Rarotonga star
| Rarotonga star | ||||||||||||
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| Systematics | ||||||||||||
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| Scientific name | ||||||||||||
| Aplonis cinerascens | ||||||||||||
| Hartlaub & Finsch , 1871 |
The Rarotonga starling ( Aplonis cinerascens ) is a songbird species from the genus of the song starling ( Aplonis ). It is endemic to the island of Rarotonga in the southern Cook Islands .
features
The Rarotonga star reaches a height of 21 cm and a weight of 77 to 88 g. The general appearance is gray-brown. The forehead and top of the head are mouse-brown with a faint purple sheen. The coat, back and rump are mouse-brown with gray feather edges. The wings and tail are dull brown. The inner arm wings have lighter hems. The chin, throat, chest and upper abdomen are mouse-brown. Broad, bright feather tips can be seen on the chest and stomach. The lower abdomen and the tail-coverts are whitish. A sometimes dark brown inner ring and a narrow yellow outer ring run around the light yellow iris. The bill and legs are black. The sexes are similar. The juvenile birds have not yet been described.
Vocalizations
The song is described as lovely and the most melodious of all Rarotonga's songbirds. The call includes beeps, whistles and bell-like tones.
habitat
The habitat includes mostly undisturbed mountain forests, but also disturbed marginal forests in the rugged hinterland from 150 m to the highest point of the island at 600 m. Sometimes it can also be observed at low altitudes of up to 30 m, but much less often in the coastal regions than was previously the case.
Way of life
Eating behavior
The Rarotonga Star feeds on fruits in the canopy and on flower nectar or it picks insects from the leaves. He goes in search of food singly or in pairs.
Reproductive behavior
The breeding season extends from August to December. The nest is built in a tree hollow four to six meters above the ground and lined with dead leaves and plant fibers. Preferred breeding trees include Bischofia javanica , Homalium acuminatum, and Hernandia moerenhoutiana . The nest box is used again and again in the later years. The clutch consists of at least two eggs.
status
The IUCN classifies the Rarotonga Starling in the category of "endangered" ( vulnerable ). In the 19th century the species was still considered common and in 1973 not yet rare. In the 1980s, however, only between 100 and 3000 specimens were estimated. In 1997 the population was estimated to be around 500 and in 2010 1200 based on a detailed field study at one location that was extrapolated to the entire suitable habitat on the island. In 2011, the population was estimated at 2,350 specimens based on samples taken in nine distant inland valleys. It is likely that the Rarotonga star has disappeared from the lowlands in the past 40 years, and while the population is currently viewed as stable, it could be declining unnoticed. When the last inventory was made in 2011, the starlings were relatively localized and not evenly distributed in their range. The main threat is competition with the Shepherd Maina ( Acridotheres tristis ), the spread of which is discussed as the cause of the decline of many endemic land birds on Rarotonga. Other threats include rats, exotic bird diseases and climate change.
literature
- Hartlaub, G. & Finsch, O .: On a collection of Birds from Savai and Rarotonga Islands in the Pacific . In: Proceedings of the Zoological Society of London, 1871. pp. 29–30 (first scientific description)
- Mayr, Ernst (1942): Birds collected during the Whitney South Sea Expedition. 48. Notes on the Polynesian species of Aplonis. American Museum Novitates 1166: p. 1-6. On-line
- Pratt, HD; Bruner, PL; Berrett, DG (1987): A field guide to the birds of Hawaii and the tropical Pacific. Princeton University Press, Princeton: p. 273
- Craig, Adrian; Feare, Chris (2009): Sturnidae In: Del Hoyo, J, A Elliott, and D Christie (Eds.) Handbook of the Birds of World Volume 14: Bush-shrikes to Old World Sparrows. P. 723
swell
- ↑ Aplonis cinerascens in the IUCN Red List of Threatened Species 2013.2. Listed by: BirdLife International, 2012. Retrieved March 16, 2013.