Comparison of models of the relationship between annual population growth and human-caused mortality for wolves in North America.

1<p>Expanded model descriptions:</p><p>(i) General additive model (GAM) that allowed regional differences, fit in the ‘mgcv’ package of R with cross-validation used to determine the optimum amount of smoothing. GAM models allow curvilinear functions if the data support curvature.</p><p>(ii) General linear model (normal errors with log link) with no regional effect on slope and intercept.</p><p>(iii) General linear model (normal errors with log link) that allowed regional differences in the slope and intercept.</p><p>(iv) Constant total mortality (no effect of human offtake on total mortality), with regional differences.</p><p>(v) Constant total mortality (no effect of human offtake on total mortality).</p>2<p>Number of parameters in the model (non-integer values are expected for general additive models).</p>3<p>The coefficient of determination (R²) adjusted for degrees of freedom.</p>4<p>Akaike model weight.