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Scops owl

The Scops owls (Otus) comprise a genus of small to medium-sized nocturnal birds in the owl family Strigidae, characterized by prominent ear tufts, cryptic mottled plumage in shades of gray, brown, or rufous for camouflage, and forward-facing yellow eyes; with approximately 59 recognized species as of 2024, it represents one of the most diverse owl genera worldwide.^[1] These owls are exclusively Old World in distribution, ranging from Europe and Africa through southern Asia to Southeast Asia and various islands, including Madagascar and the Philippines, though they are absent from Australia and the Americas.^[2] Typically measuring 17–35 cm in length and weighing 50–250 g depending on the species, Scops owls are primarily insectivorous, foraging on moths, beetles, and other invertebrates, supplemented occasionally by small vertebrates like lizards or birds.^[3] Scops owls inhabit a wide array of environments suited to their elusive nature, from dense tropical rainforests and montane woodlands to arid savannas, semi-open scrublands, and even urban parks with mature trees, often perching motionless during the day to blend with bark or foliage.^[3] Many species are sedentary, but others, such as the Eurasian scops owl (Otus scops), undertake long-distance migrations between Eurasian breeding grounds and sub-Saharan African wintering areas, crossing the Sahara Desert annually.^[4] Breeding behaviors vary but generally involve cavity nesting in tree hollows or old woodpecker holes, with females laying 2–6 eggs that incubate for about 24–30 days; parental care emphasizes nocturnal activity and territorial calls, which are simple, repetitive whistles unique to each species and crucial for identification.^[3] Recent taxonomic revisions, driven by genetic analyses and vocal studies, continue to refine species boundaries, with several new taxa described in the last decade, highlighting ongoing biodiversity discoveries in remote island populations.^[5] Conservation concerns affect about one-third of species, primarily due to habitat loss from deforestation and agriculture, though many remain common where suitable wooded areas persist.^[1]

Taxonomy and classification

Etymology and historical context

The term "Scops owl" originates from the Greek word skōps (σκώψ), denoting a small horned owl, which was adopted into Latin as scops to describe these diminutive species. The genus name Otus, introduced by Thomas Pennant in 1769 for the Indian scops owl (O. bakkamoena), derives from the Greek ōtos (ὦτος), referring to an eared or horned owl and alluding to the prominent ear tufts characteristic of the group.^[6] The Eurasian scops owl (Otus scops), the type species of the genus, was first described by Carl Linnaeus in 1758 under the name Strix scops in his Systema Naturae. Early taxonomic efforts often conflated Old World scops owls with New World screech owls due to superficial similarities in size and plumage, placing both in Otus or related genera; however, 20th-century studies using vocalizations and morphology established the New World forms as a distinct genus, Megascops, recognizing Otus as an Old World endemic within the family Strigidae.^[7]^[8] In the 19th century, revisions by ornithologists such as Richard Bowdler Sharpe advanced the classification through detailed descriptions of numerous Otus taxa in works like the Catalogue of the Birds in the British Museum, splitting forms based on geographic variation and subtle morphological differences. The 20th and early 21st centuries brought further refinements, including mergers of subspecies into full species via bioacoustic analysis and the frequent recognition of cryptic species, exemplified by the description of the Príncipe scops owl (Otus bikegila) in 2022 from São Tomé and Príncipe. By 2025, Otus stands as the largest genus in the owl family Strigidae, encompassing approximately 59 species according to HBW/BirdLife, confined to the Old World.^[5]^[1]

Current species recognition

The genus Otus encompasses approximately 59 recognized species of small, nocturnal owls within the family Strigidae, all native to the Old World and characterized by their cryptic plumage and insectivorous diets.^[9] These species exhibit considerable diversity, with many restricted to specific islands or regions, reflecting the genus's high endemism. Notable examples include the Eurasian scops owl (Otus scops), a migratory species breeding across Europe and western Asia before wintering in sub-Saharan Africa; the African scops owl (Otus senegalensis), which has a broad distribution throughout sub-Saharan Africa and is adapted to a variety of woodland habitats; the Indian scops owl (Otus bakkamoena), resident in forests from the Indian subcontinent through Southeast Asia; and the giant scops owl (Otus gurneyi), the largest member of the genus at approximately 30 cm in length, endemic to the Philippines where it inhabits lowland and montane forests.^[10]^[11]^[12] Recent taxonomic advancements have expanded the recognized diversity within Otus. In 2022, the Príncipe scops owl (Otus bikegila) was formally described as a new species from Príncipe Island in the Gulf of Guinea, distinguished by its unique vocalizations and genetic divergence from continental relatives.^[5] Similarly, in 2021, the Bornean subspecies of the Rajah scops owl (Otus brookii brookii) was rediscovered in the montane forests of Mount Kinabalu, Malaysia, after more than 125 years without confirmed sightings, prompting evaluations for its potential recognition as a distinct full species based on preliminary vocal and morphological evidence.^[13] Species delineation in Otus relies primarily on differences in vocalizations, plumage characteristics, and genetic markers, as these traits often reveal reproductive isolation in this morphologically conservative genus.^[10]^[14] This integrative approach has driven numerous taxonomic splits, especially among island populations where geographic isolation promotes divergence; Indonesia alone hosts over 10 Otus species, many endemic to individual islands in the Greater and Lesser Sunda chains.^[5]^[15]

Phylogenetic relationships and formerly placed taxa

The genus Otus within the family Strigidae is polyphyletic, comprising multiple independent lineages that are interspersed with other owl genera, reflecting convergent evolution in morphology and ecology.^[16] Molecular studies have positioned Otus closest to the New World genus Megascops (screech owls), with which it shares a recent common ancestor, supported by analyses of mitochondrial and nuclear DNA sequences.^[17] Major clades within Otus include continental African lineages, widespread Asian groups, and insular radiations across the Indian Ocean and Southeast Asian islands, often resulting from repeated overwater dispersal events.^[18] Key molecular analyses from the 2010s, such as those employing multi-locus datasets (including cytochrome b, ND2, and nuclear introns), have elucidated these relationships while highlighting the role of vocal mimicry in diversification.^[18] For instance, Fuchs et al. (2008) demonstrated multiple colonization waves in Indian Ocean Otus species using combined mitochondrial and nuclear markers, revealing cryptic divergences driven by isolation. Subsequent work in the 2020s, including Bayesian phylogenetic reconstructions from mtDNA and nuclear genes, has refined these clades and confirmed the recognition of approximately 59 species through integrative taxonomy combining genetics, vocalizations, and biometrics.^[5] Several taxa formerly classified within Otus have been transferred to other genera based on phylogenetic, vocal, and morphological evidence. The New World screech owls, previously included in Otus, were reassigned to Megascops due to distinct multi-noted songs and genetic divergence from Old World lineages.^[17] Similarly, African white-faced owls were moved to Ptilopsis owing to unique facial disk morphology and nuclear DNA differences.^[18] The Flammulated Owl was separated into the monotypic genus Psiloscops based on vocal patterns, mitochondrial sequences, and subtle plumage traits.^[19] The giant scops owl (Otus gurneyi) was formerly placed in the monotypic genus Mimizuku but has been reassigned to Otus based on molecular evidence showing it within the Otus clade.^[20] More recently, the Cyprus Scops Owl (Otus cyprius) was elevated from a subspecies of the Eurasian Scops Owl (O. scops) to full species status in 2015, justified by divergent two-note calls and cytochrome b sequences indicating deep genetic isolation.^[21] Cryptic speciation is prevalent in Otus, with over 20 pairs of morphologically indistinguishable taxa delimited primarily by vocal repertoires and genetic markers rather than plumage or size. For example, the Sokoke Scops Owl (Otus ireneae) represents a split from the broader African scops owl complex, distinguished by its unique short, whistled calls and mitochondrial DNA haplotypes, highlighting how acoustic and molecular data uncover hidden diversity in this genus.^[22]

Evolutionary history

Fossil record

The fossil record of the genus Otus is limited, primarily due to the small body size of scops owls, which reduces the likelihood of bone preservation in the paleontological record. Most known specimens come from Quaternary deposits, with earlier occurrences providing evidence of the genus's antiquity within the Strigidae family. The earliest definitive fossil attributed to Otus is a distal end of a right humerus recovered from late Miocene sediments in western Kenya, dated to approximately 16.5–18.5 million years ago. This specimen suggests that Otus had already emerged during the early radiation of strigids in Africa, aligning with broader diversification patterns in the Old World owl clade during the Miocene. Key fossil species highlight the genus's historical presence in insular environments, particularly in the Atlantic and Indian Oceans. In the North Atlantic, Otus mauli, an extinct scops owl from the Madeira Archipelago, is known from multiple bones including a humerus, ulna, and tarsometatarsus recovered from Quaternary cave deposits on Madeira Island; this species, slightly larger than modern continental Otus, likely persisted until the late Pleistocene or early Holocene. Similarly, Otus frutuosoi from São Miguel Island in the Azores represents another extinct insular form, described from fossil elements such as a coracoid and humerus found in a volcanic tube; dated to the late Holocene (approximately 500 years ago), its extinction is linked to human colonization. In the Indian Ocean, Pleistocene and Holocene remains from the Mascarene Islands include bones of giant scops owls (assigned to Mascarenotus, a lineage derived from Otus ancestors), such as M. sauzieri from Rodrigues, which were roughly twice the size of typical Otus species and adapted to predation on larger insular prey. In Asia, Late Pleistocene to Holocene fossils of Otus sp. have been identified from cave deposits on Palawan Island in the Philippines, including skeletal fragments that indicate continuity with modern Southeast Asian forms and suggest the genus's resilience through glacial cycles.^[23]^[24]^[25] Fossils provide insights into Otus evolutionary patterns, particularly adaptations in isolated populations. Island forms often exhibit size extremes, with gigantism evident in the Mascarene species, reflecting ecological shifts such as specialization on flightless prey unavailable on continents; conversely, some Atlantic insular fossils show modest size increases but no clear dwarfism trend specific to Otus. The genus appears to have avoided major extinction events, with no evidence of significant losses during Pleistocene glaciations; instead, Asian and oceanic remains demonstrate persistence and dispersal into new habitats post-glaciation.^[26] Significant gaps persist in the Otus fossil record, owing to the fragility of small owl bones, which are prone to post-depositional destruction. Many inferences about the genus rely on fragmentary or associated strigid remains rather than complete Otus skeletons, limiting precise reconstructions of its pre-Quaternary distribution and morphology. Ongoing discoveries from insular sites may fill these voids, but the overall scarcity underscores the challenges in tracing the full evolutionary history of this diverse genus.^[27]

