Owl
| Owl | ||||||||||
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Brillenkauz ( Pulsatrix perspicillata ) |
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| Systematics | ||||||||||
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| Scientific name | ||||||||||
| Pulsatrix perspicillata | ||||||||||
| ( Latham , 1790) |
The Spectacled ( Pulsatrix perspicillata ) is a large, high-contrast colored owl art from the family of authentics owl (Strigidae). The distribution area of the owl ranges from southern Mexico across Central America and large parts of northern South America to northern Argentina. The animals inhabit the closed forest of the tropics and subtropics, but also occur in plantations and tree groves. The diet consists primarily of smaller mammals up to the size of opossums, and birds up to the size of pigeons and smaller owls. The owl is classified by the IUCN as safe (" least concern ") due to its large distribution area and the apparently stable population .
description
Spectacled owls are large, broad-winged owls with strong legs and toes, feathered almost to their claws, and large claws. The body length is 43–52 cm, the weight 571–982 g. This makes them significantly larger and almost twice as heavy as a tawny owl . As with all species of the genus Pulsatrix , the sexes do not differ in terms of coloration, but the species shows a clear sex dimorphism in terms of body size and weight. Females of the nominate form have a wing length of 318-350 mm, males only reach 305-335 mm. Female of the subspecies P. p. saturata weigh 765–982 g, males only 591–761 g.
The color is very contrasting. In adult birds of the nominate form, the upper side of the trunk and the upper wing-coverts are monochrome dark brown, the wings and the tail are banded pale gray-brown on this basis. A broad, dark brown transverse band stretches across the chest, the rest of the underside of the trunk is monochrome pale yellow to yellowish red-brown. The tarsometatarsi and toes are more whitish reddish brown feathered.
Eyebrows, nostrils and cheek strips, the lower edge of the face veil and the throat are pure white, the rest of the face is dark brown. The rest of the head and the neck are monochrome blackish brown and clearly darker than the rest of the upper side. The bill and wax skin are yellowish horn-colored, the tip of the beak has a greenish tone. The featherless parts of the toes are whitish or pale gray, the claws are blackish. The iris is bright yellow-orange.
Fledglings are very different from adults. The face veil is more or less heart-shaped and monochrome blackish. The rest of the head and the entire trunk are solid white. The upper wing-coverts are banded gray-brown on a white background, wings and tail are lightly banded on a brown background. The adult dress takes up to five years to develop.
Vocalizations
The courtship and district call of both partners is a series of initially ascending and then, towards the end, quieter and deeper throaty knocking sounds, such as "pok-pok-bogbogbogbobobo" . A two-syllable, screeching call similar to a steam whistle is also known mainly from females .
distribution and habitat
The distribution area of the owl ranges from southern Mexico across Central America and large parts of northern South America, excluding the Andes, to northern Argentina. The total distribution area covers about 12.7 million km². Owls inhabit the closed forest of the tropics and subtropics with large and old trees, but also plantations and tree groves. The species occurs from sea level to 1500 m altitude.
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Systematics
The number of subspecies of the owl as well as the species delimitation within the genus Pulsatrix are controversial to this day. Four subspecies are largely undisputed:
- Pulsatrix perspicillata perspicillata ( Latham , 1790) ; largest part of the distribution area.
- Pulsatrix p. saturata Ridgway , 1914 ; North of the distribution area from southern Mexico to northern Costa Rica and west of Panama . The dark areas of the head and the back are equally dark, slate black, the sides of the abdomen and sometimes the chest are finely banded in dark.
- Pulsatrix p. chapmani Griscom , 1932 ; from the east of Costa Rica to the northwest of Ecuador .
- Pulsatrix p. boliviana L. Kelso , 1933 ; from Bolivia to the north of Argentina.
Another subspecies Pulsatrix p. trinitatis Penard & Bangs , 1918 , is recognized by several institutions, but was combined with the nominate form by König and Weick. A separation of the subspecies Pulsatrix perspicillata pulsatrix made by König and Weick as a separate species Pulsatrix pulsatrix has not yet been generally accepted.
nutrition
The diet consists primarily of small mammals, occasionally larger mammals up to the size of possums and birds up to the size of pigeons and smaller owls are preyed. In addition, caterpillars and other large insects are also eaten, including crabs and large spiders . The hunt takes place almost exclusively at night. The birds change from high seat guard to high seat guard and observe the ground, the prey is then flown to and grabbed on the ground.
Reproduction
The brood biology in the field has hardly been studied. Large caves in tree trunks or strong side branches are used for breeding. The clutch normally comprises two eggs, which are only incubated by the female for about 35 days. The nestlings are also largely fed by the female, who during this time is provided with prey by the male. The young birds leave the cave when they are around five or six weeks old; like many young owls, they are then barely able to fly. They remain dependent on their parents for several months, sometimes for almost a year.
Existence and endangerment
There is no reliable information on the size of the world population, BirdLife International gives a very rough estimate of 0.5 to 5.0 million individuals. The population trend is assessed as stable, so overall the IUCN classifies the owl as safe ("least concern").
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Individual evidence
- ↑ a b BirdLife International (2010) Species factsheet: Pulsatrix perspicillata. Online . Retrieved August 3, 2010
- ^ A b c Claus König, Friedhelm Weick: Owls of the World . Christopher Helm, London 2008, ISBN 978-0-7136-6548-2 : p. 351
- ↑ a b c Avibase: Brillenkauz. Online , accessed August 5, 2010
- ↑ International Ornithologist's Union: IOC World Bird List, version 2.5 - Owls. Online ( Memento of the original from July 17, 2010 in the Internet Archive ) Info: The archive link was inserted automatically and has not yet been checked. Please check the original and archive link according to the instructions and then remove this notice. , accessed August 5, 2010
- ↑ SACC 2008: Proposal (# 326) to South American Classification Committee: Elevate the subspecies pulsatrix of the Spectacled Owl (Pulsatrix perspicillata) to species. ( Online , accessed August 5, 2010)
literature
- Claus König , Friedhelm Weick: Owls of the World . Christopher Helm, London 2008, ISBN 978-0-7136-6548-2 : pp. 158–159 and 350–351
Web links
- Pulsatrix perspicillata in the endangered Red List species the IUCN 2010. Posted by: BirdLife International, 2009. Accessed August 3 of 2010.
Other web links
- Videos, photos and sound recordings for Pulsatrix perspicillata in the Internet Bird Collection