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Picture Courtesy: https://www.manoramayearbook.in/current-affairs/world/2019/05/11/Flightless-bird-returns-from-the-dead.html

Context: The Aldabra rail species, a flightless subspecies of the white-throated rail, went extinct due to the submersion of the Aldabra atoll off the southeast coast of Africa. The atoll was submerged beneath the waves for a significant period (around 136,000 to 118,000 years ago), causing a turnover in the fauna and leading to the extinction of the flightless rail.

About Aldabra Rail

Appearance

• About the size of a chicken, with a stocky build and short legs.
• Plumage is mainly brown and gray, with a rusty-red head and chest and a white throat.
• Short wings, which are incapable of flight.
• Strong legs and feet, adapted for running and foraging on the ground.

Habitat

• Found only on the Aldabra Atoll, a remote group of islands in the Indian Ocean, north of Madagascar.
• Inhabits dense forests, scrublands, and mangroves.
• Prefers areas with plenty of ground cover, where it can hide from predators.

Diet

• Omnivorous, feeding on a variety of invertebrates, fruits, and seeds.
• Uses its strong beak to probe the ground for food.
• Eat small reptiles and amphibians.

Behaviour

• Solitary birds, except during breeding season.
• Ground-dwelling, spending most of their time foraging on the forest floor.
• Can run quickly and swim if necessary.
• Vocal birds, with a variety of calls and songs.

Reproduction

• Breeds monogamously, with pairs defending their territories.
• The female lays 2-4 eggs in a nest on the ground.
• Both parents incubate the eggs and care for the chicks.
• Chicks are precocial, able to walk and feed themselves soon after hatching.

Evolutionary history

• The Aldabra rail is a subspecies of the white-throated rail, which is found on Madagascar and other islands in the Indian Ocean.
• The white-throated rail is capable of flight, but the Aldabra rail lost its ability to fly due to the lack of predators on the Aldabra Atoll.
• This is an example of iterative evolution, where a population evolves in a similar way to an extinct ancestor.
• Fossil evidence suggests that there was a flightless rail on the Aldabra Atoll about 136,000 years ago, which went extinct when the atoll was submerged by rising sea levels.
• The atoll later re-emerged, and the white-throated rail recolonized it.
• The recolonized population eventually evolved into the modern Aldabra rail, losing its ability to fly once again.

Conservation status

• The Aldabra rail is classified as Least Concern by the IUCN, but it is threatened by habitat loss and introduced predators.
• Conservation efforts are underway to protect the Aldabra Atoll and its unique wildlife.

Interesting facts ●The Aldabra rail is the only living flightless bird in the Indian Ocean. ●It is one of the few examples of iterative evolution in the animal kingdom. ●The Aldabra rail is an important part of the Aldabra Atoll ecosystem, helping to control insect populations and disperse seeds.

PRACTICE QUESTION Q. Why is the Aldabra rail making headlines? A) Breakthrough in avian genetics B) Rediscovery after presumed extinction C) Unprecedented migratory patterns D) Successful cloning experiment Answer: B Explanation: The Aldabra rail is in the news for its rediscovery after presumed extinction, showcasing its unique evolutionary journey of becoming flightless twice.