Ducks are among the most diverse and widespread bird families, yet many species are on the brink of extinction due to habitat loss, hunting, and environmental changes. In this article, we highlight 15 of the world’s rarest ducks still found in the wild, ranking them from rare to the rarest based on population estimates and conservation status.
Each species faces unique challenges, and while some have benefited from conservation efforts, others continue to decline at an alarming rate.
Eaton’s pintail (Anas eatoni)
- Conservation status: Vulnerable.
- Estimated population: 20,000-32,000 mature individuals.
- Range and distribution: Endemic to the Kerguelen and Crozet Islands in the southern Indian Ocean.
- Threats: Introduced predators (feral cats), habitat disturbance, and potential climate change impacts.
Eaton’s pintail is a small dabbling duck restricted to the subantarctic Kerguelen and Crozet Islands. It inhabits freshwater lakes, pools, and marshes during the breeding season but moves to coastal areas and sheltered bays in winter when inland waters freeze.
The species was once heavily hunted by sealers and scientific expeditions but now faces its biggest threat from introduced feral cats, which prey on the ducks during their post-breeding flightless period.
While the last comprehensive population estimate (from the 1980s) suggested a relatively large population, more recent data is lacking, and potential declines are not well monitored. Conservation efforts remain minimal, and the species’ remote habitat offers some protection, but monitoring and predator control are needed to ensure its long-term survival.
Marbled duck (Marmaronetta angustirostris)
- Conservation status: Near threatened.
- Estimated population: Fewer than 20,000 individuals.
- Range and distribution: Fragmented populations across southern Europe, northern Africa, and western to central Asia.
- Threats: Wetland drainage, agricultural expansion, water management projects, and hunting.
The marbled duck is a nomadic waterfowl species inhabiting shallow, eutrophic wetlands, often favoring brackish or freshwater environments with dense vegetation. It breeds in Spain, Turkey, and parts of the Middle East, migrating to wintering grounds in North Africa and the Sahel zone.
Historically widespread, its range has become increasingly fragmented, with habitat loss due to wetland drainage and agriculture being the primary driver of decline. In the early 2000s, populations in Iraq suffered a severe crash following the destruction of the Mesopotamian marshes, which were a key breeding site.
Although some localized increases have been noted, particularly in the western Mediterranean, the global population trend remains uncertain and likely declining.
Conservation efforts include wetland protection, captive breeding and reintroduction programs, and legislative protections in key countries. However, continued habitat degradation, illegal hunting, and water management projects pose significant risks.
White-headed duck (Oxyura leucocephala)
- Conservation status: Endangered.
- Estimated population: Around 20,000 individuals, with fluctuations.
- Range and distribution: Spain, North Africa, Western and Central Asia.
- Threats: Habitat loss, illegal hunting, and hybridization with the invasive ruddy duck.
The white-headed duck is a highly aquatic, stiff-tailed diving duck found in Spain, North Africa, and across Central Asia, where it breeds in shallow, vegetated wetlands. During winter, it moves to larger brackish or saline lakes.
Once numbering over 100,000 individuals, habitat destruction and hunting drove populations to as low as 19,000 by the 1990s. Hybridization with the invasive North American ruddy duck has also threatened the species, particularly in Western Europe, leading to culling programs aimed at preventing interbreeding.
Conservation efforts, particularly in Spain, have helped stabilize and increase local populations, with numbers showing some recovery in recent years. However, habitat loss, hunting, and genetic dilution from hybridization remain serious challenges, requiring continued international conservation actions.
Scaly-sided merganser (Mergus squamatus)
- Conservation status: Endangered.
- Estimated population: Approximately 3,600 to 4,800 individuals.
- Range and distribution: Breeds in Russia, China, and North Korea; winters mainly in China, with smaller numbers in neighboring countries.
- Threats: Habitat loss due to deforestation, river pollution, illegal hunting, and human disturbance.
The scaly-sided Merganser, also known as the Chinese merganser, is an endangered species native to East Asia. It breeds along clear, fast-flowing rivers in forested mountainous regions of southeastern Russia, northeastern China, and North Korea. During the non-breeding season, it migrates to central and southern China, with smaller populations wintering in neighboring countries.
The global population is estimated at approximately 3,600 to 4,800 individuals. Major threats to the species include habitat loss from deforestation, river pollution, illegal hunting, and human disturbance. Conservation efforts focus on habitat protection, reducing human disturbance, and providing artificial nesting sites to support population recovery.
Philippine duck (Anas luzonica)
- Conservation status: Vulnerable.
- Estimated population: 3,300-6,700 mature individuals.
- Range and distribution: Endemic to the Philippines, recorded on all major islands and several smaller ones.
- Threats: Illegal hunting, habitat loss due to wetland conversion, and pesticide use.
The Philippine duck is an endemic species found across the major islands of the Philippines, relying on a variety of freshwater and coastal wetlands, including mangroves, lakes, rivers, and rice fields. Once widespread, its population has declined sharply due to overhunting, wetland conversion for agriculture and aquaculture, and pesticide contamination affecting food sources.
