Philippines shrike
| Philippines shrike | ||||||||||||
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| Scientific name | ||||||||||||
| Lanius validirostris | ||||||||||||
| Ogilvie-Grant , 1894 |
The Philippines shrike ( Lanius validirostris ) is a songbird belonging to the genus of the real shrike ( Lanius ) within the family of the shrike (Laniidae). The medium-sized, strongly contrasting with gray, brown and orange brown, black and white colored Strangler is in a respective sub-species on the two main islands of the Philippines , Luzon and Mindanao , and on Mindoro endemic . The species, about the biology of which only a few details are known, occurs in the fringes of tropical oak - pine mixed forests and in open secondary forests at altitudes above 1000 meters.
Philippines shrike are resident birds; probably they roam small areas outside the breeding season. They feed mainly on insects, especially beetles.
The Philippines strangler belongs to the species group around chess shrike and Tibetan shrike . With the latter in particular, it shares many morphological and some behavioral characteristics.
The type specimen comes from the mountain forests of northern Luzon . The scientific species name is made up of the Latin adjective validus (= strong, strong ) and the Latin noun rostrum (= beak ), which means thick -billed , a feature that is also expressed in an English trivial name Strong-billed Shrike .
In view of the limited habitat and its ongoing endangerment, the IUCN lists the species in the early warning level NT = near threatened .
Appearance
The Philippines shrike is a medium-sized shrike with a body length of 21-22 centimeters. This makes it a little smaller than the Tibetan shrike, probably its closest relative. With an otherwise largely identical color distribution, it differs from him primarily through its somewhat more matt plumage and the lack of white wing markings. The beak is more powerful in relation to the somewhat smaller body size. The weight varies between 34 and 45 grams, but these figures are not very representative. There is no color dimorphism . Females appear to be slightly smaller than males on average. The subspecies L. v. validirostris is the largest representative of the species, the Philippines shrike from the comparatively small island of Mindoro ( L. v. tertius ) are the smallest.
The head, neck, shoulders, coat and back are uniform and unmarked, dark slate-gray, with the color intensity varying individually and between the subspecies. Blackish-brown hues can predominate on the lower back. The black mask typical of a strangler is very narrow over the base of the beak and runs - widening - over the eyes to the ear covers . It often has a fine white border towards the top. The upper wing covers and the wings are black-brown. A brownish feather border, which is often noticeable in the Tibetan strangler, is missing; there are also no white drawings on the long, slightly stepped, black-brown tail and on the wings. The entire underside is matt white except for the blackish-brown rump and the reddish-brown under tail-coverts. The flanks are faded orange-brown. The mighty beak is black, the legs blackish. The iris is dark brown. Females are colored the same, but light, dark undulations can often be seen on the flanks (especially in young individuals). Young birds have differently dark waves on the top on a dark brown background, the face mask is only recognizable as a dark spot in the area of the ear covers. The underside is rather light gray and clearly wavy.
Information on the type and phenology of moulting is not available.
Vocalizations
The song of the species is similar to that of some warblers . It is a rather quiet warble, interspersed with shrill whistles and harsh, pressed tones. It is said to be very similar to that of the buffalo head shrike . The alarm call is a croaking, lined up Chrrr ... chrrr and a sharp, multiple lined up Tz (j) ǝk ... tz (j) ǝk ... tz (j) ǝk. The latter in particular corresponds to the alarm call of the Tibetan strangler.
distribution and habitat
The known deposits are on the two main islands of the Philippines, Luzon and Mindanao, as well as on the much smaller island of Mindoro, south of Luzon. It is not known whether the species occurred or occurs on other islands, or whether it is also represented in other suitable habitats on the islands mentioned . Further breeding occurrences are suspected, especially on the Eastern Visayas .
On Luzon the nominate form is proven in the Central Mountain Range and in the Sierra Madre , on Mindoro the distribution areas of L. v. tertius in the north and central part of the mountain range that runs through the islands from north to south, with Mount Halcon as the highest mountain. The occurrences of L. v. hachisuka are located in the Mount Malindang National Park , in the mountains of Misamis Oriental , in the Kitanglad region and on and around Mt. Apo .
In these areas, the species prefers to inhabit the edge zones of original, light oak-pine mixed forests and secondary forests , natural clearings and clearings created by logging as well as bush-covered grasslands in the vicinity of these mountain zones. She avoids the interior of denser forests. The Philippines shrike is not represented as a breeding bird below 1200 (1000) meters, the highest breeding records come from heights of around 2400 meters.
