Post by Eaglehawk on Jan 9, 2020 6:00:20 GMT
Short-eared Owl - Asio flammeus
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Subfamily: Asioninae
Genus: Asio
Species: Asio flammeus
The short-eared owl (Asio flammeus) is a species of typical owl (family Strigidae). Owls belonging to genus Asio are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or may not be visible. Asio flammeus will display its tufts when in a defensive pose. However, its very short tufts are usually not visible. The short-eared owl is found in open country and grasslands. The word flammeus is Latin for "flaming, or the color of fire".
Description
The short-eared owl is a medium-sized owl measuring 34–43 cm (13–17 in) in length and weighing 206–475 g (7.3–16.8 oz). It has large eyes, a big head, a short neck, and broad wings. Its bill is short, strong, hooked and black. Its plumage is mottled tawny to brown with a barred tail and wings. The upper breast is significantly streaked. Its flight is characteristically floppy due to its irregular wingbeats. The short-eared owl may also be described as "moth or bat-like" in flight. Wingspans range from 85 to 110 cm (33 to 43 in). Females are slightly larger than males. The yellow-orange eyes of A. flammeus are exaggerated by black rings encircling each eye, giving the appearance of them wearing mascara, and large, whitish disks of plumage surrounding the eyes like a mask.
Separation from long-eared owl
Over much of its range, short-eared owls occurs with the similar-looking long-eared owl. At rest, the ear-tufts of long-eared owl serve to easily distinguish the two (although long-eared owl can sometimes hold its ear-tufts flat). The iris-colour differs: yellow in short-eared, and orange in long-eared, and the black surrounding the eyes is vertical on long-eared, and horizontal on short-eared. Overall the short-eared tends to be a paler, sandier bird than the long-eared. There are a number of other ways in which the two species the differ which are best seen when they are flying: a) short-eared often has a broad white band along the rear edge of the wing, which is not shown by long-eared; b) on the upperwing, short-eared owls' primary-patches are usually paler and more obvious; c) the band on the upper side of short-eared owl's tail are usually bolder than those of long-eared; d) short-eared's innermost secondaries are often dark-marked, contrasting with the rest of the underwing; e) the long-eared owl has streaking throughout its underparts whereas on short-eared the streaking ends at the breast; f) the dark markings on the underside of the tips of the longest primaries are bolder on short-eared owl; g) the upperparts are coarsely blotched, whereas on long-eared they are more finely marked. The short-eared owl also differs structurally from the long-eared, having longer, slimmer wings: the long-eared owl has wings shaped more like those of a Tawny Owl. The long-eared owl generally has different habitat preferences from the short-eared, most often being found concealed in areas with dense wooded thickets. The short-eared owl is often most regularly seen flying about in early morning or late day as it hunts over open habitats.
Subspecies
As of 2009, there are ten recognized subspecies of the short-eared owl:
Some authorities recognize a further subspecies:
Range
The short-eared owl occurs on all continents except Antarctica and Australia; thus it has one of the most widespread distributions of any bird. A. flammeus breeds in Europe, Asia, North and South America, the Caribbean, Hawaii and the Galápagos Islands. It is partially migratory, moving south in winter from the northern parts of its range. The short-eared owl is known to relocate to areas of higher rodent populations. It will also wander nomadically in search of better food supplies during years when vole populations are low.
World Range
Behaviour
Nesting and reproduction
Sexual maturity is attained at one year. Breeding season in the northern hemisphere lasts from March to June, peaking in April. During this time these owls may gather in flocks. During breeding season, the males make great spectacles of themselves in flight to attract females. The male swoops down over the nest flapping its wings in a courtship display. These owls are generally monogamous.
The short-eared owl nests on the ground in prairie, tundra, savanna, or meadow habitats. Nests are concealed by low vegetation, and may be lightly lined by weeds, grass, or feathers. Approximately 4 to 7 white eggs are found in a typical clutch, but clutch size can reach up to a dozen eggs in years when voles are abundant. There is one brood per year. The eggs are incubated mostly by the female for 21–37 days. Offspring fledge at a little over four weeks. This owl is known to lure predators away from its nest by appearing to have a crippled wing.
Diet and foraging habits
In flight
Hunting occurs mostly at night, but this owl is known to be diurnal and crepuscular as well. Its daylight hunting seems to coincide with the high-activity periods of voles, its preferred prey. It tends to fly only feet above the ground in open fields and grasslands until swooping down upon its prey feet-first. Several owls may hunt over the same open area. Its food consists mainly of rodents, especially voles, but it will eat other small mammals such as mice, ground squirrels, shrews, rats, bats, muskrats and moles. It will also occasionally predate smaller birds, especially when near sea-coasts and adjacent wetlands at which time they attack shorebirds, terns and small gulls and seabirds with semi-regularity. Avian prey is more infrequently preyed on inland and centers on passerines such as larks, icterids, starlings, tyrant flycatchers and pipits. Insects supplement the diet and short-eared owls may prey on roaches, grasshoppers, beetles, katydids and caterpillars. Competition can be fierce in North America with the Northern Harrier, with which the owl shares similar habitat and prey preferences. Both species will readily harass the other when prey is caught.