Molecular phylogenetics and divergence

Molecular phylogenetic analyses indicate that Otus belongs to the typical owl family Strigidae, which diverged from barn owls (Tytonidae) around 40 million years ago during the Eocene-Oligocene transition; the crown radiation within Strigidae occurred in the Oligocene-Miocene, with intra-generic divergences in Otus beginning approximately 12 million years ago during the Miocene, driven primarily by island colonization events across the Old World, as evidenced by mitochondrial and nuclear DNA sequences showing multiple synchronous dispersals to archipelagos like the Indian Ocean and Wallacea.^[28] These radiations are marked by low genetic divergence among island endemics, indicating rapid speciation following allopatric isolation.^[29] Recent studies, including a 2022 analysis incorporating multi-locus DNA datasets from 51 individuals across 39 Otus taxa, have refined the genus phylogeny and described new species, such as Otus bikegila from Príncipe Island; these works confirm rapid speciation in regions like Wallacea. Parallel diversification of highland and lowland clades in the Philippines, part of Wallacea, occurred approximately 2 million years ago, with low genetic divergence reflecting ecological and vocal barriers that limit hybridization.^[5]^[29] Recent phylogenomic research has also revealed extensive paraphyly within Strigidae genera, including Otus, highlighting convergent evolution in morphology and vocalizations.^[16] The evolution of adaptive traits in Otus species, such as vocal divergence and plumage camouflage, has a strong genetic foundation, with owl songs exhibiting innate, non-learned structures tied to mitochondrial and nuclear loci that correlate with phylogenetic splits.^[29] Estimates of effective population sizes in island endemics, derived from sequence diversity, indicate historical bottlenecks, particularly in single-island species like those in the Gulf of Guinea and Comoros, where reduced genetic variation reflects founder effects from Miocene colonizations.^[18] Ongoing phylogenomic research aims to resolve remaining cryptic species complexes within Otus, potentially uncovering additional adaptive radiations and refining divergence timelines through improved molecular clocks.^[5]

Physical characteristics

Morphology and size variation

Scops owls of the genus Otus are small to medium-sized members of the Strigidae family, with body lengths typically ranging from 17 to 23 cm and weights from 50 to 135 g across most species.^[30]^[31] Size variation is notable within the genus; for instance, the Sokoke scops owl (Otus ireneae) represents one of the smallest at 16–17 cm long and 50–60 g, while the giant scops owl (Otus gurneyi) is among the largest at 30–35 cm in length.^[32]^[33] The Flores scops owl (Otus alfredoi) exemplifies a compact species at 19–21 cm.^[34] These owls exhibit key anatomical adaptations suited to their nocturnal lifestyle. Their large, forward-facing eyes, tubular in shape with a high concentration of rod cells, provide enhanced vision in low light, though without a reflective tapetum lucidum. Wings are short and rounded, promoting agile flight and maneuverability through forested habitats.^[35] Small ear tufts enhance camouflage by resembling tree branches, while the feet feature a reversible outer toe that enables a flexible, zygodactyl-like grip for perching. Skeletal features include a lightweight cranium with large orbits to accommodate the eyes and asymmetric ear openings that facilitate precise sound localization by creating interaural time and intensity differences.^[36] The legs are relatively short and strong, with tarsal structure optimized for grasping branches during rest and hunting. Sexual dimorphism is reversed compared to many birds, with females generally 10–20% larger than males in body size and mass, aiding in egg production and territorial roles.^[5]^[37]

