Pink-headed Duck

A bird with extraordinary characteristics

About half a century after the extinction of the Himalayan quail in northern India, another monotypic species vanished from the region: the Pink-headed duck, also known as the Bengali pink-headed duck. Although much has been written about this duck, many reports remain incomplete or contradictory. Few studies have been conducted on this long-known and always considered rare bird species. Its biology is largely unknown, but one thing is certain: the Pink-headed duck was exceptional in many ways.

The pink-headed duck gets its name from the striking dark pink coloration of its head and neck, which contrasts sharply with the chocolate-brown body of adult males. This distinctive coloring makes it almost unmistakable. Females and juveniles also have a pink-tinged head but are generally paler overall.

In a study published in 2016, Daniel B. Thomas and Helen F. James demonstrated that the pink color comes from a carotenoid pigment, which is extremely unusual for ducks. Until recently, only the pink-eared duck (Malacorhynchus membranaceus) from Australia provided evidence that any species of waterfowl displayed carotenoid-colored plumage, similar to what is seen in flamingos. The authors of the study noted that the pink-headed duck possessed an evolutionarily rare trait among waterfowl. And this is not the only unique feature of the species…

Pink-headed duck – Fact sheet

Alternative name	Bengali pink-headed duck, Gulab-sir, Golablal-ser, saknal, dumrar, umar, Pato Cabecirrosa
Scientific name	Rhodonessa caryophyllacea, Anas caryophyllacea, Fuligula caryophyllacea, Netta caryophyllacea, Callichen caryophyllaceum
Original range	Northeast India, Bangladesh, Northern Myanmar, Bhutan, and Nepal
Last sighting	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 the British naturalist John Latham first scientifically described the pink-headed duck in 1790, he assigned it to the genus of true ducks (Anas). However, due to its distinct differences from other dabbling ducks (Anatini), the German zoologist Ludwig Reichenbach created the monotypic genus Rhodonessa in 1853.

Several features support keeping the pink-headed duck in its own genus. These include a slightly lobed hind toe, a unique courtship behavior, and a tendency to feed on the water surface. Additionally, the duck exhibits unique physical characteristics such as a spindle-shaped enlargement of the trachea in males and the absence of the metallic coloration of the secondary feathers, which is characteristic of dabbling ducks. Another remarkable feature is the pink-headed duck’s white or pale yellow eggs, which are nearly perfectly spherical with a diameter of around four centimeters. This distinct trait sets them apart from all other duck eggs.

The pink-headed duck’s phylogenetic relationships have sparked much debate in the scientific community. 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 would have merged the two genera if not for the different eggs.

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

In their aforementioned 2016 study, Thomas and James also found that the pink-headed duck is a sister taxon to the red-crested pochard (Netta rufina). This means 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 have been rejected by most scientists because the species exhibits numerous traits that distinguish it from other duck species.

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 modern diving ducks and belongs to a lineage that diverged from the others more than 2.8 million years ago.

Widespread yet rare

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

“Since it was first described in 1790 the species has at no time been recorded as common anywhere. In fact it was always considered rare enough to be taken notice of, even by such sportsmen as seldom bother to vet their bags and to whom the significance of a duck is merely how it tastes!”

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

The British paleontologist Julian P. Hume emphasized in a 2018 article on the extinction of the pink-headed duck that the species was once widespread in South Asia but was never truly common. Most records come from India, particularly the northeast, as well as five reports from Myanmar and a few from Bhutan, Nepal, and Bangladesh. The birds were usually seen alone or in pairs, very rarely in groups.

All sightings occurred in wet lowland areas, particularly at freshwater basins, ponds, and watercourses surrounded by dense aquatic vegetation or swamps with thick reeds. The pink-headed duck was not observed in flowing waters.

In a 2017 study, Ericson used genetic analyses to show that the pink-headed duck was not only rare in modern times but likely had been so 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 rarity of this duck species are largely unknown, as little is known about its lifestyle and biology. It is possible that the small population size is related to factors such as foraging or reproduction. Scientists agree that the rarity can be considered genuine and not due to insufficient fieldwork.

 Why did the pink-headed duck go extinct?

The exact timing of the pink-headed duck’s extinction is unknown. Various estimates exist, but most experts agree it occurred in the first half of the 20th century.

David Day reports in The Doomsday Book of Animals (1981) that the pink-headed duck was still relatively common in the 1880s and was only shot in small numbers. In the 1890s, about half a dozen of these birds could be found at the winter market in Calcutta. They were usually sold alive, as their value lay primarily in their role as ornamental birds. While some, like the British zoologist Thomas C. Jerdon in The Birds of India (1864), described them as tasty, most, including Sálim Ali, considered them to be of poor flavor.

The price development at the markets in Calcutta indicates increasing rarity: while a duck cost 15 rupees in the 1890s, the price had risen to 100 rupees by 1915. By the early 1920s, the pink-headed duck had almost disappeared. John A. S. Bucknill, a British judge and ornithologist, wrote in The Disappearance of the Pink-headed Duck (1924) that wildfowl hunters in Bihar and Orissa, who regularly participated in duck hunts in Bengal, no longer saw the pink-headed duck.

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 had been converted into farmland, further restricting the duck’s habitat. Another severe disadvantage was the autumn molt, during which the birds lost their ability to fly and became even more vulnerable to dangers.

