Cambodia tailor bird
| Cambodia tailor bird | ||||||||||||
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Cambodia tailor bird ( Orthotomus chaktomuk ) |
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| Scientific name | ||||||||||||
| Orthotomus chaktomuk | ||||||||||||
| Mahood et al., 2013 |
The Cambodia tailor's bird ( Orthotomus chaktomuk ) is a songbird species from the stalksinger family (Cisticolidae). The approximately 8 to 9 cm long birds have a reddish head plumage, a slate-gray body top and a light gray belly. Their distribution area is in southern Cambodia , where they inhabit the floodplains of the Mekong , Tonle Sap and Bassac . Orthotomus chaktomuk feeds on small arthropods , which it catches in the branches of bushes. The breeding biology of the species is unexplored, it may breed between March and April.
The Cambodia Tailor Bird was set up in 2013 by a research group led by Simon Mahood . This was preceded by discussions about birds found in field studies that could not be clearly assigned to the gray tailor bird ( O. ruficeps ). The closest relative of the Cambodia tailor bird is the barley tailor bird ( O. atrogularis ). The population of the species is unknown. Since the current land and water use in Cambodia is causing the habitat it uses to decline, it could fall into the IUCN's Near Threatened category. A corresponding assessment is still pending.
features
Physique and coloring
The Cambodia tailor bird has a body length of about 8–9 cm. Adult birds can weigh 7 to 8 g. In view of the few individuals measured so far, it is not yet possible to say with certainty whether there is a gender dimorphism in terms of size . The wing length is 45–47 mm, the tail measures 41–42 mm. The elongated, slender and slightly downward curved bill becomes 13-14.5 mm long, the barrel has a length of 19.0 to 19.5 mm.
There are slight differences in color between the sexes. The male is colored reddish-cinnamon brown on the forehead and the skull. In the female, the apex coloration is less strong and does not extend so far back. The cheeks, beard streaks and ear covers are white in both sexes. The stripes on the cheeks and under the beard are dark gray, which gives the cheek area a black and white speckled appearance. The neck, back and rump are medium gray, slightly darker in the male than in the female. The flight feathers are a little darker than the coat and have a slight brownish tinge. Fresh hand wings have whitish inner flags, which probably turn yellow-brown over time. The thumb wing and axillary feathers are white. The slightly rounded tail is likely medium gray when fresh and has a dark gray subterminal band and white lace hems. The throat and chin are striped white and black, whereby the intensity of the black color is greatest on the throat, where hardly any white feathers are visible. On the other hand, it disappears towards the sides of the neck and towards the chest, often only light gray stripes can be seen on the stomach. Males show a very dark throat region, whereas in females the drawing is usually only hinted at. The abdomen is whitish gray, the thigh plumage is whitish yellow. The upper beak is dark horn-colored, while the lower beak is light pink. The legs and toes are also light pink, the iris is orange-brown.
Immature individuals are usually lighter in color than adult birds and do not have such pronounced throat markings. Their wings usually have an olive-brown edge and their tail is shorter than that of adults .
Vocalizations
The males' singing is long lasting, often lasting more than a minute. It consists of a rapid sequence of chirping syllables that form rising or falling phrases and often culminate in a particular sound. The female responds to these utterances with a high trill.
distribution
The known range of the Cambodia tailor bird is in southern Cambodia . It extends from the south-eastern floodplains of the Tonle Sap south along the river of the same name to its mouth in the Mekong . From there it extends upstream to Kampong Cham in the northwest , and in the south it encompasses the common marshland of Bassac and Mekong up to the Cambodian southern border. The exact extent of the distribution area is not known, but it apparently does not extend beyond the alluvial plains of Tonle Sap Bassac and Mekong. In view of the regional vegetation, an occurrence in Vietnam is unlikely, the species area covers less than 10,000 km².
habitat
The Cambodia tailor bird lives in bushland near the river, which is regularly flooded, at least during the rainy season. It consists mainly of bushes 2 to 6 m high that are close together. The vegetation is seldom broken up by grass or trees. O. chaktomuk avoids forests, where it is replaced by the barley tailor bird ( O. atrogularis ). In more open forms of vegetation, for example in gardens, it is replaced by the red- fronted tailor's bird ( O. sutorius ). Corresponding habitats in Cambodia are between 3 and 25 m above sea level.
