The relationship between standard deviation (SD) of first arrival dates and mean first arrival date (shown as day of the year, 1 = Jan 1 etc.) for 18 species recorded at rural sites (solid symbols) and urban sites (open symbols) in Western Poland.

<p>The relationship between standard deviation (SD) of first arrival dates and mean first arrival date (shown as day of the year, 1 =  Jan 1 etc.) for 18 species recorded at rural sites (solid symbols) and urban sites (open symbols) in Western Poland.</p

The relationship between rural and urban trends in first arrival dates in Western Poland 1983–2010.

<p>Points below the line represent species whose migration trend was stronger (more negative) in urban areas than rural areas and <i>vice versa</i>. Solid symbols represent short distance migrants, open symbols long distance migrants.</p

First arrival dates for rural (solid symbols and lines) and urban observations (open symbols and dotted lines) averaged over seven short distance migrants (lower part of graph) and 11 long distance migrants (upper part of graph) in Western Poland 1983–2010.

<p>Regression lines superimposed. Note than the same set of species was included in all years and in both habitats.</p