Stuart Baker speculated in Indian Ducks and their Allies (1908) that the pink-headed duck could only survive until the mid-20th century because it lived in inaccessible plains of northern India inhabited by tigers. These areas were also crisscrossed by deep, crocodile-infested rivers and sparsely populated. The increasing settlement during the colonial period eventually led to the destruction of the duck’s natural habitat, as the land was cleared and drained for agriculture. The introduction of the invasive water hyacinth (Pontederia crassipes) also altered the wetlands to their detriment.

Alongside habitat destruction, historical hunting was another cause for the disappearance of the pink-headed duck. In the late 19th and early 20th centuries, when hunting levels in India were still high, the species was hunted year-round, as mentioned by Bucknill. During this period, the populations of several waterfowl species in South and Southeast Asia declined due to human disturbances, hunting pressure, and egg collecting.

Pink-headed ducks were highly sought after by hunters and later as ornamental birds due to 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. Pink-headed ducks were also present in zoos and wildlife parks, although they never reproduced in captivity.

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

Unconfirmed sightings and search efforts

The last confirmed sighting of the pink-headed duck in the wild occurred in 1949 in India, and the species likely survived in captivity until around the same time. Legal protections in India that prohibit the capture, killing, and egg collecting of the pink-headed duck have been in place only since 1956 – possibly too late to prevent the species’ extinction.

Between 1950 and 1960, the Bombay Natural History Society intensified its efforts to find evidence of the pink-headed duck’s existence. Dieter Luther reports in Die ausgestorbenen Vögel der Welt (1986) that a leaflet with a colored illustration of the pink-headed duck and the red-crested pochard (to avoid confusion) was distributed in the species’ range. However, this search effort yielded no reports, and among the tens of thousands of wild ducks shot each winter in the range, none were pink-headed ducks.

There were many unconfirmed sightings extending into the early 1960s. In 1988, birdwatchers reported a sighting of the species on the banks of the Brahmaputra River. In the largely unexplored north of Myanmar, there have been unconfirmed reports of pink-headed duck sightings for decades, sparking hope and further search efforts.

Thi Ngoc Ha Nguyen cited numerous reasons in his report Pink-headed Duck survey in the Hukaung Valley (2003) that suggest the pink-headed duck might still exist in the Kachin State in northern Myanmar. However, a thorough investigation of the Nat Kaung River area in 2005 failed to locate the species. Instead, the scientists encountered Indian spot-billed ducks (Anas poecilorhyncha) and red-crested pochards, which are often confused with the pink-headed duck. There is still hope, as some believe the pink-headed duck might be nocturnal and thus not seen.

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

Does the pink-headed duck still live?

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

In 2007, studies were published on the Sompeta wetland in the Indian state of Andhra Pradesh. Here, the pink-headed duck was once mentioned, albeit in small numbers, as a game bird. Researchers identified potentially suitable habitats for the species but found no individuals. They noted that the core area of the Pedda Beela wetland is flooded year-round and has dense vegetation, making extensive efforts necessary to ascertain the presence of the pink-headed duck.

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

“The pink-headed duck has no real reason to be extinct in Myanmar. It was historically recorded there, there’s plenty of food, Myanmar doesn’t have the same environmental and human impact that India had and Myanmar has been closed for decades. But modern history shows it isn’t being seen, so we have to ask ourselves: 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 yielded disappointing results. Throughout the trip, there was a notable absence of bird species, particularly ducks, both in the lake and its river system. The loss of biodiversity can be attributed to habitat destruction around the lake. Reports from local fishermen and hunters suggest that the pink-headed duck may have lived there until recently, possibly even until 2010, although the last confirmed sighting from this region dates back to 1910. One local reported seeing the duck among a group of other ducks in 1998. Another resident recalled that pink-headed ducks were regularly seen in the area until around 2014, when the habitat around the lake was still intact.

There is hope

Many of the expeditions in recent years have been based on anecdotal reports and unconfirmed sightings, suggesting that the pink-headed duck may still exist. These reports and sightings leave open the possibility that the species could survive in Myanmar’s largely inaccessible regions, such as elephant grasslands, swamps, and floodplains.

According to a 2024 Re:wild report, Richard Thorns, in his tireless search for the pink-headed duck, has developed strategic and methodical ways to work with local and international partners. Their strategies include interviewing local farmers and hunters with illustrated maps, searching flooded wetlands with boats and elephants, and using ten floating platform cameras in their latest expedition – a technique never before tried.

After discovering that a key habitat where pink-headed ducks might potentially occur had been destroyed by regional gold mining, Thorns and his team developed new ideas for alternative habitats to investigate. Thorns has also explored hypotheses about the flight paths and migratory behavior of the pink-headed duck, suggesting the species might follow the monsoon seasons, flying to the Hukaung Valley during the rainy season and then migrating south during the dry season.

The next expedition will take the team (unfortunately without Thorns due to recent travel restrictions for foreigners) to the northwest of Myanmar, into the Hukaung Valley Tiger Reserve. This area contains pristine wetlands located above any mining regions.

Thorns and his team are not giving up hope and will continue their search for the pink-headed duck. The rediscovery of other waterfowl, such as the Madagascar pochard (Aythya innotata), believed to be extinct until it was found in northern Madagascar in 2006, is proof that it is indeed possible to rediscover the pink-headed duck someday.