Way of life
nutrition
The diet of the Cambodia tailor bird is made up of insects and other arthropods that the birds pick up from leaves. They move in all levels of the vegetation. During the flood season, they balance on branches just above the water surface to catch spiders, flies, caterpillars or grasshoppers. They swallow their prey immediately.
Social behavior
Adult specimens were observed almost exclusively in bisexual pairs, often supplemented by a young bird seasonally. Before the moult, mixed-sex pairs of young birds or of young and adult birds were also sighted, last year's individuals also appeared alone.
Reproduction
There is no reliable knowledge about the breeding biology of the Cambodian tailor bird. Based on the changed reaction of males and females to the playing of songs in March and April - males responded intensely, females hardly - it can be assumed that the breeding season lies within this period. Observations of the species are generally difficult because it usually resides in the interior of bushes and often only appears in the outer branches on vocal recordings.
Systematics
The taxonomic history of the species dates back to 2009. During a routine examination of wild birds for avian flu in January of that year, four tailor birds of the genus Orthotomus were found in southern Cambodia. A comparison of different photos of the animals led to a determination as a gray tailor bird ( O. ruficeps ), which was mainly indicated by the confusion of the place of discovery with a coastal area. Three years later, another bird was found near Phnom Penh that looked very similar to the other four and was accordingly classified as a gray tailor bird . In June 2012, photos of this second site aroused the interest of Simon Mahood , who suggested that the birds could be assigned to their own species. In extensive field studies, two adult males, two immature females and another immature male were caught, which Mahood compared with the hide of various tailor-made birds. Mahood and his co-authors Ashish Joshia Ingty John , Jonathan Charles Eames , Carl Oliveros , Robert G. Moyle , Hong Chamnan , Colin M. Poole , Howie Nielsen and Frederick H. Sheldon finally described a new species for these birds on the 2013 they justified with differences in coloration, characteristic vocalizations and genetic monophyly . They gave her the specific epithet chaktomuk . It refers to the Chaktomuk ( Georgian "four faces" ), the landscape along the Tonle Sap, the Mekong and the Bassac and their marshes.
The molecular genetic investigations of the authors classified O. ckaktomuk as the closest relative of the barley tailor bird ( O. atrogularis ). Both species form the sister clade of the gray and rust cheek cutters ( O. sepium ). The samples from O. atrigularis and O. chaktomuk differed only slightly with 1.3% of the base pairs, which suggests a relatively young speciation probably in the Pleistocene (around 2 million years ago).
status
No statement can be made about the population of the Cambodia tailor bird. The species is evidently a very common bird in its habitat, but has a clearly limited range. Their habitat is heavily influenced by anthropogenic influences such as clearing, agriculture and water use. On the one hand, the succession of scrubland through forests is being held back by human land use; on the other hand, the dam construction measures along the Mekong are likely to lead to a changed flood regime and thus to increased arable farming. This could mean that many habitats along the Mekong could fall dry. In view of the relatively small distribution area, Mahood and colleagues therefore suggested a preliminary classification as Near Threatened (type of warning list) by the IUCN or BirdLife International . However, should the species occur more frequently along the Tonle Sap than previously assumed, it should be classified as harmless. An official hazard classification is still pending.
swell
literature
- Simon P. Mahood, Ashish Joshia Ingty John, Jonathan C. Eames, Carl H. Oliveros, Robert G. Moyle, Hong Chamnan, Colin M. Poole, Howie Nielsen, Frederick H. Sheldon: A new species of lowland tailorbird (Passeriformes: Cisticolidae: Orthotomus) from the Mekong floodplain of Cambodia . In: Forktail . tape 29 , 2013, p. 1–14 ( online [PDF; 652 kB ]).
Individual evidence
- ↑ a b Mahood et al. 2013, p. 2.
- ↑ Mahood et al. 2013, pp. 5-6.
- ↑ Mahood et al. 2013, p. 5.
- ↑ Mahood et al. 2013, pp. 6-7.
- ↑ a b c d Mahood et al. 2013, p. 8.
- ↑ Mahood et al. 2013, pp. 7–8.
- ↑ Mahood et al. 2013, pp. 1–2.
- ↑ Mahood et al. 2013, p. 12.
- ↑ Mahood et al. 2013, pp. 8–9.
Web links
- Photos for Orthotomus chaktomuk in the Oriental Bird Club image database , accessed June 29, 2013
- xeno-canto: sound recordings - Orthotomus chaktomuk