Conservation efforts include protected areas such as Naujan Lake National Park, Olango Island (a Ramsar wetland), and Northern Sierra Madre Natural Park, as well as critical habitat designations in Camarines Sur and Isabela.
However, enforcement against illegal hunting remains weak, and wetland destruction continues to be a major concern. Without stronger conservation actions and better habitat management, the species’ decline is likely to continue.
Meller’s duck (Anas melleri)
- Conservation status: Endangered.
- Estimated population: Approximately 2,000 to 5,000 individuals.
- Range and distribution: Endemic to eastern and northern Madagascar.
- Threats: Habitat loss, hunting, and disturbance.
Meller’s duck is a species endemic to Madagascar, primarily found in the eastern and northern high plateau regions. Its preferred habitats include inland freshwater wetlands such as small streams, lakes, rivers, woodland ponds, and marshes, especially in humid forested areas. The species is known for its territorial behavior during the breeding season, with pairs defending territories of up to 2 km in length.
The global population is estimated to be between 2,000 and 5,000 individuals, and the species is currently classified as Endangered. The primary threats to Meller’s duck include habitat loss due to deforestation and wetland degradation, hunting, and human disturbance.
Conservation efforts are focused on habitat protection and management, as well as mitigating human-induced threats to ensure the species’ survival.
Brown teal (Anas chlorotis)
- Conservation status: Near threatened.
- Estimated population: Around 2,500-3,000 individuals.
- Range and distribution: Restricted to New Zealand, with key populations in Northland and Great Barrier Island.
- Threats: Introduced predators, habitat modification, road mortality, and climate-related changes.
The brown teal was once widespread across New Zealand’s North, South, Stewart, and Chatham Islands, but habitat loss and predation by introduced species such as cats, mustelids, and rats drastically reduced its range. By the early 2000s, the species was mainly restricted to Great Barrier Island and small areas of Northland, with fewer than 1,000 birds remaining.
Thanks to intensive conservation efforts, including predator control, habitat restoration, and reintroduction programs, populations have rebounded, and the species is now classified as near threatened.
The population has grown to approximately 2,500-3,000 individuals, with new subpopulations established in protected areas. However, habitat degradation, road mortality, and potential climate-related changes remain threats, requiring continued management to sustain the recovery.
Auckland teal (Anas aucklandica)
- Conservation status: Near threatened.
- Estimated population: Approximately 1,000-2,500 individuals.
- Range and distribution: Endemic to New Zealand’s Auckland Islands, with stable populations on several predator-free islets.
- Threats: Potential introduction of invasive mammalian predators, habitat disturbance, and environmental changes.
The Auckland teal is a flightless duck species endemic to the Auckland Islands, located south of New Zealand. Historically, it was extirpated from the main Auckland Island due to introduced predators such as cats and pigs but has maintained stable populations on several smaller, predator-free islands in the group.
While the current population is considered stable, the Auckland teal remains vulnerable to potential threats, particularly the accidental introduction of invasive mammals to its remaining habitats. Conservation efforts focus on maintaining biosecurity measures to prevent such introductions and monitoring the existing populations to ensure their continued stability.
Blue duck (Hymenolaimus malacorhynchos)
- Conservation status: Endangered.
- Estimated population: Between 1,500 and 2,500 mature individuals.
- Range and distribution: Fragmented populations in New Zealand’s North and South Islands.
- Threats: Predation by introduced mammals, habitat degradation, and human disturbance.
The blue duck, or whio, is a unique riverine species endemic to New Zealand. Historically widespread, its range is now limited to fragmented populations in the forested mountain regions of the central North Island and the western South Island. The global population is estimated at approximately 1,500-2,500 mature individuals and is decreasing.
Major threats to the blue duck include predation by introduced mammals such as stoats, habitat degradation from deforestation and water pollution, and human disturbances like hydroelectric development and recreational activities.
Conservation efforts focus on predator control, habitat protection, and public awareness campaigns to mitigate these threats. Despite these initiatives, the species remains endangered, with its small and fragmented populations continuing to face significant challenges.
Laysan duck (Anas laysanensis)
- Conservation status: Critically endangered.
- Estimated population: Between 500 and 700 mature individuals.
- Range and distribution: Populations on Laysan Island, Midway Atoll, and Kure Atoll in the Northwestern Hawaiian Islands.
- Threats: Limited range, habitat degradation, introduced predators, disease, and environmental catastrophes.
The Laysan duck is one of the rarest waterfowl, surviving on a few small islands in the Northwestern Hawaiian chain. Its population has collapsed due to habitat destruction by introduced rabbits, but conservation efforts, including habitat restoration and translocation, have helped increase numbers.
Despite these efforts, the species remains critically endangered, as it is highly vulnerable to storms, droughts, and disease outbreaks. The establishment of new populations, such as the recent translocation to Kure Atoll, is a key strategy to reduce extinction risk.
White-winged duck (Asarcornis scutulata)
- Conservation status: Critically endangered.
- Estimated population: Approximately 250-1000 mature individuals.
- Range and distribution: Now restricted to scattered sites in India, Southeast Asia, and Sumatra.
- Threats: Habitat loss and degradation, disturbance, hunting, and collection of eggs and chicks.
