Table 2.

Overview and short description of breeding stages and nest stages

DOI: http://dx.doi.org/10.7554/eLife.07770.014

Breeding stage	Description	Nest stage
Unpaired	Bird does not show increased prosocial behaviour towards specific individual	Pre-nesting
No nest	Paired but without nest
Territorial	Pair defending nest site without nest material	Early nesting
Nest inspection	Pair inspecting different nest boxes
Nest building	Pair bringing nest material to nest box	Later nesting
Laying	Pair's female laying eggs
Incubation	Pair members incubating