Have received this prompt reply from Errol Newman about the Barnacle. It is indeed a Bedfordshire bird which usually spends the mid-winter at Slimbridge with one or two others.
N 4 24/07/05 MA near Roxton, Bedfordshire
S 4 Sighted (R) 02/04/07 Coate Water, Swindon (121 km, SW, 1 yr 252days)
S 4 Sighted 25/05/07 Cassington GP, Oxfordshire (80 km, WSW, 1 yr 305days)
S 4 Sighted (R) 02/11/07 EN WWT New Grounds, Gloucestershire (151 km, WSW, 2 yrs
S 6 Sighted 09/05/09 ANO Drayton Bassett pits, Staffordshire (107 km, WNW, 3 yrs 289days)