Pink-headed duck

A bird with extraordinary traits

About half a century after the extinction of the Himalayan quail in northern India, another monotypic species disappeared there: the pink-headed duck, also known as the carnation duck. Although much has been written about this duck, many accounts remain incomplete or contradictory. Only a few studies have been conducted on this long-known bird that was always considered rare. Its biology is largely unknown, but one thing is certain: the pink-headed duck was extraordinary in many ways.

The pink-headed duck owes its name to the striking dark pink head and neck, which form a strong contrast to the chocolate-brown body of adult males. This characteristic coloration makes it almost unmistakable. Females and juveniles also have a pink-tinged head, but are overall paler.

In a study published in 2016, Daniel B. Thomas and Helen F. James were able to show that the pink color comes from a carotenoid pigment that is extremely unusual in ducks. Until recently, only the pink-eared duck (Malacorhynchus membranaceus) from Australia provided evidence that any kind of waterbird can have carotenoid-colored plumage like we know from flamingos. The authors of the study found that the pink-headed duck possessed an evolutionarily extremely rare trait among waterbirds. And this is not the only special feature of this duck species …

Pink-headed duck – fact sheet

alternative names	Bengali pink-headed duck, Gulab-sir, Golablal-ser, saknal, dumrar, umar, Pato Cabecirrosa
scientific names	Rhodonessa caryophyllacea, Anas caryophyllacea, Fuligula caryophyllacea, Netta caryophyllacea, Callichen caryophyllaceum
original range	northeastern India, Bangladesh, northern Myanmar, Bhutan and Nepal
last record	1949
causes of extinction	habitat loss, hunting
IUCN status	critically endangered (very small and restricted population)

Why the pink-headed duck deserves its own genus

When British naturalist John Latham first described the pink-headed duck scientifically in 1790, he placed it in the genus of dabbling ducks (Anas). Because of its clear differences from other dabbling ducks (Anatini), however, the Saxon zoologist Ludwig Reichenbach created the monotypic genus Rhodonessa in 1853.

Various traits argue for keeping the pink-headed duck in its own genus. These include a slightly lobed hind toe, a special courtship behavior, and the tendency to feed at the water’s surface. In addition, the duck shows unique physical traits such as a spindle-shaped expansion of the trachea in the male and the lack of the metallic coloration of the secondaries that is characteristic of dabbling ducks. Another remarkable feature is the white or pale yellow eggs of the pink-headed duck, which, with a diameter of around four centimeters, are almost perfectly spherical. This peculiarity clearly distinguishes them from all other duck eggs.

The relationships of the pink-headed duck led to many debates in science. Ornithologists Allan O. Hume and Charles H. T. Marshall suggested in The Game Birds of India, Burmah and Ceylon (1879) that the species was closely related to the genus Anas, and they would have merged the two genera—if it had not been for the different eggs.

American bird expert Paul A. Johnsgard published a study in 1961 in which, based on feather-protein analyses of museum specimens, he concluded that the pink-headed duck is closely related to the diving-duck genera Netta and Aythya. His findings were confirmed in 1998 by phylogenetic studies by ornithologist Bradley C. Livezey.

Thomas and James also found in their above-mentioned 2016 study that the pink-headed duck is a sister taxon of the red-crested pochard (Netta rufina). That is, they share a common ancestor and are more closely related to each other than to other duck species. Proposals, such as Livezey’s, to place the pink-headed duck in the genus Netta were rejected by most researchers because the species has numerous traits that distinguish it from other ducks.

In 2017, Swedish paleontologist Per G. P. Ericson showed in a study that the pink-headed duck belongs to the diving-duck radiation, which also includes the genera Aythya and Netta. It is thus the sister taxon of all living diving ducks and belongs to a lineage that split from the others more than 2.8 million years ago.

Widespread, yet still rare

The pink-headed duck was always considered rare. Indian ornithologist Sálim Ali wrote:

“Since it was first described in 1790, the species was never recorded as common anywhere at any time. In fact, it was always considered so rare that even hunters, who rarely pay attention to what they shoot and for whom the value of a duck lies only in its taste, took notice of it.”

The Pink-headed Duck Rhodonessa caryophyllacea (Latham), Wildfowl Trust Annual Report 11, 1960, pp. 55–60, S. Ali.

British paleontologist Julian P. Hume also emphasized in 2018 in an article about the extinction of the pink-headed duck that the species used to be widespread in South Asia, but was never truly common. Most records come from India, especially from the northeast of the country, as well as five reports from Myanmar and a few from Bhutan, Nepal and Bangladesh. The birds were mostly seen alone or in pairs, only very rarely in groups.

