A birding-trip to Zeeland on 17/02/2002 in S-Holland produced some nice species, who are sadly much scarcer and harder to find in Belgium:
Long-tailed Duck, Lesser White-Fronted geese, ....... and of course huge numbers of winterbirds and geese.

A interesting raptor was also present of which I believe that it is a bird coming from the interbreeding zone between 'Buteo buteo' and 'vulpinus'.

Lesser White-Fronted Geese near Serooskerke.

Note the underwing pattern with rufous underwing-coverts, dark carpal patch, paler(white + mixed light rufous) belly with dark brown rear end.

Note the tail and upperwing pattern! again quite a lot of rufous tones and note especially the white primary-flashes.
The bird is a 2 cy bird with mixed characters of 'Buteo buteo' and 'Buteo vulpinus', originating from the interbreeding zone between the two species.