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Subject: Biodiversity

1. Ecology & Ecosystems
2. Indian Biodiversity

  • NHAI proposal for sound barrier near Ranganathittu Bird Sanctuary

    Why in the News?

    The National Highways Authority of India has proposed constructing a soundproof barrier wall along a highway stretch passing close to the Ranganathittu Bird Sanctuary in Karnataka to minimise the impact of traffic noise on wildlife.

    About Ranganathittu Bird Sanctuary

    • Located near Srirangapatna, Karnataka
    • Situated on the banks of the Cauvery River
    • Declared a bird sanctuary in 1940

    What is the NHAI Proposal?

    • Construction of a sound barrier wall along a highway stretch near the sanctuary
    • The objective is to reduce vehicular noise and disturbance
    • Proposal applies to the eco sensitive zone and buffer area of the sanctuary
    • Clearance required from the National Board for Wildlife

    Why are Sound Barriers Important Near Protected Areas?

    • Noise pollution affects
      • Bird breeding behaviour
      • Nesting success
    • Feeding and migration patterns
      • Traffic movement can fragment habitats
      • Sound barriers act as mitigation measures, not expansion approvals

    Legal and Regulatory Framework

    • Wildlife clearance mandatory for projects near protected areas
    • Eco sensitive zones notified under the Environment Protection Act, 1986
    • NBWL clearance required for projects affecting wildlife habitats
    • Reflects principle of sustainable infrastructure development
    [2020] Which of the following Protected Areas are located in Cauvery basin? 1. Nagarhole National Park 

    2. Papikonda National Park 

    3. Sathyamangalam Tiger Reserve 

    4. Wayanad Wildlife Sanctuary 

    Select the correct answer using the code given below: 

    (a) 1 and 2 only (b) 3 and 4 only (c) 1, 3 and 4 only (d) 1, 2, 3 and 4

  • Karimpuzha Wildlife Sanctuary  

    Why in the News?

    A recent faunal survey in Karimpuzha Wildlife Sanctuary recorded several species for the first time, significantly enhancing biodiversity data of Kerala’s youngest wildlife sanctuary.

    About Karimpuzha Wildlife Sanctuary

    • Located in Nilambur Forest Division, Kerala
    • Spread over 227.21 sq km
    • Notified as a Wildlife Sanctuary in 2020
    • Part of the Western Ghats biodiversity hotspot
    • Landscape ranges from low elevation tropical forests to montane ecosystems

    Key Findings

    • Birds
      • 171 bird species recorded during the survey
      • 8 species newly recorded in the sanctuary
      • Total bird species now 247
      • New records include Grey headed fish eagle, Eurasian hoopoe, Barn owl and Pallid harrier
    • Butterflies
      • 177 butterfly species documented
      • 20 new additions recorded
      • Total butterfly diversity increased to 223 species
      • Evidence of altitudinal migration observed in species like Common albatross and Lesser albatross
    • Odonates
      • 42 species recorded during the survey
      • 7 species newly added
      • Total odonate diversity now 63 species
      • Includes species such as Merogomphus tamaracherriensis and Rhodothemis rufa
    • Other Observations
      • Recorded moths, over 70 spider species and freshwater fish
      • Presence of elephant herds indicates habitat continuity and ecological integrity
    [2020] With reference to Indian elephants, consider the following statements: 1. The leader of an elephant group is a female. 

    2. The maximum gestation period can be 22 months. 

    3. An elephant can normally go on calving till the age of 40 years only. 

    4. Among the States in India, the highest elephant population is in Kerala. 

    Which of the statements given above is/are correct? 

    (a) 1 and 2 only (b) 2 and 4 only (c) 3 only (d) 1, 3 and 4 only

  • Wetlands as a National Public Good

    Why in the News?

    India marked World Wetlands Day under the theme “Wetlands and Traditional Knowledge”, and on the occasion added two new Ramsar sitesPatna Bird Sanctuary in Uttar Pradesh and Chhari-Dhand in Gujarat—taking the country’s total Ramsar sites to 98.

