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Subject: Biodiversity

1. Ecology & Ecosystems
2. Indian Biodiversity

  • Khiamniungan Tribe

    Why in the News?

    • The Prime Minister of India recently mentioned the Khiamniungan tribe of Nagaland in his Mann Ki Baat episode, highlighting their traditional practice of cliff-honey hunting and rich cultural heritage.

    About the Khiamniungan Tribe

    • One of the major Naga tribes inhabiting both:
      • Eastern Nagaland (India)
      • North-Western Myanmar
    • Their homeland lies along the Indo-Myanmar border.
    • The term “Khiamniungan” means “source of great water/river”.
    • Language: Khiamniugan, a Sino-Tibetan Naga language.
    • Social Structure: Traditionally based on a clan system.

    Festivals

    • Tsokum Sumai: Celebrated in September–early October.
      • Purpose: Invoke blessings for a rich harvest.
    • Khaotzao Sey Hok-ah Sumai: Marks the end of agricultural activities for the year.

    Economy & Livelihood

    • Agriculture is the primary occupation.
    • Traditionally practiced jhum cultivation.
    • Renowned for cliff-honey hunting, practiced for centuries.
    Consider the following pairs: Tribe State (2013)

    (1). Limboo (Limbu) : Sikkim 

    (2). Karbi : Himachal Pradesh 

    (3). Dongaria Kondh : Odisha 

    (4). Bonda : Tamil Nadu 

    Which of the above pairs are correctly matched? 

    (a) 1 and 3 only 

    (b) 2 and 4 only 

    (c) 1, 3 and 4 only 

    (d) 1, 2, 3 and 4

  • New Species of ‘Shadow’ Damselfly Discovered in Kodagu’s Western Ghats 

    Why in the News?

    A new damselfly species, Protosticta sooryaprakashi, commonly called the Kodagu Shadowdamsel, has been discovered in the Western Ghats, Karnataka. The finding underscores the rich but still understudied biodiversity of the region.

    Species Details

    • Common Name: Kodagu Shadowdamsel
    • Scientific Name: Protosticta sooryaprakashi
    • Family: Platystictidae (Shadowdamsels)

    Discovery Location

    • Found along the Sampaje River banks (Kodagu District)
    • Also observed in Agumbe high-altitude forests
    • Habitat: Shaded, riparian vegetation in the Western Ghats

    Distinctive Features

    • Males show a sky-blue marking on the prothorax (behind the head).
    • Body: Dark brown to black, unlike the crimson thorax of the related Protosticta sanguinostigma.
    • Unique genital ligula: Tip shaped like a duck’s head (important taxonomic marker).
    • Smaller, more delicate, with weak fluttering flight.
    In which of the following states is the lion-tailed macaque found in its natural habitat? (2013)

    1. Tamil Nadu 

    2. Kerala 

    3. Karnataka 

    4. Andhra Pradesh 

    Select the correct answer using the codes given below. 

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

  • Rustic Bunting Spotted in NCR for the First Time

    Why in the News?

    A Rustic Bunting (Emberiza rustica) — a rare migratory passerine bird — was spotted for the first time in the National Capital Region (NCR) at Najafgarh Jheel (Delhi–Gurugram border) on 28 November 2025.

    About Rustic Bunting (Emberiza rustica)

    General Features

    • Passerine bird, slightly larger than a sparrow.
    • Distinctive markings:
      • Males: black head + reddish breast band
      • Females: reddish flank streaks

    Breeding Range

    • Breeds across the northern Palearctic region.
    • Prefers wet coniferous woodlands.

    Migration Pattern

    • Winters in SE Asia & East Asia (Japan, Korea, eastern China).
    • Shows altitudinal migration.
    • Extremely rare visitor to India; usually recorded only in:
      • Northeast India
      • Himalayan belt (Ladakh, Kashmir, Arunachal Pradesh)

    Status in India

      • Very few sightings historically: Ladakh (2023, 2024), Arunachal Pradesh (2025), Kashmir (2022) and Jammu & Kashmir’s Kangan (2022 — fifth record for India).
    • First Ever Record for Delhi NCR
      • Sighted at Najafgarh Jheel, confirming its first occurrence within a 100 sq km NCR radius.

    IUCN Status

    • 2025 IUCN Red List:
      • Status changed from Vulnerable → Near Threatened
      • Reason: Decline has slowed down over the last decade.
    Consider the following: (2014)

    1. Bats

    2. Bears

    3. Rodents

    The phenomenon of hibernation can be observed in which of the above kinds of animals?

