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Energy expenditure during flight in relation to body mass: effects of natural increases in mass and artificial load in Rose Coloured Starlings.

Schmidt-Wellenburg CA, Engel S, Visser GH - J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol. (2008)

Bottom Line: The harness itself did not affect ef, i.e. U and C flights were not different. ef was allometrically related with body mass m (in g).The slopes were not significantly different between the treatments, but ef was increased by 5.4% in L compared to C flights (log10(ef) = 0.050 + 0.47 x log10(m) for C, and log10(ef) = 0.073 + 0.47 x log10(m) for L).We did not observe an effect of treatment on breast muscle size and wingbeat frequency.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Rhythms and Behaviour, Max Planck Institute for Ornithology, Von-der-Tann-Str. 7, Andechs, Germany. schmidt-wellenburg@orn.mpg.de

ABSTRACT
Rose Coloured Starlings (Sturnus roseus) flew repeatedly for several hours in a wind tunnel while undergoing spontaneous variation in body mass. The treatments were as follows: flying unrestrained (U), with a control harness of 1.2% of their body mass (C), or with a harness of 7.4% of their body mass, which was either applied immediately before the flight (LS) or at least 9 days in advance (LL). Energy expenditure during flight (ef in W) was measured with the Doubly Labelled Water method. Flight costs in L(S) and LL were not significantly different and therefore were pooled (L). The harness itself did not affect ef, i.e. U and C flights were not different. ef was allometrically related with body mass m (in g). The slopes were not significantly different between the treatments, but ef was increased by 5.4% in L compared to C flights (log10(ef) = 0.050 + 0.47 x log10(m) for C, and log10(ef) = 0.073 + 0.47 x log10(m) for L). The difference in ef between C, LS and LL was best explained by taking the transported mass m transp (in g) instead of m into account (log10(ef) = -0.08 + 0.54 x log10(m transp)). Flight costs increased to a lesser extent than expected from interspecific allometric comparison or aerodynamic theory, regardless of whether the increase in mass occurred naturally or artificially. We did not observe an effect of treatment on breast muscle size and wingbeat frequency. We propose that the relatively low costs at a high mass are rather a consequence of immediate adjustments in physiology and/or flight behaviour than of long-term adaptations.

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Body mass characteristics and treatment of individuals during the experimental flights. We indicated the treatments at natural body mass (in g) for single individuals. Crosses refer to U, triangles to C, open circles to LS, and grey circles to LL flights
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Fig1: Body mass characteristics and treatment of individuals during the experimental flights. We indicated the treatments at natural body mass (in g) for single individuals. Crosses refer to U, triangles to C, open circles to LS, and grey circles to LL flights

Mentions: Fourteen Rose Coloured Starlings flew repeatedly (up to 9 times) in the wind tunnel of the Max Planck Institute for Ornithology, Seewiesen, Germany (Engel et al. 2006a). Between the flights, body mass of the birds varied spontaneously between 56.1 and 89.9 g. Within individuals, variation in body mass (maximum-minimum) ranged from 2 to 30% of the minimum body mass (Fig. 1). During the experimental flights, birds flew either unrestrained (U), carried a control harness (C), which was applied immediately before the flight, or a loaded harness (L), which was applied either immediately before the flight (LS) or at least 9 days before the experimental flight (LL; see below).Fig. 1


Energy expenditure during flight in relation to body mass: effects of natural increases in mass and artificial load in Rose Coloured Starlings.

Schmidt-Wellenburg CA, Engel S, Visser GH - J. Comp. Physiol. B, Biochem. Syst. Environ. Physiol. (2008)

Body mass characteristics and treatment of individuals during the experimental flights. We indicated the treatments at natural body mass (in g) for single individuals. Crosses refer to U, triangles to C, open circles to LS, and grey circles to LL flights
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC2493526&req=5

Fig1: Body mass characteristics and treatment of individuals during the experimental flights. We indicated the treatments at natural body mass (in g) for single individuals. Crosses refer to U, triangles to C, open circles to LS, and grey circles to LL flights
Mentions: Fourteen Rose Coloured Starlings flew repeatedly (up to 9 times) in the wind tunnel of the Max Planck Institute for Ornithology, Seewiesen, Germany (Engel et al. 2006a). Between the flights, body mass of the birds varied spontaneously between 56.1 and 89.9 g. Within individuals, variation in body mass (maximum-minimum) ranged from 2 to 30% of the minimum body mass (Fig. 1). During the experimental flights, birds flew either unrestrained (U), carried a control harness (C), which was applied immediately before the flight, or a loaded harness (L), which was applied either immediately before the flight (LS) or at least 9 days before the experimental flight (LL; see below).Fig. 1

Bottom Line: The harness itself did not affect ef, i.e. U and C flights were not different. ef was allometrically related with body mass m (in g).The slopes were not significantly different between the treatments, but ef was increased by 5.4% in L compared to C flights (log10(ef) = 0.050 + 0.47 x log10(m) for C, and log10(ef) = 0.073 + 0.47 x log10(m) for L).We did not observe an effect of treatment on breast muscle size and wingbeat frequency.

View Article: PubMed Central - PubMed

Affiliation: Department of Biological Rhythms and Behaviour, Max Planck Institute for Ornithology, Von-der-Tann-Str. 7, Andechs, Germany. schmidt-wellenburg@orn.mpg.de

ABSTRACT
Rose Coloured Starlings (Sturnus roseus) flew repeatedly for several hours in a wind tunnel while undergoing spontaneous variation in body mass. The treatments were as follows: flying unrestrained (U), with a control harness of 1.2% of their body mass (C), or with a harness of 7.4% of their body mass, which was either applied immediately before the flight (LS) or at least 9 days in advance (LL). Energy expenditure during flight (ef in W) was measured with the Doubly Labelled Water method. Flight costs in L(S) and LL were not significantly different and therefore were pooled (L). The harness itself did not affect ef, i.e. U and C flights were not different. ef was allometrically related with body mass m (in g). The slopes were not significantly different between the treatments, but ef was increased by 5.4% in L compared to C flights (log10(ef) = 0.050 + 0.47 x log10(m) for C, and log10(ef) = 0.073 + 0.47 x log10(m) for L). The difference in ef between C, LS and LL was best explained by taking the transported mass m transp (in g) instead of m into account (log10(ef) = -0.08 + 0.54 x log10(m transp)). Flight costs increased to a lesser extent than expected from interspecific allometric comparison or aerodynamic theory, regardless of whether the increase in mass occurred naturally or artificially. We did not observe an effect of treatment on breast muscle size and wingbeat frequency. We propose that the relatively low costs at a high mass are rather a consequence of immediate adjustments in physiology and/or flight behaviour than of long-term adaptations.

Show MeSH
Related in: MedlinePlus