    What are Wetlands?

    Wetlands are areas of land saturated with water either permanently or seasonally. They include lakes, ponds, marshes, floodplains, mangroves, lagoons, peatlands and man made systems like tanks and kulams.

    Key Facts and Significance

    • India has lost nearly 40 percent of its wetlands in the last three decades
    • Around 50 percent of remaining wetlands show ecological degradation
    • Wetlands act as natural flood buffers, groundwater recharge zones and water purifiers
    • They support biodiversity, fisheries, agriculture and local livelihoods
    • Coastal wetlands like mangroves reduce cyclone and storm surge impacts

    Policy and Institutional Framework

    • Wetlands Conservation and Management Rules, 2017 provide legal framework for identification, notification and protection
    • National Plan for Conservation of Aquatic Ecosystems focuses on planning, monitoring and outcome based restoration
    • Coastal Regulation Zone framework protects coastal wetlands
    • Ramsar designation under the Ramsar Convention gives global recognition and conservation responsibility
    • India has 98 Ramsar sites, highest in South Asia
    [2022] If rainforests and tropical forests are the lungs of the Earth, then surely wetlands function as its kidneys.” Which one of the following functions of wetlands best reflects the above statement? (a) The water cycle in wetlands involves surface runoff, subsoil percolation and evaporation. 

    (b) Algae form the nutrient base upon which fish, crustaceans, molluscs, birds, reptiles and mammals thrive. 

    (c) Wetlands play a vital role in maintaining sedimentation balance and soil stabilisation. 

    (d) Aquatic plants absorb heavy metals and excess nutrients.

  • [3rd February 2026] The Hindu OpeD: Wetlands as a national public good

    PYQ Relevance

    [UPSC 2023] Comment on the National Wetland Conservation Programme initiated by the Government of India and name a few India’s wetlands of international importance included in the Ramsar Sites. 

    Linkage: The question links environmental governance with ecosystem conservation, focusing on policy design, implementation gaps, and international commitments under the Ramsar Convention. It allows integration of wetlands’ role in climate resilience, disaster risk reduction, and sustainable development using current NPCA/NWCP reforms.

    Mentor’s Comment

    Wetlands are among India’s most degraded ecological assets despite being critical for water security, flood control, climate resilience, and livelihoods. This topic is important because it brings together environmental governance, federalism, disaster management, and sustainable development, making it highly relevant for GS III.

    The article is valuable for aspirants as it goes beyond laws and schemes and highlights why implementation has failed, fragmented institutions, project-based restoration, and neglect of hydrological systems. It introduces the idea of wetlands as national public goods, a strong analytical frame that can be used in mains answers to show conceptual clarity.

    Why in the News

    World Wetlands Day 2026 renews global attention on wetlands, coinciding with India’s worsening degradation record. Nearly 40% of India’s wetlands have vanished in three decades, and 50% of remaining wetlands show ecological degradation. This marks a sharp contrast with traditional community-managed systems that sustained wetlands for centuries. Despite the presence of regulatory frameworks like the Wetlands (Conservation and Management) Rules, 2017, degradation continues due to fragmented implementation, project-based restoration, and weak governance. 

    Why are wetlands ecologically and economically critical?

    1. Hydrological regulation: Supports groundwater recharge, flood buffering, and sediment control through natural flow regimes.
    2. Livelihood security: Sustains fishing, grazing, agriculture, and cultural practices across rural and peri-urban landscapes.
    3. Climate resilience: Absorbs cyclonic impacts, sea-level rise, and extreme rainfall, especially in coastal zones.
    4. Biodiversity conservation: Maintains habitats for migratory birds, aquatic species, and riparian ecosystems.

    What has driven large-scale wetland degradation in India?

    1. Land-use conversion: Replaces natural wetlands with real estate, roads, and networks, permanently altering hydrology.
    2. Encroachment pressures: Intensifies in highly populated regions due to weak land demarcation and enforcement.
    3. Hydrological disruption: Dams, embankments, canals, mining, and sand extraction block or divert natural flows.
    4. Pollution loading: Converts wetlands into sewage sinks through untreated wastewater and industrial effluents.
    5. Groundwater over-extraction: Reduces inflows, accelerates drying, and collapses ecological function.

