According to experts, the main reasons for their extinction are disturbance to the habitat, especially forest areas and mangroves, encroachment, climatic changes, illegal fencing, laying roads and highways in the core of forests, deforestation, mining projects in addition to poaching and illegal trade.

"Among avifauna, the bird Double Banded Jerdon's Courser, presumed to have been extinct was spotted again but has become rare. Some other terrestrial animals, which are endangered or vulnerable and rarely spotted include scaly ant-eaters or pangolin, a nocturnal primate called Slow Loris, Indian mouse deer, snakes like the King Cobra and species of the felidae family such as fishing cats and rusty spotted cats," said wildlife conservationist and president of Eastern Ghats Wildlife Society Kantimahanti Murthy.

Adding to the list of near-extinct species, curator of Indira Gandhi Zoo Park B Vijaya Kumar said, "The bison (Indian Gaur), salt water crocodile, water monitor lizard, palm civets, Asiatic wild dogs, barking deer, hog deer and chausinga are some of the animals facing extinction."

It's not just the mammals, reptiles and birds, but the marine fauna too has shown signs of becoming extinct. AU professor of zoology DE Babu said, "Since the last two decades, two species of commercially valued fish have gone totally extinct. These are saw-headed fish and another of the hilsa category called TenualosaToli. Over-exploitation and offshore oil exploration in the East and West Godavari basin might have led the juveniles to migrate. Even horse shoe crab are nearing extinction."

There are other marine creatures like white shark, striped tiger shark, rice paddy eel, electric ray, soft corals like zoanthus, which are highly endangered as well. "Some of these have dwindled by more than 80% from the river ecosystem of Vizag, Srikakulam, East and West Godavari," added the zoologist.