Mass-scaling exponents (95% confidence intervals in parentheses) calculated as the mean value of log body mass and log metabolic rate for all measured Carabidae (20 species comprising a total of 560 individuals) and for two individual clades (clade 1: n=13, clade 2: n=7) by different regression methods: ordinary least squares (OLS), phylogenetic generalized least squares (PGLS) and standardized major axis (SMA)