Red-necked Shrike
| Red-necked Shrike | ||||||||||||
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Red-rump Shrike (Figure 2) |
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| Scientific name | ||||||||||||
| Lanius gubernator | ||||||||||||
| Hartlaub , 1882 |
The red- rumped shrike ( Lanius gubernator ) is a songbird from the genus of the real shrike ( Lanius ) within the family of the shrike (Laniidae).
The only roughly house sparrow-sized , somewhat clumsy-looking, rust-brown, gray and black-marked species occurs in individual, widely separated islands of distribution of different sizes north of the equator and north of the rainforest area from the Ivory Coast eastwards to about Lake Albert . The red-rumped shrike is the smallest Lanius species.
Like most representatives of the genus, the red- rump shrike is also a hide hunter who searches the area for prey, mainly insects , from an elevated viewing point and beats them on the ground. It mostly lives in pairs, but family groups have also been observed, which make cooperative breeding appear not unlikely.
The species was named after Eduard Schnitzer , who was governor of the then province of Equatoria . (Latin gubernare = to govern, to lead); The common English name Emin's Shrike also goes back to Eduard Schnitzer, who was named as Governor Emin Pascha.
According to the IUCN , the species is currently (2017) not endangered. Their relationship within the genus is not clear. The similar but larger rust-coated shrike, which is distributed south of the equator, is considered a sister species . No subspecies are described.
As with some African lanius species, only a few biological details are known about the red-rumped shrike.
Appearance
The red-rump shrike measures between 14 and 16 centimeters and weighs a little over 20 grams. It is the smallest representative within the genus of the real strangler. The sex difference is small in terms of coloration.
In terms of plumage, the species is similar to the rust-coated shrike, but due to its small size it can hardly be confused with it; in addition, the distribution areas of the two species are widely separated. Also similar, migrating male Neuntöter should on the basis of color differences (rust-brown rump, white wing box when Rotbürzelwürger, gray-brown rump, usually lack of white wing box, the red-backed shrike) and the size be sure distinguishable. L. gubernator clearly differs from the red- tailed shrike ( Lanius phoenicuroides ), which also appears in the boreal winter in the distribution area of the red- tailed shrike, by its black tail; this is reddish brown in the red-tailed shrike.
Adult males have a light slate-gray head except for the black face mask that is typical of the strangler. The slightly darker slate-gray color of the neck, the upper section of the mantle and part of the shoulder feathers merges slightly into the rich chestnut brown of the lower part of the mantle, the back and the rump as well as the upper tail covers. The inner control feathers are dark brown, the outer ones white. The chin, throat and upper chest are white. Chest, belly and rump in different intensities and variably reddish-brown in color or breathy. The wing feathers are dark brown to black, the five inner arm wings are white at the base, which creates a clear white, sickle-shaped speculum in the flying bird , which is always visible even in the seated individual and is relatively large at 12 mm. The black face mask begins at the base of the beak and runs - slightly widening - to far behind the ear covers . The dark eyes are almost completely covered by her. At the top, the face mask is delimited by a fine, white stripe. The mighty hooked bill is dark brown to black, the legs are gray-black. Females are similar in color distribution to males, but the colors are generally more indistinct, the contrasts more washed out and the gray parts on the upper side more extensive than with fully colored males. The face mask is narrower and absent or only indicated on the forehead; the white wing mirror is smaller or cannot be seen at all when sitting. The underside is blushed reddish brown; the banding, which is otherwise common in female stranglers, is missing. Male juveniles are brownish on the top, reddish brown on the underside and clearly banded, especially on the flanks. Female juveniles are dark gray-brown on the upper side and clearly banded black, especially on the crown and neck; on the underside they resemble juvenile males. The face mask is shorter and narrower in both sexes than in adults and is gray-brown in color.
Vocalizations
The singing and calls of the species are little known. Apparently no sound recordings exist yet. The red-rumped shrike does not seem to be particularly noticeable acoustically. He is seen more often than heard. When a group gets together, their acoustic activity increases. The singing is described as a pleasant, rather quiet chirping and trilling, interspersed with whistles and rough, croaking phrases in the manner of a strangler. In addition, different, mostly rough, hoarse, repeated calls, which are transcribed with chark ... chark or zu ... zu .
distribution and habitat
Only a few islands of distribution are secured, which extend from the Ivory Coast in the west to South Sudan and northern Uganda in the east. All known breeding areas are between the dry Sahel zone and the coast of the Atlantic , or the humid rainforest areas of the Congo Basin . Outside of these isolated distribution areas, the species is occasionally observed, for example in Mali . It seems to be rare, at least nowhere, but, as recently documented breeding occurrences in central Ghana and Burkina Faso as well as evidence of the species in many protected areas suggest, it could also have been overlooked regionally due to its inconspicuous behavior. According to current knowledge, the greatest distribution density is in the east of the breeding area in the extreme NE of the Democratic Republic of the Congo and in NW Uganda. The red-rump shrike has so far been found at heights between 150 and 1500 meters.
The main habitat of the species appears to be tree-covered grasslands of the Guinea-Sudan savannah type. This moderately dry type of landscape is mainly characterized by different tall grasses and different tree species such as Isoberlinia doka , Daniellia oliveri and Parkia biglobosa . There are denser tree-lined sections with otherwise short or no undergrowth, as well as gallery forests along rivers. In these areas, crops are grown and the trees are used to collect firewood, so that the species also appears on cultivated areas and in the vicinity of human settlements. L. gubernator is also found sporadically to the north of it, in the dry bush savannahs south of the Sahel . Within these landscape types, open, as short-grassed or vegetation-free areas as possible, loosened up with trees or bushes, form breeding habitats of special quality.
