Spain’s White-Headed Ducks Have a Signature Color Right in the Name. And That Isn’t Even Their Most Remarkable Hue

From their whisk-broom tails to males’ bright sky-blue bills, white-headed ducks are among the oddest in the world. Mild-mannered outside of breeding season, they star in a spectacular springtime courtship display in the wetlands of Europe, North Africa, the Middle East and Central Asia. Come spring, males perform a series of intricate dances that include sideways swimming, exuberant splashing and beating their puffed-up neck feathers with their bills to produce bubble trails.

Their exceptionally long and stiff tail feathers are part of the show, waving like flags, spreading like fans and slapping the water like paddles. In Spain, white-headed ducks also star in a spectacular conservation success story. Decades of draining wetlands for agriculture and development in the past century shrank habitat and tanked numbers across the ducks’ range.

Hunting took a further toll on the global population, which had been estimated at some 100,000 in the 1930s. By the late 1970s, most European populations had gone extinct, and in Spain, only 22 birds remained at a single location. That shocking tally launched a national campaign to restore and protect wetlands, improve water management, and ban hunting.

Spain’s white-headed duck population has now rebounded to some 2,500 and expanded across the country. Elsewhere, however, the story isn’t as upbeat. Globally, the species continues to decline and is listed as endangered on the IUCN Red List.

Sizable populations in the eastern part of the duck’s range receive little protection. Pollution, water loss and other effects of human activities continue to destroy their habitats. What’s more, another threat has emerged: ruddy ducks.

Specimens of this invasive American species escaped from a British wildlife reserve and spread eastward. Reaching Spain’s white-headed duck breeding grounds in the 1980s, the aggressive foreigners beat out native males for mates. By the early 1990s, fertile hybrids proved as dominant as their ruddy duck progenitors—raising fears that interbreeding would drive white-headed ducks to genetic extinction.