Lovely views of YWT North Cave Wetlands' first Black-throated Diver this morning. Interesting to see how the white flanks varied depending upon the bird's attitude. When actively feeding the characteristic flank patch was displayed, becoming a longer white side when loafing. Very fresh plumage and faint scalloping on the mantle indicate a juvenile I assume. Later on a quick walk round the boardwalk at YWT Askham Bog revealed a showy Marsh Tit and several Lesser Redpolls and Siskins in a Goldfinch flock.