25 of the world’s rarest owls, some are on the brink of extinction

The Siau scops owl and the Pernambuco pygmy owl are currently the rarest owls in the world, with likely fewer than 50 individuals remaining in the wild. Their populations are so critically low that they may soon vanish entirely unless immediate conservation action is taken. Close behind them are the Annobon scops owl, Seychelles scops owl, and Moheli scops owl, which still have estimated populations exceeding 200-300 birds, making them rare but still observable in the wild under the right conditions.

This article highlights not only the rarest owls by population size but also those facing severe threats from deforestation, climate change, and invasive species. Some may persist in isolated refuges, while others are already at the edge of extinction. Without urgent conservation efforts, several of these species may disappear within decades, and new names will inevitably join the list as their numbers continue to decline.

Itombwe owl (Tyto prigoginei)

• Conservation status: Endangered.
• Estimated population: 2,500-7,000 mature individuals.
• Range and habitat: Found in the Itombwe Mountains, Democratic Republic of Congo, montane and bamboo forest interspersed with grassland.
• Threats: Habitat loss from forest clearance for small-scale agriculture and livestock grazing.

The Itombwe owl was described from a single specimen collected in 1951, and remained unrecorded until its rediscovery in 1996 in the southeastern Itombwe Forest. The recent finding expanded its known range southward by nearly 95 kilometers (59 miles) and lowered its known altitude by 600 meters (2000 feet). Despite the large extent of montane forest in central Africa, surveys in Nyungwe Forest (Rwanda), Kibira (Burundi), and Mt. Kabogo (Tanzania) have not confirmed its presence. The species appears to require a mix of grassland and montane or bamboo forest, but it was netted in a slightly disturbed area, suggesting some tolerance for human activity.

Forest degradation remains a serious concern in Itombwe, as agricultural expansion, worsened by a maize blight since the 1990s, has driven further deforestation. Gallery forests on the central plateau, including areas where the species was rediscovered, are being degraded by farming and livestock grazing. Conservation efforts include the gazettement of the Itombwe Forest as a community reserve, though boundaries still need to be defined. Further surveys using playback of an unconfirmed owl recording from Nyungwe Forest may help clarify the species’ range and conservation needs.

Sokoke scops owl (Otus ireneae)

• Conservation status: Endangered.
• Estimated population: 2,000-5,000 mature individuals.
• Range and habitat: Arabuko Sokoke Forest, Kenya, and the East Usambara Mountains, Tanzania.
• Threats: Habitat loss, climate change, illegal logging, human encroachment.

The Sokoke scops owl is a small, range-restricted species found primarily in the coastal forests of Kenya and Tanzania. Once thought to be confined to the Arabuko Sokoke Forest, it was later discovered in the East Usambara Mountains and the Dakatcha woodlands. However, its habitat remains highly fragmented, and the species is almost entirely dependent on specific forest types, particularly Cynometra and Brachylaena-dominated woodlands.

Recent studies suggest a decline of 22.5% in its population over a 16-year period within its primary habitat, the Arabuko-Sokoke Forest. Climate change models predict a dramatic shift in its distribution, with a potential 64% reduction in suitable habitat by 2080. Illegal logging, especially of Brachylaena huillensis, threatens nesting sites, and human encroachment continues to pressure the species’ remaining forest patches. Conservation efforts are limited, but continued habitat protection, monitoring, and potential nest-box programs could help mitigate further declines.

Anjouan scops owl (Otus capnodes)

• Conservation status: Endangered.
• Estimated population: 2,300-3,600 mature individuals.
• Range and habitat: Anjouan (Ndzuani), Comoros.
• Threats: Habitat loss, deforestation, invasive species, cyclones.

The Anjouan scops owl was rediscovered in 1992 after being unrecorded since 1886. Once considered critically endangered due to its small range and suspected low population, new research has revealed a much larger and more adaptable population than previously thought. The species is now estimated to number 3,450 individuals in the dry season and up to 5,450 in the wet season, equating to 2,300-3,600 mature individuals. It inhabits native forests, degraded forests, and even plantations, provided large trees remain for nesting and roosting.