    Why are existing policy frameworks insufficient?

    1. Fragmented governance: Distributes responsibility across departments without integrated watershed planning.
    2. Weak implementation: Lacks consistent, high-quality execution despite the presence of legal frameworks.
    3. Project-centric approach: Focuses on beautification rather than ecological functionality.
    4. Data gaps: Suffers from outdated or inaccurate cadastral maps and incomplete inventories.
    5. Limited enforcement: Fails to prevent degradation despite notification and regulatory provisions.

    How effective are current regulatory instruments?

    1. Wetlands (Conservation and Management) Rules, 2017: Provides a legal framework but lacks implementation consistency.
    2. National Plan for Conservation of Aquatic Ecosystems (NPCA): Shifts focus to structured planning and outcome-based management but requires stronger monitoring.
    3. Coastal Regulation Zone (CRZ): Aims to preserve coastal ecological integrity but faces infrastructure-driven dilution.
    4. Ramsar designation: Recognises ecological value but remains largely non-binding and incentive-oriented.

    Why are urban and coastal wetlands at special risk?

    1. Urban runoff absorption: Urban wetlands receive stormwater, sewage, and solid waste, increasing contamination.
    2. Flood buffering loss: Degradation converts wetlands into flood-prone zones rather than safety buffers.
    3. Coastal vulnerability: Mangroves and lagoons face dual pressures from landward development and rising seas.
    4. Disaster exposure: Weakens natural protection against cyclones, storm surges, and shoreline erosion.

    What governance failures constrain wetland conservation?

    1. Institutional capacity gaps: Limits state-level ability to manage complex hydrological systems.
    2. Sectoral silos: Separates water, land, urban planning, and environment decision-making.
    3. Limited accountability: Weak monitoring and absence of measurable performance indicators.
    4. Community exclusion: Undermines local stewardship and conflict resolution mechanisms.

    What pragmatic approaches can be taken?

    1. Watershed-scale planning: Ensures conservation beyond isolated wetland boundaries.
    2. Functional restoration: Prioritises ecological processes over aesthetic beautification.
    3. Demarcation and mapping: Strengthens legal clarity and dispute prevention through updated cadastral records.
    4. Infrastructure alignment: Integrates wetland protection into roads, embankments, and drainage planning.
    5. Institutional strengthening: Builds national capacity through training, accreditation, and governance reforms.

    How can technology strengthen wetland governance?

    1. Remote sensing: Enables real-time tracking of encroachment, inundation, and vegetation change.
    2. Drones and GIS: Improves mapping accuracy and monitoring frequency.
    3. Time-series analytics: Supports early warning and adaptive management strategies
    4. Revised NPCA guidelines: Allow science-based monitoring and management plans.

    Conclusion

    Wetlands cannot survive as isolated conservation projects. Treating them as national public goods demands integrated governance, functional restoration, institutional accountability, and community stewardship. India’s water security and climate resilience depend on this shift.

  • Vishwamitri River  

    Why in the News?

    The Vishwamitri River, flowing through Vadodara in Gujarat, has drawn attention due to the presence of a large urban population of mugger crocodiles, earning it the title India’s Crocodile River.

    About Vishwamitri River

    • A small non perennial river in eastern Gujarat
    • Origin: Western and southern slopes of the Pavagadh Hills
    • Course: Flows westward through Vadodara city
    • Tributaries: Dhadar and Jambuva
    • Outfall: Arabian Sea via the Gulf of Khambhat
    • Total length: 200 km
    • Characterised by highly meandering and sinuous course

    Biodiversity Along the River

    • Mammals: Porcupine, Indian civet, Jungle cat
    • Reptiles: Cobras, Pythons, Checkered keelback, Bengal monitor
    • Supports a major population of Mugger crocodile

    Mugger Crocodiles 

    • Scientific name Crocodylus palustris
    • Distribution: Iran to Bangladesh, Nepal to Sri Lanka
    • In India found in 15 states
    • Also called Indian crocodile
    • 2025 census recorded 442 muggers
    • Found within a 21 km urban stretch in Vadodara
    • Freshwater rivers, lakes, ponds, hill streams
    • Can survive in coastal saltwater lagoons
    • IUCN Red List: Vulnerable
    [2017] If you want to see gharials in their natural habitat, which one of the following is the best place to visit? 