No information is available on settlement density and area size.
hikes
Whether the species is resident or undertakes seasonal migrations is largely unknown. However, since L. gubernator was only observed in Mali between August and November, one suspects at least small-scale migration of individual populations.
Food and subsistence
There is hardly any data available on these aspects either. Apparently the species is predominantly or exclusively insectivore . Representatives of the beetles , catching terror and grasshoppers seem to be among the preferred prey animals.
The main hunting strategy is, as with almost all representatives of this species of bird, high seat hunting . L. gubernator searches the immediate area for suitable prey from an elevated viewing point (bush, tree, termite mound , or even telephone line) . If he discovers one, he slides off the raised hide and hits it on the ground. Smaller prey animals are consumed on the spot, larger ones carried to a feeding place and eaten there. It is not known whether the red-rump shrike impaled prey and maintains skewers . The hunting method requires a good view of the ground, so it is not possible anytime and anywhere. The species therefore also prey on insects in flight and was observed when searching the foliage for insects.
Behavior and brood
Like all species of this genus, the red-necked shrike is also diurnal; he usually lives in pairs, about whose formation and existence nothing is known. Occasionally the species is observed in groups, probably family groups, which may indicate (at least occasional) cooperative breeding . Similar behavior was found in his suspected closest relative, the rust-coated shrike. Nothing is known about the nest location and nest construction. Average clutch size, incubation duration and breeding success have not yet been documented either. As far as we know, the main breeding season is at the beginning of the respective rainy season . In South Sudan and the Democratic Republic of the Congo this is in March and April, in the west a little earlier.
Systematics
The species was first described in 1882 by Carl Johann Gustav Hartlaub . Apparently the documents were collected by Emin Bey himself and given to Hartlaub for determination. In a later article, Hartlaub named Langomeri in Uganda as the place where the type specimen was collected .
Despite the extensive distribution area, the geographical variation is very small, so that no subspecies are recognized. The similar, mainly south of the equator widespread rust-coated shrike is considered a sister species. Since more recent molecular biological studies do not exist, the relationship of the species within the genus must be assessed as unclear.
Persistence and Threat
There are no studies on the population of the species. It is considered rare in places and does not seem to be common anywhere. It is also unknown whether the occurrences are restricted to individual distribution islands or whether one can assume a distribution belt, as Lefranc suspects. A total of 10 states report the species as a breeding bird. The birds found relatively far north of the known breeding areas in Mali are likely to be non-breeders. The HBW measures the size of the distribution area at 130,000 km² and assumes a total population of less than 70,000 individuals. Due to the size of the distribution area and the fact that the habitat of the species is not exposed to any immediate danger, the IUCN assesses the population situation of the species as LC = least concern .
literature
- Tony Harris, Kim Franklin: Shrikes & Bush-Shrikes. Including wood-shrikes, helmet-shrikes, flycather-shrikes, philentomas, batises and wattle-eyes. Christopher Helm, London 2000, ISBN 0-7136-3861-3 .
- Norbert Lefranc, Tim Worfolk: Shrikes. A Guide to the Shrikes of the World. Pica Press, 1997, ISBN 1-4081-3505-1 .
- Reuven Yosef & International Shrike Working Group (2018): Emins's Shrike (Lanius gubernator) . In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, DA & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (retrieved from http://www.hbw.com/node/60474 on August 28, 2018).
- Evgenij N. Panov: The True Shrikes (Laniidae) of the World - Ecology, Behavior and Evolution. Pensoft Publishers, Sofia 2011, ISBN 978-954-642-576-8 .
Individual evidence
- ↑ Bo Beolens, Michael Watkins, Michael Grayson: The Eponym Dictionary of Birds. Bloomsbury, London / New York 2014, ISBN 978-147-290-573-4 .
- ↑ a b c Lanius gubernator in the Red List of Threatened Species of the IUCN 2017.3. Listed by: BirdLife International, 2012. Retrieved August 28, 2018.
- ↑ a b c d e Reuven Yosef & International Shrike Working Group (2016): Emin's Shrike (Lanius gubernator) . In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, DA & de Juana, E. (eds.). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. (downloaded from http://www.hbw.com/node/60474 on September 12, 2016).
- ↑ a b c d e f T. Harris, K. Franklin: Shrikes & Bush-Shrikes… 2000, p. 202.
- ^ A b T. Harris, K. Franklin: Shrikes & Bush-Shrikes ... 2000, p. 203.
- ^ A b c Norbert Lefranc, Tim Worfolk: Shrikes. A Guide to the Shrikes of the World. 1997 p. 105
- ^ A b c Norbert Lefranc, Tim Worfolk: Shrikes. A Guide to the Shrikes of the World. 1997 p. 106
- ↑ Adult male
- ↑ Photos of the species: 1 adult female; 6 young birds, probably female.
- ^ Françoise Dowsett-Lemaire & Robert J. Dowsett: Exploration of Digya National Park, Ghana . In: Dowsett-Lemaire Misc. Rep. 57 (2009)
- ^ Marco Pavia, Giovanni Boano, Fabrizio Silvano & Karama Mamadou: New bird records from southwestern Burkina Faso . In: Malimbus 34 (2012)
- ↑ Gustav Hartlaub: Diagnoses of new species from Central Africa, collected by Dr. Emin Bey . In: Ornithological Centralblatt . tape 7 , 1882, p. 91-92 ( biodiversitylibrary.org ).
- ↑ Gustav Hartlaub: About some new birds from the upper Nile area . In: Journal of Ornithology. (= 4 ). tape 10 , 1882, p. 321-329 ( biodiversitylibrary.org ).
