The commonest small duck in most areas, and often forms fairly large flocks away from breeding grounds. Found in most wetlands, agricultural fields, and tidal mudflats. Often in compact groups, easily flushed with fast, seemingly vertical take-off. Fly close together in sync, often twisting with very fast wingbeats. Male often heard giving football-whistle ‘krik’. ID: Usually the smallest and darkest brown duck in the marsh. Compact and deep-bodied, it sits high in the water. Large square head on a short neck with small bill — the rubber duck of ponds. Male rich chestnut head with green mask, finely patterned body. At distance a white vertical flank line and black-bordered yellow butt stand out. Eclipse and juv males initially identical to females. Distinct dark eyeline. In flight plain-winged except for green speculum bordered by white. Eurasian ssp ‘Common’ Teal ‘carolinensis’ is scarce but regular with its cousin (1:400). Male has similar appearance but white breast line is horizontal (not vertical), coarser flank vermiculations, and bolder face lines. Birds showing both vertical and horizontal lines occur, some of these are hybrids. Females identical except for broader white rear border to speculum — good luck with this one!