    (a) Bhitarkanika Mangroves 

    (b) Chambal River 

    (c) Pulicat Lake 

    (d) Deepor Beel

  • Shettihalli Wildlife Sanctuary  

    Why in the News?

    The Forest Minister of Karnataka recently visited Shettihalli Wildlife Sanctuary amid controversy over a proposal to reduce the sanctuary boundary.

    About Shettihalli Wildlife Sanctuary

    • Located in Karnataka, in Shimoga (Shivamogga) district
    • Lies along the Tunga River
    • Tunga Anicut Dam situated within the sanctuary
    • Provides habitat for otters and water birds
    • Mandagadde Bird Sanctuary forms part of Shettihalli
    • Mandagadde is an island nesting site in the Tunga River

    Prelims Pointers

    • Shettihalli lies on the Tunga River
    • Mandagadde Bird Sanctuary is part of it
    • Presence of displaced human settlements is a management challenge
    • Supports rich avifauna and large mammals
    • Forest types range from dry deciduous to evergreen
    [2019] Consider the following pairs: 

    Famous place :    River 

    1. Pandharpur :    Chandrabhaga 

    2. Tiruchirappalli : Cauvery 

    3. Hampi :             Malaprabha

    Which of the pairs given above are correctly matched? 

    (a) 1 and 2 only (b) 2 and 3 only (c) 1 and 3 only (d) 1, 2 and 3

  • Rare Rusty spotted Cat sighted in Rajasthan 

    Why in the News?

    A Rusty spotted Cat, one of the smallest wild cats in the world, was recorded alive for the first time in the Shergarh Sanctuary of Baran district, Rajasthan, through camera trap evidence in January 2026.

    About Rusty spotted Cat

    • Among the world’s smallest felines
    • Nocturnal, shy, and solitary in nature
    • Comes together only during breeding season
    • Primarily a carnivore
    • Plays an ecological role in seed dispersal through fruits sticking to its fur

    Conservation Status

    • Near Threatened (NT) by the International Union for Conservation of Nature (IUCN)
    • Faces threats from habitat loss, road kills, and low detectability

    Habitat and Distribution

    • Forests and scrublands
    • Found in Uttar Pradesh, Gujarat, Maharashtra, and South India
    • First live record in the Hadoti region of Rajasthan
    • Earlier road kill recorded in Shahabad area of Baran district in December 2023

    About Shergarh Sanctuary

    • Located in Baran district
    • Part of the Hadoti region
    • Dry deciduous forest ecosystem
    • Increasing use of camera trapping for wildlife monitoring
    [2023] Consider the following fauna: 

    1. Lion-tailed Macaque 

    2. Malabar Civet 

    3. Sambar Deer 

    How many of the above are generally nocturnal or most active after sunset? 

    (a) Only one (b) Only two (c) All three (d) None

  • New Plant Species Discovered in Nagaland: Hoya nagaensis

    Why in the News?

    Researchers from Nagaland University have discovered a new plant species, Hoya nagaensis, in the high-altitude forests of Nagaland, highlighting the biodiversity richness of Northeast India and the conservation value of community-managed forests.

