The RSPB's Avocet Cruise reveals the the Exe estuary as a winter wonderland. Anna Turns dons her binoculars and hops onboard

Every winter people flock to the Exe Estuary at low tide to see one of Devon’s best wildlife spectacles. The holiday tourist season may well be over, but this is peak season for avian visitors arriving for their seasonal stay at one of the world’s great wetlands. John Allan, RSPB Cruise Co-ordinator, explains. “The RSPB has organised Avocet cruises like this one for over 26 years, every winter from November until late February, with about 80 people on board each trip.”

The Exe Estuary is unique – there’s no other estuary in Devon that compares. It’s such an important feeding ground for wintering waders, ducks and geese. The wide, shallow estuary is like a giant food store, and each outgoing tide exposes vast sand and mud banks. As the boat leaves the dock, I overhear one lady describe the view over the mudflats as “a little piece of heaven…”.

David Back is one of six RSPB volunteer guides onboard to help us distinguish between shags and cormorants, or oystercatchers and curlews. David travels regularly down to the Exe from Okehampton, and for him “it’s the best place in Devon to see birds like these in their numbers”.

This place is also the hotspot for seeing a very special bird – the avocet. The Exe is home to between 400 and 650 of these magnificent birds which migrate in from Holland each winter. The elegant avocet is so symbolic of the UK’s bird protection movement that it became the emblem for RSPB. A century ago, avocets were nationally extinct as a breeding species due to poaching and habitat loss. But during the Second World War, East Anglian marshes were flooded to deter invasion by German troops, and this provided ideal habitat for the avocets. The return of these birds since the 1940s has been one of bird conservation’s greatest success stories.

“It’s the best place in Devon to see birds like these in their numbers”

Rosemary Vincent is one lady who has travelled many miles to see these birds with their distinctive pied plumage. She has come by train on a day trip from Dorset, and would never miss out on a chance to see avocets. “They’re just so beautiful,” she says, “it’s worth all the travelling, and oh, look at that…” as she points up at a massive flock of Brent geese flying overhead.

As the commentary guide explains, every winter over 40,000 birds, including Brent geese, hundreds of black-tailed godwits and red-breasted mergansers, flock to the Exe Estuary from as far afield as Siberia and Greenland. Each wader has evolved its own distinct beak shape and size, so species aren’t in direct competition for the same food source. As the boat cruises past the shingle beds, curlew feed on the mussel beds with their characteristic long, down-curved beaks. Curlews are the largest European wader, and the female has a longer bill than the male, so in really hard times they’ll be more likely to find food.

Suddenly, the commentary guide calls out. “At nine o clock, look, there’s our first Great northern diver. That’s a great spot as these are rare even here, and oh look, it’s eating a crab.” Then one avid observer comments, “it must take a while for the crab to stop nipping!”

But it’s not just the rarities that are interesting. Oystercatchers, often seen along the Devon shoreline, have some of the most bizarre eating habits. With their long, straight, red beak, they eat mussels, but some birds are ‘prisers’ (prising shells open with their beaks), and some are ‘hammerers’ (breaking open the shells by smashing them). Prisers only mate with prisers, and hammerers pair up to mate too, so each method of feeding is passed on to their chicks by genetics, not taught. It seems everyone onboard is learning something new on this trip.

David Lewis, from Sidmouth, admits he’s not a ‘twitcher’. It’s his first time on this Avocet cruise, and that’s just what the RSPB is about – they are keen to entice everyone, no matter what their experience in birds. “So, it’s great to have the RSPB volunteers on hand to help spot individual birds and answer any questions.”

We learn that the avocets have a unique ‘swishing’ movement of their beaks through the water. With slender, up-curved bills, they sweep the mud in search of tasty morsels. Prey is located by touch, as water and mud is drawn into the opened bill, and they sift out tiny aquatic insects, crustaceans and worms from the mud.

And as if to demonstrate real ‘twitching’, next to me I hear a couple discussing whether the bird they just spotted was a juvenile Great-crested grebe in winter plumage or a Slovenian grebe... a tricky one.

"As the tide comes in my favourite place to be is up at Bowling Green Marsh – when the light is just right the flocks come overhead and it’s just spectacular.”

Colin Scott, a retired engineer from Exeter, is kitted out with his 400mm camera lens (he left his really long lens at home today). He was already a keen amateur photographer before birds came into his life. Nowadays he tries to get every shot he can of birds on the Exe. “It’s always different,” says Colin who has been coming on these boat trips for the last couple of years, and he’s coming back again next week. He points out a couple of mergansers floating in the middle of the channel. “They’re such beautiful birds, and they’re harder to see from land, so it’s great being on the water for close up views.” Then all talking stops as Colin snaps some close-up images of these birds flying past us. “And as the tide comes in my favourite place to be is up at Bowling Green Marsh – when the light is just right the flocks come overhead and it’s just spectacular.”

At high tide in winter, birds flock north towards Topsham, where there reserve at Bowling Green Marsh is a vital rest area for many of the Exe waders. If you get the timing just right, you’ll see thousands of waders arriving all at once… a true wildlife spectacle.

First, flocks of small waders such as dunlin with shorter legs fly back as the tide rises. Birds with longer legs can still feed as the tide continues to rise, so long-legged waders arrive later. Avocets can even swim a bit, unusual for waders, so they have an extra advantage, and are one of the last species to leave the mudflats.

For four months of the year, these RSPB boat trips provide a chance for everyone to get a close-up wildlife encounter. There is a build-up of migrants throughout winter, with the biggest flocks accumulating by late February. And then they’re gone again. These bird migrants will fly back to their breeding grounds just as the familiar dawn chorus begins again in our gardens.

As the boat comes back into dock at Exmouth, the rain that has held off all afternoon finally arrives. And just as I drive home along the M5 past Exeter, a grey heron flies low over the motorway, seemingly out of context – but I can guess where he has come from.

Avocet Cruises this month

Full cruises last 3� to 4 hours. Adults �14, children �6.6 November 12.30pm, depart Starcross.21 November 11.30am, depart Starcross.23 November 1.30pm, depart Exmouth.

Mini-cruises last 1� hours. Adults �10, children �4.7 November 1pm, depart Topsham, Trouts Boatyard.Book:"rspb.org.uk, 01392 432691

PHOTOS: rspb-images.com