Pellets
Because of the high pH in the stomach of owls they have a reduced ability to digest bone and other hard parts, they eject pellets containing the remains of their prey.
Calls
Short-eared owls have a scratchy bark-like call. Raspy waowk, waowk, waowk or toot-toot-toot-toot-toot sounds are common. A loud eeee-yerp is also heard on breeding grounds. However, short-eared owls are silent on the wintering grounds.
Conservation status
Globe icon.
The examples and perspective in this article may not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (December 2010)
It is listed as declining in the southern portion of its range. It is listed as of special concern, threatened, or endangered in some states and common in northern portion of breeding range.
It is listed as endangered in New Mexico state. Its appearance at the Calverton Executive Airpark on Long Island has prompted the New York State Department of Environmental Conservation to take the lead on ruling whether a massive redevelopment of the airport will receive the necessary environmental permits.
The owls beyond the Andes: Divergence between distant populations suggests new species
Date: November 11, 2015
Source: Pensoft Publishers
They might be looking quite identical, while perched above humanised farmlands and grasslands across several continents, but each of the populations of two owl species, living in the opposite hemispheres, might actually turn out to be yet another kind. This suggestion has been made by Dr. Nelson Colihueque and his team from Universidad de Los Lagos, Chile, based on new genetic divergence analyses of the Common Barn and the Short-eared Owl populations from southern Chile and comparing them with those from other geographic areas. The study is published in the open-access journal ZooKeys.
Although much has been known about the two widespread owl species, the knowledge about them has so far been restricted mainly to aspects such as their diet, conservation status and habitats. On the other hand, their genetic divergence in comparison with populations in distant areas has received little attention. Moreover, their taxonomical status is still based on traditional identification rather than modern methods such as the herein utilised mitochondrial COI sequencing.
Thus, the Chilean research team concluded a significant genetic divergence among the populations of both species from a few distinctive groups. In the case of the Common Barn Owl they compared the new analysis of its South American representatives with already available such data about populations from North America, Northern Europe and Australasia. For the Short-eared Owl, they compared Chilean and Argentinean birds with North American and North Asian.
One of the reasons behind such an evolutionary divergence might be the geographic isolation, experienced by the peripheral South American populations of both owl species. It is a consequence of the Andean Mountains acting as a natural barrier.
"In the case of the Common Barn Owl, the existence of geographic barriers to gene flow among populations on different continents is to be expected, and this in combination with its non-migratory or short-distance migratory behaviour, should contribute to promote the genetic divergence," further explain the authors.
In conclusion, the researchers call for additional studies to clarify the taxonomic identification of these owl populations.
Story Source:
Pensoft Publishers. "The owls beyond the Andes: Divergence between distant populations suggests new species." ScienceDaily. www.sciencedaily.com/releases/2015/11/151111165329.htm (accessed November 12, 2015).
Journal Reference:
Nelson Colihueque, Alberto Gantz, Jaime Rau, Margarita Parraguez. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence. ZooKeys, 2015; 534: 135 DOI: 10.3897/zookeys.534.5953
Abstract
In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy.
zookeys.pensoft.net/articles.php?id=5953
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Strigiformes
Family: Strigidae
Subfamily: Asioninae
Genus: Asio
Species: Asio flammeus
The short-eared owl (Asio flammeus) is a species of typical owl (family Strigidae). Owls belonging to genus Asio are known as the eared owls, as they have tufts of feathers resembling mammalian ears. These "ear" tufts may or may not be visible. Asio flammeus will display its tufts when in a defensive pose. However, its very short tufts are usually not visible. The short-eared owl is found in open country and grasslands. The word flammeus is Latin for "flaming, or the color of fire".
Description
The short-eared owl is a medium-sized owl measuring 34–43 cm (13–17 in) in length and weighing 206–475 g (7.3–16.8 oz). It has large eyes, a big head, a short neck, and broad wings. Its bill is short, strong, hooked and black. Its plumage is mottled tawny to brown with a barred tail and wings. The upper breast is significantly streaked. Its flight is characteristically floppy due to its irregular wingbeats. The short-eared owl may also be described as "moth or bat-like" in flight. Wingspans range from 85 to 110 cm (33 to 43 in). Females are slightly larger than males. The yellow-orange eyes of A. flammeus are exaggerated by black rings encircling each eye, giving the appearance of them wearing mascara, and large, whitish disks of plumage surrounding the eyes like a mask.