All sightings took place in wet lowland areas, especially at freshwater basins, ponds and waterways surrounded by tall aquatic vegetation, or at swamps with dense reeds. By contrast, the pink-headed duck was not observed on flowing waters.

In the study published in 2017, Ericson was able to show through genetic analyses that the pink-headed duck was not only rare in modern times, but probably has been for up to 100,000 years. According to the study, the effective population size fluctuated between 15,000 and 25,000 individuals during the last 150,000 years of the Pleistocene.

The reasons for the duck’s rarity are largely unknown, since little is known about its way of life and biology. The small population size may be related to factors such as foraging or reproduction. Scientists agree that the rarity can be considered real and is not due to insufficient fieldwork.

Why did the pink-headed duck go extinct?

The exact time of the pink-headed duck’s extinction is not known. There are very different statements about this, but most experts agree that it happened in the first half of the 20th century.

In The Doomsday Book of Animals (1981), David Day reports that the pink-headed duck was still relatively common in the 1880s and was shot only in small numbers. In the 1890s, about half a dozen of these birds were found at the winter market in Calcutta. They were mostly sold alive, because their value lay above all in their role as ornamental birds. Although some, such as British zoologist Thomas C. Jerdon in The Birds of India (1864), described them as tasty, most people—including Sálim Ali—considered them not very palatable.

The development of prices on the markets in Calcutta suggests increasing rarity: while a duck still cost 15 rupees in the 1890s, the price was already 100 rupees by 1915. By the beginning of the 1920s, the pink-headed duck had almost disappeared. John A. S. Bucknill, a British judge and ornithologist, wrote in 1924 in The Disappearance of the Pink-headed Duck that wildfowl hunters in Bihar and Orissa who regularly took part in duck hunts in Bengal no longer got to see any pink-headed ducks.

Bucknill also mentioned that the pink-headed duck, which did not undertake seasonal migrations and was restricted to India, was hunted year-round. Since the 1870s, many wetlands were converted into farmland, further restricting the duck’s habitat. Another serious disadvantage was the autumn molt, during which the birds lost their ability to fly and thus became even more vulnerable to danger.

In Indian Ducks and their Allies (1908), Stuart Baker suggested that the pink-headed duck could survive into the middle of the 20th century only because it lived in hard-to-reach plains of northern India inhabited by tigers. These areas were also crossed by deep rivers infested with crocodiles and were only sparsely populated. The increasing settlement during the colonial period ultimately led to the destruction of the duck’s natural habitat, as the land was cleared and drained to make it usable for agriculture. The introduction of the invasive water hyacinth (Pontederia crassipes) also altered the wetlands to its disadvantage.

Besides habitat destruction, historic hunting was another cause of the pink-headed duck’s disappearance. At the end of the 19th and the beginning of the 20th century, when hunting levels in India were still high, the species—as Bucknill mentioned—was hunted year-round. During this period, population numbers of several waterbird species declined in South and Southeast Asia due to human disturbance, hunting pressure, and egg collecting.

Pink-headed ducks were coveted by hunters and later as ornamental birds because of their unusual coloration. They were kept in aviaries by ornithologists such as Jean T. Delacour in Clères, France, and Alfred Ezra in Foxwarren Park, England. Zoos and game parks also kept pink-headed ducks; however, the birds never bred in captive-breeding programs.

Other duck species, such as the endangered white-winged duck (Cairinia scutulata), still exist today in parts of South and Southeast Asia. This suggests that hunting is not the sole reason for the pink-headed duck’s decline. Overall, the loss of habitat is considered the main cause of the species’ extinction. Hunting and the species’ life cycle (temporary flightlessness) further accelerated this process.

Unconfirmed sightings and search efforts

The last confirmed sighting of the pink-headed duck in the wild took place in India in 1949, and probably around the same time the species survived in human care. In India, legal protection measures banning the capture, killing and collection of eggs of the pink-headed duck have existed only since 1956—possibly too late to prevent the species’ extinction.

Between 1950 and 1960, the Bombay Natural History Society stepped up its efforts to find evidence that the pink-headed duck still existed. Dieter Luther reports in Die ausgestorbenen Vögel der Welt (1986) that a leaflet with a color illustration of the pink-headed duck and the red-crested pochard (to avoid confusion) was distributed throughout its range. However, this search campaign produced no reports, and among the tens of thousands of wild ducks shot each winter within the range, there was no specimen of the pink-headed duck.

There were many unconfirmed sightings that extend into the early 1960s. In 1988, birdwatchers also reported a sighting of the species on the banks of the Brahmaputra River. From the largely unexplored north of Myanmar, there have been unconfirmed reports of pink-headed duck sightings for decades, which fuels hope and spurs further searches.

