Model selection results from cubic spline model fitted to male chamois body mass data.

Models are distinguished by the functional forms of α0 and β0. Specifically, we allowed α0 and β0 to be constant across years (α0; β0), vary linearly with year (α0(y); β0(y)), quadratically with year (α0(y2); β0(y2)) or linearly with population density (α0(d); β0(d)). Maximum log-likelihoods (LL) and ΔAICs are shown for each site. The most parsimonious models for each site are highlighted in bold (i.e. have a ΔAIC value that is ≤6 and lower than all simpler nested versions; see Richards [40]). n is sample size for each site.