Separation from long-eared owl
Over much of its range, short-eared owls occurs with the similar-looking long-eared owl. At rest, the ear-tufts of long-eared owl serve to easily distinguish the two (although long-eared owl can sometimes hold its ear-tufts flat). The iris-colour differs: yellow in short-eared, and orange in long-eared, and the black surrounding the eyes is vertical on long-eared, and horizontal on short-eared. Overall the short-eared tends to be a paler, sandier bird than the long-eared. There are a number of other ways in which the two species the differ which are best seen when they are flying: a) short-eared often has a broad white band along the rear edge of the wing, which is not shown by long-eared; b) on the upperwing, short-eared owls' primary-patches are usually paler and more obvious; c) the band on the upper side of short-eared owl's tail are usually bolder than those of long-eared; d) short-eared's innermost secondaries are often dark-marked, contrasting with the rest of the underwing; e) the long-eared owl has streaking throughout its underparts whereas on short-eared the streaking ends at the breast; f) the dark markings on the underside of the tips of the longest primaries are bolder on short-eared owl; g) the upperparts are coarsely blotched, whereas on long-eared they are more finely marked. The short-eared owl also differs structurally from the long-eared, having longer, slimmer wings: the long-eared owl has wings shaped more like those of a Tawny Owl. The long-eared owl generally has different habitat preferences from the short-eared, most often being found concealed in areas with dense wooded thickets. The short-eared owl is often most regularly seen flying about in early morning or late day as it hunts over open habitats.
Subspecies
As of 2009, there are ten recognized subspecies of the short-eared owl:
- A. f. bogotensis – Chapman, 1915: found in Colombia, Ecuador and northwestern Peru
- A. f. domingensis – (Statius Müller, 1776): found on Hispaniola
- A. f. flammeus – (Pontoppidan, 1763): nominate, found in North America, Europe, northern Africa and northern Asia
- A. f. galapagoensis – (Gould, 1837) - Galápagos Islands
- A. f. pallidicaudus – Friedmann, 1949: found in Venezuela, Guyana and Suriname
- A. f. ponapensis – Mayr, 1933: found on east Caroline Island
- A. f. portoricensis – Ridgway, 1882: found in Puerto Rico
- A. f. sandwichensis – (A. Bloxam, 1827): Pueo or Hawaiian Short-eared Owl - found in the Hawaiian Islands
- A. f. sanfordi – Bangs, 1919: found on the Falkland Islands
- A. f. suinda – (Vieillot, 1817): found from southern Peru and southern Brazil to Tierra del Fuego
Some authorities recognize a further subspecies:
- A. f. cubensis – Garrido, 2007: found in Cuba
Range
The short-eared owl occurs on all continents except Antarctica and Australia; thus it has one of the most widespread distributions of any bird. A. flammeus breeds in Europe, Asia, North and South America, the Caribbean, Hawaii and the Galápagos Islands. It is partially migratory, moving south in winter from the northern parts of its range. The short-eared owl is known to relocate to areas of higher rodent populations. It will also wander nomadically in search of better food supplies during years when vole populations are low.
World Range
Behaviour
Nesting and reproduction
Sexual maturity is attained at one year. Breeding season in the northern hemisphere lasts from March to June, peaking in April. During this time these owls may gather in flocks. During breeding season, the males make great spectacles of themselves in flight to attract females. The male swoops down over the nest flapping its wings in a courtship display. These owls are generally monogamous.
The short-eared owl nests on the ground in prairie, tundra, savanna, or meadow habitats. Nests are concealed by low vegetation, and may be lightly lined by weeds, grass, or feathers. Approximately 4 to 7 white eggs are found in a typical clutch, but clutch size can reach up to a dozen eggs in years when voles are abundant. There is one brood per year. The eggs are incubated mostly by the female for 21–37 days. Offspring fledge at a little over four weeks. This owl is known to lure predators away from its nest by appearing to have a crippled wing.
Diet and foraging habits
In flight
Hunting occurs mostly at night, but this owl is known to be diurnal and crepuscular as well. Its daylight hunting seems to coincide with the high-activity periods of voles, its preferred prey. It tends to fly only feet above the ground in open fields and grasslands until swooping down upon its prey feet-first. Several owls may hunt over the same open area. Its food consists mainly of rodents, especially voles, but it will eat other small mammals such as mice, ground squirrels, shrews, rats, bats, muskrats and moles. It will also occasionally predate smaller birds, especially when near sea-coasts and adjacent wetlands at which time they attack shorebirds, terns and small gulls and seabirds with semi-regularity. Avian prey is more infrequently preyed on inland and centers on passerines such as larks, icterids, starlings, tyrant flycatchers and pipits. Insects supplement the diet and short-eared owls may prey on roaches, grasshoppers, beetles, katydids and caterpillars. Competition can be fierce in North America with the Northern Harrier, with which the owl shares similar habitat and prey preferences. Both species will readily harass the other when prey is caught.