Plumage patterns and color morphs

Scops owls (genus Otus) exhibit cryptic plumage characterized by mottled gray-brown or rufous tones that closely resemble tree bark, providing effective camouflage in their woodland habitats. The upperparts feature fine vermiculations and dark streaks, while the facial disk displays concentric patterns of buffy and darker rings, often bordered by short, inconspicuous ear tufts that can be raised during displays. Underparts are typically paler with longitudinal dark streaks, and the tail and flight feathers show barring in dark and pale tones.^[30]^[31]^[5] Color polymorphism is prevalent in many species of scops owls, with individuals occurring in gray (or gray-brown) and rufous (reddish-brown) morphs, sometimes with intermediates; this variation is genetically controlled and present in both sexes. For instance, the Eurasian scops owl (Otus scops) displays gray-brown plumage with blackish streaks or warmer rufous tones, while the collared scops owl (Otus lettia) shows grayish-brown to light rufous upperparts with buffy vermiculations and whitish underparts finely streaked darker on the breast. Juveniles hatch with soft, downy white plumage that transitions to the adult-like patterned feathers by fledging, typically within 40-80 days.^[5]^[38]^[39]^[40] Plumage patterns vary regionally, with African species like the African scops owl (Otus senegalensis) featuring gray or brownish upperparts with tawny edging and heavy streaking on the head and breast, often forming pale shoulder bands from whitish scapulars. In Asian forms, such as the Oriental scops owl (Otus sunia), weakly marked grayish-brown or rufous plumage predominates, with barred tails and minimal sexual dimorphism beyond slight size differences. These patterns enhance crypsis, reducing detection by predators through bark-like mimicry, though seasonal feather wear can alter the intensity of coloration over time.^[41]^[40]^[42]^[30]

Distribution and habitat

Global range across Old World regions

Scops owls of the genus Otus are confined to the Old World, with approximately 58 species distributed across Europe, Africa, Asia, and Australasian island chains, but absent from the Americas and Antarctica.^[2]^[43] In Africa, approximately 20 species occupy sub-Saharan regions, from widespread continental forms like the African scops owl (Otus senegalensis) to island endemics such as those in the Indian Ocean archipelago, including six or seven species restricted to Madagascar, the Comoros, and the Seychelles, and the recently described Príncipe scops owl (Otus bikegila) in the Gulf of Guinea.^[44]^[18]^[5] In Asia, more than 20 species range from the Himalayas through Southeast Asia to Indonesia, with particularly high endemism in the Wallacea region, where over 40 islands support unique taxa like the Wallace's scops owl (Otus silvicola) on Flores and Sumbawa, the Moluccan scops owl (Otus magicus) in the northern Moluccas, and the Rinjani scops owl (Otus jolandae) on Lombok.^[45]^[46]^[15] Europe hosts primarily the Eurasian scops owl (Otus scops), with breeding populations in southern and central areas extending eastward into western Asia, though no breeding occurs in Australia despite proximity to Australasian endemics.^[4] Migration patterns vary across the genus, with 5–10 species exhibiting partial or full migratory behavior; for instance, the Eurasian scops owl breeds in Europe and winters in sub-Saharan Africa south of the Sahara, while the pallid scops owl (Otus brucei) migrates from central Asia to similar African wintering grounds.^[4]^[47] In contrast, most island-dwelling species remain sedentary within their restricted ranges.^[48] Recent observations indicate range expansions in some urban settings, such as increased breeding density of the Eurasian scops owl in northern Italian cities due to suitable green spaces.^[49] Conversely, contractions linked to deforestation have reduced distributions for certain taxa, such as those affecting the Torotoroka scops owl (Otus madagascariensis) in western Madagascar.^[50]

Habitat types and adaptations

Scops owls of the genus Otus primarily occupy diverse woodland environments, including deciduous and evergreen forests, as well as open savannas and acacia-dominated areas with sparse ground cover. Many species favor habitats rich in mature trees for nesting and roosting, such as tree hollows or cavities in riparian zones and mixed bushveld. Coastal and wetland fringes, including mangroves, support several African taxa like the African scops owl (Otus senegalensis), which thrive in forest edges and wooded savannas. While predominantly arboreal, certain species, including the Eurasian scops owl (Otus scops), have shown flexibility by utilizing semi-urban settings like parks, gardens, and agricultural plantations with scattered trees, allowing persistence amid human-modified landscapes.^[30]^[51]^[52]^[53]^[42] Physiological and behavioral adaptations enable Scops owls to exploit varied environmental conditions. African species exhibit tolerance to arid and semi-arid zones, such as dry broadleaved woodlands and mopane savannas, where their strictly nocturnal lifestyle minimizes evaporative water loss during peak daytime heat, supplemented by metabolic water derived from prey. Island endemics, like the Pemba scops owl (Otus pembaensis), display flight adaptations including broad, rounded wings that facilitate agile, short-distance maneuvers through dense forest understories, reducing energy expenditure in cluttered habitats. Their cryptic plumage, with grayish-brown mottling resembling tree bark, enhances survival in these settings.^[51]^[54]^[55] Microhabitat selection emphasizes concealment and structural support. Daytime roosts are typically in dense foliage or against tree trunks, where elongated body postures and bark-like patterns provide effective camouflage against predators. Altitudinal ranges vary widely, from sea level in lowland mangroves to elevations exceeding 3,000 meters in Himalayan foothills for species like the Oriental scops owl (Otus sunia). Overall, Scops owls prefer tropical and subtropical climates, though habitat fragmentation poses risks to connectivity in woodland-dependent taxa, with declines noted in fragmented agricultural mosaics.^[40]^[30]^[56]

