The Madagascar fish eagle is currently the world’s rarest eagle, with no more than 240 mature individuals. The Great Nicobar serpent eagle may soon surpass it in rarity, though its exact population remains uncertain, with some estimates as low as 200 mature individuals. This article highlights not only the rarest eagles by population size but also those facing severe threats from habitat destruction, hunting, and prey loss. Some species still number in the thousands, but with ongoing deforestation and human pressures, their survival is far from guaranteed.
With patience, luck, and the right location, these magnificent birds can still be observed in the wild, but for many, their future remains highly uncertain. Each species on this list is experiencing significant challenges, and without urgent conservation action, some could disappear within decades.
Bateleur (Terathopius ecaudatus)
- Conservation status: Endangered.
- Estimated population: Fewer than 20,000 mature individuals.
- Range and habitat: Woodland savannas across sub-Saharan Africa, now mostly restricted to large protected areas.
- Threats: Habitat loss, poisoning, pesticide exposure, and persecution.
The bateleur is a distinctive African eagle known for its short tail, striking coloration, and agile flight. Once widespread across sub-Saharan Africa, it has experienced severe declines, with its population estimated to have dropped by 50-79% between 1976 and 2022 due to habitat destruction, poisoning, and human persecution. Previous estimates suggested a global population in the tens of thousands, but recent data place the number at 10,000-20,000 mature individuals. Some local populations, such as in South Africa and Namibia, have collapsed by as much as 75% over the past decades.
The species primarily inhabits woodland savannas, preferring large protected areas but sometimes occurring in unprotected farmlands. It is particularly vulnerable to indirect poisoning, often from carcasses baited with pesticides meant for predators like lions and hyenas. Additionally, the widespread use of pesticides in agriculture has further impacted its survival. Conservation efforts focused on poison control, habitat protection, and public awareness will be critical to preventing further declines.
Steller’s sea eagle (Haliaeetus pelagicus)
- Conservation status: Vulnerable.
- Estimated population: 3,500-4,500 mature individuals.
- Range and habitat: Breeds in Russia’s Far East and winters in Japan and nearby regions. Prefers coastal forests and river valleys.
- Threats: Habitat loss, overfishing, lead poisoning, and human disturbance.
The Steller’s sea eagle is one of the world’s largest eagles, with a global population of 3,500-4,500 mature individuals, including 1,700-1,800 breeding pairs. It relies on intact riverine and coastal forests for breeding and is highly dependent on fish stocks, particularly salmon and cod. Overfishing, habitat destruction, and industrial expansion in Russia have reduced key nesting and foraging areas, while changes in prey availability force many eagles to scavenge near human settlements, increasing their exposure to pollution and disease.
Lead poisoning is a major threat, with 20-25% of examined wintering eagles in Japan suffering from acute toxicity due to ingestion of lead fragments from deer carcasses left by hunters. Mercury and cadmium contamination, electrocution, and entanglement in fishing gear further contribute to mortality. Conservation efforts include protected reserves in Russia, lead ammunition bans in Japan, and power line modifications, but the species remains at risk. If current trends continue, some populations could decline by 50% within the next century, making ongoing protection efforts crucial.
Papuan eagle (Harpyopsis novaeguineae)
- Conservation status: Vulnerable.
- Estimated population: 3,000-3,700 mature individuals.
- Range and habitat: Endemic to New Guinea; prefers primary rainforest but also occurs in forest clearings and gallery forests.
- Threats: Hunting for ceremonial use, habitat loss, and deforestation.
The Papuan eagle, also known as the New Guinea eagle, is a large, forest-dwelling raptor found only in New Guinea, where it primarily inhabits undisturbed tropical rainforests. Unlike most large eagles, it is known to hunt on the ground, preying on marsupials, rats, pigs, and birds, as well as extracting animals from tree cavities. It is highly dependent on intact forests, though some individuals have been recorded in selectively logged areas. The species appears to reproduce slowly, with only one active nest ever documented, containing a single chick.
