World Turtle Day — India's Ancient Mariners & Conservation Mission

📋 What's Inside — 11 Sections

Click any section below to jump directly to its full notes

Core Concept & World Turtle Day

Origin, ATR founding, date, purpose & global significance

Classification & Types

Turtle vs tortoise, 7 sea species, taxonomy, key features

Evolutionary History

220 million years, Proganochelys, Eunotosaurus, survival record

India's Turtle Diversity

30 freshwater + 5 sea species, key data, state-wise stats

Nesting Geography

Gahirmatha, Rushikulya, Devi, Arribada, spatial distribution

Legal & Conservation Framework

WPA 1972, Articles 48A, 51A(g), CITES, CMS, constitutional links

Conservation Programmes

Operation Olivia, TEDs, NMCG-WII, Namami Gange, sanctuaries

Threats & Ecological Role

Bycatch, climate, smuggling, ecosystem services, sex-ratio shift

Inter-linkages & Connections

Namami Gange, Bhitarkanika, IUCN, Ramsar, linked concepts

Current Affairs

Live 2025–2026 updates: nesting records, satellite tagging, ATR

PYQ & Traps

Statement T/F table, common exam traps to avoid

MCQ Practice

5 UPSC-style MCQs with detailed explanations

Quick Revision

10-bullet rapid recall capsule + one-liner

Core Concept & World Turtle Day

What Is World Turtle Day?

World Turtle Day — Key Facts at a Glance
Parameter	Detail
Date	May 23 — every year (annual)
Founded	2000 — by American Tortoise Rescue (ATR)
ATR Founded	1990 — by Susan Tellem & Marshall Thompson (Los Angeles, USA)
Significance of May 23	Susan Tellem's birthday (born May 23, 1945) — chosen as the date
2026 Edition	26th Annual World Turtle Day — theme: "Turtle Protector Pledge"
2025 Reach	100+ million people across ~70 countries
Primary Goals	Raise awareness; combat illegal trade, habitat loss, pet trade, climate threats
India Observed By	NMCG (National Mission for Clean Ganga) + WII (Wildlife Institute of India)
Tagline/Campaign	"Shellebrate" — celebrates turtles and tortoises globally

Why Turtles Matter — Ecological Significance

Indicator species: Their health reflects the health of marine and freshwater ecosystems.
Nutrient cycling: Sea turtles transport nutrients from the ocean to beaches during nesting — fertilising coastal vegetation.
Seagrass maintenance: Green turtles graze on seagrass beds, keeping them healthy and productive (vital for dugongs, fish, carbon storage).
Jellyfish control: Leatherback turtles consume jellyfish, preventing jellyfish blooms that harm fishing industries.
River cleaning: Freshwater turtles act as natural scavengers in river systems — Ganga turtles consume decomposing matter, including bodies, helping river purification.
Coral reef ecosystems: Hawksbill turtles feed on sponges, preventing sponge overgrowth on coral reefs.
Ancient survivors: Turtles have survived ~220 million years — outlasting dinosaurs, ice ages, and 5 mass extinctions.

📌 Micro-Fact

The Jal Shakti Minister, inaugurating an NMCG-WII digital platform for freshwater biodiversity (April 2025), noted that turtles have been worshipped in Indian culture from time immemorial — from the Kurma avatar of Vishnu to their documented role in Ganga river purification.

💡 Exam Tip

UPSC often asks about May 23 observances in current affairs questions. Remember: World Turtle Day (May 23) vs World Sea Turtle Day (June 16) — two separate observances. The May 23 event is organised by ATR, a non-governmental, non-UN body.

🐢 World Turtle Day = May 23 · Founded 2000 · ATR (USA) · 26th edition 2026 · India: NMCG + WII · 61% of turtle species threatened or extinct globally

Scientific Classification & Types of Turtles

Turtle vs Tortoise vs Terrapin — Key Distinctions

🐢 TURTLE (broader group)

Includes all chelonians — marine, freshwater & land
All tortoises ARE turtles
NOT all turtles are tortoises
Order: Testudines (Chelonia)
Shell = carapace (upper) + plastron (lower)
Shell fused with spine & ribs — cannot be removed

🏔️ TORTOISE (land turtles)

