File(s) under permanent embargo
Moult and basal metabolic costs in males of two subspecies of stonechats: the European Saxicola torquata rubicula and the East African S. t. axillaris
The circannual patterns in resting metabolic rate (RMR) of males of two subspecies of stonechats, the European Saxicola torquata rubicula and the East African S. t. axillaris, are compared. As the birds from the two subspecies were raised and kept under comparable laboratory conditions, differences in metabolic rate between the two subspecies had to be genetically determined. RMR peaked during moult in both subspecies. During the rest of the year RMR was fairly constant in both subspecies and assumed to reflect basal metabolic rate (BMR). African stonechats had a 22% lower mass specific BMR than European stonechats, which is thought to reflect a genetical physiological adaptation to the differences in environmental circumstances they experience in the field. A low BMR makes an animal more susceptible to cold. Hence, the relatively high plumage mass in the African compared to the European stonechat may be functionally linked to its relatively low BMR. Moult costs, calculated from the plumage masses and the differences in RMR inside and outside the moult period, tended to be higher in the European compared to the African stonechats. These data and an interspecific comparison of moult costs over various species of birds support the earlier notion by Lindström et al. (1993) that moult costs are more closely linked with BMR than with body mass or rate of moult. The relation between moult costs and BMR and the fact that the efficiency of moult is extremely low (3.8 and 6.4% for European and African stonechats, respectively) suggest that the maintenance of specific tissues necessary for moult is a large cost factor. Alternatively, impaired insulation during moult may necessitate an increased metabolic capacity which may be associated with an increased RMR.
History
Journal
OecologiaVolume
104Issue
4Pagination
424 - 432Publisher
SpringerLocation
Heidelberg, GermanyPublisher DOI
ISSN
0029-8549eISSN
1432-1939Language
engPublication classification
C1.1 Refereed article in a scholarly journalCopyright notice
1995, SpringerUsage metrics
Categories
Keywords
moultfeather synthesis costsbasal metabolic ratecircannual metabolic patternslatitudinal metabolic effectsScience & TechnologyLife Sciences & BiomedicineEcologyEnvironmental Sciences & EcologyMOLTWHITE-CROWNED SPARROWSECOLOGICAL ENERGETICSENERGY-EXPENDITUREFALCO-TINNUNCULUSCIRCADIAN PHASETROPICAL BIRDGROWTH-RATESBODY SIZEPHOTOPERIODEcology
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC