Scops Owls

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Scops Owls
African scops owl (Otus senegalensis)

African scops owl ( Otus senegalensis )

Systematics
Class : Birds (aves)
Order : Owls (Strigiformes)
Family : Real owls (Strigidae)
Genre : Scops Owls
Scientific name
Otus
Pennant , 1769

The scops owls ( Otus ) are a genus of the real owls (Strigidae). This contains about 50 species that occur in the Palearctic , the Afrotropic , the Oriental , in the Indo-Malay fauna region and with one species also in the northernmost Australis . The greatest biodiversity is in the Indomalay region, where many island species have emerged. Only the eponymous scops owl ( Otus scops ) lives in southern Central Europe . It is the only obligatory long-distance migrant among the real owls.

features

Scops Owl ( Otus scops )

Owls of the genus Otus are small to medium-sized birds with a maximum body length of 28 centimeters. The smallest species weigh around 50 g, the heaviest a little over 300 grams.

They are inconspicuous, mostly bark-colored gray-brown or brown; the ventral side of many species is clearly dark, longitudinally dashed. Some species show different (mostly reddish-brown or gray-brown) color morphs. The feather ears present in all species are far apart; in some species they end bluntly, giving the head a horned appearance. The feather ears vary in length depending on the species and are often created, so that some species are referred to as earless . All scops owls have a face veil, the edge of which is usually clear. In some species the legs are feathered up to the toes, in others, however, largely featherless.

Most scops owls are nocturnal hunters of large flying insects. Vertebrates such as mice, shrews, birds, reptiles and amphibians are more rarely and only regularly captured by the larger species, but play a certain role as occasional prey in all species. Some species have specialized in geckos hunting at night .

Most scops owls are resident birds. In addition to the Eurasian scops owl, in which most populations are obligatory far-migrants , the northern populations of the striped scops owl ( Otus brucei ), the Japanese scops owl ( Otus semitorques ) and the oriental scops owl ( Otus sunia ) also migrate . Small-scale migrations and vertical compensatory movements are also reported by other species.

As far as known, scops owls are predominantly cave breeders; they use natural or woodpecker holes as a nesting opportunity. In a few species broods in buildings and the use of birds of prey or crow nests as a nesting surface are known.

distribution

Regions with the greatest biodiversity
More than 80 percent of all species of scops owls breed in these areas

Scops owls are common in Africa, with the exception of the desert areas and the rainforest belt, in southern Europe and in Central, South and Southeast Asia. The genus is absent in central and northern Europe and largely in the boreal zone of Asia. The Eurasian scops owl and the oriental scops owl penetrate the furthest north, the northernmost settlement areas of which are on the southern edge of the taiga , or in the woods along the river on Sakhalin . The genus Otus is not represented in North and South America , and no owls of the genus Otus breed in Australia .

Many species are endemic to very small areas or islands . Very large, contiguous areas are covered by the Eurasian scops owl ( Otus scops ), the oriental scops owl ( Otus sunia ), the striped scops owl ( Otus brucei ), the necked scops owl ( Otus lettia ), the Hindu necked owl ( 0tus bakkamoena ) and the African scops owl ( Otus senegalensis ).

The habitats of the scops owls are very diverse; Loosely tree-lined landscape structures of various kinds seem to be the most attractive for most species of this genus. Some species prefer dry habitats and penetrate to the edge of deserts. The East Asian scops owls, on the other hand, are also inhabitants of tropical forests. But even these usually avoid dense forests and prefer open forest regions, fault zones after logging, fires or storm events, as well as the edge areas of the forests. Trees that accompany rivers are also preferred by many tropical species. Landscapes with a strongly anthropogenic design such as rubber or fruit plantations, cemeteries or large parks are often used as living spaces. The coconut palm fringes along the tropical coasts also form suitable habitats for some species .

Species of the genus Otus occur both in lowland areas and in montane regions. For example, the Manado scops owl ( Otus manadensis ) breeds in parks and on the outskirts of many coastal cities in Sulawesi as well as in the cloud forests at altitudes of over 2500 meters.

Systematics

Depending on the scientific opinion, the genus Otus comprises between 43 and 51 species. The species status of some island species in the Sunda Archipelago and the Comoros is unclear.