Family: Testudinidae — land-dwelling only
Dome-shaped, high shell; stumpy, elephant-like feet
Herbivores; longest-living land animals (80–150 years)
~50 species, 15+ genera worldwide
Terrapin = freshwater/brackish water turtles (semi-aquatic)
India examples: Indian Star Tortoise (Geochelone elegans)

Seven Sea Turtle Species of the World

7 Sea Turtle Species — IUCN Status & India Presence
Species	Scientific Name	IUCN Status	In India?	Key Fact
Olive Ridley	Lepidochelys olivacea	Vulnerable	✅ Yes — nests	Most abundant; famous for Arribada mass nesting
Green Turtle	Chelonia mydas	Least Concern*	✅ Yes — nests	Only herbivore; named for green fat under shell
Loggerhead	Caretta caretta	Vulnerable	✅ Yes — no nesting	Largest hard-shell sea turtle; powerful jaws
Hawksbill	Eretmochelys imbricata	Critically Endangered	✅ Yes — nests	Feeds on sponges; shell used in illegal trade (tortoiseshell)
Leatherback	Dermochelys coriacea	Vulnerable	✅ Yes — nests	Largest sea turtle (~700 kg); only species without hard shell
Kemp's Ridley	Lepidochelys kempii	Critically Endangered	❌ No	Smallest sea turtle; nests only in Gulf of Mexico (Mexico/USA)
Flatback	Natator depressus	Data Deficient	❌ No	Nests only in Australia; not listed on CMS Appendix I

*Green turtle recently reclassified to Least Concern globally; some populations still endangered.

Key Biological Features — UPSC Fact Points

220 M

Years on Earth

Sea species (world)

Sea species (India)

~350

Total turtle species

61%

Threatened/Extinct

9,000 km

Olive Ridley migration

Navigation: Turtles navigate using Earth's magnetic field; females return to their birth beach to nest.
Temperature-dependent sex determination (TSD): Warmer nests produce more females — climate change is skewing sex ratios.
Lifespan: Sea turtles can live 80–100+ years; some tortoises exceed 150 years.
Clutch size: Olive Ridley lays ~100 eggs per clutch; nests 1–3 times per season.
Leatherback size: Largest sea turtle — up to 700 kg, 1.8 m in length.
Olive Ridley size: Smallest — ~45 kg, ~70 cm length; olive-green heart-shaped carapace.

⚠ Common Trap

"All tortoises are turtles but not all turtles are tortoises" — frequently confused in UPSC questions. Also: Loggerhead is found in Indian waters but does NOT nest on Indian coasts — 4 species nest in India (Olive Ridley, Green, Hawksbill, Leatherback).

5 of 7 sea turtle species found in India — all CITES Appendix I · Loggerhead in Indian waters but does NOT nest · Flatback = Australia only · All 7 species under threat except Flatback (Data Deficient)

Origin & Evolutionary History of Turtles

220 Million Years — The Turtle Survival Story

~260 Million Years Ago

Eunotosaurus africanus — small lizard from South Africa with thick arching ribs; considered the ancestor of all tortoises, sea turtles, and terrapins.

~220 Million Years Ago (Late Triassic)

Proganochelys quenstedi — first fully-shelled turtle; possessed teeth on roof of mouth (not jaw). Shell structure largely resembled modern turtles. Coexisted with dinosaurs.

~150 Million Years Ago (Late Jurassic)

Kayentachelys aprix — oldest known North American turtle; from the suborder Cryptodira (neck-hiders, includes most modern species).

~110 Million Years Ago (Cretaceous)

Land-dwelling stem turtles began semi-aquatic lives as ancient continents split — Gondwana breakup drove migration of turtle lineages into separate ocean basins.

66 Million Years Ago

Turtles survived the K-Pg extinction event that wiped out non-avian dinosaurs. Resilience attributed to burrowing ability, low metabolism, and dietary flexibility.

Eocene (~56–34 Ma)

Family Testudinidae (tortoises) likely originated in Asia; began migrating to other continents. Indian Star Tortoise (Geochelone elegans) lineage established in South Asia.

Modern Era

~350 species of turtles globally; classified into 2 suborders — Cryptodira (neck-hiders — most sea turtles, freshwater turtles) and Pleurodira (side-neck turtles — mostly southern hemisphere).

