According to the differential allocation hypothesis, an individual will invest more in an offspring when mated to a high than low qality mate. The blue/green eggshell coluration of pied flycatcher (Ficedula hypoleuca), has been suggested to be a sexually selected trait working as a post-mating signal of female phenotypic quality that influence male willingness to invest in nestlings. We tested the egg signaling hypothesis by moving clutches between nests to see if the male adjusted his investment according to the old or the new color of the eggs. Egg colour was measured by reflectanc spectometry and male feeding effort was quantified by videofilming and by recording nestling body mass. Our result showed no adjusted effort in male feeding rat of nestlings in relation to egg colour.