Thames Estuary and her Avocets

There is something about the sludgy mudflats of the Thames Estuary that says “home” to me. Maybe it is the briny smell of the thick clinging mud. A mud that caked my childhood Wellington boots as I flipped rocks, and hunted under the carpets of Bladderwort in search of crabs. Perhaps it is the fascination of the war monuments that doubled as kid’s climbing frames, or the dilapidated jetties that we fished for eels from.

The Thames at Coalhouse Fort was one of the places that we would go bird watching as a family. Migrating Wheatears on the concrete sea wall was the annual highlight, while the haunting twilight call of the Curlew was the soundtrack. One bird of the estuary that was sure to bring the twitchers out in force was the occasional sighting of the rarest and most elegant of British birds – the Avocet.

Historic Radar Tower along the Thames at Coalhouse Fort

Back in those days the Avocet was an impossible dream for a young birder like me. It was an impossible dream for most birders at that time, its scarcity having given it pride of place as the emblem of the Royal Society for the Protection of Birds (RSPB). The Thames was polluted and it wasn’t uncommon to find hospital waste and landfill overspill washed up on the shores. Indeed, sixty years ago the Thames was declared to be biologically dead by the London Natural History Museum.

Dilapidated jetty on the Thames. A good childhood fishing spot

Over the decades since that fatal declaration, much work has been done to clean over 200 miles of river. This work has resulted in an extraordinary turnaround that now sees the Thames ranked as one of the world’s cleanest city rivers. The Thames still looks like strong milk tea on a bed of grey rice pudding, but the waters are significantly less polluted and are able to support a wide range of biodiversity. The return of the buffet of marine mollusks and invertebrates created a welcoming habitat for Avocets. First the occasional sighting, followed by regular sightings, until eventually the mudflats became the winter home to thousands of these black and white beauties.

My first sighting was a special moment. A small flock of Avocets were huddled in the distance, facing a strong wind that chased the Thames out into the English Channel. They were unmistakable in their black and white attire. A striking pattern for a good sized wader, at up to 45 cm (18 inches), when most of the other large waders in the area were in their winter browns. The huddle of Avocets filled my binoculars and my heart. A birding ambition realised on my own doorstep, shortly before moving overseas and leaving the mudflats behind.

Thurrock Thameside Nature Park is 4.8 km (3 miles) to the east of Coalhouse Fort. Formally opened by Sir David Attenborough in 2013 on the site of a disused landfill, it now provides a restored home to coastal wildlife. It also happens to provide a visitor centre with warm coffee and sweet cakes to recover from those freezing winter walks. During a visit home, I stood outside the centre in amazement as I watched a flock Avocets swooping down to the freshly exposed mud. The shrinking tide brought the estuary to life. The birds were too far away to get a good photograph, so I walked closer to the nearby bird hide.

A lone distant Avocet followed a narrow channel carved into the mud, as the tide snapped at its ankles. Freshly exposed mud is where the richest pickings can be found. A bounty of aquatic worms and small crustaceans were exposed and the small bird on a vast mudflat was taking advantage of the opportunity.

I watched it strut across the mud leaving deep footprints as it walked. I wondered how it keeps its whites so white in such a grey habitat. It walked along, stooping its head and swishing its long, slender, upwardly curved beak from side to side, grabbing and filtering for tasty snacks.

Back at the river at Coalhouse Fort, I walked down to the shoreline. The February east wind carried a murderous blade that slashed at flesh and stabbed at clothing. It was the kind of wind that would bring tears to the eyes if it didn’t freeze them in the ducts. My hands were pushed tight into my pockets as I scanned the mudflats. The low squinting sun cast a million diamonds sparkling across the usually grey world of the Thames. A black silhouette strutted into view, only about 25 meters away. This was the closest I’d been to an Avocet. Usually I wouldn’t bother lifting the camera in this light, but the silhouette of the elegant bird was so striking that I fired off some shots. Without gloves, it wasn’t long before my hands sought the sanctuary of warm pockets again.

After a period of absence, the Avocet returned to the United Kingdom in the 1940s. Since then the population has increased dramatically. Close to 10,000 birds now overwinter on UK estuaries and wetlands. The importance of these winter feeding sites has received international recognition. The Thames Estuary has been designated a RAMSAR site of national and international importance, a Site of Special Scientific Interest, and a Special Protection Area. Perhaps the Avocet can look forward to a thriving future on the mudflats of South East England, at least in the short term.

Back in the bird hide at the Thameside Nature Park, a small group of Avocets walked close to the shoreline. The low winter sun gave just enough light for me to get some detailed shots of these beautiful birds – the blue legs could just be made out above their muddy boots, and the long curved beak that gives the bird its scientific name Recurvirostra avosetta, the word recurvirostra meaning “curved backwards bill”.

Presently, the avocet was joined by others. Three busy birds marched in a military line, swishing their bill from side to side with an action that could strike a match. In the distance I watched a small flock fly low over the tide line in search of fresh feeding areas. The birds’ urgent movement reflected the race to eat as much as possible before the rising tide closed the buffet for another few hours.

Feeding Avocets on the Thames Estuary

The world needs success stories like the return of the Avocet. Stories like this remind us that with nothing more than commitment followed by targeted action a dead habitat can come back to life, becoming home not just for a single species but for an entire ecosystem. Commitment and action of this type can come from anywhere, including a home owner committing to bring their own garden or yard back to life for native flora and fauna.

I still return to my childhood home along the Thames Estuary. Each time I visit, I always go to the river and feel that same sense of joy when the smart black and white of the elegant Avocet swiping its beak through the delicious grey sludge comes into view.

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Categories: Uncategorized, United KingdomTags: , , , , ,


I am a wildlife blogger and traveler, using images & stories to inspire wild connections.


  1. What a thrill that must have been when you saw the avocets. I’ve always been fascinated by these birds because of their reverse curved bills. Not sure if I’ve ever seen a live avocet, but it would be so wonderful to see. I really like the video clip that shows them sweeping the ground in search of food ahead of the tide. Beautiful post, David.

    Liked by 1 person

  2. Hi David, this is a wonderful story! It’s remarkable how people were able to clean up the Thames, and to help avocets return to the Thames Estuary. Freshwater ecosystems are come of the most crucial – and threatened – habitats of all, so this success story is extra special.

    Liked by 1 person

    • It’s so encouraging. Living so close, I didn’t really notice it getting cleaner. When you go away and then come back you really notice the improvement in biodiversity. We need more positive stories to show what kind of a world we can live in, if we want it.

      Liked by 1 person

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