Turtles in Indian Cultural & Historical Context

Kurma Avatar: Vishnu's second avatar — the cosmic tortoise that supported Mt. Mandara during Samudra Manthan (churning of the cosmic ocean). Turtle worship documented in Vedic texts.
Chandragupta Maurya (3rd century BC): Among earliest state-level wildlife protection measures in India — forest superintendents appointed under Arthashastra.
Ganga purification role: Hindu tradition of immersing bodies in Ganga — freshwater turtles naturally decompose organic matter, aiding river health. Recognised in Namami Gange programme.
Taxonomy origin: Order name Testudines from Latin testa (shell); alternative name Chelonia from Greek chelone (tortoise).

📌 Micro-Fact

"Turtles survived the dinosaurs. It would be a tragedy if they couldn't survive us." — Susan Tellem, co-founder, American Tortoise Rescue (ATR), 2026 press release marking the 26th World Turtle Day.

💡 Exam Tip

The most important dates for UPSC: turtles first appear ~220 million years ago (Triassic period). Modern turtles belong to Order Testudines / Chelonia. Do not confuse with Reptilia (broader class) — turtles ARE reptiles.

Turtles = ~220 million years old · Proganochelys = first fully-shelled turtle · Survived K-Pg extinction that killed dinosaurs · Order: Testudines · Two suborders: Cryptodira + Pleurodira

India's Turtle Diversity — Key Data & Statistics

Freshwater turtle species

Under Schedule I, WPA 1972

Sea turtle species

Turtle species in UP

Species that nest on Indian coast

1.51 M

Olive Ridley nests, Odisha 2024–25

India's 5 Sea Turtle Species

Sea Turtles in India — Key Nesting & Protection Facts
Species	Nests in India?	Key Nesting Sites	IUCN	WPA 1972
Olive Ridley	✅ Yes — major	Gahirmatha, Rushikulya, Devi (Odisha); Tamil Nadu; Andamans	Vulnerable	Schedule I
Green Turtle	✅ Yes	Lakshadweep, Andaman & Nicobar Islands	LC (some pops. EN)	Schedule I
Hawksbill	✅ Yes — limited	Andaman & Nicobar Islands	Critically Endangered	Schedule I
Leatherback	✅ Yes — limited	Andaman & Nicobar (Little Andaman)	Vulnerable	Schedule I
Loggerhead	❌ No nesting	Present in Indian Ocean waters; does not nest on Indian coast	Vulnerable	Schedule I

India's Freshwater Turtle Diversity — State & River Focus

Freshwater Turtle Hotspots in India
State / Region	Species Count	Key Species / Sites
Uttar Pradesh	15 of 30	Ganga-Yamuna-Chambal system; Brahmani, Morpankhi, Kala Kacchua; Turtle Wildlife Sanctuary (Varanasi)
Ganga Basin (overall)	13 species (Upper Ganga)	Includes critically endangered Three-Striped Roof Turtle (Batagur dhongoka), Brown Roofed Turtle, Indian Tent Turtle
Assam / Northeast	High diversity	Hajong Tortoise Lake (Biodiversity Heritage Site); Brahmaputra floodplains
Rajasthan / Madhya Pradesh	Chambal-focused	Chambal Sanctuary — shared habitat with Gharial and River Dolphin
Odisha	Sea + freshwater	World's largest Olive Ridley rookery; Bhitarkanika mangrove complex

Notable Critically Endangered Freshwater Species — India

Key Critically Endangered Freshwater Turtles in India
Species	Scientific Name	Habitat	Key Threat / Note
Three-Striped Roof Turtle	Batagur dhongoka	Ganga-Brahmaputra	Added CITES Appendix II + Schedule I (WPA) in 2022; severe trade threat
Northern River Terrapin	Batagur baska	Coastal rivers	Rescued from brink by conservationist Shailendra Singh (Behler Award)
Red-Crowned Roofed Turtle	Batagur kachuga	Ganga system	Reintroduced at Chambal-Ganga confluence via TSA + NMCG + UP Forest Dept.
Black Softshell Turtle	Nilssonia nigricans	Assam rivers	Considered semi-sacred; temples maintained breeding pools
Indian Softshell Turtle	Nilssonia gangetica	Ganga, Mahanadi	Listed in WPA Schedule I; Ganga scavenger species

✅ Key Fact

Indian biologist Shailendra Singh was awarded the Behler Turtle Conservation Award — considered the "Nobel Prize" of turtle conservation — for saving three critically endangered turtle species (Northern River Terrapin, Red-Crowned Roofed Turtle, Black Softshell Turtle) from extinction.

