Papuan consecration

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Papuan consecration
Systematics
Subclass : New-jawed birds (Neognathae)
Order : Birds of prey (Accipitriformes)
Family : Hawk species (Accipitridae)
Subfamily : Consecrations (Circinae)
Genre : Consecration ( circus )
Type : Papuan consecration
Scientific name
Circus spilothorax
Salvadori & D'Albertis , 1875

The Papuan Harrier ( Circus spilothorax ) is a bird of prey from the family of the hawk-like (Accipitridae) endemic to New Guinea . Like many other New Guinean bird species, this consecration has also been little researched and its way of life has only recently been described in more detail. As one of the largest species in its genus , it mainly eats ground-dwelling birds and small mammals. It breeds from April to May in a ground nest that it builds in tall grass or in sugar cane fields.

Their presumed distribution area includes all of New Guinea with the exception of the Vogelkop Peninsula , the Owen Stanley Mountains and the southwestern lowlands. The total population of the Papuan Harrier is estimated at 3600 birds, the species is probably threatened by slash and burn and global warming.

features

Appearance and build

The Papuan consecration is a relatively large and difficult consecration . She shows a clear sexual dimorphism in terms of size and color, with the female being larger and heavier than the male. There is only very little data available on the Papuan consecration, the dimensions given come from a few individuals and are therefore not very representative.

Males reach a wing length of around 380 mm and a tail length of 214–224 mm. The male tarsus is 84–84 mm long. The wing length of the female is between 388 and 418 mm; its tail becomes about 225 mm long. The tarsus of the female measures 90–92 mm. Data on the weight of the birds are not available; Based on the egg size, the body mass of the female was estimated at around 890 g, making the Papuan consecration the largest and heaviest representative of its genus.

Male Papuan harriers show two morphs : a melanistic morph, which is characterized by almost entirely black plumage and occurs mainly in the lowlands, and a lighter morph with more white and gray components, which is the more common variant with around 80% of all individuals and at heights over 1500 m dominated even more. Melanistic males are almost completely black, with the exception of the gray tail feathers, a narrow white spot at the base of the wings of the hand and, in rare cases, lighter dashes on the head and chest. In contrast, the lighter morph shows a light gray or white underside, which is darkly dashed to different degrees. These dotted lines increase in intensity and density towards the head, so that the head appears darker than the rest of the body. The undersides of the wings are white, only the wing edge and the tips of the hand wings are colored black. Black predominates on the upper side of the fuselage, but the white rump and, in places, light dashes on the head stand out. The arm wings and tail feathers are gray, the tips of the arm and hand wings are clearly banded in black. On the upper side, arm wings , inner hand wings , as well as the hand covers and the inner edges of the arm covers are colored gray; the thin black border of the wings and wing covers contrasts with this. The thumb wing and the rest of the top are uniformly black.

The females, on the other hand, are predominantly brown and beige and are very similar to those of the marsh harrier ( C. approximans ). The underside of the body and the under wing coverts are reddish-dashed on a cream-colored background, with the dashes extending from the neck to the pants, the plumage on the leg. The face veil typical of the genus is dense, dark and radially dashed and thus stands out clearly from the rest of the plumage. The top of the body is uniformly dark brown, sometimes the female shows white lines on the head. The tail is darkly banded on a gray background, as are the undersides of the arm wings. The base of the hand wings is lighter in color and rather weakly banded. The outermost tips of the hand wings are black on both sides. The upper side of the wing is gray, with the exception of the dark brown small and medium arm covers. The wings and large arm covers show a dark edge on the top. The black color of the hand wings is limited in the female to the extreme tips.

Juvenile birds of both sexes are similar to adult females, but have light lines on their heads and backs. The beak is black regardless of age, and the yellow to light yellow legs are common to both juvenile and adult birds. The iris is yellow in adult birds, in young birds it is darker to brown.

