Parental Energy Expenditure During Brood Rearing in the Great Tit (Parus major) in Relation to Body Mass, Temperature, Food Availability and Clutch Size

• DOI: 10.2307/2389916
• Publication Date: 2006-06-17T10:54:42Z
• Authors: J. M. Tinbergen; M. W. Dietz
• Keywords: Avian clutch size

1. Quantification of the energetic needs reproducing animals provides a basis for understanding patterns in reproduction. The doubly labelled water technique enables this to be carried out under natural conditions. 2. Daily energy expenditure 32 female Great Tits (Parus major) tending nestlings 11-12 days old (DEE(par)) and at night five females was measured using technique. 3. Average DEE(par) 95.1 kJ (24 h)-1 (1.10 W) close most predictions based on interspecific allometric relationships. Night metabolism estimated 0.68 W. 4. Individual variation could explained by body mass (+), ambient temperature (-), clutch size (+) food availability (-) but not tarsus length, age, brood or nestling mass. significant factors together accounted differences found between years broods 64% variation. Possible causal pathways are discussed. 5. related with an exponent 1.99; significantly steeper than 0.67-0.75 reported literature. Analysis intraspecific 10 species young, revealed variable trends