India: 30 freshwater species (26 under Schedule I) + 5 sea species (all Schedule I) · UP = most freshwater diversity (15 spp.) · 4 of 5 sea species nest on Indian coast · Loggerhead — NO Indian nesting

Nesting Geography — Gahirmatha, Rushikulya & Arribada

Arribada — The Mass Nesting Phenomenon

Arribada — Key Facts for UPSC
Parameter	Detail
Term meaning	Arribada = Spanish for "arrival by sea" — mass simultaneous nesting
Species	Only Olive Ridley (L. olivacea) and Kemp's Ridley (L. kempii) exhibit Arribada
Trigger	Lunar cycles, wind, ocean temperature, chemical cues — exact mechanism still studied
Scale	Hundreds of thousands of females nest simultaneously on same beach within days
Season in India	December–March (peak); migration from September (9,000 km from Pacific)
Clutch	~100 eggs per nest; 1–3 nesting events per season per female
Incubation	~45–60 days; sex determined by temperature (>29°C → more females)

Major Nesting Sites in India — Spatial Data

Key Olive Ridley Nesting Sites — India
Site	State	Significance	Protection Status
Gahirmatha Beach	Odisha (Kendrapara)	World's largest known sea turtle rookery; ~8 lakh turtles annually; within Bhitarkanika complex	Gahirmatha (Marine) Wildlife Sanctuary
Rushikulya River Mouth	Odisha (Ganjam)	Second major site; 6.98 lakh nests protected in Feb 2025 alone under Operation Olivia	No-fishing zone (Dec–May, 20 km offshore)
Devi River Mouth	Odisha (Puri/Kendrapara)	Third Odisha site; restricted from trawling Nov–May within 20 km	Odisha Marine Fisheries Regulation Act, 1982
Chennai / Kovalam coast	Tamil Nadu	Active nesting; dead turtles washing ashore (bycatch); conservation by forest dept + NGOs	WPA 1972 protections apply
Andaman & Nicobar Islands	A&N UT	Nesting for Hawksbill, Leatherback, Olive Ridley, Green Turtle	Diverse PA network
Lakshadweep	Lakshadweep UT	Key Green Turtle nesting site	Marine PAs, CRZ regulations

Bhitarkanika Complex — Geographic Context

Bhitarkanika National Park — mangrove ecosystem; protects nesting habitat.
Gahirmatha Marine Wildlife Sanctuary — waters surrounding Bhitarkanika; directly includes the world-famous nesting beach at Ekakulanasi Island.
The Gahirmatha nesting beach is on Ekakulanasi Island — a barrier island with wide, erosion-resistant beaches, calm ocean currents, and low human activity.
River: Rushikulya originates from Rushyamala Hills in Eastern Ghats (Kandhamal district, Odisha); flows southeast into Bay of Bengal.
In 2025, Ekakulanasi Island saw 1.7 lakh turtles nesting after a 33-year gap — attributed to natural beach restoration and conservation enforcement.

📌 Micro-Fact

Record Nesting 2024–25: Odisha recorded 1.51 million nests — 6.07 lakh at Gahirmatha + 9.04 lakh at Rushikulya — the highest on record for Indian shores.

⚠ Common Trap

Students often confuse Bhitarkanika National Park with the Gahirmatha (Marine) Wildlife Sanctuary. They are separate protected areas — Bhitarkanika is a terrestrial/mangrove NP; Gahirmatha is the marine sanctuary in the surrounding waters. Both are in Kendrapara district, Odisha.

Gahirmatha = world's largest Olive Ridley rookery · Arribada = mass nesting (Spanish "arrival by sea") · Only Olive Ridley + Kemp's Ridley show Arribada · Record 1.51 million nests in Odisha 2024–25

Legal & Conservation Framework

Constitutional Provisions — Wildlife Protection

Constitutional Articles Relevant to Turtle / Wildlife Conservation
Article	Provision	Relevance
Art. 48A	DPSP — State shall protect & improve environment; safeguard forests & wildlife	Direct mandate for turtle conservation policies
Art. 51A(g)	Fundamental Duty — protect & improve natural environment including forests, lakes, rivers, wildlife	Citizen's duty to protect turtle habitats
Art. 21	Right to Life — extended to cover right to healthy environment (SC judgments)	Environmental litigation basis
Art. 246 + 7th Sch.	Concurrent List Entry (after 42nd Amendment, 1976) — forests & wildlife protection	Both Centre & State can legislate; Central law prevails on conflict
42nd Amendment, 1976	Moved forests & wildlife from State List to Concurrent List	Enabled WPA 1972 national enforcement framework

