Blue-necked bird of paradise
| Blue-necked bird of paradise | ||||||||||||
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Blue-naped bird of paradise, the female on the left, the male on the right. |
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| Parotia lawesii | ||||||||||||
| EP Ramsay , 1885 |
The blue-naped bird of paradise ( Parotia lawesii ), also known as the blue-naped bird of paradise , is a species of bird from the family of birds of paradise (Paradisaeidae). It occurs exclusively in the east of New Guinea. As is characteristic of a bird of paradise, the male has three elongated decorative feathers on each side of the head.
The population of the blue-naped bird of paradise is classified by the IUCN as safe ( least concern ). In addition to the nominate form, a second subspecies is the Helena bird of paradise ( Parotia lawesii helenae ), which is occasionally granted its own species status.
description
Body type and measurements
The males of the blue-necked bird of paradise reach a body length of 27 centimeters, of which the tail plumage accounts for 7.3 to 8.4 centimeters. The females remain slightly smaller with a body length of 25 centimeters. With them 9.2 to 10.3 centimeters are allotted to the tail plumage. The beak measures between 2.9 and 3.7 centimeters in the males and between 2.6 and 3.6 centimeters in the females. The males weigh between 153 and 195 grams, the females between 122 and 180 grams. There is a pronounced gender dimorphism.
male
The males have a velvety black plumage. On the front of the head, directly at the base of the beak, there are some small silver-colored feathers that the bird can set up. Immediately behind it is a feather comb consisting of bronze-colored feathers that can also be straightened up. A narrow strip of intensely iridescent dark blue to purple feathers runs in the neck. Behind each eye, at the level of the ear covers, there are feather ears made of elongated, pointed feathers. Three of the feathers are strongly elongated like a wire and end in small ovals. The coat and back have a silky sheen and can have a bronze to greenish sheen.
The chin and throat shimmer purple in certain lighting conditions. The feathers on the chest have an intense emerald green to greenish yellow shine and can also shine purple or magenta in certain light. The beak is glossy black, the iris is cobalt blue with a narrow yellowish ring. One of the noticeable features is that, according to the current state of knowledge, the males can change the color of the iris and outer ring, so that the iris is yellowish and surrounded by a cobalt blue ring. The legs and feet are reddish gray.
In their first year of life, the males initially resemble the adult females and then gradually switch to the plumage of the adult males. The change can first be observed on the head. This is followed by the wings and then the tail plumage. In young males, the breast plumage is more bronze in color, while in older males it is a clearer green.
female
The females have a black-brown head with a short, dirty-whitish streak of beard. The nape of the neck is a little more brownish than the plumage of the head, some also have a dark maroon spot on the nape of the neck. The coat, the back, the rump and the upper tail-coverts are strong chestnut brown. The chin and throat are light reddish brown. The rest of the underside of the body is strong cinnamon brown with darker thighs and lower tail covers. The entire underside of the body is strong and evenly striated black-brown. The beak is black-brown. The iris, legs and feet are colored as in the adult males.
Distribution area, subspecies and habitat
The blue-necked bird of paradise only occurs in eastern New Guinea. According to current knowledge, the Owen Stanley Mountains represent the southwestern distribution limit. From there, the distribution area extends over the Bismarck Mountains and Mount Hagen to the mountains on the eastern tip of New Guinea. In the western part of the distribution area, the distribution area of the Blue-Necked Bird of Paradise overlaps with that of the Carola Bird of Paradise .
There are two subspecies:
- Parotia lawesii lawesii - EP Ramsay, 1885 - highlands in the east-central region of New Guinea to the southern mountain slopes in the southeast of New Guinea
- Parotia lawesii helenae - De Vis, 1897 (Helena bird of paradise) - Occurrence in the area of the northern watershed in southeast New Guinea. The distribution area extends here as far as Milne Bay .
The habitat of this bird of paradise species are mountain forests at medium altitude, including mixed oak forests that have not yet been affected by logging, forests with logging and secondary forests . It also occurs in forest remnants that have remained between the extensively cultivated gardens of the indigenous population of this region. It is more common in the interior of the forest than on the edge of the forest. They are most often found at altitudes between 1200 and 1900 meters, but can also come down to an altitude of 500 meters and occasionally occur at altitudes of 2300 meters.
Way of life
The blue-naped bird of paradise mainly eats fruit and small amounts of arthropods . On the basis of fecal analyzes it has been concluded that around 95 percent of its nutritional needs are covered with fruits. The fruits of ray aralia play a particularly important role in his diet. Arthropods are mainly found in the epiphyte growth on trees. It has also been reported that they eat larger shell snails. However, this has now been disproved: It only happens that the males carry empty housings to their communal courtship areas.
The flight of the blue-necked bird of paradise is fast and straightforward. A short glide phase follows every four wing beats.
Reproduction
Like the vast majority of birds of paradise, the blue-necked bird of paradise is polygynous , which means that the male mates with several females if possible. The respective female raises the offspring alone. However, some females show mate loyalty and return to the same male over several breeding seasons to mate with them.