Flight image

The Papuan consecration hunts in a deep, fluttering gliding flight with wings angled to the V and looking down over dense, flat vegetation; often she also lets one or both legs hang. In addition, she sometimes sails at a greater height with horizontally spread wings. In addition, the Papuan consecration performs conspicuous courtship flights during the mating season, which are characterized by ups and downs at great heights and subsequent spiraling falls. Compared to other consecrations, however, it shows less agility in flight, which is probably due to its relatively strong physique.

In the field, the long, slender wings and the narrow tail are particularly important distinguishing features.

Spreading and migrations

Presumed distribution area of ​​the Papuan consecration

The distribution of the Papuan Harrier is limited to New Guinea, making the species the only one of its kind that occurs exclusively in the equatorial region. There are different details about the exact distribution area; only the northeast part of the island is given by all authors as part of the distribution area. In the Owen Stanley Mountains , in southwest New Guinea and on the Vogelkop Peninsula , the Papuan consecration is apparently missing. During the dry season from April to September, a large part of the population moves to the highlands in order to return to lower areas during the rainy season. In the lowlands around Kurik , the Papuan consecration is completely absent during the dry season. From the north of Australia individual sightings are reported again and again, possibly the Papuan consecration has already brooded successfully at Cape York .

habitat

The Papuan consecration mainly lives in wide, open and humid areas, such as riverside meadows, grasslands, swamps, moors or sugar cane plantations up to 3800 m. It is absent in forest areas.

behavior

Hunting and feeding

Ground dwellers such as the pygmy quail ( Coturnix chinensis ) are often struck by the Papuan Harrier

Birds make up the majority of the diet of the Papuan Harrier. Among them, earth quail ( Coturnix ) and other ground-dwelling birds such as crab claws ( Rallus pectoralis ) are preyed on. Small passerines as Mohrenschwarzkehlchen ( Saxicola caprata ) are much more difficult to hunt for Papuan Harrier, but are also found in Gewöllen and nests. Mammals make up a smaller part of the prey, mainly rats ( Rattus ). There are also isolated amphibians in the prey.

Papuan harriers are often observed together with black kites ( Milvus migrans ) on the fronts of field fires, where they chase birds and small mammals fleeing from the vegetation. They come down on the prey from a height of about four to five meters, while most other species of harrier usually hunt at a lower height and try to hunt their prey with quick flight maneuvers. This rather atypical hunting method of the Papuan consecration is probably due to their size and weight, which make them less agile than other species. Captured animals are usually bitten off in a sitting area or on the floor before they are eaten or fed.

Social behavior

Little is known about the social behavior of the species. What is certain is that, as has also been observed with other species of the genus, the birds occasionally come together in groups in which they sleep a short distance from one another and consume their prey. However, the breeding business does not take place in colonies.

Reproduction and breeding

Like most other consecrations, male Papuan harriers show sightseeing flights at high altitudes, which consist of a few sinusoidal ups and downs; however, they fly much slower than other species. At the top of every upswing the male utters a call; then it spins towards the nesting site, with the female following it.

The Papuan Harrier breeds during the dry season from early April to around mid-May. The nest is round or oval and consists of a loose arrangement of twigs, leaves or reeds. It has a depth of around 25 cm and a diameter of 50 to 75 cm and is built in high vegetation, mostly close to bodies of water or in sugar cane fields .

The eggs of the Papuan Harrier are white. So far, a total of three nests have been examined, two of which contained three chicks and the third two eggs. A measured egg measured 49 × 43 mm. The only breeding pair observed so far began nest building and mating at the end of March; on May 10, two nestlings and one egg were found in the nest, with the eggs probably being laid at the beginning of April. The time it takes for the young to hatch is estimated at 31 days.