Wildlife Protection Act, 1972 — Turtle Provisions

WPA 1972 — Key Provisions for Turtle Protection
Provision	Detail
Schedule I	Highest protection; absolute ban on hunting; offences attract maximum penalty (up to 7 years imprisonment + ₹25,000 fine for 2nd offence). All 5 sea turtles + 26 of 30 freshwater turtles listed here.
Smuggling = non-bailable	Turtle smuggling is a non-bailable offence under WPA 1972 (Class 1 water animal)
Penalty	First offence: up to 3 years + ₹25,000 fine; Repeat: up to 7 years + ₹25,000 fine
Schedule I amended 2022	Three-Striped Roof Turtle (Batagur dhongoka) added to Schedule I (WPA) in 2022
WCCB	Wildlife Crime Control Bureau (WCCB) — statutory body under MoEFCC; combat organised wildlife crime including turtle smuggling; maintain centralised wildlife crime data bank

International Conventions & Treaties

International Framework for Sea Turtle Protection
Convention / Treaty	Full Name	Turtle Provisions
CITES	Convention on International Trade in Endangered Species	All 7 sea turtle species under Appendix I — international commercial trade strictly prohibited
CMS	Convention on Migratory Species of Wild Animals	All sea turtles (except Flatback) under Appendix I; binding protection; Flatback only on Appendix II
CBD	Convention on Biological Diversity	General biodiversity protection; no species-specific sea turtle provisions
UNCLOS	UN Convention on Law of the Sea	Relevant for high-seas turtle protection; bycatch regulations
Ramsar Convention	Convention on Wetlands	Relevant for freshwater turtle habitats; Brijghat-Narora stretch of Ganga is a Ramsar site

State-Level Laws — Odisha Focus

Odisha Marine Fisheries Regulation Act, 1982 — empowers Indian Coast Guard (ICG) to enforce no-fishing zones near Olive Ridley nesting sites.
Odisha Marine Fisheries Regulation Rules, 1983 — coastal waters off Devi and Rushikulya declared no-fishing zones during breeding season (Dec–May, 20 km offshore).
Mandatory TED rule: Odisha government mandates all mechanised fishing trawlers to use Turtle Excluder Devices (TEDs).
Maharashtra Wildlife Protection Amendment Bill, 2026 — passed by Maharashtra Assembly (March 2026); amends Section 12 of WPA for human-wildlife conflict management (not turtle-specific but relevant to WPA dynamics).

⚖ Landmark Judgment

Alok Krishna Agarwal vs. Union of India & State of Odisha — Supreme Court's Central Empowered Committee (CEC) petitioned on turtle protection in Odisha. March 2003: CEC imposed complete ban on gill-net boats near three mass-nesting sites. April 2004: Final CEC orders — trawlers prohibited Nov–May within 20 km of Devi and Rushikulya sites. This CEC direction became the foundation for Odisha's marine fisheries no-fishing zone regime.

⚖ Landmark Judgment

Indian Flap Shell Turtle Case (SC, 2020) — Bench of Justices Ashok Bhushan & Indu Malhotra held that identification of turtle species (confirmed as Lissemys punctata / Indian Flap Shell) by a veterinary surgeon is determinative for WPA Schedule prosecution. Upheld criminal proceedings where HC had erroneously quashed them.

All 5 sea turtles + 26 freshwater species = Schedule I WPA 1972 · All 7 sea species = CITES Appendix I · Constitutional foundation: Art. 48A (DPSP) + Art. 51A(g) (Fundamental Duty) · Smuggling = non-bailable offence

