Individual quality and reproductive effort mirrored in white wing plumage in both sexes of south polar skuas
Hanssen, S.A., Bustnes, J.O., Tveraa, T., Hasselquist, D., Varpe, Ø., Henden, J.A. 2009. Individual quality and reproductive effort mirrored in white wing plumage in both sexes of south polar skuas. Behavioural Ecology 20: 961–966.