In addition to the Philippines shrike, the subspecies L. s. nasutus of the chess strangler only one type of strangler. Their distribution is clearly separated from that of the Philippine shrike: Chess shrike loosely populate grasslands with trees or bushes in the plains and the hill step.
Biological details
Little information is available on the biology of the species. Their informative value must be viewed critically, as they are based on only a small number of observations.
Philippines shrike are resident birds . Vertical migration and roaming around outside the breeding season are suspected. The species lives in pairs and appears to have a monogamous permanent partnership.
Philippines shrike, like most other species of shrike, are hide hunters . From an exposed seat guard, you observe the surroundings in a similar upright position as the Tibetan strangler; if they discover a prey, slide off the hide and hit it on the ground. The diet apparently consists mainly or exclusively of insects , mainly medium-sized and large beetles . The particularly powerful beak could be an adaptation to this food. It is possible that the Philippine shrike occasionally hunt on the ground.
The species is likely to be territorial, at least during the breeding season. There is no information on nest construction, type of nest, clutch and clutch size, or the duration of the brood. Individuals collected in February had significantly enlarged gonads . Feeding Philippines stranglers were observed in mid-May.
Systematics
The systematic position of the species within Lanius has not been fully clarified. It is assumed that the Tibetan strangler is the sister species of the Philippines strangler, and that the chess shrike is to be placed in the very closest relatives. The differentiation into three subspecies indicates a very early settlement of the archipelago. The chess shrike, which also occurs in the Philippines, is only represented in one subspecies, so it seems to have reached the archipelago later.
Three subspecies are described. A poorly differentiated fourth subspecies, L. v. quartus Rand & Rabor 1957 from Malindang, Mindanao is no longer recognized and to L. v. hachisuka posed.
- Lanius v. validirostris Ogilvie-Grant , 1894 : Luzon. Described above; largest subspecies.
- Lanius v. hachisuka Ripley , 1949 : Mindanao. In the size between the nominate form and L. v. tertius . White on the underside greatly reduced. Flanks intensely rust-brown.
- Lanius v. tertius Finn Salomonsen , 1953 : Mindoro. Smallest subspecies. Underside almost entirely washed out reddish brown.
Stock situation
Both the stock situation and the population dynamics are largely unclear. Due to the relatively small distribution area, the fragmented occurrence and the risk of habitat loss as a result of deforestation, the species was placed in the early warning level NT (= near threatened) in 1994. This classification was confirmed in 2012. In contrast to this rather pessimistic classification, more intensive research recently has shown that the Philippines shrike is not uncommon in suitable habitats and that the mountain forests are relatively safe from human interference at the moment.
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 .
- R. Yosef, E. de Juana: Mountain Shrike (Lanius validirostris) . In: J. del Hoyo , A. Elliott, J. Sargatal, DA Christie, E. de Juana (Eds.): Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona 2013, accessed July 7, 2016.
- 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
- ↑ a b c d e f g h i j R. Yosef, E. de Juana: Mountain Shrike (Lanius validirostris) . In: J. del Hoyo , A. Elliott, J. Sargatal, DA Christie, E. de Juana (Eds.): Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona 2013, accessed July 7, 2016.
- ↑ a b Lanius validirostris in the IUCN Red List of Threatened Species 2014.3. Listed by: BirdLife International, 2012. Retrieved July 7, 2016.
- ↑ Very good photos - scroll down to get an overview
- ↑ a b c EN Panov: The True Shrikes (Laniidae) ... 2011, p. 659.
- ↑ a b c d e f g T. Harris, K. Franklin: Shrikes & Bush-Shrikes… 2000, p. 212.
- ↑ EN Panov: The True Shrikes (Laniidae) ... 2011, pp. 659-660.
- ^ T. Harris, K. Franklin: Shrikes & Bush-Shrikes ... 2000, p. 211.
- ↑ EN Panov: The True Shrikes (Laniidae) ... 2011, pp. 663–664.
- ↑ a b c EN Panov: The True Shrikes (Laniidae) ... 2011, p. 662.
- ^ Austin Loomer Rand and Dioscoro S. Rabor: The Races of the Shrike, Lanius validirostris . In: Fieldiana Zoology v.39, no.11 (1958)