Conservation Programmes & Key Initiatives

Operation Olivia — Indian Coast Guard's Marine Mission

Operation Olivia — Complete Fact Profile
Parameter	Detail
Launched By	Indian Coast Guard (ICG)
Year Started	Early 1980s (annual, Nov–May each season)
Target Species	Olive Ridley turtle (Lepidochelys olivacea)
Primary Sites	Gahirmatha Beach, Rushikulya River Mouth, Devi River Mouth (Odisha)
Scale (cumulative)	5,387+ surface patrol sorties; 1,768+ aerial surveillance missions
Boats impounded	366 illegal boats seized
2025 impact	6.98 lakh Olive Ridley turtles protected at Rushikulya (Feb 2025)
Key tools	Drone surveillance, satellite monitoring, MoUs with NGOs, TED promotion
Legal empowerment	ICG empowered under Odisha Marine Fisheries Regulation Act, 1982

Turtle Excluder Devices (TEDs)

What: Specially designed net (cone-shaped) with an opening/trapdoor that allows trapped turtles to escape from trawl nets while retaining the fish catch.
Mandated by: Odisha government — mandatory for all mechanised fishing trawlers in state waters.
Problem addressed: Bycatch — accidental entrapment of turtles in fishing nets is the primary cause of Olive Ridley mortality in Indian waters.
Adoption: ICG actively promotes TED adoption among local fishing communities; MoUs with NGOs for conservation education.

NMCG-WII Freshwater Turtle Conservation — Namami Gange

NMCG + WII — Key Freshwater Turtle Conservation Milestones
Initiative	Year	Detail
Biodiversity Conservation & Ganga Rejuvenation Project	2016	WII designated lead knowledge partner of NMCG; Ganga Aqualife Conservation Monitoring Centre (GACMC) established
Turtle Wildlife Sanctuary (Varanasi)	Notified	On Ganga near Varanasi, UP; protects freshwater turtles in 30-km stretch
Turtle Sanctuary near Prayagraj	2020	Set up under Namami Gange; covers 30 km across Prayagraj, Mirzapur, Bhadohi districts
Red-Crowned Roofed Turtle Reintroduction	2025	30 captive-bred juveniles released at Chambal-Ganga confluence (Narora) — UP Forest Dept + TSA + NMCG
Kukrail Gharial & Turtle Rehabilitation Centre	Active	Lucknow, UP; captive breeding and rehabilitation of endangered turtles
Ganga Aqualife Rescue & Rehabilitation Centre (GARRC)	Active	Narora, UP (Bulandshahar district); head-starting facility on middle Ganga (Brijghat-Narora Ramsar site)
Digital Platform for Freshwater Biodiversity	April 2025	Launched by Jal Shakti Minister at NMCG-WII review; comprehensive hub for rivers, biodiversity, conservation case studies

Turtle Survival Alliance (TSA) India — Key NGO Interventions

TSA India + NMCG: Partnership for freshwater turtle conservation in Ganga basin.
WWF-India: Turtle conservation in UP since 2012; focuses on Three-Striped Roof Turtle, Brown Roofed Turtle, Indian Tent Turtle in collaboration with UP Forest Dept.
Haiderpur Wetland Habitat Assessment (2020): Nine turtle species found; five documented through indirect evidence near Prayagraj.
Assam Biodiversity Board: Declared Hajong Tortoise Lake (home to threatened freshwater species) a Biodiversity Heritage Site.
Pilibhit Tiger Reserve (May 2025): Long-term strategic plan unveiled to curb illegal turtle trafficking and restore habitats.

Satellite Tagging — Tracking Turtle Migrations

December 2025: Odisha Forest Department + WII fitted satellite transmitters on several Olive Ridley turtles at Gahirmatha Marine Sanctuary — to track long-distance migratory and nesting behaviours.
Earlier tagging: Non-corrosive metal tags on Olive Ridley turtles — one tracked turtle travelled 1,000 km from Odisha to Andhra Pradesh coast in 51 days.

✅ Key Fact

Inclusion of Turtle Rehabilitation Centres in the Namami Gange Programme since 2017 has significantly reduced turtle smuggling in the Ganga basin.