Together with the genera Megascops , Macabra , Pyrroglaux , Gymnoglaux , Psiloscops and Mimizuku , Otus forms the tribe Otini within the subfamily Striginae. The monotypical genera Pyrroglaux , Gymnoglaux , Mimizuku and the two species of the new genus Ptilopsis were recently separated from Otus . The separation of the genus Mimizuku from Otus was revised by a genetic study in 2011 and the red-eared owl was returned to the genus Otus by the International Ornithological Union in 2012 . Also the screech owls of the Nearctic and Neotropical , which were previously assigned to the scops owls, are genetically far separated from the genus Otus and are grouped together in the genus Megascops .

The Ponderosa scops owl ( Otus flammeolus ), which is considered the only nearctic representative of the scops after being separated from Megascops , is not closely related to either Otus or Megascops , according to the latest DNA studies . König & Weick suggest the generic name Psiloscops for them. Some taxa that are listed as subspecies of the Hindu necked owl ( Otus bakkamoena ) in the current system are given species status by König & Weick.

In 2008, König & Weick included the following 51 species in the genus Otus .

Existing conditions and endangerment

The population conditions of many species of this genus are very difficult to assess. The majority of the species inhabit small areas or islands and accordingly only occur in a small number of individuals, so that in some cases there is an increased threat potential despite the current stable population. The growing population narrows the habitat of the species; in addition, the East Asian scops owls and those of the Comoros are threatened by the uncontrolled progress of logging in many places and by the conversion of primary forests into plantations. Very little is known about very many of these species; In particular, there is almost no reliable information on breeding biology and diet for many of the potentially threatened species, so that the basics of effective protective measures hardly exist.

Birdlife international lists only 43 species in the genus Otus . Of these, 18 are not at any risk level. 11 species are on the warning list (" near threatened "). 13 species are listed in the endangerment levels, 4 of them as critically endangered . For one species ( Otus alius ) of the Nicobar Islands , the data situation is not sufficient for a population assessment.

According to Birdlife internationally, the following species are threatened with extinction:

  • Anjouan scops owl ( Otus capnodes ): It was lost for a long time and was found again in 1992. The total population is a maximum of 200 breeding pairs.
  • Mohéli scops owl ( Otus moheliensis ): This scops owl was first described in 1998. Their population of around 150 breeding pairs is threatened by increasing logging.
  • Comoros scops owl ( Otus pauliani ): The total population of this owl is likely to be around 1000 breeding pairs; it can evidently stay in cleared areas if at least some cave trees remain. It is particularly endangered by the introduction of the Shepherd's Maina ( Acridotheres tristis ), which as a cave competitor is clearly superior to the Scops Owl , which is only 19 centimeters tall.
  • Siau Scops Owl ( Otus siaoensis ): This species is only known from one hide. There are no living records. On Siau , a small volcanic island north of Sulawesi , deforestation is proceeding very rapidly, so that the possible habitats of this owl are severely disturbed and rapidly decreasing in size. If the Siau Scops Owl isn't already extinct, it is at least very rare.

literature

Web links

Commons : Otus  - collection of images, videos and audio files

swell

  1. ↑ König & Weick (2008) pp. 233-280
  2. ↑ König & Weick (2008) p. 273
  3. ↑ König & Weick (2008) p. 52; 233-279
  4. ↑ Hector C. Miranda Jr. Daniel M. Brooks, and Robert S. Kennedy: Phylogeny and Taxonomic Review of Philippine Lowland Scops Owls (Strigiformes): Parallel Diversification of Highland and Lowland Clades In: The Wilson Journal of Ornithology 123 (3): S. 441-453. 2011
  5. ↑ IOC World Bird Names Version 2.11 ( Memento of May 13, 2007 in the Internet Archive )
  6. ↑ König & Weick (2008) pp. 56 and 233
  7. ↑ König & Weick (2008) p. 280
  8. ↑ König & Weick (2008) pp. 233-279
  9. ↑ Avibase Sulawesi Scops-Owl (kalidupae) , accessed June 17, 2020
  10. ↑ Avibase Sunda Scops-Owl (cnephaeus) , accessed June 17, 2020
  11. ↑ Data sheet Birdlife international
  12. ↑ König & Weick (2008) p. 265