Despite this more optimistic outlook, the owl remains at risk due to ongoing deforestation driven by agriculture, timber harvesting, and charcoal production. Invasive species such as Black Rats and Common Mynas may also impact nesting success. Conservation efforts are underway, including proposals to protect Mount Ntringui and Moya Forest, as well as community-led sustainable land management initiatives. While the species’ situation has improved, long-term habitat preservation remains crucial for its survival.

Pemba scops owl (Otus pembaensis)

• Conservation status: Vulnerable.
• Estimated population: Approximately 3,000 mature individuals.
• Range and habitat: Endemic to Pemba Island, Tanzania; occurs mainly in Ngezi and Msitu Mkuu forests, as well as dense clove and mango plantations.
• Threats: Habitat loss from agricultural expansion, deforestation for firewood and charcoal, and fragmentation due to human population growth.

The Pemba scops owl is restricted to Pemba Island, where it occupies both primary and secondary forest, as well as old clove plantations. Surveys estimate the global population at approximately 3,000 mature individuals, but this number is declining due to habitat destruction. The highest densities are found in the native forests of Ngezi and Msitu Mkuu, with lower numbers in secondary forests and old plantations. Although the species can persist in modified habitats, it remains heavily dependent on mature forests with large trees for roosting and nesting.

Habitat destruction continues as a major concern, with Zanzibar losing an estimated 1.2% of its forest annually due to deforestation for agriculture, charcoal, and fuelwood. The growing human population places increasing pressure on the island’s limited forested areas. Conservation efforts include the establishment of Ngezi-Vumawimbi Nature Reserve and community forest initiatives, but enforcement remains a challenge. Further studies on the owl’s population trends, habitat use, and potential restoration of forest connectivity are critical for its long-term survival.

Karthala scops owl (Otus pauliani)

• Conservation status: Endangered.
• Estimated population: Approximately 2,300 mature individuals.
• Range and habitat: Restricted to Mount Karthala, Grand Comoro, in remaining montane forests.
• Threats: Deforestation for agriculture, logging, invasive species, and habitat fragmentation.

Endemic to Mount Karthala on Grand Comoro, this scops owl has one of the smallest ranges of any owl species, confined to approximately 133 square kilometers (51 square miles) of montane forest at elevations of 800-2,000 meters (2,600-6,500 feet). A 2019 population survey estimated a global population size of 3,452 individuals including approximately 2,300 mature birds. Despite this, habitat loss remains a major concern, with agriculture, logging, and road expansion rapidly reducing available forest. Secondary forests are also at risk of conversion into farmland, further shrinking the owl’s habitat.

In addition to deforestation, invasive species pose a serious threat. The black rat and common myna (Acridotheres tristis) are suspected to prey on eggs and compete for nest sites, adding pressure to an already declining population. While nesting and feeding ecology remain poorly studied, conservation efforts must address both habitat loss and invasive species control. Proposals include forest restoration, preventing further agricultural expansion, and engaging local communities in conservation efforts. Establishing protected status for Karthala’s forests remains a priority, but no official reserve has been created. Without intervention, continued habitat degradation could push the species toward a higher threat category.

Red owl (Tyto soumagnei)

• Conservation status: Vulnerable.
• Estimated population: 1,250-3,750 mature individuals.
• Range and habitat: Endemic to Madagascar’s eastern rainforests; found in primary and secondary humid forests, with hunting occurring in open areas near forest edges.
• Threats: Habitat destruction due to slash-and-burn agriculture, logging, and fires.

The red owl is a rare and elusive species endemic to Madagascar’s eastern rainforests, where it was historically known from Amber Mountain to Mantadia National Park. Recent discoveries have expanded its known range southward, including Tsitongambarika and Kalambatritra. While likely present in all major remaining forest blocks, it is difficult to detect due to its nocturnal habits. Surveys at Bemanevika New Protected Area have found it to be relatively common, with an estimated 30 individuals in the area. Based on estimated densities in optimal habitat, a precautionary global population estimate places its numbers at 1,250-3,750 mature individuals.

