Sasia
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Malay mouse woodpecker ( S. abnormalis ) |
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| Hodgson , 1837 |
Sasia (mouse woodpecker ) is a genus of woodpeckers with one species in western and central equatorial Africa and two species in Southeast Asia . Sasia forms with two other genera the subfamily Picumninae (dwarf woodpeckers), which includes thirty very small, short-tailed woodpeckers; the majority of them are native to tropical South America. They are among the smallest woodpeckers in the world. The latest molecular genetic studies suggest that the African species of Sasia has split off and is classified in the monotypic genus Verreauxia .
Mouse woodpeckers are inhabitants of the lower strata of tropical forests, where they prey on their food consisting mainly of ants in the lower branch regions, in the bushy undergrowth, in the bamboo and grass thickets. They live in pairs or small groups and, as far as is known, raise their brood in small, self-made caves.
Overall, little is known about the biology of this genus, and there are no quantitative data on the population or population trends. In spite of the sometimes considerable interventions in the habitat of all three species, the IUCN currently regards the mouse woodpeckers as not endangered (LC = least concern).
features
Mouse woodpeckers are very small, almost tailless woodpeckers with a maximum body length of 10 centimeters with a dark olive-green top and orange-red to rust-red or gray underside. The large head merges almost seamlessly into the relatively massive and clumsy looking trunk. All three species are just under 10 centimeters long and weigh a maximum of around 12 grams. Habitually they are vaguely reminiscent of a wren , which they come close to in size and weight.
The two Southeast Asian species, the Malay mouse Specht ( S. abnormis ) and the Rötelmausspecht ( S. ochracea ) are very similar. The upper side of S. abnormalis is deeply dark green, of the bank vole woodpecker greenish with a differently pronounced rust-red tinge. The cheeks and the entire underside of both species are intensely reddish-orange to rust-reddish. The wings and the very short tail are dark brown. The iris is reddish, the three-toed legs are reddish-orange. The pointed bill, broad at the base, is slightly curved, the upper bill is dark, the lower bill lighter, and greenish-yellow at the base. The eyes are surrounded by a round, reddish-pink, bare skin area. The weakly pronounced sexual dimorphism is limited to the different coloring of the forehead: in males this is wholly or partially yellow, in females it is colored like the rest of the cheek plumage. The clearest distinguishing feature of the two species is a wavy white stripe behind the eyes of both sexes of the bank vole woodpecker. It is completely absent from the Malay Mouse Woodpecker.
The African species, the gray-bellied mouse woodpecker ( S. africana ) has a largely unmarked, dark-gray underside with a very similar dark olive-green upper side coloration. The gray ear covers are partially bordered white behind the eyes and towards the neck. The only external gender difference is the male's rust-red forehead; in the female, like the rest of the skull, this is dark olive-green.
The vocalizations of these woodpecker species are varied, but only one high, weak trill ti ti ti… is known from the gray-bellied mouse woodpecker . Long kih kih kih kih… rows and single or repeated tic and tsit sounds can be heard from the Malay mouse woodpecker , a high trill ti iiiiiii… from the bank vole woodpecker . The latter two types drum frequently and relatively loudly, but this is not known from the gray-bellied mouse woodpecker.
distribution and habitat
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The distribution area of S. africana stretches from South Cameroon southwards to northwestern Angola , eastwards over the Central African Republic and most of the Democratic Republic of the Congo to Uganda . S. abnormalis is distributed from northeast India and southern Nepal southwards via Myanmar and Thailand (approximately to the Isthmus of Kra ), eastwards via southern China to Vietnam . The suspected occurrences in northwestern Cambodia are not confirmed. The habitats of S. ochracea extend from the estuary of the Saluen southwards across the entire Malay Peninsula to East Sumatra , Nias , North and Central Java . Furthermore, large parts of Borneo are inhabited by this species. In the northern part of this distribution area (southwards about to the Isthmus of Kra) both species occur together. No information is available about the distribution of the habitats or possible hybridization of the two species.
All three species inhabit the lowest sections of tropical forests, especially dense undergrowth in secondary forests , bush regions near waterways and bamboo thickets , mostly at heights below 5 meters. S. ochracea in particular seems to be strongly bound to bamboo trees. Open land is not populated by any species. S. africana and S. abnormalis tend to inhabit lowlands and middle elevations (the latter in Thailand at altitudes up to 1300 meters), while S. ochracea has been found in their southern distribution areas up to 1850 meters, in their northern ranges up to 2600 meters.
There are different, sometimes contradicting information about the distribution density, but the smallness of the species, their very mobile way of life in the dense undergrowth of their habitat and the inaccessibility of their distribution areas must be taken into account. All three species seem to be quite common, at least regionally, but to be completely absent elsewhere in their respective distribution zone. For example, there is no evidence of S. abnormalis from Singapore, which has been ornithologically well recorded , although the species is found on the rest of the Malay Peninsula.
behavior
Very little is known about the behavior of the representatives of the genus Sasia . All three species are fast, agile fliers who move nimbly and skillfully in the dense vegetation of their habitat. For this reason and because of their small size, they are very difficult to observe. Mouse woodpeckers appear to live in pairs or small family groups; they are often found associated with other bird species.
Their diet consists of ants and other insects, partly also of larvae, which at least from the gray-bellied mouse woodpecker and the sun mouse woodpecker are also captured by hammering the feeding tunnels. This is not known from the bank vole woodpecker, it wins its prey primarily by searching the substrate surface and by poking, techniques that the other two species also use.
As far as is known, all three species breed in self-made tree or bamboo holes. No information is available on the incubation period; the clutch size is usually two or a maximum of four eggs. The breeding seasons are very variable. Nestlings of the gray-bellied mouse woodpecker were found between July and February, the two Southeast Asian species usually breed between February and July.
