Elevation, climate and bird abundance distribution along the latitudinal gradient defined by the sampling localities in Fig 1B.

<p>A) Elevation, B) temperature, C) precipitation seasonality, D) precipitation. Climate variables are averages provided by the WorldClim-Global Climate Data facility (<a href="http://www.worldclim.org/" target="_blank">http://www.worldclim.org</a>) for the 1950–2000 and 2050–2070 periods (see text). The abundances along the gradient of the meadow pipit (E) and the chiffchaff (F) are also reported.</p>