The species relies on primary and secondary forests for breeding but also hunts in open habitats such as rice paddies and cultivated areas. Its diet consists mostly of small native mammals, with some insects, frogs, and reptiles. The population is inferred to be declining due to deforestation, with Madagascar’s primary rainforest cover decreasing by approximately 19% over three generations. Ongoing habitat loss is expected to continue at a rate of 15-29% by 2029, driven by slash-and-burn agriculture, logging, and human expansion. Additionally, climate change models predict a 72% reduction in its ecological niche by 2050. Conservation efforts focus on habitat protection, with the species occurring in several national parks and protected areas, though continued monitoring and expanded protection are needed.

Cloud-forest pygmy owl (Glaucidium nubicola)

• Conservation status: Vulnerable.
• Estimated population: 800-4,800 mature individuals.
• Range and habitat: Endemic to the west slope of the Andes in Colombia and Ecuador, found in very humid primary cloud forest on steep slopes.
• Threats: Deforestation, logging, agriculture, road expansion, and gold mining.

The cloud-forest pygmy owl is a rare and poorly understood species restricted to humid cloud forests of Colombia and Ecuador. Although it was once thought to have a continuous distribution, its habitat is now highly fragmented, with confirmed records mostly from Pichincha (Ecuador) and scattered locations in Colombia. Due to limited surveys, its presence in other regions remains uncertain. Recent niche modeling studies suggest that it may occur further south than previously recorded, but no new populations have been confirmed.

With ongoing deforestation across the Choco region and western slopes of the Andes, the species is experiencing severe habitat loss. Previous estimates placed the population at 1,500-7,000 mature individuals, but given a suspected 30-49% decline between 1998 and 2008, a 2024 projection suggests the population is now likely between 800 and 4,800 mature individuals. The primary threats include logging, agriculture, road construction, and gold mining, which continue to fragment its already limited range. Conservation efforts focus on increasing protected areas and enforcing habitat protection policies, but habitat destruction remains a serious concern.

Negros scops owl (Otus nigrorum)

• Conservation status: Vulnerable.
• Estimated population: Fewer than 2,500 mature individuals.
• Range and habitat: Endemic to the islands of Negros and Panay, Philippines; found in humid lowland and montane forest.
• Threats: Severe habitat loss due to deforestation, agriculture, timber extraction, and charcoal burning.

The Negros scops owl is a recently recognized species, split from the Philippine scops owl (Otus megalotis). It is widely distributed on Negros and occurs in low densities on Panay, but remains poorly studied. No formal population estimate exists, yet the species is thought to have a small and declining population, inferred to be fewer than 2,500 mature individuals due to its restricted range and extensive deforestation. It appears to be encountered far less frequently than O. megalotis or O. everetti within its range.

Forest destruction poses a critical threat to the Negros scops owl, as Negros retained only 4% forest cover by 1988, and Panay had just 8%. Remaining forest fragments continue to shrink due to agricultural expansion, logging, and charcoal production, making conservation efforts increasingly urgent. While the species is assumed to occur in some protected areas, targeted conservation actions are lacking. More research is needed to assess its population size and density, while reforestation and enforcement against illegal logging are essential to protect the remaining habitats.

Sulu boobook (Ninox reyi)

• Conservation status: Vulnerable.
• Estimated population: 1,000-2,500 mature individuals.
• Range and habitat: Sulu Archipelago, Philippines; found in primary and secondary forest, forest edges, mature mangroves, large trees near villages.
• Threats: Extensive deforestation from agriculture, livestock grazing, and logging.

The Sulu boobook is a recently recognized species restricted to six islands in the Sulu Archipelago, with Tawi-Tawi holding the largest known population. Its estimated global population is 1,000-2,500 mature individuals, with all subpopulations believed to contain fewer than 1,000 mature birds. Deforestation remains a critical threat, with many of these islands losing large portions of their forest cover due to agriculture, grazing, and timber extraction. Oil palm plantations continue to pressure the remaining secondary and primary forests, particularly on Tawi-Tawi.

Although little is known about its ecology, it likely shares habitat preferences with the Philippine boobook (Ninox philippensis), occurring in primary and tall secondary forests, as well as mature mangroves and large trees near human settlements. Conservation efforts should prioritize habitat protection, population surveys, and community awareness initiatives to prevent further decline.

