Abstract
The Metabolic Theory of Ecology predicts that the slope of the rate–temperature relationship, E , remains consistent across traits and organisms, acting as a major determinant of large‐scale ecological patterns. Although E has recently been shown to vary systematically, we have a poor understanding of its ecological significance. To address this question, we conducted a common‐garden experiment involving six damselfly species differing in distribution, estimating E at the level of full‐sib families. Each species was sampled throughout its latitudinal range, allowing us to characterise variation in E along a latitudinal gradient spanning 3600 km. We show that E differs among populations and increases with latitude. E was right‐skewness across species, but this was largely an artefact of the latitudinal trend. Increased seasonality towards higher latitude may contribute to the latitudinal trend in E . We conclude that E should be seen as a trait involved in local adaptation.