Systematics

The systematic position of the Papuan consecration has been unclear for some time and has been subject to several revisions and changes in the past. At first it was treated as a subspecies of the European Marsh Harrier ( C. aeruginosus ) , like other harriers inhabiting wetlands . With the division of this taxon into four separate species at the end of the 1980s - Marsh harrier, Marsh harrier ( C. approximans ), Reunion harrier ( C. maillardi ) and mangrove antler ( C. spilonotus ) - the Papuan harrier was regarded as a subspecies of the mangrove antler. Although it resembles this in the plumage, the distribution areas are spatially separated from each other. Some authors therefore put Papuan consecration as swamp consecration, but this view was not generally recognized either. It is now recognized by most authors, including James Ferguson-Lees , as a separate species, following an assessment by Robert Simmons from 2000. However, Simmons treats the Papuan consecration as a subspecies of the mangrove consecration in his most recent work. Results of DNA analyzes , which could possibly provide new information on the status of the taxon, are still pending.

Existence and endangerment

The population of the Papuan consecration was estimated in 2009 on the basis of small-scale population censuses and area sizes at a maximum of 3600 birds and 740 breeding pairs.

In New Guinea, bushfires pose a great threat to the nests of the Papuan consecration, especially since they are systematically cleared in the dry season and destroy the clutch of the Papuan consecration. Due to the increasingly frequent dry phases due to regional global warming, this risk is currently increasing. In 2009 Simmons and Legra classified the Papuan consecration as "endangered". However, since the species status of the Papuan consecration could not yet be proven by DNA analysis, BirdLife International did not accept this proposal. The Peregrine Fund, on the other hand, classifies the stock as "vulnerable".

References

literature

  • James Ferguson-Lees, David A. Christie: Raptors of the World. Houghton Mifflin Harcourt, Boston MA 2001, ISBN 0-618-12762-3 , pp. 144-145, pp. 503-505.
  • CGA Young: Zoological Results of the Dutch New Guinea Expedition, 1939. No. 5: The Birds. 1939, pp. 7-8. (Online as PDF )
  • Robert E. Simmons: Harriers of the World: Their Behavior and Ecology (= Oxford Ornithology Series 11). Oxford University Press, Oxford et al. 2000, ISBN 0-19-854964-4 .
  • Robert E. Simmons, Leo AT Legra: Is the Papuan Harrier a globally threatened species? Ecology, climate change threats and first population estimates from Papua New Guinea. In: Bird Conservation International. 19, No. 1, 2009, pp. 1-13. (Online as PDF )
  • Robert E. Simmons: The Nest, Eggs, and Diet of the Papuan Harrier from eastern New Guinea. In: Journal of Raptor Research 44, No. 1, March 2010. pp. 12-18.

Web links

Individual evidence

  1. ↑ a b c d e f James Ferguson-Lees, David A. Christie: Raptors of the World . Houghton Mifflin Harcourt, 2001, ISBN 0618127623 , pp. 144-145, pp. 503-505.
  2. ^ A b c d Studies on the Papua New Guinea Harrier www.natural-research.org. Retrieved February 18, 2010.
  3. ↑ a b c d e f g Robert E. Simmons: The Nest, Eggs, and Diet of the Papuan Harrier from eastern New Guinea. In: Journal of Raptor Research 44, No. 1, March 2010. pp. 12-18.
  4. ^ A b Robert E. Simmons: Harriers of the World: Their Behavior and Ecology . Oxford University Press , 2000, ISBN 0198549644 .
  5. ↑ a b c d e f g h i Robert E. Simmons, Leo AT Legra: Is the Papuan Harrier a globally threatened species? Ecology, climate change threats and first population estimates from Papua New Guinea. In: Bird Conservation International. 19, No. 1, 2009, pp. 1-13.
  6. ^ A b c C. GA Junge: Zoological Results of the Dutch New Guinea Expedition, 1939. No. 5: The Birds. 1939, pp. 7-8.
  7. ↑ a b c d Papuan Harrier Circus spilothorax . Global Raptor Information Network, www.globalraptors.org, January 9, 2010. Retrieved March 13, 2010.
This version was added to the list of articles worth reading on November 9, 2010 .