The relationship between barn owl productivity responses and vole population variability in ten districts of the Czech Republic.

<p>The upper panels show the degree of synchrony between the barn owl productivity and vole population variability using the non-detrending (a) and detrending approach (b). The lower panels show the strength of the productivity response to vole population variability without detrending (c) and with detrending (d). The dashed lines indicate 95% confidence intervals for the regression line.</p

The Taylor’s power law relationships for the vole time series data.

<p>The upper panels show the relationship between variance and mean for non-detrended (a) and detrended (b) data. The lower panels show the relationship between the coefficients of variation (CV) and mean for non-detrended (c) and detrended (d) vole data.</p

The relationship between barn owl productivity responses and autumn vole index using non-detrended (a, c) and detrended (b, d) time series, based on the data from the whole Czech Republic.

<p>The barn owl responded to the increased vole population densities by increasing the mean number of clutches per site (a, b) and the mean number of fledglings per site (c, d). The regression was weighted by reciprocals of variance for annual means of owl productivity. The dashed lines indicate 95% confidence intervals for the regression line.</p

(a) Map of the districts in the Czech Republic showing the distribution of barn owl nesting sites and (b) the dynamics of barn owl productivity (solid lines) and the common vole numbers (dashed line) in autumn during the period 1998–2013.

<p>The shaded areas in (a) indicate the 10 districts used in the analysis of vole population variability effects on the strength of the responses in the barn owl productivity parameters. Barn owl productivity was measured as the annual number of successfully produced fledglings (solid line). Vole numbers were measured by a vole index based on the number of active burrow entrances per hectare.</p