Red shoulder star
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Red-shouldered gloss star ( Lamprotornis nitens ), Namibia |
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| Lamprotornis nitens | ||||||||||||
| ( Linnaeus , 1766) |
The Cape Starling ( Lamprotornis nitens ), from the genus " Actual starlings ," is an endemic widespread in southern Africa passerine bird of the family of starlings . It has a strongly metallic, shimmering, iridescent plumage in blue to purple hues and is considered a monogamous bird. It feeds on various insects and fruits, but also on people's leftovers. It belongs to the genus Common Starlings, to which 22 species are currently counted, and its species is not considered endangered.
features
Physique and plumage
The fully grown red-shouldered gloss star is about 23-27 cm long and weighs 75-105 grams. Size and weight vary from region to region, as is the color, which ranges from blue to greenish-blue tones. The plumage has uniform, strongly iridescent metallic shimmering colors, especially on the upper side. It has so-called structure feathers, which produce their colors without pigments by refraction. The special shine is caused by the melanosomes embedded in the structure of the feathers in the melanocytes , which are under a keratin film . The special feature of these melanosomes are their platelet-like and hollow shape. The platelets are single and / or multi-layered. They can be arranged uniformly in their order or alternating (alternating). The head plumage, neck, sides of the neck as well as throat and chest are kept in shiny, strong shades of blue. The plumage around the ear covers usually appears in dark to black tones. On the short tail, the upper tail covers as well as shoulders, back and wings have strong blue to greenish-blue hues. Its name Rotschulterglanzstar comes from the few reddish-purple feathers on the shoulders, which are often barely recognizable. The appearance of the colors depends very much on the lighting conditions. One and the same bird can have very different intensities in its colors and appearance. The color of the legs and the beak are black.
The young birds have an inconspicuous matt plumage on the upper side. The ventral side is dark gray to black. The plumage reaches its adult color and shine after about six months.
eyes
In adult glossy red-shouldered starlings, the eyes have a shimmering iris in yellowish / orange tones . The stern to piercing-looking look, which is caused by the disproportionately large eyes, is typical of the real starlings. The eyes of the juveniles do not yet have distinctive colors and are gray. After about three months, the eyes will slowly turn yellow / orange. Like most bird species, except for the nocturnal birds, the red-shouldered starlings see their environment differently than we humans do. In contrast to humans, the star has four and not just three types of photoreceptors (also called photoreceptors ) on the retina for color vision . In addition to the thinner rod-shaped receptors responsible for black and white vision, four cone-shaped receptor types are responsible for perception in starlings (tetrachromatic vision). Three of the four cone-shaped receptor types are responsible for the area of light that is visible to humans (trichromatic vision), which make the three primary colors red, green and blue visible. The fourth receptor is responsible for the perception in the area of ultraviolet light , which is not visible to humans. The incidence of light stimulates the various types of receptors within the strongly folded membranes, which are provided with different colored oil droplets, with different intensities. The responsible receptors react more or less strongly to the different wavelengths of light, so that the different colors and hues are perceived. The additional UV receptor compared to humans allows starlings to perceive our environment in a much more differentiated or different way. With the help of the UV receptors, the star is able to better and more easily recognize differences in other conspecifics, the degree of ripeness of the fruit or traces that we cannot see.
Vocalizations
His singing is long-lasting, warbling, varied tones. In some cases, he not only imitates different species of birds, but also other sounds from his environment.
Habitat and Distribution
The red-shouldered star lives in the sub-Saharan countries of southern Gabon , western and southern Angola , southern Zambia , Zimbabwe , Namibia , Botswana , Mozambique and South Africa , including the independent enclaves of Swaziland and the Kingdom of Lesotho . It also migrates through the Democratic Republic of the Congo , in which it does not breed. Its distribution area amounts to about 3,000,000 km². A considerable population is also found in the area of the Kalahari with isolated trees.
The red-shouldered gloss star colonizes very different habitats. Areas with widely spaced trees, plantations, bushland, savannas and overgrown grasslands belong to it. It is also at home in urban areas , parks and gardens.
Way of life
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The red-shouldered starling is a widespread sociable bird in southern Africa. Outside the breeding season, it often occurs in larger flocks.
It usually feeds continuously and hopping on the ground on insects such as ants, grasshoppers, beetles and caterpillars, as well as on fruits and the nectar of various plants. It is not tied to certain types of plants. The gregarious bird also eats its food in association with other starlings. It also occurs together with antelopes, which it frees from the ectoparasites .
The red-shouldered star is used to people around him. He does not reject leftover food either.
Reproduction
In the breeding season, the monogamous couples withdraw to build nests. The nests are usually built in natural tree hollows or in holes made by woodpeckers and African bearded birds (Lybius), or in holes in the ground such as in sandbanks. Artificial man-made nesting sites are also used. (Incubators, metal tubes, other cavities) He builds the nests out of dry grass, feathers, cow and horse dung and snake skins. The nests are used regularly over many years. A couple has been observed who have used their nest for 20 years.