In his report Pink-headed Duck survey in the Hukaung Valley (2003), Thi Ngoc Ha Nguyen listed numerous reasons suggesting that the pink-headed duck might still exist in Kachin State in northern Myanmar. A thorough survey of the area on the Nat Kaung River in 2005, however, was unable to locate the species. Instead, the scientists encountered Indian spot-billed ducks (Anas poecilorhyncha) and red-crested pochards, with which the pink-headed duck is often confused. There is still hope, though, because some believe the pink-headed duck might be possibly nocturnal and therefore was not seen.

Many reported sightings in northeastern India or northern Myanmar are due to confusion with the red-crested pochard. Male red-crested pochards have a striking orange head, whereas the pink-headed duck has a pink-tinged head. A similar body shape encourages confusion, especially with swimming birds. Female and juvenile pink-headed ducks are paler and resemble dark female red-crested pochards, which can also have a pink-tinged head. Female pink-headed ducks, viewed in flight or from a distance, may also resemble the Indian spot-billed duck.

Is the pink-headed duck still alive?

The International Union for Conservation of Nature (IUCN) lists the pink-headed duck as “critically endangered”, because the species has not been clearly confirmed in the wild since 1949. Credible reports from northern Myanmar in recent years, however, suggest that further surveys of remote wetlands are needed to determine whether the duck is truly extinct. The IUCN estimates that if the population still exists, it comprises fewer than 50 individuals.

In 2007, surveys in the Sompeta wetland in the Indian state of Andhra Pradesh were published. The pink-headed duck was once mentioned there as a game bird, albeit in small numbers. The researchers identified potentially suitable habitats for the species but did not find any individuals. They pointed out that the core area of the wetland, Pedda Beela, is flooded year-round and has dense vegetation, so extensive efforts would be needed to determine whether the pink-headed duck is present.

As part of the initiative Search for Lost Species, Richard Thorns, John Hodges, Pilar Bueno and Errol Fuller set out in 2017 to look for the pink-headed duck, missing since 1949, at Indawgyi in Kachin State, Myanmar’s largest natural lake, and its surrounding area. The team believes that northern Myanmar is the most likely place where the bird might still exist. Thorns, who has devoted his life to searching for the pink-headed duck for more than 20 years and has traveled to Myanmar nine times, says:

“There is no real reason why the pink-headed duck should be extinct in Myanmar. Historically it was recorded there, there is plenty of food, Myanmar does not have the same environmental and human impacts as India, and Myanmar was isolated for decades. But modern history shows that it is not seen, so we have to ask: What is happening that is preventing it from being seen?”

Researchers to Explore Swampy Wetland in the First Search for Lost Species Expedition, Re:wild, 2017. URL: https://www.rewild.org/press/search-for-the-lost-pink-headed-duck-gets-underway-in-myanmar

The search expedition at Indawgyi Lake produced sobering results. Throughout the entire trip there was a striking absence of bird species, especially ducks, both in the lake and in the river system. The loss of biodiversity can be explained by the destruction of the habitat around the lake. Reports from local fishers and hunters suggest that the pink-headed duck may have lived there until fairly recently—perhaps even until 2010—although the last confirmed sighting from this region dates to 1910. One local reported seeing a pink-headed duck in 1998 in a group of other ducks. Another resident recalled that pink-headed ducks were regularly in the area until about 2014, when the habitat around the lake was still intact.

There is hope

Many expeditions in recent years were based on anecdotal reports and unconfirmed sightings suggesting that the pink-headed duck may still exist. The reports and sightings leave open the possibility that the species could have survived in Myanmar in largely inaccessible regions such as elephant grass landscapes, swamps, and floodplains.

As reported in a 2024 Re:wild article, Richard Thorns has found strategic and methodological ways to work with local and international partners in his tireless search for the pink-headed duck. Their strategies include interviewing local farmers and hunters using illustrated cards, searching flooded wetlands with boats and elephants, and on the latest expedition they also deployed ten cameras on floating platforms—a technique that had never been tried before.

After Thorns and his team found that an important habitat where pink-headed ducks might potentially occur was destroyed by regional gold mining, they developed new ideas for alternative habitats they could investigate. Thorns has also explored hypotheses about flight routes and migratory behavior of the pink-headed duck. For example, the species might follow the rainy seasons—flying to the Hukaung Valley in the wet season and then moving south in the dry season.

The next expedition will take the team (unfortunately without Thorns due to the latest travel restrictions for foreigners) up to northwestern Myanmar to the tiger reserve in the Hukaung Valley. There are untouched wetlands there that lie above any mining areas.

Thorns and his team are not giving up hope and will continue searching for the pink-headed duck. The rediscovery of other ducks such as the Madagascar pochard (Aythya innotata)—once thought extinct—in 2006 in northern Madagascar is proof that it is indeed possible that the pink-headed duck may one day be found again.