Behavior and ecology

Daily activity and vocalizations

Scops owls exhibit a strictly nocturnal lifestyle, emerging from roosts at dusk to engage in foraging, territorial defense, and other activities, with peak activity periods occurring shortly after sunset and before dawn.^[30] During the day, they remain concealed in tree cavities, dense foliage, or against bark, relying on camouflage to avoid detection by predators.^[30] While primarily nocturnal, some individuals display limited diurnal activity, particularly grey morphs, which may forage or provision nests before sunset or in early morning, comprising up to 44% of total activity in certain populations.^[57] Their vocalizations are diverse and play key roles in communication, with the primary advertisement call being a monotonous, monosyllabic hoot often rendered as "tjü" or "kiew," repeated at rates of 22-26 times per minute to claim territory and attract mates.^[58] In the Eurasian scops owl (Otus scops), this hoot has an average fundamental frequency of 1.32 kHz (ranging from 1.17-1.50 kHz), lasts approximately 278 ms, and is delivered at intervals of about 2.72 seconds.^[58] Females produce similar hoots at higher pitches, and paired individuals often engage in duets to reinforce territorial boundaries.^[30] Alarm calls consist of loud, piercing notes emitted in response to threats, alerting mates or offspring.^[30] Silent flight, achieved through fringed trailing edges on wing feathers that disrupt airflow and minimize noise, allows these owls to approach prey undetected during nocturnal hunts.^[59] They depend primarily on acute hearing for locating prey in low-light conditions, with vision playing a secondary role compared to auditory cues.^[30]

Diet, foraging, and reproduction

Scops owls are primarily insectivorous, with insects comprising 80–98% of their diet depending on the species and location. Common prey includes moths (Lepidoptera), beetles (Coleoptera), and orthopterans such as bush-crickets (Tettigoniidae), which can dominate up to 87% in northern populations.^[60]^[61] Small vertebrates, including lizards, small birds, and rodents, make up the remaining 2–20%, more frequently consumed by larger species or during seasonal shifts.^[61] In temperate regions like central Italy, diets post-breeding (late summer to winter) show increased vertebrate intake (up to 20%) alongside beetles, contrasting with the orthopteran-heavy summer diet.^[61] Foraging occurs nocturnally, leveraging their cryptic plumage and ear tufts for camouflage while perched in trees or shrubs. These owls employ hawking techniques, launching short sallies (typically 2–6 m) from perches to capture flying insects like beetles or butterflies in mid-air, or gleaning prey directly from foliage and twigs.^[60] Ground feeding is rare and opportunistic, with most prey seized on vegetation or during brief flights; larger items are torn apart before feeding to young nestlings.^[60] Feeding rates vary from 1.4 to 11 deliveries per hour at nests, supporting high-energy demands during the breeding season.^[60] Reproduction is seasonal, with breeding from spring (April–August) in temperate zones to year-round in tropical populations. Nests are typically unlined tree cavities, occasionally old nests of other birds or artificial boxes, where females lay clutches of 2–5 eggs.^[30] Incubation, performed solely by the female, lasts 24–30 days and begins after the second egg, while males provision her with food.^[30] Chicks hatch asynchronously, leading to intense sibling competition and brood reduction, with significant nestling mortality (often around 50% in observed broods) due to starvation of smaller siblings.^[30] Both parents feed the young, which fledge after 25–30 days but remain dependent for 4–5 weeks; wild lifespan is typically 4–6 years, with a maximum recorded of 6.9 years, limited by predation and environmental factors.^[30]^[62]

Conservation status

Overall threats and population trends

Scops owls (genus Otus) face several anthropogenic pressures that impact their populations across their Old World range. Habitat loss, primarily driven by deforestation and agricultural expansion, is a predominant threat, affecting forest-dependent species through fragmentation and degradation of woodland and savanna habitats. Pesticide use in agricultural areas further exacerbates declines by reducing the availability of insect prey, which forms the core of their diet. Climate change poses an emerging risk by potentially disrupting migration patterns and altering prey phenology in seasonal environments. Population trends vary among the approximately 54 species in the genus, with widespread taxa such as the Eurasian scops owl (Otus scops) exhibiting stable or slowly decreasing numbers, while about 25% of species show declines linked to range contractions. According to IUCN assessments as of 2024, the majority of species are classified as Least Concern, but approximately 10 are Near Threatened, several are Vulnerable, Endangered, or Critically Endangered (including 3 Critically Endangered species: Siau, Annobón, and Príncipe scops owls), and several remain Data Deficient due to limited data. No species is currently listed as Extinct, though ongoing habitat pressures suggest potential future escalations in threat levels for endemics.^[3]^[63] Monitoring Scops owl populations presents significant challenges owing to their nocturnal habits, cryptic plumage, and elusive behavior, often necessitating indirect methods such as acoustic surveys based on territorial calls rather than direct sightings.

