Aldabra Brush Warbler
Encyclopedia
The Aldabra Brush Warbler (Nesillas aldabrana) is an extinct bird
in the acrocephalid
warbler
family
. It was endemic to the atoll of Aldabra
in the Seychelles
.
and Malcolm Penny
on basis of a male, a female and a nest with 3 eggs. Juveniles were never found.
After the discovery the brush warbler was lost until a new survey was made by Robert Prys-Jones of the British Museum of Natural History from 1974 to 1976. At the end of 1975 he found six further birds which were all males. The birds were ringed and photographed.
Unfortunately in 1983 only one male was left and the Aldabra Brush Warbler became the rarest and in its occurrence most restricted bird in the world. It was restricted to a 10 ha large coastal strip on the Aldabran island of Malabar. Following intensive surveys, the extinction of this bird was confirmed in 1986. It is listed as officially extinct by the IUCN since 1994.
The possible reasons for its extinction could be attributed to the presence of rats, cats and goats introduced
to the atoll many years previously.
Bird
Birds are feathered, winged, bipedal, endothermic , egg-laying, vertebrate animals. Around 10,000 living species and 188 families makes them the most speciose class of tetrapod vertebrates. They inhabit ecosystems across the globe, from the Arctic to the Antarctic. Extant birds range in size from...
in the acrocephalid
Acrocephalidae
Acrocephalidae is a family of oscine passerine birds, in the superfamily Sylvioidea....
warbler
Warbler
There are a number of Passeriformes called "warblers". They are not particularly closely related, but share some characteristics, such as being fairly small, vocal and insectivorous....
family
Family (biology)
In biological classification, family is* a taxonomic rank. Other well-known ranks are life, domain, kingdom, phylum, class, order, genus, and species, with family fitting between order and genus. As for the other well-known ranks, there is the option of an immediately lower rank, indicated by the...
. It was endemic to the atoll of Aldabra
Aldabra
Aldabra, the world's second largest coral atoll, is in the Aldabra Group of islands in the Indian Ocean that form part of the Seychelles. Uninhabited and extremely isolated, Aldabra is virtually untouched by humans, has distinctive island fauna including the Aldabra Giant Tortoise, and is...
in the Seychelles
Seychelles
Seychelles , officially the Republic of Seychelles , is an island country spanning an archipelago of 115 islands in the Indian Ocean, some east of mainland Africa, northeast of the island of Madagascar....
.
Description
This bird reached a total length of 18-20 cm. The wings were approximately 6.3 cm and the tail was 8.6 cm.Discovery and extinction
The Aldabra Brush Warbler was discovered by British ornithologists Constantine Walter Benson, Malcolm Penny and Tony Diamond in 1967 and described in 1968 by Constantine Walter BensonConstantine Walter Benson
Constantine Walter Benson OBE was a British ornithologist. He is considered the last of a line of British Colonial officials who made significant contributions to ornithology.-Education and career:...
and Malcolm Penny
Malcolm Penny
Malcolm Penny is a British zoologist who is known for his ornithological field work on Aldabra and the Seychelles. In 1964 he graduated in zoology at the University of Bristol. He led scientific expeditions to Aldabra and the Seychelles in the Indian Ocean and he worked as conservationist for the...
on basis of a male, a female and a nest with 3 eggs. Juveniles were never found.
After the discovery the brush warbler was lost until a new survey was made by Robert Prys-Jones of the British Museum of Natural History from 1974 to 1976. At the end of 1975 he found six further birds which were all males. The birds were ringed and photographed.
Unfortunately in 1983 only one male was left and the Aldabra Brush Warbler became the rarest and in its occurrence most restricted bird in the world. It was restricted to a 10 ha large coastal strip on the Aldabran island of Malabar. Following intensive surveys, the extinction of this bird was confirmed in 1986. It is listed as officially extinct by the IUCN since 1994.
The possible reasons for its extinction could be attributed to the presence of rats, cats and goats introduced
Introduced species
An introduced species — or neozoon, alien, exotic, non-indigenous, or non-native species, or simply an introduction, is a species living outside its indigenous or native distributional range, and has arrived in an ecosystem or plant community by human activity, either deliberate or accidental...
to the atoll many years previously.