Text provided by the Portuguese Tourist Office (with minimal corrections)

A wintering ground for many migratory birds.  The Estuary has an enormous variety of natural habitats and biotopes that provide refuge, feeding or breeding areas for an infinite number of live organisms, from zooplankton to fish, crustaceans, amphibians, reptiles and eventually mammals, such as the otter, all depending on the preservation of the Estuary for their survival.

The beaches of the isles of Faro, Barreta, Culatra, Armona and Tavira form a natural barrier to the Ocean.  Behind are the vast expanses of dunes and after those a labyrinth of lagoons and small sand isles, mud flats and canals.  At low tide other salty habitats are uncovered, because the sea penetrates right up to land, forming marches and salt marshes. With such physical diversity, it is not surprising that the Formosa Estuary attracts such a variety of life forms, that were able to adapt their needs to the food resources available and to the various degrees of salinity.

Among these varieties are the common caiman or the sultan chicken, simultaneously one of the most representative and most endangered inhabitants of this area.   Chosen as the symbol of the Formosa Estuary Natural Park, the sultan chicken is a large bird with bluish feathers and bright red feet and beak. It is very rare and it is estimated that the population does not exceed twenty individual birds.

Among the most characteristic species are the common caiman.  Other birds such as the dwarf sea swallow, the grey plover, the tailor bird, the waders, the common hawthorn, the straight beaked kingfisher, ducks, water cocks and some birds of prey such as the hunting kestrel also visit this protected zone. More that 50 species of fish, little known crustaceans (Monte Gordo shrimp, estuary shrimp, moorish crab), bivalve molluscs (good, white and pointed cockles, mussels and other shellfish); amphibians (common toad and frog), reptiles (woodland lizard, water snakes, snake mouse and chameleon) contribute to the important fauna in this Park.

The flora varies from the sandy zones (armenias, sea thistles, sand cactuses) to the marches where the existence of some species depends on their resistance to submersion by seawater. Of this immense variety, the Algarve limonium, which constitutes a local endemic species, is particularly important.

Phoenicians, Romans, Arabs and Christians developed the land, leaving remains that can still be seen. Fuzeta, an ancient village that lived on tuna fishing, the crossroads of the Olhao streets with their moorish terraces, the 37 churches of Tavira and the old Arab principality that gave rise to Faro, are good examples of this. The Natural Park is also responsible for preserving this cultural heritage and this has accounted for the recovery of the tide mill at Marim, a traditional tuna fishing boat and some Roman salting tanks.

Together with these initiatives, the Natural Park has also started up a project for breeding the native water dogs, that had become almost extinct. It has also built a recuperation centre for birds of prey.