Earlier estimates placed the population at 3,200-4,000 mature individuals, but considering the ongoing decline, we estimate 3,000-3,700 mature individuals remain. Despite being legally protected, the Papuan Eagle faces severe hunting pressure, as its tail and flight feathers are highly valued in traditional headdresses. Deforestation for agriculture and infrastructure projects is an increasing threat, while logging roads open new areas to hunting. The species persists in some protected areas, such as the Crater Mountain Wildlife Management Area, but enforcement of hunting bans remains weak.
Wallace’s hawk eagle (Nisaetus nanus)
- Conservation status: Vulnerable.
- Estimated population: 1,500-6,000 mature individuals.
- Range and habitat: Southeast Asia, found in lowland and hill forests.
- Threats: Deforestation, habitat fragmentation, palm oil expansion, and fires.
The Wallace’s hawk-eagle is a secretive raptor of the lowland and hill forests of Southeast Asia, primarily found in Sumatra, Borneo, Peninsular Malaysia, Thailand, and Myanmar. It prefers evergreen forests, typically below 1,000 meters (3,280 feet), but has shown some adaptability to degraded habitats. However, extensive deforestation and habitat fragmentation continue to threaten its survival.
Its global population was last estimated at 2,500-9,999 mature individuals in 2000, but due to sustained habitat loss, it is likely much lower today. Given that the species has experienced a 35% decline over the last 25 years, and considering that conservation efforts have been limited, a more realistic estimate may fall between 1,500 and 6,000 mature individuals. The species continues to decline as forests are cleared for palm oil plantations, agriculture, and logging. While it persists in some degraded landscapes, its long-term survival depends on better forest protection and stronger conservation measures.
Pinsker’s hawk-eagle (Nisaetus pinskeri)
- Conservation status: Endangered.
- Estimated population: 1,300-3,600 mature individuals
- Range and habitat: Endemic to the Philippines, primarily on Mindanao; inhabits forests from lowlands up to 1,900 m.
- Threats: Deforestation, habitat degradation, and possible hunting.
The Pinsker’s hawk eagle or south Philippine hawk eagle is a forest-dependent raptor endemic to the Philippines, with its largest population on Mindanao and smaller, fragmented populations on Negros, Bohol, Samar, and Leyte. It inhabits primary and selectively logged forests from lowlands up to 1,900 meters (6,200 feet), though it struggles to survive in heavily degraded habitats.
Its numbers are estimated between 1,300 and 3,600 mature individuals, but the species has experienced a 15-30% decline over the past three generations (since 1996) due to deforestation for agriculture and logging. While some populations persist in protected areas, weak enforcement allows continued habitat loss. Conservation efforts have slowed deforestation in some regions, but further action is needed to secure its future.
Javan hawk eagle (Nisaetus bartelsi)
- Conservation status: Endangered.
- Estimated population: Approximately 1,022 mature individuals.
- Range and habitat: Endemic to Java, Indonesia, inhabiting rainforests across 10,800 sq km.
- Threats: Deforestation, illegal pet trade, and human disturbances.
Found only in Java, Indonesia, the Javan hawk-eagle is one of the world’s rarest raptors, with an estimated 511 breeding pairs (around 1,022 mature individuals) remaining in the wild. A 2023 study revised population estimates upward, but this is attributed to improved survey methods rather than actual population growth. Despite its protected status as Indonesia’s national bird, the species remains at risk due to deforestation, illegal wildlife trade, and habitat fragmentation.
A 2021 study in Gunung Picis Ponorogo Nature Reserve confirmed ongoing breeding activity, with young individuals observed, suggesting that some populations are still reproducing successfully. However, poaching remains a major issue, as these eagles are highly sought after in the pet trade. Conservation efforts focus on habitat protection, anti-poaching measures, and community engagement, but illegal trade and habitat loss continue to threaten the species’ future.
Solitary eagle (Buteogallus solitarius)
- Conservation status: Near Threatened.
- Estimated population: 1,000-2,500 mature individuals.
- Range and habitat: Western Mexico to northern Argentina; found in humid montane and premontane forests.
- Threats: Deforestation, habitat fragmentation, hunting, climate change.