Pellets
Because of the high pH in the stomach of owls they have a reduced ability to digest bone and other hard parts, they eject pellets containing the remains of their prey.
Calls
Short-eared owls have a scratchy bark-like call. Raspy waowk, waowk, waowk or toot-toot-toot-toot-toot sounds are common. A loud eeee-yerp is also heard on breeding grounds. However, short-eared owls are silent on the wintering grounds.
Conservation status
Globe icon.
The examples and perspective in this article may not represent a worldwide view of the subject. Please improve this article and discuss the issue on the talk page. (December 2010)
It is listed as declining in the southern portion of its range. It is listed as of special concern, threatened, or endangered in some states and common in northern portion of breeding range.
It is listed as endangered in New Mexico state. Its appearance at the Calverton Executive Airpark on Long Island has prompted the New York State Department of Environmental Conservation to take the lead on ruling whether a massive redevelopment of the airport will receive the necessary environmental permits.
The owls beyond the Andes: Divergence between distant populations suggests new species
Date: November 11, 2015
Source: Pensoft Publishers
They might be looking quite identical, while perched above humanised farmlands and grasslands across several continents, but each of the populations of two owl species, living in the opposite hemispheres, might actually turn out to be yet another kind. This suggestion has been made by Dr. Nelson Colihueque and his team from Universidad de Los Lagos, Chile, based on new genetic divergence analyses of the Common Barn and the Short-eared Owl populations from southern Chile and comparing them with those from other geographic areas. The study is published in the open-access journal ZooKeys.
Although much has been known about the two widespread owl species, the knowledge about them has so far been restricted mainly to aspects such as their diet, conservation status and habitats. On the other hand, their genetic divergence in comparison with populations in distant areas has received little attention. Moreover, their taxonomical status is still based on traditional identification rather than modern methods such as the herein utilised mitochondrial COI sequencing.
Thus, the Chilean research team concluded a significant genetic divergence among the populations of both species from a few distinctive groups. In the case of the Common Barn Owl they compared the new analysis of its South American representatives with already available such data about populations from North America, Northern Europe and Australasia. For the Short-eared Owl, they compared Chilean and Argentinean birds with North American and North Asian.
One of the reasons behind such an evolutionary divergence might be the geographic isolation, experienced by the peripheral South American populations of both owl species. It is a consequence of the Andean Mountains acting as a natural barrier.
"In the case of the Common Barn Owl, the existence of geographic barriers to gene flow among populations on different continents is to be expected, and this in combination with its non-migratory or short-distance migratory behaviour, should contribute to promote the genetic divergence," further explain the authors.
In conclusion, the researchers call for additional studies to clarify the taxonomic identification of these owl populations.
Story Source:
Pensoft Publishers. "The owls beyond the Andes: Divergence between distant populations suggests new species." ScienceDaily. www.sciencedaily.com/releases/2015/11/151111165329.htm (accessed November 12, 2015).
Journal Reference:
Nelson Colihueque, Alberto Gantz, Jaime Rau, Margarita Parraguez. Genetic divergence analysis of the Common Barn Owl Tyto alba (Scopoli, 1769) and the Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile using COI sequence. ZooKeys, 2015; 534: 135 DOI: 10.3897/zookeys.534.5953
Abstract
In this paper new mitochondrial COI sequences of Common Barn Owl Tyto alba (Scopoli, 1769) and Short-eared Owl Asio flammeus (Pontoppidan, 1763) from southern Chile are reported and compared with sequences from other parts of the World. The intraspecific genetic divergence (mean p-distance) was 4.6 to 5.5% for the Common Barn Owl in comparison with specimens from northern Europe and Australasia and 3.1% for the Short-eared Owl with respect to samples from north America, northern Europe and northern Asia. Phylogenetic analyses revealed three distinctive groups for the Common Barn Owl: (i) South America (Chile and Argentina) plus Central and North America, (ii) northern Europe and (iii) Australasia, and two distinctive groups for the Short-eared Owl: (i) South America (Chile and Argentina) and (ii) north America plus northern Europe and northern Asia. The level of genetic divergence observed in both species exceeds the upper limit of intraspecific comparisons reported previously for Strigiformes. Therefore, this suggests that further research is needed to assess the taxonomic status, particularly for the Chilean populations that, to date, have been identified as belonging to these species through traditional taxonomy.
zookeys.pensoft.net/articles.php?id=5953
