Birdwatching on the Estuaries of Portugal’s Alentejo Coast

Black-winged Stilt (photo: Anthony Toole)

Black-winged Stilt (photo: Anthony Toole)

We spotted our first birds within half-an-hour of leaving Lisbon Airport. Crossing over the Tagus estuary on the 17.2 km Vasco da Gama Bridge, the longest in Europe, we gazed over a vast area of mud flats, dotted with waders too distant to identify. On reaching the eastern bank, however, we detoured onto ever narrowing side roads and stopped on a quiet cul-de-sac in the midst of a series of lagoons.

Though some of these were irregular in outline, the rectilinear banks of others proclaimed their artificial origins. They had been scoured out of the saline marshland to create brackish ponds from which the water evaporated to leave a harvest of salt. Now abandoned, they had been reclaimed by Nature.

Common species, such as coot, moorhen and mallard paddled over the surface, while black-winged stilts daintily picked their ways across the shallows, occasionally dipping their heads into the water to capture a nourishing morsel. In the surrounding fields, cows grazed contentedly, ignoring the scores of cattle egrets that stood around them, and even perched on their backs.

The fields themselves were aglow with flowers, while the trees were fully verdant, in contrast to those of the lingering winter we had left behind in England. Even the poppies displayed a more vivid red than we were used to.

In Your Bucket Because…

  • The Tagus and Sado estuaries, to the east and south-east of Lisbon, are among the most important wetland sites in Europe.
  • Many of the birds belong to species not seen in the British Isles or Northern Europe.
  • Good for anyone who wishes to see birds in relatively close proximity without the need to enter a hide.

The Tagus Estuary

Covering some 34,000 hectares, the Tagus estuary is the largest wetland in Western Europe. Almost one-third is composed of intertidal mud flats, which house an enormous array of invertebrates, making it one of the most important stop-over sites for migrating birds. Around 50,000 individuals spend their winters here. An area of 14,000 hectares, which includes rivers, salt marshes and agricultural land, makes up a nature reserve, established in 1976. Four years later, it was recognised as a wetland of international importance under the Ramsar Convention, an inter-governmental treaty signed in 1971 to protect and promote sustainable development of the world’s wetlands. In 1994, it became a Special Protection Area for wild birds under a European Union directive.

Cattle Egrets (photo: Anthony Toole)

Cattle Egrets (photo: Anthony Toole)

Strolling along the road, we stopped to scan the pools and flatlands with binoculars. These pauses yielded sightings of several grey herons, a much rarer purple heron and a pair of marsh harriers. On the muddy banks of a small, tidal river were two Kentish plovers and a squacco heron. We also caught the first glimpses of the white herons that would become a recurrent feature of our progress over the next five days.

We returned to our transport and drove the short distance to Hortas, a small nature reserve on the shoreline of the estuary. Here dunlin, godwit and grey plovers pecked at the gravel between the fishing boats stranded by the tide.

After lunch in the nearby small town of Alcochete, we drove south, and after an hour, turned west at Alcacer and along the southern shore of the Sado estuary. I insisted on stopping to photograph a stork nesting on top of a tall pole. I need not have been so anxious to do so. We saw hundreds of them, on poles, pylons, chimney stacks and occasionally even trees.

The Sado River Estuary

This broad, shallow estuary is also a Ramsar site and Special Protection Area for birds. Its waters contain more than forty fish species, while its margins harbour many amphibians and reptiles, including lizards, snakes and terrapins. Pods of bottle-nose dolphins frequent the estuary. Some 40,000 waders, which include avocets, dunlin and godwit spend the winter here.

A sandy track led us through cork trees and eucalypts to another extensive area of salt pans, where the noises of chirping frogs drowned any birdsong. These we traced to a concrete water channel, which was alive with edible frogs, a hybrid of marsh frog and pool frog that shared a common ancestor as far back as the last Ice Age. Though they are a fertile hybrid, they only produce fully viable offspring if a female breeds with a male of one of the parent species.

Bee Eaters (photo: Anthony Toole)

Bee Eaters (photo: Anthony Toole)

Colourful bee-eaters flitted among the shrubs, while a black-winged kite and a booted eagle circled overhead. Among the pools, we spotted spoonbills, glossy ibises, little egrets and a small number of flamingos.

A second detour brought us to Carrasqueira, and a unique jumble of wooden jetties to which tiny fishing boats were moored. While carefully picking our way through the unstable-looking labyrinth, we watched redshanks, turnstones and bar-tailed godwits foraging along the shoreline.

We followed the road north along a 15-kilometre spit to our night’s accommodation in the river-mouth holiday resort of Troia. The spit was no more than 500 metres wide at its widest, and consisted of a series of sand hills, held in place by shrubs, conifers and eucalypts. To our east lay the Sado river estuary, and to the west, the Atlantic.


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  1. Barbara Radcliffe Rogers says

    It was a pleasure to read about this beautiful part of Portugal that so many people skip over on their way to the Algarve. It’s the only place I’ve been where you can enjoy birding among half-submerged Roman ruins, and the area has so many other interesting sights, including prehistoric sites and excellent seafood restaurants. Thank you for remiding me of it and pointing out its natural attractions.


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