This elegant wading bird breeds widely in southern and western Portugal, overwintering mainly in the Algarve and the Tagus and Sado estuaries to the south of Lisbon. It can be found in any shallow wetland, freshwater or salty, both on the coast and inland. Saltpans, such as those found in the Castro Marim Reserve, are particularly favoured as breeding areas, although pairs have bred successfully even at small village water treatment plants.
Formerly regarded mainly as a summer visitor, the population still includes a proportion of birds which have spent the winter in Africa. Numbers have increased substantially in Iberia since the 1980s as this opportunistic species has taken advantage of artificial habitats like reservoirs and rice fields.
Black-winged Stilts, or close relatives, occur widely across warm temperate to tropical zones across the globe. Within their respective ranges there is a surprising degree of nomadism, resulting in birds being discovered in unlikely places. For example, one ringed in Portugal was recovered in Hungary. Extralimital breeding also occurs occasionally, even as far north as the British Isles. Such events may increase as a result of global warming.
Unlike many wading birds which probe mud for their prey, the stilt’s fine, pointed bill has evolved to take its invertebrate food from the water’s surface or below with a firm grip, but flying insects are also pursued or sometimes plucked out of the air with a vertical jump.
In the breeding season Black-winged Stilts remain gregarious, nesting in loose colonies. Birds pair only for one season. Interactions within a group, involving various forms of display, are complex and not fully understood. Pairs defend their nest sites vigorously, calling stridently. At other times of the year flock sizes are usually small, but larger aggregations can occur. I once counted over 4000 at a shallow lake in Pakistan.
Although adapted to sites without cover in hot countries, stilts are not averse to seeking a little shade when the opportunity beckons. In Crete I came across one sitting quietly on the edge of a coastal lagoon, the long legs folded beneath the body, in the shadow cast by a large domestic goose. It wasn’t going to move, for me or anything else!