Mangrovedar finch
| Mangrovedar finch | ||||||||||||
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Mangrovedar finch ( Camarhynchus heliobates ) |
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| Scientific name | ||||||||||||
| Camarhynchus heliobates | ||||||||||||
| ( Snodgrass & Heller , 1901) |
The Mangrovedarwin's finch ( Camarhynchus heliobates , syn .: Geospiza heliobates ) is a species of bird from the genus of the tree finches ( Camarhynchus ) in the group of the Darwin's finches (Geospizini). These are now placed with the tangaren (Thraupidae) or sometimes with the bunting (Emberizidae). Its name refers to its habitat, the mangrove forest .
The Mangrovedar Finch is one of the rarest birds on earth and is threatened with extinction. Only about 50 to 100 specimens of this species can be found on the Galápagos Islands . After rats, which have since been decimated with poison baits, the fly Philornis downsi is now the biggest enemy of the Mangrovedar finch. The fly lays its eggs in bird nests, the larvae then attack the newly hatched young birds. Further threats are birdpox , inbreeding effects due to the small population and hybridization with the woodpecker finch . The species makes special demands on its habitat and is therefore susceptible to changes in its habitat.
description
The mangrovedar finch reaches a body length of 14 cm and a weight of 18 g. It is a medium-sized Darwin's finch with a typically short tail and a relatively long, pointed beak with a curved ridge and an almost straight dill edge. The top is dull brownish with olive on the rump . The underside is whitish with faint dashed lines. As with other tree finch species, the head region in males can turn black with age. The beak is pale, the legs black.
distribution
The Mangrovedarwinfink lives on to Ecuador belonging Galapagos Islands . Previously, stocks were known in at least six mangrove areas in the east of the island of Fernandina and in the east, south and west of the island of Isabela . The last sighting on Fernandina dates back to 1971, during a new inventory no specimens were discovered and it can be assumed that the species no longer occurs as a breeding bird on Fernandina. Until recently there were still two populations on Isabela, specimens of the smaller population at Cartago Bay were last sighted in 2009, 2011 and 2012 no more mangrovedar finches were found there. At the moment only the population in northwest Isabela exists.
Habitat and way of life
The Mangrovedar Finch inhabits dense mangrove swamps and feeds on insects , larvae , spiders and some vegetable food. The breeding season overlaps with the onset of heavy rains, usually in December and January. It generally lasts until the end of the rainy season around May, but successful breeding has also been observed in September. The nests are built in tall trees in places with tall mangroves that are often flooded when the tide is high. This habitat is rather rare on the Galapagos Islands. Mangroves that are separated from the sea, with tall trees and abundant leaf litter and dead wood are preferred by the species, since the leaf litter that has not been washed out is the preferred forage substrate of the Mangrovedarwin finch.
Web links
- Geospiza heliobates inthe IUCN Red List of Threatened Species 2015.1. Listed by: BirdLife International, 2015. Retrieved February 3, 2016.
- UNEP-WCMC Species Database
- Videos, photos and sound recordings of Camarhynchus heliobates in the Internet Bird Collection
Individual evidence
- ↑ a b c d e f IUCN
- ↑ Roland Knauer: "The fight for the last chicks" . In: Image of Science . Konradin Medien GmbH, Leinenfelden-Echterdingen September 2017, p. 95 .
- ^ Alvaro Jaramillo, Eduardo de Juana: Mangrove Finch (Geospiza heliobates). In: Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona 2018 ( online ).
- ↑ Lucinda P. Lawson et al. : Slow motion extinction: inbreeding, introgression, and loss in the critically endangered mangrove finch (Camarhynchus heliobates) 2016 in: Conservation Genetics , DOI: 10.1007 / s10592-016-0890-x ( Online )