Specific species concerns and protection efforts

The Siau Island scops owl (Otus siaoensis) is classified as Critically Endangered by the IUCN, with a remaining population estimated at 1–49 mature individuals; the species has not been reliably observed since 1866, though unconfirmed video evidence from 2017 suggests possible persistence, primarily threatened by extensive logging and removal of native forest habitat on Siau Island, Indonesia, where only about 50 ha of suitable forest remains.^[64]^[65] Similarly, the Annobón scops owl (Otus feae) is also Critically Endangered, with a population of 50-249 individuals on Annobón Island, Equatorial Guinea, facing ongoing decline due to habitat alteration, destruction, and potential impacts from invasive species.^[66]^[67] Conservation efforts for Philippine scops owls, such as the Visayan scops owl (Otus nigrorum), include targeted habitat restoration and protection programs to counter deforestation, which affects 14 of the country's 16 owl species reliant on forest ecosystems.^[68]^[69] Several scops owl species, including the Siau Island, Flores (Otus alfredi), and Eurasian (Otus scops) scops owls, are listed under CITES Appendix II to regulate international trade and prevent further population declines.^[70] In Indonesia, national parks and protected areas safeguard numerous endemic scops owls; for instance, Ruteng Nature Recreation Park supports a key subpopulation of the Endangered Flores scops owl, while other sites like Gunung Gede-Pangrango National Park protect species such as the Rinjani scops owl (Otus rinjaniensis).^[70] Research and monitoring initiatives in Africa emphasize acoustic surveys to track elusive scops owls, as demonstrated by a 2023 project on Príncipe Island using passive acoustic monitoring to assess the distribution and threats to the newly described Príncipe scops owl (Otus bikegila).^[71]^[72] BirdLife International supports such efforts across the continent to inform conservation strategies for scops owls in biodiversity hotspots. In the Gulf of Guinea, community education programs promote awareness of newly discovered species like the Príncipe scops owl, encouraging local involvement in habitat protection and threat mitigation to support its survival in old-growth forests.^[5]^[48] A notable success story is the Eurasian scops owl, whose European population has remained stable or shown localized increases, such as in agricultural landscapes with reduced intensive farming practices, contributing to overall resilience despite broader habitat pressures.^[10]^[73]

