| Ashy-faced owl | |
|---|---|
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| Ashy-faced owl | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Aves |
| Order: | Strigiformes |
| Family: | Tytonidae |
| Genus: | Tyto |
| Species: | T. glaucops |
| Binomial name | |
| Tyto glaucops (Kaup, 1852) | |
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The ashy-faced owl (Tyto glaucops) is a species of bird in the barn-owl family Tytonidae. It is found on the Caribbean island of Hispaniola, on Dominica, and on several other islands of the Lesser Antilles. [3]
The ashy-faced owl was formally described in 1852 by the German naturalist Johann Jakob Kaup and given the binomial name Strix glaucops. [4] The specific epithet is from Ancient Greek glaukos meaning "blue-grey" or "glaucous". [5] Kaup specified the type locality as Jamaica. This was an error and has been corrected to Hispaniola. [6] The ashy-faced owl is now placed in the genus Tyto that was introduced in 1828 by Gustaf Johan Billberg. [3]
The taxonomy of the ashy-faced owl is unsettled. At one time it was considered conspecific with the barn owl sensu lato (Tyto alba). [7] After the separation the International Ornithological Committee (IOC) long treated it as monotypic but in July 2023 moved two subspecies from the American barn owl (Tyto furcata) into it. [3] The North American Classification Committee of the American Ornithological Society (AOS/NACC) and the Clements taxonomy retain it as monotypic. [8] [9] In 2022 the AOS/NACC rejected a proposal to make that move. [10] BirdLife International's Handbook of the Birds of the World (HBW) has long treated the ashy-faced owl as having the three subspecies recognized by the IOC, and adds a fourth that the other three taxonomies do not recognize as part of any species. [11]
This article follows the IOC treatment with these three subspecies: [3]
The ashy-faced owl is 27 to 33 cm (11 to 13 in) long. Males weigh about 260 to 350 g (9.2 to 12 oz) and females about 460 to 540 g (16 to 19 oz). Adults of the nominate subspecies T. g. glaucops on Hispaniola have a silvery gray facial disc. Their upperparts are dark grayish brown with paler and dusky vermiculation. Their wings have buff or tawny mottling and their underparts are tawny with some darker barring. They have light, dark, and intermediate morphs. Their iris is blackish brown, their bill yellowish horn, and their legs and feet grayish brown. The ashy-faced owl is generally described as having a mix of red and brown coloration, long thin legs, a heart-shaped face, and silver-grey feathers. [12] Juveniles are similar to adults with a darker gray face. [7]
Subspecies T. g. insularis has a vinaceous-brown facial disc. Its upperparts are blackish gray with sparse white spots and streaks. Its wings are darker than its upperparts and have tawny mottling and feather edges. Its underparts are cinnamon-buff with dusky mottling and a few white spots. Subspecies T. g. nigrescens is very similar to insularis but has almost no white on its upperparts and less mottling on its underparts. [13]
The nominate subspecies of the ashy-faced owl is found on the island of Hispaniola, which is shared by the Dominican Republic and Haiti, and on Île de la Tortue of the northwestern Haitian coast. T. g. insularis is found on the islands of St. Vincent, Bequia, Union, Carriacou, and Grenada in the southern Lesser Antilles. T. g. nigrescens is found on the island of Dominica in the north-central Lesser Antilles. [3] [7] [13]
On Hispaniola the ashy-faced owl inhabits a wide variety of landscapes, both natural and human-altered. The former include open woodlands, denser broadleaf forest, and scrublands. The latter includes farmlands, oil-palm plantations, solitary buildings, and villages and towns. Tyto glaucops is most often found in lowland areas, but can sometimes be found at higher elevations, such as foothills. [14] In elevation it ranges from sea level to 2,000 m (6,600 ft). They have a preference for habitats that have a balance between open spaces for hunting and enough canopy cover for nesting. [14] The ashy-faced owl is known for being solitary and territorial by nature. This requires them to inhabit large and undisturbed areas of land in order to maintain a stable population. [15] The other two subspecies also use essentially all available habitats on their small islands. [7] [13]
The ashy-faced owl is a year-round resident throughout its range, though on Hispaniola young may disperse quite widely from their natal site. [7] [13]