    (a) 1 and 2 only (b) 2 only (c) 1, 2 and 3 only (d) Hibernation cannot be observed in any of the above

  • Grey Seal Milk Complexity  

    Why in the News?

    A study published in Nature (Nov 2025) found that grey seal milk contains 332 different oligosaccharides33% more than human breast milk, previously considered the most complex.

    Key Findings

    Highest Oligosaccharide Diversity

    • Grey seal milk contains 332 oligosaccharides
      (Human milk: ~100).
    • This is the largest number ever recorded in any mammal’s milk.

    Functions of Oligosaccharides

    • Boost immunity (protect against bacteria & viruses).
    • Support gut microbiome formation.
    • Aid digestive tract development.
    • Provide energy and growth support for pups.

    Why Grey Seal Milk is So Complex?

    • Grey seals:
      • Live in harsh, high-risk environments.
      • Mothers fast for ~18 days while feeding pups.
      • Pups grow extremely rapidly during this period.
    • Complex sugars help pups survive extreme conditions and develop strong immunity quickly.

    Study Details

    • Conducted by the University of Gothenburg (Sweden).
    • Samples collected from Atlantic grey seals on a small Scottish island.
    • Analytical method used: Deep mass spectrometry.
      • A very advanced method of mass spectrometry that can detect hundreds to thousands of molecules in a sample with very high accuracy.
    Consider the following: 

    1. Bats 

    2. Bears 

    3. Rodents 

    The phenomenon of hibernation can be observed in which of the above kinds of animals? 

    (a) 1 and 2 only 

    (b) 2 only 

    (c) 1, 2 and 3 only 

    (d) Hibernation cannot be observed in any of the above

    This PYQ is chosen because it directly addresses the peculiar biological feature (hibernation) that allows mammals to survive challenging environmental conditions, which conceptually mirrors the adaptive features of the grey seal

  • Hawfinch Sighting in Jim Corbett National Park  

    Why in the news?

    • A Hawfinch (Coccothraustes coccothraustes), a bird species native to Europe, North Africa, and temperate Asia, was recorded on 23 November in the Dhela zone of Jim Corbett National Park, Uttarakhand. This is considered a vagrant bird sighting.

    About Hawfinch (Coccothraustes coccothraustes)

    • Family: Fringillidae (Finches)
    • Size: ~18 cm
    • Wingspan: 29–33 cm
    • Distinctive Feature: Very powerful, heavy bill capable of cracking extremely hard seeds/nuts.
    • Plumage: Males and females similar; males slightly darker.

    Native Range

    • Europe and North Africa
    • Temperate Asia, including:
      • Mongolia and Kazakhstan
    • Not native to India.

    Status in India

    • Sighting classified as a vagrant record—bird appears outside its usual distribution range.
    • Only two previous records in the Indian subcontinent:
      • Muzaffarabad (1908) – PoK
      • Aliabad (2017) – PoK
    • This is one of the very few confirmed sightings.
    Why is a plant called Prosopis juliflora often mentioned in the news? (2018) 

    (a) Its extract is widely used in cosmetics. 

    (b) It tends to reduce the biodiversity in the area in which it grows

    (c) Its extract is used in the synthesis of pesticides

    (d) None of the above

    This question tests the critical concept of non-native or exotic species impacting biodiversity, which is the implicit environmental concern raised by the Hawfinch sighting.

  • Ningaloo Reef Mass Coral Mortality 

    Why in the News?

    A new survey in 2025 shows that nearly 70% of corals in Australia’s UNESCO World Heritage–listed Ningaloo Reef have died due to the most intense and prolonged marine heatwave on record.

    About Ningaloo Reef  

    • Located in Western Australia.
    • A UNESCO World Heritage Site.
    • One of the largest fringing reefs in the world (~260 km long).
    • Important for marine biodiversity, supporting whale sharks, turtles, reef sharks, and diverse coral species.

    Extent of Coral Mortality

    • ~70% mortality recorded in latest survey.
    • In eight northern lagoon sites (Osprey → Tantabiddi Sanctuary Zones), mortality >60%.
    • Of 1,600+ corals assessed in March, only ~600 survived by October.

    Species Impact

    • Highly Affected (Dominant Species Lost)

        • Staghorn corals: Acropora tenuis, Acropora millepora and Acropora spicifera
        • Thin birdsnest coral (Seriatopora hystrix).
    • Relatively Resilient

      • Veron’s tube coral (Echinopora ashmorensis)
      • Lesser knob coral (Cyphastrea microphthalma)
    • Structural decline:
      • Dead corals now overgrown by sponges, turf algae, reducing reef stability & biodiversity.

