Allometric relationships for MMR in temperate-zone birds

<p>. Least squares allometric regression for log MMR (measured in a hop-flutter wheel) against log M_b for five species of temperate-zone birds for which MMR has been recorded (solid line). For comparison, the allometric regression equation for MMR for tropical birds from <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034271#pone.0034271-Wiersma1" target="_blank">[5]</a> is included as the dashed line. MMR values for other temperate-zone bird species include satin bowerbird <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034271#pone.0034271-Chappell3" target="_blank">[49]</a>, red-eyed vireo <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034271#pone.0034271-Pierce1" target="_blank">[42]</a> and house sparrow <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0034271#pone.0034271-Chappell2" target="_blank">[41]</a>.</p

Correlations between BMR vs. M_sum for house sparrows

<p>. Raw BMR and M_sum (upper panel) were significantly positively correlated, but mass-independent residuals (lower panel) were not (<i>R²</i> = 0.060, <i>P</i> = 0.134), indicating that the correlation between raw metabolic values was driven by body mass.</p

Correlations between BMR and M_sum for black-capped chickadees

<p>. Raw BMR and M_sum (upper panel) were significantly positively correlated, but mass-independent residuals (lower panel) were not (<i>R²</i> = 0.048, <i>P</i> = 0.470), indicating that the correlation between raw metabolic values was driven by body mass.</p

Allometric least squares regression equations for log metabolic rates (ml O₂ min⁻¹) against log body mass (Mb, g) for the four study species.

<p>Sample sizes (n) for the different metabolic measurements are provided in parenthesis.</p

Correlation between mass-independent residuals of thermogenic (M_sum) and exercise (MMR) metabolic rates for American goldfinches.

<p>The correlation was not significant (<i>R²</i> = 0.065, <i>P</i> = 0.279).</p