Courtship area
The males have traditional courtship areas, which, like several species of bowerbirds, they carefully clean of leaves and similar organic materials and then decorate with objects such as snail shells, snake skins, feathers, bones, limestones, mammal droppings and the like. In contrast to the bowerbirds, the objects play no role in courtship, that is, they are not presented to the female. The respective courtship area is between 0.5 and 20 square meters in size. The courtship areas can be located directly next to each other: In 25 males examined more closely, the distance between the individual courtship areas was between 5 and 350 meters with an average of 77 meters. Males whose courtship grounds are less than 15 meters apart can not only hear each other, but also see each other. These males repeatedly disturbed each other during courtship. Females visit the courtship areas individually or in small groups consisting of up to eight individuals. Of 84 observed visits by females, mating also occurred in 39 percent of the cases. In the majority of cases it was a single female appearing at the courtship area.
Jewelry objects at the courtship area and courtship behavior
The objects with which the males decorate the courtship are not presented to the female during the actual courtship. The displayed jewelry objects usually disappear from the respective courtship area within 24 hours. It has been observed several times that males steal objects from one another. In most cases, however, it is females who pick them up. It is thought possible that the females use the laid out snake skins to lay the nests with it, eat the limestone as an additional mineral source and use the mammal droppings to smear the nests with it and thus keep potential predators away from the nests. However, no correlation could be established between the number of objects laid out and the number of matings in the males observed. However, females stay longer near a courtship area where objects are presented. Their presence can attract more females and thus lead to a selection advantage for males who use them frequently and in large numbers to decorate their courtship areas.
The actual courtship of the male consists of a series of complex, ritualized dance steps and movements while the feathers of the neck, head and neck are raised at the same time. They are usually initiated by an increasingly ritualized cleaning of the courtship area, in which the male finally only pauses and lowers his beak, but no longer picks and removes anything. During courtship, among other things, the elongated feathers of the chest and neck are spread like a skirt and the elongated decorative feathers of the head are pushed forward. The iridescent shimmer of the feathers comes into its own in the various, often very rapid movements. The courtship ends when the feathers are put back on and then fly onto a branch near or above the courtship area.
Nest and clutch
The females build the nests high up in trees. So far only a few nests have been examined in more detail. All nests were shallow shell nests. Pigs' excrement was found on the edge of one nest, which supports the assumption that females use the decorative objects laid out in the courtship area when building the nest. According to current knowledge, the clutch consists of only one single egg. It has a cream-colored shell with elongated brown, gray and purple spots, typical of the species belonging to the subfamily of the True Birds of Paradise .
The incubation period and the time that the nestling spends in the nest from hatching to escaping have not yet been described.
Life expectancy
To date, not enough blue-naped birds of paradise have been ringed and found to be able to make statements about the life expectancy of this species from these data. A single adult male ringed on October 29, 1978 was recaptured in the same location on December 7, 1986. Life expectancy is therefore likely to be well over nine years.
attitude
Blue-necked birds of paradise have been kept on various occasions in Papua New Guinea, Europe or the USA. The keeping requires an aviary that is sufficiently large, has light and dark places and a flat bathing area. Up until the end of the 20th century, however, there were no successful offspring of this species. The descriptions of courtship behavior were mainly made on captured males. The descriptions of courtship behavior by Clifford and Dawn Frith are based on two males made in the Baiyer River Sanctuary , Papua New Guinea and the Rotterdam Zoological Garden , respectively.
Hybrids with other birds of paradise
The tendency of birds of paradise to cross with other species in their family was already described by Anton Reichenow at the beginning of the 20th century and thus almost earlier than for any other bird family. Most of the hybrids that are discovered are males - deviating plumage features are more noticeable in them than in the more inconspicuously colored females. Deviating from a female has been scientifically described, consisting of a junction of the neck Blue Bird of Paradise with the Blue Bird of Paradise emerged.
Trivia
The name of the Helena bird of paradise, a subspecies of the blue-naped bird of paradise, honors Helena of Great Britain and Ireland , the third daughter of Queen Victoria .
literature
- Bruce M. Beehler , Thane K. Pratt: Birds of New Guinea; Distribution, Taxonomy, and Systematics. Princeton University Press, Princeton 2016, ISBN 978-0-691-16424-3 .
- Clifford B. Frith, Bruce M. Beehler : The Birds of Paradise - Paradisaeidae. Oxford University Press, Oxford 1998, ISBN 0-19-854853-2 .
- Eugene M McCarthy: Handbook of Avian Hybrids of the World. Oxford University Press, Oxford 2006, ISBN 0-19-518323-1 .
Web links
Single receipts
- ↑ a b c Handbook of the Birds of the World zur Blaubrust-Paradieselster , accessed on July 13, 2017
- ↑ a b Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 284.
- ↑ a b c Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 285.
- ↑ a b c Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 283.
- ^ Beehler and Pratt: Birds of New Guinea. P. 422.
- ↑ a b Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 286.
- ↑ a b Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 287.
- ↑ a b Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 288.
- ↑ Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 289.
- ↑ a b Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 291.
- ↑ a b Frith and Beehler: The Birds of Paradise - Paradisaeidae. P. 292.
- ^ McCarthy: Handbook of Avian Hybrids of the World . P. 228.
- ^ McCarthy: Handbook of Avian Hybrids of the World . P. 231.