The gharial, leatherback turtle, and swamp deer are all classified as endangered species due to habitat loss, pollution, and over-exploitation, factors that directly contribute to their declining populations. The gharial, a fish-eating crocodile, faces threats from river habitat degradation and fishing activities, while the leatherback turtle, the largest sea turtle species, is endangered due to bycatch in fisheries and coastal habitat destruction. Swamp deer, primarily found in wetland habitats, are vulnerable to poaching and loss of habitat due to agricultural expansion. This understanding aligns with the UPSC focus on biodiversity conservation and the importance of protecting endangered species for ecological balance and heritage preservation.