Secundaire sexratio onder grote nestjongen van de Buizerd Buteo buteo

Nestling Comraon Buzzards were sexed after their 30th day of life, using a combination of body mass, wing length, claw span and length of bind claw. Only nests in which all nestlings could be sexed, were used, irrespective of mortality among eggs or nestlings before day 30. The secondary sex ratio did not differ from equal, but sample size is still small (Table 1).