    Broader Ecological Significance

    • Coral reefs support ~1/3 of global marine species.
    • Mass mortality compromises: Fish breeding grounds, Shelter for marine organisms, Coastal protection and Tourism & local economies.

    Widespread Global Coral Stress

    According to the United States National Oceanic and Atmospheric Administration (NOAA):

    • 84.4% of the world’s reef areas experienced bleaching-level heat stress (Jan 2023–Sept 2025).
    • Mass bleaching in 83+ countries.
    • Marine heatwaves in 2023 lasted 4× longer than the long-term average and affected 96% of the world’s oceans.
    The scientific view is that the increase in global temperature should not exceed 2 ∘ C above pre-industrial level. If the global temperature increases beyond 3 ∘ C above the pre-industrial level, what can be its possible impact/impacts on the world? 

    1. Terrestrial biosphere tends toward a net carbon source. 

    2. Widespread coral mortality will occur. 

    3. All the global wetlands will permanently disappear. 

    4. Cultivation of cereals will not be possible anywhere in the world. 

    Select the correct answer using the code given below: 

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

  • Aravalli Hills: 90% Lose Protection, FSI Red-Flag Ignored

    Why in the News?

    • On 20 Nov 2025, the Supreme Court approved the government’s definition of Aravalli Hills as any hill 100 m or higher above local ground.
    • Problem: This definition excludes 90% of Aravalli hills, making them open for mining and construction.

    Background

    • The Aravalli Range runs from Delhi to Gujarat through Haryana and Rajasthan.
    • It is oldest fold mountains in India and plays a key role in ecology, dust control, groundwater, and wildlife corridors.
    • In 2024, the SC asked the government to create a uniform Aravalli definition.

    FSI’s Warning

    • Lower hills (20–100 m) act as natural windbreaks, blocking sand and dust from Thar desert.
    • Removing protection risks:
      • Higher air pollution in NCR
      • Loss of wildlife corridors
      • Impact on agriculture and farmer livelihoods
    If there were no Himalayan ranges, what would have been the most likely geographical impact on India? (2010)

    1. Much of the country would experience the cold waves from Siberia. 

    2. Indo-gangetic plain would be devoid of such extensive alluvial soils. 

    3. The pattern of monsoon would be different from what it is at present. 

    Which of the statements given above is/are correct? 

    (a) 1 only 

    (b) 1 and 3 only 

    (c) 2 and 3 only 

    (d) 1, 2 and 3

    The profound geographical and ecological functions of a major mountain range, which directly parallels the catastrophic risks associated with losing the Aravallis.

  • African Grey Parrot Trade in India

    Why in the News?

    • A series of RTI applications filed by The Hindu across 19 States/UTs revealed that most State Forest Departments have no records of breeders, pet shops, or ownership registrations for the African Grey Parrot, despite the species being widely available in pet markets.
    • Only Kerala reported receiving 17 breeder licence applications through the PARIVESH portal, exposing major gaps in India’s monitoring of exotic species trade.

    About Species Profile

    • African Grey Parrot (Psittacus erithacus)
    • IUCN Status: Endangered
    • CITES Status: Appendix I (Highest level of protection; commercial international trade highly restricted)
    • WPA 1972: Listed under Schedule IV (post-2022 amendments)

    Legal & Regulatory Framework (India)

    Living Animal Species (Reporting and Registration) Rules, 2024

    • Mandatory registration of all exotic live species on PARIVESH 2.0.
    • Applies to: Pet owners, Pet shops and Breeders.

    Breeders of Species Licence Rules, 2023

    To breed any CITES Appendix I species, an applicant must possess:

    • Breeding Licence from State Chief Wildlife Warden
    • CITES Import Permit
    • DGFT Import Licence Number
    • NOC from State Chief Wildlife Warden prior to import

    Wildlife Protection Act (WPA), 1972

    • African Grey Parrot → Schedule IV
    • Illegal possession/trade punishable under WPA
    With reference to the International Union for Conservation of Nature and Natural Resources (IUCN) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), which of the following statements is/are correct? (2015)

    (1) IUCN is an organ of the United Nations and CITES is an international agreement between governments. 

    (2) IUCN runs thousands of field projects around the world to better manage natural environments. 

    (3) CITES is legally binding on the States that have joined it, but this Convention does not take the place of national laws. 

    Select the correct answer using the code given below. 

