinch) or 3.8 °C (canary). In C. carduelis panting