Estuaries are the meeting places of river and sea, where mudflats, saltmarsh, and shallow channels create one of the richest habitats in the British Isles. For anyone living near the coast, these shifting landscapes offer a front-row seat to some of our most charismatic winter visitors. Among the easiest to spot—and most rewarding to learn—are three common wildfowl: shelduck, wigeon, and brent geese. Each has its own distinct look, voice, and seasonal rhythm. Here is a practical guide to telling them apart, with a few notes on safety, history, and the local larder that makes estuary living so special.

Shelduck: The Boldest Bird on the Mud

The shelduck is a large, goose-like duck, roughly the size of a small goose. Its plumage is unmistakable: a white body, a dark green head, and a broad chestnut band across the breast. The male has a bright red bill with a fleshy knob at the base; the female's bill is pinkish and lacks the knob. In flight, the wings show large white patches with black tips, and the bird often looks front-heavy. Listen for the male's soft whistling whee-oo and the female's low, growling arrrr. Shelduck are present all year, but numbers swell in winter. They nest in burrows—often old rabbit warrens—and many fly to the Wadden Sea to moult in late summer. On the estuary, they favour muddy creeks and sandy shores, where they dabble and graze.

Wigeon: The Whistling Grazer

Smaller and daintier than a mallard, the wigeon is a winter specialist. The male has a chestnut head with a creamy-yellow forehead and crown, a pinkish breast, a pale grey body, and a black rear end. The female is a warm brown with a greyish head. The whistle is a clear, penetrating whee-oo—often the first sign of a flock before you see them. Wigeon arrive from Iceland and Russia in September and leave by March. They graze on saltmarsh grass and eelgrass, often in tight flocks, and mix readily with brent geese. Look for them on wet grasslands beside the estuary, especially at high tide when they are pushed off the mudflats.

Brent Geese: Small, Dark and Chatty

The brent goose is the smallest of our geese, about the size of a mallard. Dark-bellied brent geese are dark grey-brown with a black head and neck, and a small white patch on the side of the neck. Light-bellied birds are paler. They fly in loose lines or V-formations, calling a high-pitched, rolling crronk. Dark-bellied birds arrive in October from Arctic Russia; light-bellied birds come from Canada and Greenland. Both leave in March. They graze on eelgrass, saltmarsh plants, and sometimes nearby fields. On the water, they sit low and look compact, often bobbing in choppy waves.

Practical Fieldcraft and Safety

Observing estuary wildfowl is a joy, but safety comes first. Tides can race across mudflats faster than you can walk. Always check tide tables, avoid soft mud, and never venture onto exposed mud without local knowledge. Keep dogs on leads during winter, as disturbing roosting birds can cost them vital energy. Use binoculars or a telescope to observe without getting close. The best time is often two hours either side of high tide, when birds are pushed closer to the shore. Wear sturdy footwear, carry a mobile phone, and let someone know your route. If you are new to the area, join a local guided walk to learn the safe paths.

History, Local Food and Looking After the Flock

Estuaries have long been larders and lifelines. Wildfowling was once a way of life, but now these birds are protected, and many estuaries are designated as Sites of Special Scientific Interest and Ramsar sites. The same tidal waters that feed the wildfowl also produce local food: samphire, oysters, mussels, and sea bass. After a morning's birdwatching, many coastal pubs serve these delights. Supporting local fishermen and conservation groups helps keep the estuary healthy for both people and wildlife. Remember, these birds are not for the pot—they are a spectacle to enjoy. By learning their calls and colours, you become part of a long tradition of estuary living, where nature, history, and community meet on the mud.