Poster, IBS 2015 - 7th International Conference of the International Biogeography Society, University of Bayreuth: 2015-01-08 - 2015-01-12
Body colouration has direct implications for the evolutionary success of animals. For ectotherms, which rely on external heat sources, thermoregulation through colouration seems to be crucial to sustain energy balance and overcome the rising energy demand linked to increasing body size and decreasing ambient (habitat) temperatures. Although theoretical background exists about the compensatory importance of colouration, evidence is still lacking especially on large spatial and taxonomic scales. Here we show that colour traits of two divers groups of insects, namely ground beetles and bumble bees in Central Europe strongly depends on endo- and exogenic thermal constraints. For ground beetles we found a strong positive correlation between mean body size and colour darkness. For bumble bees, we could show a strong positive correlation between body darkness and the upper elevational range limit for working females but not for drones (males). Both findings elucidate, that body colouration plays a crucial role for thermo-regulation in completely differing groups of insects, which emphasize the trans-taxonomic, evolutionary relevance of this still neglected trait.