The white-winged duck, once widespread across Southeast Asia, has experienced a significant decline in both range and population. It inhabits slow-moving wetlands near forests, relying on tree holes for nesting. The primary drivers of its decline include habitat destruction, human disturbance, and direct exploitation through hunting and egg collection.
Conservation efforts focus on habitat protection and reducing human impact, but the species remains endangered, with small, fragmented populations facing ongoing threats.
Campbell teal (Anas nesiotis)
- Conservation status: Vulnerable.
- Estimated population: Over 200 mature individuals.
- Range and distribution: Campbell Island, Dent Island, and Whenua Hou/Codfish Island, New Zealand.
- Threats: Accidental reintroduction of predators, severe weather events, and disease.
The Campbell teal, a small, flightless, and nocturnal duck, was once widespread on Campbell Island but was extirpated due to the introduction of Norway rats. By the 1970s, it survived only on Dent Island, a small rat-free islet nearby.
A captive breeding program was launched in 1984, leading to successful reintroductions first on Whenua Hou/Codfish Island in 1999 and later on Campbell Island between 2004 and 2006 after rat eradication efforts. The species has since established stable populations and was downlisted to Vulnerable in 2020.
While the conservation program has been a major success, the species remains at risk due to its restricted range, potential predator reintroductions, and extreme weather events. Ongoing monitoring and strict biosecurity measures remain essential for its continued survival.
Baer’s pochard (Aythya baeri)
- Conservation status: Critically endangered.
- Estimated population: Between 150 and 700 mature individuals.
- Range and distribution: Breeds in northeastern China; winters mainly in China, with rare sightings in South and Southeast Asia.
- Threats: Habitat loss, wetland drainage, unsustainable hunting, disturbance, and egg collection.
Baer’s pochard is a medium-sized diving duck that was once widespread across East and Southeast Asia. Historically common in the Amur and Ussuri basins of Russia and China, it has now nearly disappeared from much of its former range. It breeds around lakes with dense aquatic vegetation and winters on freshwater lakes and reservoirs.
Over the past few decades, its population has plummeted due to wetland destruction for agriculture and urban expansion, combined with excessive hunting. Conservation programs, including habitat protection and captive breeding, are underway to stabilize the species. However, it remains critically endangered, with wild populations continuing to decline.
Brazilian merganser (Mergus octosetaceus)
- Conservation status: Critically endangered.
- Estimated population: Fewer than 250 mature individuals.
- Range and distribution: Small, isolated populations in south-central Brazil; nearly extinct in Argentina and Paraguay.
- Threats: Habitat destruction, water pollution, dam construction, and human disturbance.
The Brazilian merganser is a highly specialized riverine duck, surviving in just a few remote locations in south-central Brazil. Its main “stronghold” is Serra da Canastra National Park, where recent surveys estimated 70-100 territories, equating to approximately 140-200 mature individuals.
Additional smaller populations exist in Chapada dos Veadeiros and Jalapão regions, but the species has been extirpated from Paraguay and is nearly extinct in Argentina. Once more widespread, it has suffered severe declines due to deforestation, agriculture, mining, and hydroelectric dams.
Conservation efforts include monitoring, habitat protection, awareness campaigns, and captive breeding programs, but its fragmented populations remain at risk.
Madagascar pochard (Aythya innotata)
- Conservation status: Critically endangered.
- Estimated population: Approximately 30-50 mature individuals.
- Range and distribution: Currently restricted to Lake Matsaborimena and Lake Sofia in northern Madagascar.
- Threats: Habitat degradation, limited range, low duckling survival rates.
The Madagascar pochard, once thought extinct after the last confirmed sighting in 1991, was rediscovered in 2006 at Lake Matsaborimena in northern Madagascar. Historically, this species inhabited shallow freshwater lakes and marshes with abundant vegetation, such as those in the Lake Alaotra basin. However, the rediscovered population resides in a deep volcanic lake with minimal emergent vegetation, which poses challenges for breeding success.
Conservation efforts have included establishing a captive breeding program and habitat restoration initiatives. In December 2018, captive-bred birds were reintroduced to Lake Sofia to establish a second wild population. Despite these efforts, the species remains critically endangered due to its extremely limited distribution, small population size, and ongoing threats to its habitat.
Ducks that might yet be found
While this list highlights some of the world’s rarest ducks still found in the wild, there are a few species whose status remains mysterious, with no confirmed sightings in decades.
The pink-headed duck (Rhodonessa caryophyllacea), once native to India, Bangladesh, and Myanmar, was last officially recorded in the 1950s. However, occasional unverified reports from Myanmar and remote wetlands fuel hope that a small population may persist.
Similarly, the crested shelduck (Tadorna cristata), historically found in Northeast Asia, including China, Korea, and Russia, is one of the great mysteries of ornithology. Sightings have been scarce and unconfirmed since the early 20th century, but its remote and poorly explored range leaves open the possibility of survival.
For bird enthusiasts and researchers, these species represent a challenge and an opportunity – a chance to rediscover what may still exist in the world’s most hidden wetlands. While conservation efforts focus on known populations, continued searches for these enigmatic ducks could rewrite history.