The ashy-faced owl is primarily a nocturnal hunter, though in the absence of competing diurnal predators, some may hunt during the day. Its diet is mostly small vertebrates including mammals, birds, reptiles, and amphibians, but it also feeds on invertebrates. [7] [13] A study published in 2010 compared the diets of ashy-faced and American barn owls (Tyto furcata pratincola) in the Dominican Republic. Barn owls had first arrived on Hispaniola around 1950. The author examined the regurgitated pellets the owls produce, which contain the undigested bones, fur, and feathers of their prey. It was found that they each consume over 100 species of prey, with 92 species being in common between the two. Small mammals predominated in both diets, particularly so in the American barn owl, and made up the greatest proportion of the biomass. Both caught a similar proportion of bats, but the ashy-faced owl caught more birds. Amphibians and reptiles were also consumed more often by the ashy-faced owl than by the American barn owl. The ashy-faced owl is shown to exhibit dietary competition with the invasive barn owl species, Tyto alba , which established itself in Hispaniola around the 1950s. This introduction led to a dietary overlap with the ashy faced owl population. This has led to competition and implications for resource partitioning and effects on the ecological niche stability of the ashy-faced owl. [16] No conclusion could be reached as to whether the competition for food caused by the arrival of the American barn owl was detrimental to the native species. [16]
The nominate subspecies of the ashy-faced owl on Hispaniola breeds mostly between January and June. Eggs of T. g. nigrescens have been reported in September and nestlings in April. There are no data specific to the breeding season of T. g. insularis. The ashy-faced owl nests in cavities, both natural and human-made. Natural holes in tree trunks and branches, the walls of sinkholes, earthen banks, and cliffs are used. The ashy-faced owl has been shown to exhibit behaviors of using existing nests of other bird species such as the endemic Palmchat (Dulus dominicus). This nesting choice is atypical for the Tytonidae family, displaying an opportunistic style of nest site selection. Opportunistic nesting demonstrates a flexibility in their nesting ecology, which is advantageous considering the limited habitat space on Hispaniola and its neighboring islands. [17] The species also nests in human structures such as barns, church steeples, abandoned buildings, nest boxes provided for them, and even the attics of occupied dwellings. [7] [13] Ashy-faced owls have a preference for nests in secluded areas, including tree cavities and abandoned nests. These nesting choices seem to relate to decreased predation and increased fledgling survival . [18]
On Hispaniola the ashy-faced owl makes a "hissing cry, prefaced by a series of higher-pitched ratchety clicks and a c. 2–3 seconds screeching call likened to criiisssssh. [7] Other vocalizations of the nominate subspecies and those of the other two subspecies have not been well studied, but anecdotally include a wide variety of "screeches, wheezes, purrs, snores, twitters, hisses and yelps". [7] [13]
The ashy-faced owl serves an ecological role as a nocturnal predator, helping to maintain the population of rodent species. Through their predatory behaviors, they serve an essential role in maintaining environmental balance in forests and agricultural ecosystems by curbing the small mammal populations. [15]
The IUCN has assessed the ashy-face owl as being of Least Concern. Though it has a somewhat limited range and its population size is not known, the latter is believed to be stable. No immediate threats have been identified. [1] The species is "[w]idespread and locally common on Hispaniola". The "[s]tatus of Lesser Antillean subspecies [is] insufficiently known, but nigrescens appears to be common on Dominica, whereas insularis is rare on St Vincent and Grenada and in Grenadines, and might be vulnerable to habitat destruction and pesticide usage." [13]
The bird family Tytonidae, which includes the barn owlsTyto and the bay owlsPhodilus, is one of the two families of owls, the other being the true owls or typical owls, Strigidae. They are medium to large owls with large heads and characteristic heart-shaped faces. They have long, strong legs with powerful talons. They also differ from the Strigidae in structural details relating in particular to the sternum and feet.