The breeding season is from September / October to February / March, in which the pairs lay between 2 and 6 greenish blue, slightly reddish speckled eggs, which are only incubated by the females for 12-14 days. The young birds are fed by both parents and are usually supported by several helping conspecifics. After about 20 days, the young birds fledge and remain in the group for at least a week.
Enemies and parasites
It is reported that red-shouldered starlings have fallen prey to peregrine falcons and elected mountain eagles .
There are also reports of several breeding parasites that the starlings use as adoptive parents. Birds from the honey indicator family (Indicatoridae) and the jay cuckoo , which belongs to the African bearded bird family (Lybiidae), are said to use the starlings as host parents.
Existence and endangerment
There is no reliable information on the size of the world population, but the species is very common in most of its range and the population is stable. The red shoulder star is therefore classified by the IUCN as 
(= least concern - not endangered).
Systematics
The red-shouldered gloss star of the genus actual gloss starlings ( Lamprotornis ) is related to six other species, two of which are directly related. One of these is its sister species the enlightening star ( Lamprotornis chalcurus ).
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Taxonomic classification of red-shouldered gloss star ( Lamprotornis nitens )
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literature
- The red shoulder star (Lamprotornis nitens). 2012. Lamprotornis nitens. IUCN Red List of Threatened Species. Version 2014.3. International Union for Conservation of Nature. (on-line)
- A. Craig, C. Feare: Cape Glossy Starling (Lamprotornis nitens). 2009. In: J. del Hoyo, A. Elliott, J. Sargata, DA Christie, E. de Juana (Eds.): Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona 2014. ( online , accessed March 22, 2015)
- S. Butchart, J. Ekstrom: Species factsheet: Lamprotornis nitens. BirdLife International. Retrieved September 9, 2014.
- AJFK Craig: Glossy starling: Kleinglansspreeu (Lamprotornis nitens). In: The Atlas of Southern African Birds.
- Rion E. Lerm: The breeding ecology of Cape glossy starlings at a nest site in the Kalahari. 2014.
- PAR Hockey, WRJ Dean, PG Ryan: Roberts Birds of southern Africa. 7th edition. Voelcker Bird Book Fund, Cape Town 2005
- Biodiversity explorer. iziko museums of Cape Town "The web of life in southern Africa". Accessed March 22, 2015. (online)
- IJ Lovette, DR Rubenstein: A comprehensive molecular phylogeny of the Starlings (Aves: Sturnidae) and mockingbirds (Aves: Mimidae) _ Congruent mtDNA and nuclear trees for a cosmopolitan avian radiation. In: ScienceDirect. Columbia University. Accessed on March 22, 2015. ( Full text, PDF ( Memento from December 16, 2011 in the Internet Archive ))
- Rafael Maia, Dustin R. Rubenstein, Matthew D. Shawkey: Key ornamental innovations facilitate diversification in an avian radiation. In: PNAS. 110, 26, 2013, pp. 10687-10692. doi: 10.1073 / pnas.1220784110 . ( Full text , accessed March 26, 2015)
- Frederike Woog: Seeing and being seen - the color vision of birds. In: Der Falke - Journal for Bird Watchers. 5/2009. ( Schattenblick.de . Accessed July 11, 2015.)
- GE Hill, KJ McGraw (Ed.): Bird Coloration. Vol. 1: Mechanisms and Measurements ; Vol. 2: Function and Evolution. 2006.
Web links
Individual evidence
- ↑ a b c d e f A. Craig, C. Faere: Handbook of the Birds of the World Alive. . hbw.com, 2015. Retrieved March 22, 2015.
- ↑ Rafael Maia, Dustin R. Rubenstein, Matthew D. Shawkey: Key ornamental innovations facilitate diversification in an avian radiation. In: PNAS. 110, 26, 2013, pp. 10687-10692. (pnas.org)
- ↑ Frederike Woog: See and be seen - color vision of birds. In: Der Falke - Journal for Bird Watchers. 5/2009. (schattenblick.de)
- ↑ AJFK Craig: Glossy starling: Kleinglansspreeu (Lamprotornis nitens). In: The Atlas of Southern African Birds. Retrieved September 9, 2014; Rion E. Lerm: The breeding ecology of Cape glossy starlings at a nest site in the Kalahari. 2014.
- ↑ a b c d e ( Lamprotornis nitens ) . In: Roberts Birds of southern Africa. biodiversityexplorer.org, 2015. Retrieved March 22, 2015.
- ^ A b S. Butchart, J. Ekstrom: Red-shouldered Glossy-starling ( Lamprotornis nitens ) . birdlife.org, 2015. Retrieved March 22, 2015.
- ↑ Irby J. Lovette, Dustin R. Rubenstein: A comprehensive molecular phylogeny of the Starlings. ( Memento of the original from November 17, 2015 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. on: columbia.edu , 2007, accessed March 22, 2015.