Blakiston’s fish owl (Ketupa blakistoni)

• Conservation status: Endangered.
• Estimated population: 1,000-1,700 mature individuals.
• Range and habitat: Found in Russia’s (Far East and Kunashir), northeastern China, and Japan (Hokkaido); prefers old-growth forests along rivers with open water.
• Threats: Logging, riverbank development, dam construction, overfishing, and disturbance.

Blakiston’s fish owl is one of the largest owls in the world, requiring undisturbed riverine forests with large, hollow trees for nesting and shallow, fish-rich waters for hunting. The species has two recognized subspecies: B. b. doerriesi (mainland) and B. b. blakistoni (island). While the mainland population remains highly fragmented and in decline, conservation efforts in Hokkaido, including artificial nest boxes and supplementary feeding, have led to population stabilization.

Recent estimates place the global population at approximately 1,000-1,700 mature individuals or 500-850 breeding pairs. The island population on Hokkaido and Kunashir numbers 166-182 individuals, while the mainland population across Russia and China is estimated at 800-1,600 individuals. The species is likely extinct on Sakhalin (no confirmed records since 1974) and remains unconfirmed in North Korea. Major threats include habitat destruction from logging, infrastructure expansion, and overfishing, which reduces key prey species like salmon and trout. Conservation efforts must focus on habitat protection, sustainable forestry practices, and reducing human disturbance along key river systems.

Principe scops owl (Otus bikegila)

• Conservation status: Critically Endangered.
• Estimated population: 800-1,600 mature individuals.
• Range and habitat: Endemic to Principe, Sao Tome and Principe; restricted to native forest within Obo Natural Park.
• Threats: Habitat loss from development, introduced predators, and potential competition for nest sites.

The Principe scops owl is one of the most range-restricted owls in the world, found only in the native forests of Principe Obo Natural Park. With an estimated population of 800-1,600 mature individuals, its numbers could be even lower if its range is limited to elevations below 500 meters (1640 feet). While the island has been a UNESCO Biosphere Reserve since 2012, habitat loss continues due to small-scale logging, infrastructure development, and a proposed hydroelectric dam along the Papagaio River.

Introduced predators pose an additional risk, with the Mona monkey suspected of raiding nests, as it does with the Critically Endangered Príncipe thrush, which shares the same habitat. Black rats, feral cats, and African civets are also present, though their impact is unclear. The species also competes with the native grey parrot for tree cavities, but there is no strong evidence that this affects its breeding success. Conservation efforts should focus on limiting habitat destruction, monitoring the impact of introduced species, and ensuring that development projects do not further fragment its already small range.

Flores scops owl (Otus alfredi)

• Conservation status: Endangered.
• Estimated population: 250-2,000 mature individuals.
• Range and habitat: Endemic to Flores, Indonesia; montane and seasonally dry forest, including degraded patches.
• Threats: Deforestation, habitat fragmentation, shifting cultivation, road-building, and dry-season burn-offs.

The Flores scops owl is a rare and endangered species found only on the Indonesian island of Flores. First collected in 1896, it was rediscovered in 1994, with more recent records confirming its presence in Mbeliling (west) and Kelimutu National Park (east). Although it was previously believed to be confined to montane forest between 1,000-1,400 meters (3,300-4,600 feet), recent observations have recorded it as low as 590 meters (1936 feet) in Sisok, where it inhabits seasonally dry forest with deciduous trees.

The species faces a continued decline due to habitat destruction, with forest clearing for shifting cultivation, road-building, and dry-season burn-offs already extensive. Much of its habitat below 1,300 meters (4265 feet) has been lost, and remaining forest tracts are largely confined to steep-sided valleys and high-elevation peaks. Despite its persistence in degraded areas, its small and fragmented population remains vulnerable. Conservation efforts should prioritize habitat protection in montane forests, particularly in Ruteng Nature Recreation Park, while strengthening protection of adjacent forests to mitigate further loss.