Systematics
Sasia was first described in 1837 by Brian Houghton Hodgson using a specimen of the bank vole woodpecker collected in Nepal . Sasia is the Nepalese name of this bird. Together with Picumnus and Nesoctites, it forms the subfamily Picumninae within the family of the woodpeckers (Picidae). The genus consists of three species, S. africana , S. ochracea and S. abnormalis , whose monophyly is undisputed. Nevertheless, there are considerable morphological differences between the Southeast Asian and African species: S. africana has 8 tail feathers and four toes, the first of which is severely regressed, while S. ochracea and S. abnormalis have 10 tail feathers and only three toes. This had led to S. africana temporarily being placed in the monotypic genus Verreauxia Hartlaub , 1856 ; this separation is also used by Fuchs et al. currently approved again. According to current taxonomic assessments, S. africana is the sister species of the group S. ochracea / S. abnormalis , while the latter two are sister species. The two lines of descent were separated at least 7.9 million years ago.
- Sasia africana Syn. Verreauxia africana Verreaux, E & Verreaux, J 1855 : monotypical.
- Belly gray, not red-brown as in the Southeast Asian species; four toes, the first of which has receded, 8 control springs. Because of these differences to S. ochracea and S. abnormalis , the re-establishment of the previously existing genus Verreauxia Hartlaub , 1856, is suggested.
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- Sasia abnormalis ( Temminck 1825) : 2 subspecies that differ only in the length of their beak. 3 toes and 10 control springs. Clearly distinguished from the sister species by the lack of a white stripe above the eye.
- Sasia a. abnormal ( Temminck 1825) Almost the entire range of the species.
- Sasia a. magnirostris Hartert 1901 : Only on Nias; beak slightly longer than the nominate form .
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- Sasia ochracea Hodgson 1837 : Currently three subspecies. However, new studies show a large genetic differentiation in the nominate form alone, which makes a significantly larger number of subspecies appear justified. 3 toes, 10 control springs.
- S. o. Ochracea Hodgson 1837 : North India to Vietnam, except Southeast China and extreme North Vietnam. Very variable with great genetic variation within the subspecies. Overall lighter than the neighboring subspecies S. o. Kinneari to the northeast . Individuals from South Assam to North Myanmar were previously segregated as S. o. Querulivox Stuart Baker in 1926 .
- S. o. Kinneari Stresemann 1929 : Extreme North Vietnam, Southeast China. Overall darker than the nominate form.
- S. o .richowi Hesse 1911 : Myanmar and Vietnam. Clearly distinguished from the other two subspecies by a blackish (not reddish-pink) orbital ring and usually shorter white stripes above the eyes.
Persistence and Threat
The habitat of all three species is primarily threatened by logging and slash and burn and is one of the most endangered habitats on earth. Quantitative surveys and analyzes of the development of the population are not available. At least locally, the three representatives of the genus seem to be not uncommon. For this reason and because of the relatively large distribution areas of all three species, the IUCN evaluates the degree of danger of Sasia as LC (= least concern ) - not endangered - despite the existing risk factors .
literature
- Jérôme Fuchs, Jan I. Ohlson, Per GP Ericson, Eric Pasquet: Molecular phylogeny and biogeographic history of the piculets (Piciformes: Picumninae). In: Journal of Avian Biology. 37: 487 Á496 2006. pp. 487-496; 2006.
- Jérôme Fuchs, Per GP Ericson and Eric Pasquet: Mitochondrial phylogeographic structure of the white-browed piculet (Sasia ochracea): cryptic genetic differentiation and endemism in Indochina. In: Journal of Biogeography. (2008) 35 pp. 565-575.
- Hans Winkler , David A. Christie, David Nurney: Woodpeckers. A Guide to the Woodpeckers, Piculets, and Wrynecks of the World . Robertsbridge 1995, ISBN 0-395-72043-5 .
- Hans Winkler, David A. Christie: Family Picidae (Woodpeckers). In: J. del Hoyo, A. Elliot, J. Sargatal (Eds.): Handbook of the Birds of the World. Volume 7: Jacamars to Woodpeckers. Lynx Edicions, 2002, ISBN 84-87334-37-7 .
Individual evidence
- ↑ H. Winkler, DA Christie, GM Kirwan: African Piculet (Verreauxia africana). 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 2014. hbw.com , accessed October 30, 2014.
- ↑ data sheet p. Abnormal
- ↑ Data sheet S. africana
- ↑ Data sheet S. ochracea
- ↑ Voice examples at xeno-canto
- ↑ Winkler: Woodpeckers. ... 1995, p. 191.
- ↑ Winkler: Woodpeckers. ... 1995, p. 192 and 193.
- ↑ Winkler: Woodpeckers. ... 1995, p. 190.
- ↑ a b c d Winkler: Woodpeckers. ... 1995, p. 192.
- ↑ Winkler 1995 p. 191.
- ↑ Winkler: Woodpeckers. ... 1995, pp. 190, 191 and 192.
- ↑ Fuchs et al. (2008) p. 566.
- ↑ Winkler: Woodpeckers. ... 1995, p. 193
- ↑ Winkler: Woodpeckers. ... 1995, pp. 191, 192, 193.
- ↑ James. A. Jobling: Helm Dictionary of Scientific Bird Names . Helm-London 2011. p. 348 ISBN 978-1-4081-2501-4
- ↑ Fuchs et al. (2006) p. 488.
- ↑ a b Fuchs et al. (2006) p. 495.
- ↑ Fuchs et al. (2006) pp. 487-496.
- ↑ Fuchs et al. (2008) pp. 565-575.
- ↑ Fuchs et al. (2008) p. 566.