    About Hoya nagaensis

    • Newly identified plant species belonging to the Hoya genus
    • Genus Hoya is known for ornamental plants with distinctive flowers
    • Characterised by
      • Unique leaf shapes
      • Distinct floral features, clearly differentiating it from known species

    Location of Discovery

    • Found in Kavünhou Community Reserved Forest
    • District: Phek, Nagaland
    • Habitat: High-altitude temperate forests of the Eastern Himalaya
    • Recorded so far from only one location

    Conservation Status

    • Provisionally classified as Critically Endangered
    • Reasons
      • Extremely limited geographical range
      • Threats from shifting cultivation
      • Forest disturbance
    [2023] Consider the following statements: Once the Central Government notifies an area as a ‘Community Reserve’ 

    1. The Chief Wildlife Warden of the State becomes the governing authority of such forest

    2. Hunting is not allowed in such area

    3. People of such area are allowed to collect non-timber forest produce

    4. People of such area are allowed traditional agricultural practices

    How many of the above statements are correct? 

    (a) Only one (b) Only two (c) Only three (d) All four

    Hoya nagaensis was specifically discovered in the Kavünhou Community Reserved Forest. This PYQ tests the administrative and legal rules governing such protected areas, which are vital for the conservation of rare species in the Northeast.

  • Pygmy Hog

    Why in the News?

    India’s Pygmy hog is rapidly declining due to loss and degradation of tall grassland habitats, even though it plays a critical role in maintaining grassland ecosystem health.

    About Pygmy Hog

    • Smallest and rarest wild pig species in the world
    • One of the few mammals that builds its own nest with a roof
    • Functions as an indicator species, reflecting grassland health

    Habitat

    • Prefers undisturbed tall grasslands with early succession riverine vegetation
    • Habitat includes dense tall grasses mixed with herbs, shrubs and young trees
    • Present distribution restricted to
      • Manas National Park
      • Orang National Park

    Ecological Role

    • Forages by digging soil using its snout
    • Feeds on roots, tubers, fruits, termites, earthworms and eggs
    • Improves soil aeration and fertility
    • Aids seed dispersal, supporting grassland regeneration

    Conservation Status

    • IUCN Red List: Critically Endangered
    • Listed under Schedule I of the Wildlife Protection Act, 1972
    • Estimated wild population is very small, confined to Assam
    [2013] Consider the following: 

    1. Star tortoise 

    2. Monitor lizard 

    3. Pygmy hog 

    4. Spider monkey 

    Which of the above are naturally found in India? 

    (a) 1, 2 and 3 only (b) 2 and 3 only (c) 1 and 4 only (d) 1, 2, 3 and 4

  • BNHS and NMCG launch project to protect Indian Skimmer

    Why in the news

    Bombay Natural History Society and National Mission for Clean Ganga have launched a new conservation project in Dehradun to protect the endangered Indian Skimmer in the Ganga Basin. The project was inaugurated by the Union Minister for Jal Shakti C R Patil.

    About Indian Skimmer

    • Scientific name: Rynchops albicollis
    • IUCN status: Endangered
    • Habitat: Large rivers, estuaries, sandbars and islands
    • India hosts around 90 percent of the global population, making conservation nationally critical.

    Core objective

    • Protection of river sandbars, which are crucial nesting and breeding habitats for Indian Skimmer and other riverine birds.

    Major threats addressed

    • Sand mining on riverbeds
    • Altered river flows and sudden water releases from dams
    • Human and livestock disturbance
    • Predation and habitat fragmentation

    Geographical coverage

    • National Chambal Sanctuary
    • Upper Ganga near Bijnor and Narora
    • Ganga Yamuna confluence at Prayagraj
    • Lower Ganga near the Vikramshila Gangetic Dolphin Sanctuary in Bihar

    UPSC Prelims pointers

    • Indian Skimmer nests on exposed river sandbars.
    • India holds the largest global population share of the species.
    • Project combines science, community participation, and river planning.
    • Linked with Namami Gange ecosystem restoration goals.
    [2014] With reference to Bombay Natural History Society (BNHS), consider the following statements: 1. It is an autonomous organization under the Ministry of Environment and Forests

    2. It strives to conserve nature through action-based research, education and public awareness

    3. It organizes and conducts nature trails and camps for the general public

    Which of the statements given above is/are correct? 

    (a) 1 and 3 only (b) 2 only (c) 2 and 3 only (d) 1, 2 and 3 only