Biodiversity and Wildlife Conservation
This section covers Biodiversity and Wildlife Conservation. The exam tests the levels of biodiversity, threats, IUCN categories, protected-area types, and the difference between in-situ and ex-situ conservation.
Core rules
- Biodiversity has three levels: genetic diversity within species, species diversity, and ecosystem diversity. Biodiversity hotspots have high endemism and severe habitat loss.
- IUCN categories run from Least Concern and Near Threatened through Vulnerable, Endangered and Critically Endangered to Extinct in the Wild and Extinct. Threatened species are those in Vulnerable, Endangered or Critically Endangered categories.
- In-situ conservation keeps species in their natural habitat through national parks, wildlife sanctuaries, biosphere reserves and community reserves. Ex-situ conservation keeps them outside, as in zoos, seed banks and cryopreservation.
- Main threats are habitat loss and fragmentation, overexploitation, invasive species, pollution and climate change.
- Reserve design matters: large over small, connected over isolated, compact over elongated, and corridors between fragments. Edge effects reduce interior habitat.
Worked example
Compare one 200-hectare reserve with two 100-hectare fragments. The total area is the same, but the fragments have more edge, fewer interior species, less gene flow and higher extinction risk. A corridor can restore some connectivity. The reasoning is that area alone is not enough; shape and isolation affect survival. A species that needs deep forest will do better in the single compact block.
Traps
- Endemic does not mean endangered; endemic means native to one restricted area.
- A national park is only one type of protected area; sanctuaries and biosphere reserves also count.
- Captive breeding alone cannot save a species if its habitat is destroyed.
- Not every turtle at Gahirmatha is nesting at the same time; Olive Ridleys nest in mass arribadas.
Odisha examples include Similipal for tiger and elephant, Bhitarkanika for saltwater crocodile and mangroves, Gahirmatha for Olive Ridley turtles, Chilika for Irrawaddy dolphin, and Satkosia for gharial and tiger.