CHARLES DARWIN’S FROG

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Picture Courtesy: https://www.downtoearth.org.in/wildlife-biodiversity/charles-darwins-frog-endemic-andaman-species-breeding-in-unnatural-sites-due-to-habitat-loss-competition-for-limited-resources

Context: Charles Darwin’s frog adapts to breeding in artificial sites due to habitat loss and competition, posing conservation challenges for this vulnerable Andaman species.

Charles Darwin’s Frog

• Charles Darwin's frog, scientifically known as Minervarya charlesdarwini, is a species of frog found in the Andaman Islands. It is specifically found on the South Andaman Islands, Long Island, and North Andaman Islands.
• Originally described as Rana charlesdarwini in 1998, it was later reclassified into the genus Minervarya in 2022. It is closely related to the Andaman frog, M. andamanensis.
• The adult males of this species measure about 25–29 mm, while females are slightly larger at 29–38 mm in length.
• They have distinct features like rounded snouts, exposed tympanums, and partially webbed toes with swollen discs.
• The frogs exhibit three different colour morphs, varying from olive brown with orange markings to creamy white with dark patches.
• These frogs inhabit primary evergreen and secondary forests below 500 m in elevation. They lay their eggs in water-filled tree holes. However, they are threatened by habitat loss due to activities like clear-cutting. The species has been documented in Mount Harriet National Park and Saddle Peak National Park.

Recent Studies

• Recent studies by researchers from Harvard University and the University of Delhi have uncovered significant findings about this frog's behaviour and its implications for conservation.

Unusual Mating and Egg-Laying Behavior

• The frog species displays extraordinary mating and egg-laying behaviour, which involves spawning upside down.
• Both males and females adopt an inverted position on the walls of tree cavities during mating and egg-laying, keeping their bodies entirely above the water. This behaviour is unprecedented among frogs, as eggs are laid in water or on moist surfaces to prevent desiccation.
• The hatchlings then descend into the water below, where they mature as free-swimming tadpoles.

Implications of Behavior

• This unique upside-down spawning behaviour is believed to be an adaptation to the rapidly changing environment in the Andaman Islands.
• The frogs have increasingly been found using artificial objects such as plastic seedling bags and discarded containers for breeding. This shift from natural to artificial breeding sites is likely a response to habitat loss and fragmentation.
  

Charles Darwin’s frog is listed as vulnerable on the IUCN Red List due to its limited distribution, fragmented populations, and declining habitat.

Conclusion

• Charles Darwin's frog is a unique species of frog native to the Andaman Islands in India. They exhibit three different colour morphs and are found in forests at lower elevations. Their habitat is at risk due to human activities like clear-cutting. Efforts are needed to conserve their habitat and ensure the survival of this species in its natural environment.

Source:

Down to Earth

Wikipedia

PRACTICE QUESTION. Q. Charles Darwin's frog, an amphibian species that has been a topic of recent news, is endemic to which specific region in India known for its unique biodiversity? A) The Western Ghats in Kerala B) The Sundarbans in West Bengal C) The Andaman and Nicobar Islands D) The Eastern Ghats in Tamil Nadu  Answer: C