Consistency but low heritability of nest building behaviour in blue tits
​blue tit in nest with feathers. The proportion of feathers in a nest was both repeatable and (lowly) heritable in a Finnish population
​Nests and the wide variation they come in, even within a species, have recently begun to attract more scientific interest. Various hypotheses have been formed to explain this variation. These hypotheses often rely on the assumption that nest building behaviour is heritable and therefore able to evolve. Our study shows that, against the general assumption, nest building has, on one hand, the ability to evolve in response to environmental change. One the other hand, our study shows that this ability is not very strong as the heritability of nest construction is very low. This conclusion was reached on the basis of a 10-year study. In general, our study is one of the first to analyse nest building behaviour in a wild birds by utilising population-wide genetic information. Low heritability of nest construction imples that blue tit's ability to respond to change in the environmennt is low. Changes can be caused, for example, by global warming. These results provide crucial information on the basis of nest building behaviour, which can be further applied to other nest-building animals from fish to mammals.

Pauliina Järvinen

YLE news (in Finnish) about this finding