Long-whiskered owlet (Xenoglaux loweryi)

• Conservation status: Vulnerable.
• Estimated population: 250-1,000 mature individuals.
• Range and habitat: Endemic to northern Peru (Amazonas and San Martín regions); inhabits humid montane forests (Yunga biome).
• Threats: Habitat loss from deforestation, road construction, agricultural expansion, and potential ecotourism disturbance

The long-whiskered owlet is a small and elusive species known for its distinctive facial bristles and short tail. First described in 1976, it remained virtually unobserved for decades until rediscoveries in the early 2000s. It is now confirmed from at least 11 localities in northern Peru, primarily around Abra Patricia and the Cordillera de Colán. Recent habitat models suggest the species has a larger potential range than previously thought, though its core habitat remains limited. Despite its rarity, the population is currently considered stable, as recent forest loss in the area has been minimal. The owlet inhabits humid, mossy cloud forests with dense undergrowth, epiphytes, and bamboo, often remaining hidden in the lower canopy. Playback studies indicate it is reluctant to respond, making population assessments challenging. Some researchers speculate it has limited flight capability, relying on dense vegetation for movement.

While much of its habitat remains intact, the species faces growing conservation threats. Only 40.5% of its known range falls within protected areas, leaving much of its habitat vulnerable to deforestation, road expansion, and small-scale agriculture. Climate change models suggest mixed effects, with potential habitat losses of up to 76% by 2070 when combined with human activity. Additionally, increased ecotourism pressure, particularly from birdwatchers using playback and flash photography, may disturb the species. Continued research, habitat protection, and conservation efforts are essential to safeguarding this unique owl.

Sao Tome scops owl (Otus hartlaubi)

• Conservation status: Vulnerable.
• Estimated population: 250-1,000 mature individuals.
• Range and habitat: Endemic to Sao Tome, Sao Tome and Principe; found in primary and mature secondary forests.
• Threats: Habitat loss due to agricultural expansion, timber extraction, and infrastructure development.

The Sao Tome scops owl is restricted to the island of Sao Tome, where it is relatively widespread in suitable forest habitats. Its population is estimated at 250-1,000 mature individuals, though ongoing habitat degradation may be causing a slow decline. Large areas of Sao Tome’s forests were historically cleared for coffee and cocoa plantations, and while primary forest remains intact, expanding small farms, timber collection, and road construction are increasing pressure on the owl’s habitat.

Although protected areas and conservation laws exist, further research is needed to determine population trends, habitat requirements, and key threats. Ensuring the legal protection of remaining forests, particularly mature secondary woodlands, will be crucial for the species’ long-term survival.

Camiguin boobook (Ninox leventisi)

• Conservation status: Vulnerable.
• Estimated population: 250-1,000 mature individuals.
• Range and habitat: Endemic to Camiguin, Philippines; found in remaining broadleaf forest in the island’s center.
• Threats: Small population size, potential habitat loss from human expansion.

The Camiguin boobook is a rare, island-endemic owl restricted to Camiguin Sur in the Philippines. Its population is estimated at 250-1,400 mature individuals, but likely closer to 250-1,000 due to its apparent scarcity and preference for intact forest. Historically, deforestation reduced its range, but remaining broadleaf forests, covering approximately 70 square kilometers (27 square miles), have been stable in recent years. This species is thought to have been more widespread before large-scale habitat clearance.

While the population is currently considered stable, the species remains vulnerable due to its restricted range and potential future threats from human expansion, tourism, and land-use changes. Conservation efforts should focus on protecting the remaining forest and monitoring land-use trends to ensure its long-term survival.

Romblon boobook (Ninox spilonotus)

• Conservation status: Endangered.
• Estimated population: Fewer than 500 mature individuals.
• Range and habitat: Endemic to the Philippine islands of Sibuyan and Tablas; found in primary and tall secondary forests.
• Threats: Deforestation due to agriculture, livestock grazing, illegal logging, and gold mining.

The Romblon boobook is a recently recognized species, confirmed only on Sibuyan and Tablas, though its presence on Romblon Island itself remains unverified. Population estimates suggest that each island may hold fewer than 250 birds, placing the global population below 500 mature individuals. While it occurs in both primary and tall secondary forests, its habitat is rapidly shrinking due to agricultural expansion, livestock grazing, logging, and gold mining.

