Best time to see: Oct to Apr

Key facts

Long slim saw-billed duck of estuaries and sea in winter and rivers during the breeding season

Breeds in N. and W. Britain and Scandinavia; winters on UK coasts, including in Essex

Recognition

Male: bottle-green head with double crest, brown speckled breast; duck brown and grey with white wingbar; 58 cm

Swims fast and on the surface and dives well to catch fish – the serrations on its bill help it to hang on to them

Flight strong and powerful