The solitary eagle, also known as the black solitary eagle, is a large, dark-colored raptor with an estimated 1,000-2,500 mature individuals remaining in the wild. It is rarely observed across its fragmented range from Mexico to Argentina, occurring in humid montane forests, foothills, and steep woodlands. This species is often misidentified as a black hawk, making it difficult to assess its true status. It primarily hunts reptiles, especially snakes, and requires large territories (over 100 sq km) for foraging.
Although still listed as Near Threatened, the solitary eagle faces severe habitat loss, particularly in Venezuela, Colombia, and Ecuador, where forests are being cleared for agriculture and cattle ranching. In Venezuela, where the species is not legally protected, an estimated 35% of its habitat has been lost in the past 15 years. Climate change may further push the species to higher elevations, reducing its available habitat. Conservation efforts remain limited, and some experts suggest it should be uplisted to Endangered before further declines occur. Protecting remaining montane forests, particularly nesting areas, is critical for its survival.
Pallas’s fish eagle (Haliaeetus leucoryphus)
- Conservation status: Endangered.
- Estimated population: 1,000-2,500 mature individuals.
- Range and habitat: Breeds in South Asia, winters in Central Asia; inhabits large wetlands, lakes, and rivers.
- Threats: Wetland degradation, deforestation, prey depletion, pollution, and hydroelectric dams.
The Pallas’s fish-eagle is a large wetland-dependent raptor with a declining population estimated at fewer than 2,500 mature individuals. Previously believed to breed in Mongolia, recent studies confirm that its main breeding strongholds are in India, Bangladesh, and Myanmar, while birds migrate north of the Himalayas in summer. Satellite tracking has revealed long-distance migrations exceeding 4,000 km (2,500 miles), with some individuals flying at altitudes above 6,000 meters (20,000 ft) over the Himalayas. The species primarily preys on fish, but also hunts rodents and waterbirds when needed.
Despite occurring in several protected areas, the species is in decline due to wetland loss, deforestation of nesting sites, pollution, and overfishing. In Mongolia, hydroelectric projects are disrupting critical wintering areas, while in India and Bangladesh, wetland degradation and invasive plant species reduce prey availability. Conservation efforts, including community-led nest protection programs in Bangladesh, have shown promise, but greater habitat protection and wetland management are needed to secure the species’ future.
Chaco eagle (Buteogallus coronatus)
- Conservation status: Endangered.
- Estimated population: 800-2,000 mature individuals.
- Range and habitat: Eastern and central South America; inhabits open woodlands, savannas, and grasslands.
- Threats: Habitat loss, persecution, electrocution, and illegal trade.
The Chaco eagle, also known as the crowned solitary eagle, is a rare raptor with an estimated population of 800-2,000 mature individuals. It inhabits semi-open landscapes, including dry forests, savannas, and grasslands across eastern and central South America, particularly in the Cerrado, Chaco, and Pampas regions, but relies on tall trees for nesting. Pairs occupy vast territories of up to 600 sq km, and juveniles can disperse over 12,000 sq km. Although it can persist in some modified habitats, the species remains highly sensitive to habitat fragmentation and degradation.
Deforestation, agricultural expansion, and cattle ranching continue to reduce available habitat, while electrocution on powerlines is a major cause of mortality. In parts of its range, the eagle is persecuted due to its perceived threat to livestock. Conservation actions focus on habitat protection, population monitoring, public awareness campaigns, and retrofitting power infrastructure to reduce fatalities.
Black-and-chestnut eagle (Spizaetus isidori)
- Conservation status: Endangered.
- Estimated population: Fewer than 1,000 mature individuals.
- Range and habitat: Found in the Andes from Venezuela to Argentina, inhabiting montane forests up to 3,500 m.
- Threats: Deforestation, habitat fragmentation, and human persecution due to predation on domestic fowl.
The black-and-chestnut eagle is a high-altitude forest raptor, inhabiting the Andes Mountains from Venezuela to Argentina. It prefers montane forests between 500 and 3,500 meters (1,600-11,500 ft), nesting in tall emergent trees along steep slopes. Recent estimates suggest fewer than 1,000 mature individuals, with Colombia supporting 160-360 breeding pairs. The species has lost over 60% of its habitat, primarily due to deforestation for agriculture.