Tyto is a genus of birds consisting of true barn owls, grass owls and masked owls that collectively make up all the species within the subfamily Tytoninae of the barn owl family, Tytonidae.
The sooty owl or greater sooty owl is a medium to large owl found in south-eastern Australia, Montane rainforests of New Guinea and have been seen on Flinders Island in the Bass Strait. The lesser sooty owl, is sometimes considered to be conspecific with this species, in which case they are then together referred to as sooty owls. It is substantially smaller and occurs in the wet tropics region of North Queensland, Australia.
The Australian masked owl, also the Australasian masked owl or simply the masked owl, especially in Australia, is a barn owl of Southern New Guinea and the non-desert areas of Australia.
The grey-headed dove (Leptotila plumbeiceps) is a large New World dove. It is found from eastern Mexico to Colombia.
The Stygian owl is a medium-sized "typical owl" in subfamily Striginae. It is found in Mexico, parts of Central America, Cuba, Hispaniola, and 10 countries in South America.
The golden swallow is a swallow endemic to the Caribbean island of Hispaniola and was once native to Jamaica, but is now extirpated there. It is restricted to isolated montane forests that primarily consist of the Hispaniolan pine. This species is considered to be a vulnerable species by the International Union for Conservation of Nature (IUCN). The exact cause of its extirpation from Jamaica is unknown, but likely factors include predation by introduced mammals and habitat loss, although the habitat loss theory is not supported by much evidence. The last sighting of the nominate subspecies was in Hardwar Gap, with three birds being seen on 8 June 1989.
The lesser sooty owl is a medium-sized masked owl endemic to the wet tropics region of Australia. Once considered a subspecies of the greater sooty owl, it is distinguished by its dark plumage, heavier spotting, and higher-pitched call. The lesser sooty owl has a limited range within northeastern Australia and primarily lives in dark, sheltered areas of the rainforest.
The Hispaniolan nightjar is a nightjar species endemic to the Caribbean island of Hispaniola, which is shared by the Dominican Republic and Haiti.
The Middle American screech owl, also known as the Guatemalan screech owl or the vermiculated screech owl, is a species of owl in the family Strigidae. It is found from northern Mexico to western Panama.
The Yungas screech owl, also known as montane forest screech-owl and Hoy's screech owl, is a species of owl in the family Strigidae. It is found in Argentina and Bolivia.
The undulated antpitta is a bird in the family Grallariidae. It is found in Bolivia, Colombia, Ecuador, Peru, and Venezuela.
The gartered trogon, also known as the northern violaceous trogon, is a bird in the family Trogonidae, the quetzals and trogons. It is found in Mexico, all of Central America, and Colombia, Ecuador, Peru, and Venezuela.
The Chocó screech owl is a species of owl in the family Strigidae. It is found from central Panama to western Ecuador.
The Puerto Rican barn owl is an extinct species of barn owl that inhabited the island of Puerto Rico in the Caribbean. It is sometimes considered to be a subspecies of the ashy-faced owl.
The vermiculated screech owl, is a subspecies of Middle American screech owl, or possibly separate species of owl in the family Strigidae. It is found in Costa Rica, Nicaragua, and Panama.
The eastern barn owl is usually considered a subspecies group and together with the American barn owl group, the western barn owl group, and sometimes the Andaman masked owl make up the barn owl. The cosmopolitan barn owl is recognized by most taxonomic authorities. A few separate them into distinct species, as is done here. The eastern barn owl is native to southeastern Asia and Australasia.
The western barn owl is usually considered a subspecies group and together with the American barn owl group, the eastern barn owl group, and sometimes the Andaman masked owl make up the barn owl. The cosmopolitan barn owl is recognized by most taxonomic authorities. A few separate them into distinct species, as is done here. The western barn owl is native to Eurasia and Africa.
The American barn owl is usually considered a subspecies group and together with the western barn owl group, the eastern barn owl group, and sometimes the Andaman masked owl, make up the barn owl, cosmopolitan in range. The barn owl is recognized by most taxonomic authorities. A few separate them into distinct species, as is done here. The American barn owl is native to North and South America, and has been introduced to Hawaii.