On Tablas, deforestation has been extensive since the early 20th century, with only small forest remnants remaining. Sibuyan retains more forest cover, but illegal logging and mining continue to degrade its habitat, even inside Mt. Guiting-Guiting Natural Park, the island’s main protected area. No targeted conservation efforts exist for the species, making habitat protection, population surveys, and forest restoration initiatives critical for its survival.

Serendib scops owl (Otus thilohoffmanni)

• Conservation status: Endangered.
• Estimated population: 150-700 mature individuals.
• Range and habitat: Endemic to Sri Lanka’s wet zone rainforests; found in tall, dense secondary forests.
• Threats: Severe habitat loss, forest fragmentation, logging, and small-scale mining.

First identified by its distinctive call in 1995 and formally described in 2004, the Serendib scops owl is one of the most recently discovered species. Unlike most scops owls, it lacks ear tufts and is known for its slow, whistle-like call. It is currently known from five rainforest sites, but its true range may be larger, as it remained undetected for decades despite surveys. Population estimates suggest 150-700 mature individuals, but ongoing habitat fragmentation threatens its survival. The species is highly sensitive to deforestation, as it has never been found in forest patches smaller than 8.2 square kilometres (3.2 square miles).

Although all known locations are within protected reserves, forest loss due to settlement expansion, illegal logging, and small-scale mining continues to reduce its habitat. The species hunts in undergrowth and subcanopy at night and roosts low in dense foliage during the day, often adopting a cryptic posture to avoid predators. Further surveys and population monitoring are needed to determine its full range and ensure that critical habitat is safeguarded for this elusive species.

Cebu boobook (Ninox rumseyi)

• Conservation status: Vulnerable.
• Estimated population: Approximately 400 mature individuals.
• Range and habitat: Endemic to Cebu, Philippines; found in remaining broadleaf forests, forest patches, and occasionally near clearings and farms.
• Threats: Historical deforestation, potential loss of nesting sites, and habitat fragmentation.

The Cebu boobook is a small, earless owl endemic to Cebu Island in the Philippines. First described from a single specimen collected in 1888, it was rediscovered in 1998 after over a century without confirmed sightings. Cebu’s forests were already severely depleted by the late 19th century, with only 0.03% of original vegetation remaining by the late 20th century. However, forest loss has slowed in recent years, and surveys estimated a population of around 400 mature individuals. The species occupies forest patches of varying sizes, including remnant areas as small as 1-2 hectares (2.5-5 acres), and shows some adaptability to degraded habitats. It does not appear to prefer forest interiors over edges but may be restricted by the availability of large trees with natural cavities for nesting.

The species occurs in several protected areas, including Alcoy, Argao, Dalaguete, Tabunan, and Boljoon forests, though only the latter lacks direct conservation support. Conservation efforts should focus on monitoring population trends, preserving remaining habitat, and potentially supplementing nest sites with artificial cavities. Additional studies on prey availability and habitat preferences would aid in refining conservation strategies. While the Cebu boobook has shown some resilience, long-term survival will depend on continued habitat protection and management.

Forest owlet (Athene blewitti)

• Conservation status: Endangered.
• Estimated population: Fewer than 500 mature individuals.
• Range and habitat: Endemic to central India; found in dry deciduous forests.
• Threats: Habitat loss due to illegal logging, agriculture, forest fires, and infrastructure projects.

Once thought to be extinct, the forest owlet was rediscovered in 1997, more than a century after its last confirmed sighting. Surveys since then have located populations across several forest sites in Maharashtra, Madhya Pradesh, and Gujarat, with its stronghold in Melghat Tiger Reserve. Despite ongoing discoveries, its remaining range is fragmented, with only 10% of its habitat under protection. The species primarily inhabits dry deciduous forests, avoiding heavily degraded areas and small forest patches.

Its greatest threat is habitat loss, driven by illegal tree-cutting, agriculture, grazing, and infrastructure projects. Forest fires, competition for nesting cavities, and hunting for cultural practices further pressure the population. Conservation efforts have increased, with protected areas and awareness programs in place, but continued forest management, stricter enforcement against logging, and further population surveys are needed to secure its future.