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Formerly classified in the genus Otus, as were all species of New World screech-owls. Several authors suggested a particularly close relationship between ...
[21]
Phylogeny and Taxonomic Review of Philippine Lowland Scops ...
We constructed a phylogenetic hypothesis of the pattern of colonization of Philippine scops owls (Otus and Mimizuku). Two mitochondrial genes, ND2 and ...
[22]
Reprising the taxonomy of Cyprus Scops Owl Otus ( scops ) cyprius ...
Nov 11, 2015 · The endemic Cyprus Scops Owl Otus (scops) cyprius has been treated as a subspecies of the widespread Eurasian Scops Owl O. scops since at least ...Missing: reclassification | Show results with:reclassification
[23]
Sokoke Scops-owl Otus Ireneae Species Factsheet
The species is assessed as Endangered as it is now restricted to a very small occupied range, estimated to be between 372 km2 and 600 km2, and is threatened ...Missing: complex cryptic
[24]
https://www.mapress.com/zootaxa/2013/f/z03647p357f.pdf
[25]
https://www.sciencedirect.com/science/article/abs/pii/S0031018201002565
[26]
Late Quaternary terrestrial vertebrates from Palawan Island ...
Three species identified in the fossil assemblage are previously unrecorded from Palawan (scops-owl, Otus sp., swiftlet, Collocalia salangana, and shrew ...
[27]
Otus frutuosoi: Extinct Species of Scops Owl from Azores | Sci.News
Jun 28, 2013 · Paleontologists have identified a new species of scops owl that lived on São Miguel Island, the Portuguese archipelago of the Azores, until about 500 years ago.
[28]
Owls in the Fossil Record - The Owl Pages
Jul 14, 2003 · Fossil owls are known from the Eocene, and some living genera have been identified in Miocene, Oligocene (Brodkorb 1971; Walker, in Burton 1973) ...
[29]
[PDF] Allozyme Divergence and Phylogenetic Relationships Within the ...
Jan 5, 1991 · Our estimated diver- gence times are probably low when the separa- tion between the Strigidae and the Tytonidae is considered (34.35 Myr), but ...
[30]
Phylogeny and Taxonomic Review of Philippine Lowland Scops ...
Aug 7, 2025 · We constructed a phylogenetic hypothesis of the pattern of colonization of Philippine scops owls (Otus and Mimizuku).
[31]
A new species of scops-owl (Aves, Strigiformes, Strigidae, Otus ...
(2022) The recently discovered Principe Scops-owl is highly threatened: distribution, habitat associations, and population estimates. Bird Conservation ...
[32]
The Complete Genome Sequences of 22 Species of Owls ... - NIH
We present the complete genome sequences of 22 species of owls. Illumina sequencing was performed on DNA extracted from wild-caught specimens.Missing: Wallacea 2020s
[33]
Eurasian Scops Owl (Otus scops) - Information, Pictures, Sounds
Oct 4, 2020 · Habitat: Semi-open or open country with scattered trees or small woods, cultivated areas with groups of trees, rocky landscapes, parks, avenues ...
[34]
Sokoke scops owl - Facts, Diet, Habitat & Pictures on Animalia.bio
The Sokoke scops owl (Otus ireneae ) is a highly localized species of scops owl found in lowland forests of Kenya and Tanzania. The greatest population of this ...Missing: cryptic | Show results with:cryptic<|control11|><|separator|>
[35]
Giant Scops Owl (Otus gurneyi) - Information, Pictures, Sounds
Oct 2, 2020 · Size: Length 30-35cm. Wing length 217-274mm. Tail length 114-149mm. No weight data available. Females are larger than males. Habits: The ...
[36]
https://www.bto.org/get-involved/volunteer/projects/completed/owl/learn-about-owls/owl-hearing
[37]
Flores Scops Owl (Otus alfredi) - Planet of Birds
Sep 7, 2011 · Members of the genus Otus are the Scops and Screech owls. They are relatively small owls, with short, rounded wings.
[38]
Owl hearing - BTO
In a few owl species, the asymmetry in ear position can also be seen in the structure of the skull, as this illustration of a Tengmalm's Owl skull demonstrates.Missing: openings | Show results with:openings<|control11|><|separator|>
[39]
Sexual size dimorphism in the critically endangered Seychelles ...
Females were generally heavier and larger than males. There was some variation in plumage colouration, which was unrelated to sex, but no evidence of distinct ...
[40]
Determinants of color polymorphism in the Eurasian scops owl Otus ...
Oct 3, 2018 · Scops owl proved to be polymorphic as the three morphs were found in the two sexes and across ages. Frequency distribution of color within the ...
[41]
Collared Scops-Owl - Otus lettia - Birds of the World
Oct 22, 2024 · Collared Scops-Owl occurs in grayish brown and rufous morphs. Its facial disc is grayish to light rufous, with buff eyebrows and inner webs of ear tufts.
[42]
African Scops Owl (Otus senegalensis) - Information, Pictures
Oct 8, 2020 · Colour and patterns of this species vary individually. The facial ... Adult plumage is achieved at the age of 40-80 days, and sexual ...
[43]
African Scops Owl - Oiseaux-Birds
African Scops-Owl adult has grey plumage, overall shades of medium-grey with tawny streaking and fine grey black vermiculations, heaviest on head and breast.
[44]
Oriental Scops Owl (Otus sunia) - Information, Pictures, Sounds
Oct 4, 2020 · The Oriental Scops Owls is a very small owl with ear-tufts. A grey-brown, reddish-grey and rufous morph are known to exist.Missing: plumage variations
[45]
Otus | Animal Database | Fandom
Otus, or Scops Owls, are a genus of typical owls, the largest genus of owls, with about 45 species. They are small, agile, and restricted to the Old World.
[46]
African Scops-Owl - Otus senegalensis - Birds of the World
Jun 17, 2021 · African Scops-Owl is the most widespread species of Otus in Africa. It occupies wooded savannahs, semi-open woodland, and gardens across most of the continent ...
[47]
Wallace's Scops-Owl - Otus silvicola - Birds of the World
This account summarizes the life history of the Wallace's Scops-Owl, including information relating to its identification, systematics, distribution, habitat, ...Missing: whole- genome sequencing 2020s<|control11|><|separator|>
[48]
Distribution - Moluccan Scops-Owl - Otus magicus - Birds of the World
Oct 25, 2022 · As its name suggests the Moluccan Scops-Owl is distributed widely on the islands of the Moluccas, in eastern Indonesia. In the north ...<|separator|>