Forest loss and human persecution pose the greatest threats. As natural prey declines, the eagle increasingly preys on domestic fowl, making up as much as 36% of its diet in some areas. This has led to conflicts with farmers, resulting in retaliatory killings. Between 2000 and 2022, at least 60 individuals were recorded as killed. Conservation efforts focus on forest protection, habitat restoration, and reducing human-wildlife conflict by promoting secure poultry enclosures and local education initiatives.
Sanford’s sea eagle (Icthyophaga sanfordi)
- Conservation status: Vulnerable.
- Estimated population: Fewer than 1,000 mature individuals.
- Range and habitat: Endemic to the Solomon Islands, found in coastal and lowland forests.
- Threats: Deforestation, hunting, illegal pet trade, and habitat degradation from logging and agriculture.
Sanford’s sea-eagle is a powerful raptor endemic to the Solomon Islands, where it plays a crucial role as an apex predator. It inhabits coastal and lowland forests, scavenging along shorelines and occasionally hunting far inland. The species preys on fish, eels, flying foxes, possums, and even domestic poultry, sometimes resorting to kleptoparasitism by stealing food from ospreys. The population is estimated at 400-999 mature individuals, with numbers continuing to decline due to widespread logging, agriculture, and hunting.
Although once revered as a cultural totem, traditional taboos against hunting have broken down, leading to increased persecution. Additionally, some individuals are captured for the illegal pet trade, particularly in urban areas. Deforestation and coastal habitat loss further threaten its survival, with forest clearance accelerating in recent years. Conservation efforts focus on community-based education, habitat protection, and improved legal enforcement to curb illegal hunting and trade.
Flores hawk eagle (Nisaetus floris)
- Conservation status: Endangered.
- Estimated population: 320-1,500 mature individuals.
- Range and habitat: Endemic to Indonesia’s Lesser Sunda Islands, inhabiting forests up to 1,600 m.
- Threats: Persecution, deforestation, and habitat fragmentation.
Confined to the Lesser Sunda Islands of Indonesia, the Flores hawk eagle is one of the rarest and least understood eagles in the world. Early estimates placed the population as low as 320 mature individuals, though more recent data suggest it could be significantly higher if the species proves adaptable to degraded habitats. It primarily inhabits lowland and submontane forests, though it has been observed hunting over deforested landscapes. While its largest population is believed to be on Flores, smaller populations exist on Sumbawa, Lombok, Alor, Rinca, and Komodo, with uncertain numbers on surrounding islands.
The greatest threats to this species are hunting and persecution, as local communities often view it as a pest due to poultry predation. Deforestation has historically reduced habitat availability, though forest loss rates have slowed in recent years. Conservation efforts remain limited, and with no large-scale surveys conducted in recent years, the true population status remains uncertain. Without stronger protections, this eagle may continue to decline due to ongoing human-wildlife conflict and habitat degradation.
Philippine eagle (Pithecophaga jefferyi)
- Conservation status: Critically Endangered.
- Estimated population: Fewer than 800 mature individuals as of 2023.
- Range and habitat: Endemic to the Philippines, found in primary dipterocarp and mid-montane forests on Luzon, Samar, Leyte, and Mindanao.
- Threats: Deforestation, hunting, low juvenile survival rate, and habitat fragmentation.
With an estimated 392 breeding pairs, the Philippine eagle is among the rarest and most threatened birds of prey in the world. Found only on four Philippine islands, this forest-dependent raptor requires vast territories (up to 11,000 hectares per pair) to sustain its diet of mammals, birds, and reptiles. Once widespread, the species has suffered severe declines due to deforestation, hunting, and habitat loss. Though recent estimates suggest a slightly higher population than previously thought, the species faces low juvenile survival rates, meaning fewer young birds reach breeding age, putting long-term recovery at risk.
Despite being legally protected, hunting, accidental trapping, and habitat destruction continue to threaten its survival. Conservation programs led by the Philippine Eagle Foundation (PEF) focus on forest protection, public awareness, and captive breeding, with 29 eagles successfully hatched since 1992. However, with slow reproduction and shrinking habitat, the future of this magnificent bird remains highly uncertain without sustained conservation efforts.