Operation Olivia = ICG, since 1980s, Nov–May · 6.98 lakh turtles protected (Rushikulya, Feb 2025) · TEDs = mandatory in Odisha · NMCG-WII = lead freshwater turtle conservation framework · TSA, WWF-India = key NGO partners

Threats & Ecological Significance of Turtles

Major Threats to Turtles — Global & India-Specific

Threats to Turtles — Classification & India Context
Threat	Type	India-Specific Impact
Bycatch / Incidental capture	Anthropogenic (fishing)	Primary killer — trawl nets and gillnets trap Olive Ridley; 1,000+ dead on Chennai coast in 30 days (2025)
Illegal wildlife trade / Smuggling	Anthropogenic (trade)	Freshwater turtles smuggled to China, Indonesia, Malaysia, Taiwan, Thailand — for meat, medicine, eggs, blood
Habitat destruction	Anthropogenic	Coastal development, beach erosion, sand mining — destroys nesting beaches
Plastic pollution	Anthropogenic (marine)	Turtles mistake plastic bags for jellyfish; ingestion causes starvation, internal injuries
Climate change	Natural + Anthropogenic	Rising sand temperatures → more female hatchlings (TSD) — sex ratio skew; sea-level rise destroys nesting beaches
Illegal trawling	Anthropogenic (fishing)	Trawlers violating no-fishing zones near Odisha nesting sites — major target of Operation Olivia
Chinese sky lanterns	Cultural / pollution	Metal/bamboo frames of lanterns fall near turtle nesting sites — act as traps; documented threat in India (Olive Ridley sites)
Vessel strikes	Anthropogenic	Leatherbacks and other large turtles in shipping lanes
Pet trade	Anthropogenic (trade)	Indian Star Tortoise, Indian Flapshell — commonly trafficked as illegal pets
Predation / Natural	Natural	Dogs, birds prey on hatchlings; natural predation exacerbated by human disturbance at nesting beaches

Ecological Services of Turtles — What We Lose

Ecosystem Services Provided by Turtles
Turtle Group	Ecological Service	Benefit Lost If Extinct
Green Turtle	Grazes seagrass beds — keeps them short & healthy	Seagrass degradation → loss of carbon sink + fish nursery
Leatherback Turtle	Primary predator of jellyfish	Jellyfish bloom → damage to fisheries, marine tourism
Hawksbill Turtle	Feeds on reef sponges — maintains coral reef health	Sponge overgrowth → coral reef collapse
All nesting sea turtles	Carry marine nutrients to beaches; fertilise dune vegetation	Coastal vegetation decline; beach erosion increases
All sea turtles	Prey base for sharks, seabirds — part of oceanic food web	Disruption of marine food web
Freshwater turtles (Ganga)	Scavengers — consume decomposing organic matter including animal carcasses	River water quality degrades; organic load increases

Climate Change & Temperature-Dependent Sex Determination (TSD)

Mechanism: Sex of sea turtle hatchlings determined by incubation temperature — not genetics (TSD).
Threshold: Temperatures above ~29°C (the "pivotal temperature") produce more females; below produces more males.
Climate impact: Warming sands due to climate change → dramatically increasing female bias in hatchling populations → risk of long-term reproductive failure.
Example: Great Barrier Reef Green Turtle population — studies show >99% of new hatchlings are female in warmer northern beaches.
India relevance: ICG and Odisha Forest Dept. research on sand temperature at Gahirmatha noted in multiple reports.

★ Important

Conservationists estimate 61% of all turtle species are threatened or already extinct — as of 2026 World Turtle Day assessments. Primary drivers: smuggling, exotic food trade, pet trade, habitat destruction, climate change. Biologists warn populations could decline dramatically within decades without significant action.

Primary threat = bycatch (fishing nets) · Climate = TSD sex-ratio skew (warmer → more females) · Freshwater turtles smuggled to Southeast Asia / China · 61% of species threatened or extinct globally