Christmas Island boobook (Ninox natalis)

• Conservation status: Vulnerable.
• Estimated population: Approximately 340 mature individuals.
• Range and habitat: Endemic to Christmas Island, Australia; found in forested areas, both primary forests and older regrowth.
• Threats: Small population size, habitat loss, invasive species, climate change.

The Christmas Island boobook is a small owl restricted to Christmas Island in the Indian Ocean. Its population is estimated between 240 and 1,200 mature individuals, with the most recent survey suggesting around 340. The species occupies all habitats across the island, favoring primary forest and mature regrowth for nesting and foraging. It primarily feeds on insects and small vertebrates, nesting in tree hollows within dense forested areas. Historical habitat loss from phosphate mining reduced available habitat, but no old-growth forest has been cleared since 1988.

Long-term monitoring from 2012 to 2022 indicates the population remains stable despite past concerns over the invasive yellow crazy ant (Anoplolepis gracilipes). While the ants may impact invertebrate prey availability, no direct effect on the boobook has been confirmed. Given its small population and restricted range, the species remains vulnerable to habitat degradation, disease, and climate change. Conservation efforts focus on maintaining protected areas, controlling invasive species, and preventing further habitat loss.

Moheli scops owl (Otus moheliensis)

• Conservation status: Endangered.
• Estimated population: Fewer than 250 mature individuals.
• Range and habitat: Endemic to Moheli, Comoro Islands; primarily in humid forests but may be more widespread.
• Threats: Habitat destruction, invasive species, hunting, and climate change.

The Moheli scops owl was once thought to be restricted to a single mountain ridge, but more recent evidence suggests it may occur across much of Moheli, possibly even at lower elevations where trees remain. Despite this, the species remains highly localized, with a population estimated at 200-250 mature birds. It is most abundant in near-primary forests, with lower densities recorded in degraded habitats. However, by 1995, intact humid forest covered only 5% of Moheli, largely due to subsistence agriculture, land clearing, and erosion-prone abandoned farmland.

While no immediate conservation actions exist, the Bristol Conservation and Science Foundation has proposed expanding its forest management project to Moheli, and plans exist to extend the Reserve Marine de Nioumachoua to protect upland forests. Invasive plants (Syzygium jambos, Lantana camara, Clidemia hirta) threaten native vegetation, while introduced predators such as rats and common mynas may compete with or prey on the owls. Additionally, as the species is already near its maximum altitude range, climate change could further limit its habitat. New population surveys and habitat protection measures are urgently needed to assess its status and secure its survival.

Seychelles scops owl (Otus insularis)

• Conservation status: Critically Endangered.
• Estimated population: Approximately 240-280 mature individuals.
• Range and habitat: Endemic to Mahé, Seychelles; restricted to a small range in upland forests.
• Threats: Habitat loss, invasive predators, low reproductive success, and climate change.

The Seychelles scops owl, though critically endangered, can still be found in the montane forests of Mahe, where it occupies a small and declining range. Recent estimates place the population between 240 and 280 mature individuals, with reports of disappearing territories suggesting a slow decline. It primarily inhabits misty, high-rainfall forests between 100 and 910 metres (330-3000 feet), preferring areas with a dense canopy and tree cavities for nesting. Despite some adaptability to degraded forest and plantations, continued habitat encroachment has forced pairs to abandon sites on the edges of Morne Seychellois National Park, the species’ primary refuge.

While much of its habitat falls within a national park, ongoing forestry activities and future development projects continue to threaten its limited range. Invasive species, including black rats, feral cats, barn owls, and common mynas, pose an additional risk by preying on eggs and competing for nest sites. Breeding success is low, further limiting population growth. Conservation efforts should focus on habitat preservation, invasive species control, and monitoring to ensure the survival of this highly localized owl.

Annobon scops owl (Otus feae)

• Conservation status: Critically Endangered.
• Estimated population: Fewer than 200 mature individuals.
• Range and habitat: Endemic to Annobon Island, Equatorial Guinea; found mainly in humid upland forests.
• Threats: Habitat loss from planned infrastructure projects, road construction, and low tolerance to habitat changes.