Madagascar serpent eagle (Eutriorchis astur)
- Conservation status: Endangered.
- Estimated population: 533 mature individuals, as of 2023.
- Range and habitat: Endemic to eastern Madagascar, inhabiting lowland and mid-altitude primary rainforests.
- Threats: Deforestation, habitat fragmentation, human disturbance, and climate change.
The Madagascar serpent eagle is a secretive raptor restricted to the rainforests of eastern Madagascar, where it is rarely seen beyond the forest edge. A 2023 study estimated the population at 533 mature individuals, with its range and habitat smaller than previously thought. The species is an active hunter, preying primarily on chameleons (Furcifer and Calumma), geckos (Uroplatus), and frogs, using foot-thrusting techniques to flush prey from epiphytes and leaf litter.
Despite 95% of its habitat being within protected areas, the species remains at risk due to slash-and-burn agriculture, commercial logging, and bushfires. Climate change poses an additional long-term threat, with models predicting 94% of its ecological niche could be lost by 2050. While the species has been recorded in several national parks and reserves, ongoing research and improved protected area management are needed to prevent further population decline.
Great Nicobar serpent eagle (Spilornis klossi)
- Conservation status: Endangered.
- Estimated population: 150-370 mature individuals.
- Range and habitat: Endemic to Great Nicobar Island, inhabiting dense tropical forests.
- Threats: Deforestation, habitat fragmentation, and competition with other raptors.
The Great Nicobar serpent-eagle is one of the world’s rarest eagles, with an estimated 150-370 mature individuals, though recent density models suggest the lower end of this range (150-180 individuals) is more accurate. Found only on Great Nicobar Island, it depends on dense tropical forests, where it is rarely encountered. Experts describe the species as decidedly rare, with population estimates suggesting it is far less numerous than its relative, the Andaman serpent-eagle (Spilornis elgini), which has a significantly larger estimated population.
Despite its severe range restriction, conservation efforts remain minimal, and habitat loss continues due to deforestation and human development. The species is also thought to face competition from more adaptable raptors like the crested serpent eagle (Spilornis cheela), which is found at higher densities. With no large-scale conservation initiatives in place, the long-term survival of the Great Nicobar serpent eagle remains uncertain.
Madagascar fish eagle (Icthyophaga vociferoides)
- Conservation status: Critically Endangered.
- Estimated population: Approximately 240 mature individuals.
- Range and habitat: Found only in northwestern Madagascar, primarily in coastal wetlands, mangroves, and large freshwater lakes.
- Threats: Habitat destruction, overfishing, human disturbance, and hunting.
Restricted to the wetlands and coastal forests of northwestern Madagascar, the Madagascar fish-eagle is among the world’s most endangered raptors, with fewer than 250 mature individuals remaining. A 2005-2006 survey recorded 287 total individuals, including 196 breeding birds (around 98 pairs), showing a modest increase from previous counts. While some reports suggest that the population may have remained stable for years, no recent large-scale surveys have confirmed this, leaving its current status uncertain.
Despite possible stability, the species remains under severe threat from habitat destruction, overfishing, and direct persecution. Deforestation and wetland conversion for agriculture continue to degrade its habitat, while competition with fishermen reduces prey availability. Eagles are also shot, trapped, or taken for the illegal wildlife trade, and local accounts suggest their body parts are used in traditional medicine. Conservation programs focus on nest protection, sustainable fishing regulations, and community engagement, but without new data, the long-term survival of this rare eagle remains in question.
Will these eagles survive the coming decades?
The eagles featured in this report are among the rarest and most endangered birds of prey. While some, like the Madagascar fish eagle and Great Nicobar serpent eagle, already number in the low hundreds, others still have a few thousand individuals left, but their future remains uncertain. Deforestation, hunting, lead poisoning, and habitat destruction continue to drive their populations downward. For many of these species, conservation efforts are underway, but without stronger protections, stricter enforcement, and habitat restoration, some may vanish within decades. Protecting these eagles is not just about saving individual species, it is about preserving the ecosystems they help regulate. The time to act is now, before these majestic raptors become mere names in history books.