Report By Umme Sarah | Mount Carmel College Student Bengaluru | Last Updated at May 14 2019
Scientists find the extinct chicken-sized bird on a small island in the Indian Ocean after 136,000 years.
The bird is Aldabra white-throated rail, named after the Aldabra Atoll.
It inhabits in Seychelles and is the last surviving native flightless bird in the Indian Ocean region.
It is found in Comoros, Madagascar, Mayotte, and Seychelles.
It is a descendant of the flying white-throated rail that is believed to have independently lost its ability to fly because of the lack of predators and competing mammals made it unnecessary.
It is believed to be the last flightless bird in the Indian Ocean.
This species and many others were completely wiped out when the Aldabra A toll in the Indian Ocean has flooded 136,0000 years ago and the island has since been submerged by the ocean.
Aldabra is a gigantic coral atoll that is a UNESCO World Heritage Site. Aldabra is the world’s second-largest coral atoll.
Julian Hume who is a paleontologist said in a press release from the Natural History Museum in London that, “Aldabra went under the sea and everything was gone, there was an almost complete turn over in the fauna.
Everything went extinct.
Yet as the Aldabra rail still lives on today, something must have happened for it to have returned”.
said in a press release from the Natural History Museum in London.
“There is no other case that I can find of this happening, where you have a record of the same species of a bird becoming flightless twice,” Hume added.
According to the museum, this is one of the fastest recorded timelines of a bird losing its ability to fly and the first and only known time that a species of bird have become flightless twice.
Aldabra rails are island colonizers that migrated from Madagascar in all directions.
Those that landed on Aldabra eventually evolved to become flightless
‘The finding regarding the flightless Aldabra rail is an exceptional example of a very rare phenomenon known as “iterative evolution”, says David Martill, a professor of the University of Portsmouth.
Iterative evolution is the repeat evolution of a species from the same ancestor at different times in history.
This can be observed in many animals, such as sea cows, ammonites, and sea turtles.
“We know of no other example in rails, or of birds in general, that demonstrates this phenomenon so evidently, only on Aldabra, which has the oldest palaeontological record of any oceanic island within the Indian Ocean region, is fossil evidence available that demonstrates the effects of changing sea levels on extinction and recolonization events,” added David.