Data from: Environmental and genetic influences on body mass and resting metabolic rates (RMR) in a natural population of weasel Mustela nivalis

Body mass (BM) and resting metabolic rates (RMR) are two inexorably linked
traits strongly related to mammalian life histories. Yet, there have been
no studies attempting to estimate heritable variation and covariation of
BM and RMR in natural populations. We used a marker-based approach to
construct a pedigree and then the ‘animal model’ to estimate narrow sense
heritability (h^2) of these traits in a free-living population of weasels
Mustela nivalis – a small carnivore characterised by a wide range of BM
and extremely high RMR. The most important factors affecting BM of weasels
were sex and habitat type, whereas RMR was significantly affected only by
seasonal variation of this trait. All environmental factors had only small
effect on estimates of additive genetic variance of both BM and RMR. The
amount of additive genetic variance associated with BM and estimates of
heritability were high and significant in males (h^2 = 0.61), but low and
not significant in females (h^2 = 0.32), probably due to small sample size
for the latter sex. The results from the two-trait model revealed
significant phenotypic (r_P = 0.62) and genetic correlation (r_A = 0.89)
between BM and whole body RMR. The estimate of heritability of whole body
RMR (0.54) and body mass corrected RMR (0.45) were lower than estimates of
heritability for BM. Both phenotypic and genetic correlations between body
mass corrected RMR and BM had negative signals (r_P = -0.42 and r_A =
-0.58). Our results indicate that total energy expenditures of individuals
can quickly evolve through concerted changes in BM and RMR.