The Annobon scops owl is one of the world’s rarest owls, restricted to the small 17.5-square-kilometre (6.8 square miles) island of Annobon. First reported in 1902, it remained unconfirmed for much of the 20th century until calls were recorded in 2002, followed by nocturnal surveys in 2008-2009 that estimated a population of around 200 mature individuals. The species is largely confined to moist and cloud forests, with higher densities recorded in the southern Santa Mina Massif and upper Angañ River, though occasional sightings in dry forests suggest some adaptability.

While its habitat remains mostly intact due to Annobon’s low human population, planned infrastructure projects pose a major future threat. A road development project could cut directly through the owl’s core range, leading to widespread forest loss if completed. Other risks include airport and port expansion, which could accelerate deforestation. Conservation efforts so far include genetic studies, but further population monitoring and advocacy for a protected area in its core range are needed to secure its survival.

Pernambuco pygmy owl (Glaucidium mooreorum)

• Conservation status: Critically Endangered.
• Estimated population: Fewer than 50 individuals.
• Range and habitat: Endemic to the Atlantic Forest of Pernambuco, Brazil; formerly found in small, humid lowland forest patches.
• Threats: Severe deforestation, habitat fragmentation, and conversion to sugarcane plantations.

The Pernambuco pygmy owl is one of the world’s rarest and most endangered owls, last confirmed in 2002 at Usina Trapiche, a 100-square-kilometre (39 square miles) forest patch in northeastern Brazil. Formally described in 2002, it is a newly discovered species, known from just two specimens collected in 1980 from Reserva Biológica de Saltinho (4.8 square kilometres (1.9 square miles)). The species was first documented through tape recordings in 1990, but despite extensive playback surveys across Pernambuco and Alagoas since 2004, no further evidence of its survival has been found.

The Pernambuco Atlantic Forest has suffered extreme deforestation, shrinking from 39,500 square kilometres (15,250 square miles) to approximately 1,900 square kilometres (733 squre miles) by 2002, leaving behind highly fragmented and degraded habitat. The remaining reserves are mostly under 5 square kilometres (1.9 squre miles), offering little protection for forest-dependent species. Probability models suggest only a 31.7% chance that the owl still exists, and Brazil officially declared it extinct in 2014, though BirdLife International still classifies it as Critically Endangered. If any individuals survive, urgent conservation measures, including habitat protection and targeted surveys, are needed to confirm its persistence.

Siau scops owl (Otus siaoensis)

• Conservation status: Critically Endangered.
• Estimated population: Fewer than 50 individuals.
• Range and habitat: Endemic to Siau Island, Indonesia; confined to small highland forests.
• Threats: Severe deforestation, habitat loss, and limited range.

The Siau scops owl, one of the rarest and most elusive owls, is known only from a single specimen collected in 1866. Despite targeted surveys, it has not been confirmed in over 150 years. A 2000 estimate suggested that fewer than 50 individuals remained, but no updated population assessments exist. The species was likely always rare due to the small, volcanic nature of Siau Island, and its habitat has been rapidly disappearing. By 1998, nearly all of Siau’s lowland forest had been destroyed, with only a small patch of trees remaining at high elevations.

In response to its precarious status, conservation groups, including the Wildlife Conservation Society (WCS) and local NGO PALS, have conducted surveys in an effort to locate any surviving individuals. In 2017, a video surfaced of a purported Siau scops owl trapped inside a building, though the species’ identity remains unconfirmed. Reports from local communities suggest that small owls are still present on Siau, and unidentified calls have been recorded. However, the lack of firm evidence leaves its survival uncertain. If rediscovered, immediate conservation action will be necessary to protect the last remnants of its habitat.

Future outlook

The state of the world’s rarest and most endangered owls remains precarious. Habitat destruction, deforestation, invasive species, and climate change continue to drive many of these species toward the brink of extinction. Unfortunately, this report is ongoing, some of the owls listed here will likely vanish in the coming years, while others may stabilize or even recover with dedicated conservation efforts. At the same time, new species could enter the list as their populations dwindle under mounting threats. Only a few of the owls documented here will manage to secure a safer future, provided that conservation initiatives succeed in halting their decline. The fate of these unique birds depends on sustained efforts to protect and restore their habitats before it is too late.