    (a) 1 only 

    (b) 2 and 3 only 

    (c) 1 and 3 only 

    (d) 1, 2 and 3

  • HMDA to use bioremediation to clean up Hussainsagar lake

    Why in the News?

    The Hyderabad Metropolitan Development Authority (HMDA) has announced a new advanced bioremediation initiative using enzyme solutions and biochar-based Bokashi balls to clean and restore Hussainsagar Lake, which has long suffered from algal blooms, foul odour, sewage inflow, and industrial pollution.

    About Hussainsagar Lake

    • A 16th-century artificial lake in Hyderabad.
    • Faces severe pollution due to:
      • Sewage inflow
      • Nutrient overload (nitrates, phosphates)
      • Industrial waste
    • Problems: algal blooms, foul odour, low Dissolved Oxygen (DO), high Biochemical Oxygen Demand (BOD).

    What Is Bioremediation?

    • Definition: Use of microorganisms, enzymes, or biological materials to break down pollutants and restore ecosystems.
    • Types relevant here:
      • In-situ bioremediation – treating the lake onsite without removing water.
      • Bio-augmentation – adding microbial cultures to enhance degradation.
      • Aerobic/oxygenation systems – boost DO to improve water quality.

    New Intervention Planned by HMDA

    • Enzyme Solutions

        • Enhance microbial breakdown of organic pollutants.
        • Help reduce nutrient load responsible for algal blooms.
    • Bokashi Balls (with Biochar)

      • Bokashi = fermented organic matter rich in beneficial microbes.
      • Biochar:
        • Carbon-rich material produced from biomass.
        • Increases microbial activity, absorbs toxins, improves water clarity.
      • Purpose:
        • Reduce algae, odour, pathogenic bacteria.
        • Increase water transparency and DO levels.
    In the context of solving pollution problems what is/are the advantage/disadvantages of bioremediation technique? (2017)

    1. It is a technique for cleaning up pollution by enhancing the same biodegradation process that occurs in nature. 

    2. Any contaminant with heavy metals such as cadmium and lead can be readily and completely treated by bioremediation using microorganisms. 

    3. Genetic engineering can be used to create microorganisms specifically designed for bioremediation. 

    Select the correct answer using the code given below: 

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

  • Moss Spores Survive Months in Space

    Why in the news?

    A recent study published in iScience revealed that moss spores (Physcomitrium patens) survived nine months outside the International Space Station (ISS), enduring vacuum, cosmic radiation, microgravity, and temperature extremes. Over 80% of the spores survived and successfully germinated on return to Earth. Scientists estimate moss could survive up to 15 years in space.

    Key Findings of the Study

    • 20,000 moss spores were placed outside the ISS in March 2022.
    • Exposed to: Vacuum, Cosmic radiation, Microgravity and Extreme temperatures
    • After 283 days, the spores were retrieved.
    • Results: 80% survived
      • Among survivors, 89% germinated successfully
      • Chlorophyll levels normal except a 20% drop in chlorophyll a, but not harmful
    • Survival attributed to multiple spore wall layers offering passive protection.

    About the Species

    • Species: Physcomitrium patens
    • Model organism for plant evolutionary studies
    • Mosses are one of the earliest land plants
    • Already known for surviving:
      • Antarctica
      • Volcanic fields
      • Deserts

    Why Moss Survived – Scientific Insight

    • Multiple thick-walled layers → physical shielding
    • Ability to remain in dormant state
    • Natural mechanisms to handle:
      • Radiation
      • Desiccation
      • Freezing and thawing cycles

    Why Is This Significant?

    • Implications for Space Exploration: 
        • Ability to survive harsh space environments → potential role in: Oxygen generation, Humidity control, Soil formation on Moon/Mars.
        • Supports concepts of bioregenerative life-support systems
        • It could be used in terraforming experiments on other celestial bodies
    • Astrobiology

        • Supports the idea that primitive plant life could survive interplanetary transport.
        • Relevant to panspermia hypothesis (life spreading across planets via spores).
    • Long-term Human Habitats

      • Moss can grow with minimal resources
      • Can contribute to:
        • Closed-loop ecosystems
        • Sustainable habitats
        • Psychological well-being in isolated environments (greenery)
    Consider the following statements: (2023)

    1. Some microorganisms can grow in environments with temperature above the boiling point of water. 

    2. Some microorganisms can grow in environments with temperature below the freezing point of water. 

    3. Some microorganisms can grow in highly acidic environment with a pH below 3. 

    How many of the above statements are correct? 

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