[49]
Pallid Scops-Owl - Otus brucei - Birds of the World
Migratory in NE of range, arriving late Mar or Apr and leaving Sept/Oct; recorded in China Apr–Oct. Scarce migrant and winter visitor in S Israel photo ; ...Missing: patterns | Show results with:patterns
[50]
The recently discovered Principe Scops-owl is highly threatened
Oct 31, 2022 · The recently discovered Principe Scops-owl is highly threatened: distribution, habitat associations, and population estimates - Volume 33.
[51]
Habitat selection and breeding density of the Eurasian Scops Owl ...
May 21, 2024 · The Eurasian Scops Owl (Otus scops) is a small nocturnal raptor widely diffused in Europe, facing population increase and urban environment ...Missing: expansion | Show results with:expansion
[52]
Madagascar Scops Owl (Otus rutilus) - Information, Pictures, Sounds
Oct 19, 2020 · Size: Length 19-22cm. Wing length 151-161mm. Tail ... Distribution: North and east Madagascar. Range of Madagascar Scops Owl (Otus rutilus)
[53]
Habitat - African Scops-Owl - Otus senegalensis - Birds of the World
Jun 17, 2021 · General Habitat. Inhabits wooded savannahs, dry open broadleaved woodland, especially mopane (Colophospermum mopane) in southern Africa, but ...Missing: preferred | Show results with:preferred
[54]
African Scops Owl {Otus senegalensis} - SA-Venues.com
The African scops owl's primary habitat is woodland and a wide range of mixed bushveld. It can also be found in gardens and mangroves. In savannah woodlands, ...
[55]
Pemba Scops-owl | The Peregrine Fund
This small owl prefers woodland habitats and open areas that are dotted with trees with dense foliage. It can also be found in agricultural plantations, often ...Missing: types sources
[56]
(PDF) Drinking and bathing behaviour of raptors in an arid, warm ...
Jan 6, 2025 · Raptors are thought to obtain much of their water from their food as pre-formed and metabolic water, and therefore not by drinking.
[57]
(PDF) Habitat Use of Eurasian Scops Owls Otus scops in an ...
Aug 6, 2025 · In a mosaic of different agricultural habitats, the females showed a clear preference for extensively managed areas, such as hedges, meadows, ...
[58]
Brown and grey morphs differ in their nocturnality in the polymorphic ...
May 3, 2023 · We analyze activity patterns and hunting efficiency of color morphs in relation to day/night light in the nocturnal polymorphic scops owl (Otus ...
[59]
(PDF) Individual recognition of scops owls (Otus scops) by ...
Numerous studies have confirmed that males of several species can be individually identified by spectrographic analysis of their vocalizations.
[60]
Evolution and Ecology of Silent Flight in Owls and Other Flying ...
We hypothesize that bird flight is noisy because wing feathers are intrinsically predisposed to rub and make frictional noise.Missing: mimicry | Show results with:mimicry
[61]
On foraging ecology of the Scops owl Otus scops on the northern ...
In its diet were determined in total 884 food subjects belonging to 29 taxa. Markedly dominant were insects (97.9%), rare were spiders (0.5%), birds (0.8%) and ...
[62]
Full article: Feeding ecology of the scops owl, Otus scops (Aves
In this study, we investigated the diet of scops owls on the island of Pianosa after the breeding period through the analysis of pellets.Missing: reproduction | Show results with:reproduction
[63]
AnAge entry for Otus scops - Human Ageing Genomic Resources
AnAge entry for Otus scops. Classification (HAGRID: 01692). Taxonomy: Kingdom: Animalia Phylum: Chordata Class: Aves (Taxon entry) Order: Strigiformes
[64]
Siau Scops-owl Otus Siaoensis Species Factsheet | BirdLife DataZone
Otus siaoensis is only known from the holotype collected in 1866 on the island of Siau, north of Sulawesi, Indonesia. Given the small size of this island and ...
[65]
25 of the world's rarest owls, some are on the brink of extinction
Mar 12, 2025 · 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.Itombwe Owl (tyto... · Karthala Scops Owl (otus... · Red Owl (tyto Soumagnei)
[66]
Conservation and Management - African Scops-Owl
Jun 17, 2021 · feae. CRITICALLY ENDANGERED. CITES II. A restricted-range taxon: endemic to Annobón Island (Pagalu), Equatorial Guinea, and present in the ...Missing: illyricus invasive
[67]
https://animalia.bio/annobn-scops-owl
[68]
Visayan Scops-owl Otus Nigrorum Species Factsheet
This species has a moderately small range, confined to the islands of Panay and Negros in the West Visayas, the Philippines.
[69]
The Philippine Owl Conservation Programme: Why is it Needed?
Dec 1, 2009 · The Philippines has more threatened owls than anywhere else due to rapid deforestation, with 14 of 16 species dependent on forest habitat.
[70]
Siau scops owl - Wikipedia
The Siau scops owl (Otus siaoensis) is a critically endangered owl species. ... Conservation status. Critically Endangered (IUCN 3.1). CITES Appendix II ...
[71]
Flores Scops-owl Otus Alfredi Species Factsheet | BirdLife DataZone
The conservation status of forest birds on Flores and Sumbawa, Indonesia. ... The IUCN Red List of Threatened Species. Version 2025-2. Available at: www ...
[72]
Eurasian scops owl - Wikipedia
Its breeding range extends from southern Europe eastwards to southern Siberia and the western Himalayas. It is migratory, wintering in Africa south of the ...
[73]
Rinjani scops owl - Wikipedia
The Rinjani scops owl (Otus jolandae) is a species of scops owl found only on Lombok in the Lesser Sunda Islands of Indonesia and its neighbouring Gili Islands.
[74]
[PDF] Acoustic monitoring of the Scops owl and other threatened species ...
(2023). Acoustic monitoring of the Scops owl and other threatened species on Principe Island. Project Report for African Bird Club. Unpublished report, Santo.
[75]
(PDF) Passive Acoustic Monitoring in difficult terrains: the case of the ...
The automatic workflow developed here is an efficient method to monitor the Principe Scops-Owl and can be easily adapted for other elusive vocal species.
[76]
The demography of an increasing insular Eurasian Scops Owl (Otus ...
Jun 28, 2021 · The observed mean annual population growth rate was 1.055 (from 68 to 523 territorial males between 1981 and 2019).Missing: expansion | Show results with:expansion<|control11|><|separator|>