Inter-linkages & Connected Concepts

Conceptual Linkage Map — World Turtle Day & UPSC Topics

Inter-linkages — Turtle Conservation with Other UPSC Topics
Connected Topic	Specific Link	Why It Matters for UPSC
Namami Gange / Ganga Rejuvenation	NMCG-WII Biodiversity Conservation Initiative; freshwater turtle reintroduction; Turtle Wildlife Sanctuary	GS-III Environment + GS-II Governance
Bhitarkanika (Odisha)	Mangrove National Park; Gahirmatha Marine Sanctuary in surrounding waters; world's largest Olive Ridley rookery	Hotspot for biodiversity questions; map-based MCQs
IUCN Red List	Olive Ridley = Vulnerable; Hawksbill = Critically Endangered; Kemp's Ridley = Critically Endangered	Status matching questions in Prelims
CITES (Appendix I)	All 7 sea turtle species listed; international commercial trade prohibited	Treaty-species matching MCQs
CMS (Convention on Migratory Species)	All sea turtles (except Flatback) on Appendix I; binding conservation obligations on signatory countries	International environmental law questions
Wildlife Crime Control Bureau (WCCB)	Statutory body under MoEFCC; combats turtle smuggling; maintains wildlife crime database	Institutional matching questions
Indian Coast Guard	Operation Olivia — primary enforcement agency for Olive Ridley nesting; empowered under Odisha Marine Fisheries Regulation Act, 1982	Role of Coast Guard in conservation
Chambal Sanctuary	Shared habitat — gharials, river dolphins, freshwater turtles; Chambal-Ganga confluence release site	Biodiversity hotspot multiple species questions
Ramsar Convention	Brijghat-Narora stretch (middle Ganga) = Ramsar Wetland; hosts GARRC turtle facility	Wetland convention + biodiversity link
Climate Change & IPCC	Temperature-Dependent Sex Determination (TSD) → climate threatens sea turtle reproductive balance	Climate-biodiversity nexus questions
42nd Constitutional Amendment, 1976	Moved forests & wildlife to Concurrent List — basis for WPA 1972 national enforcement	Constitutional amendment + wildlife law link
Kurma Avatar (Art & Culture)	Second Vishnu avatar; tortoise supports Mt. Mandara; Samudra Manthan	Cross-subject linkage in Art & Culture questions

Important Institutions & Bodies — Turtle Conservation

Key Institutions — Roles & Functions
Institution	Full Name / Type	Role in Turtle Conservation
ATR	American Tortoise Rescue — US NGO, founded 1990	Organises World Turtle Day (May 23) annually since 2000
NMCG	National Mission for Clean Ganga — Govt. of India	Freshwater turtle conservation in Ganga basin; observes World Turtle Day in India with WII
WII	Wildlife Institute of India — autonomous under MoEFCC	Lead knowledge partner for NMCG; satellite tagging; GACMC; biodiversity surveys
ICG	Indian Coast Guard — defence ministry	Operation Olivia; enforcement of no-fishing zones; patrol sorties
TSA India	Turtle Survival Alliance — international NGO, India chapter	Ex-situ conservation; capacity building; freshwater turtle reintroduction with NMCG
WCCB	Wildlife Crime Control Bureau — statutory, MoEFCC	Combat organised turtle smuggling; wildlife crime database
WWF-India	World Wide Fund for Nature — international NGO, India office	UP freshwater turtle conservation since 2012; community-based nest protection
NBWL	National Board for Wildlife — statutory under WPA 1972, 2002 amendment; PM chairs	Apex body for all wildlife matters; Protected Area approvals

Namami Gange

Operation Olivia

Gahirmatha Sanctuary

Bhitarkanika NP

CITES Appendix I

CMS Appendix I

WPA 1972 Schedule I

Turtle Excluder Devices

Arribada

IUCN Red List

WCCB

Chambal Sanctuary

Brijghat-Narora Ramsar

Art. 48A + 51A(g)

Turtle Survival Alliance

World Sea Turtle Day (June 16)

Turtle conservation cuts across: Namami Gange · CITES · CMS · WPA 1972 · Indian Coast Guard · Constitutional DPSP + Fundamental Duties · Climate TSD link · Ganga scavenger role · Kurma Avatar (culture)

Current Affairs — Live 2025–2026 Updates

📊 Current Affairs — Drishti IAS / Utkarsh.com · May 2025

Operation Olivia 2025 Impact: Indian Coast Guard's Operation Olivia helped protect 6.98 lakh Olive Ridley turtles nesting at the Rushikulya river mouth in Odisha during February 2025. The operation involved 5,387+ surface patrol sorties and 1,768+ aerial surveillance missions cumulatively, with 366 illegal boats impounded.

📊 Current Affairs — Drishti IAS · May 2025

UP Leads India in Turtle Conservation (World Turtle Day 2025): Uttar Pradesh was highlighted as India's leading state in freshwater turtle conservation. UP hosts 15 of India's 30 freshwater turtle species. Conservation centres at Kukrail (Lucknow), Sarnath, and Chambal are operational. The Namami Gange Turtle Rehabilitation Centre's inclusion since 2017 has significantly reduced smuggling in the Ganga basin.

📊 Current Affairs — OdishaTV / News On Air · May & December 2025

Record Nesting + Satellite Tagging at Gahirmatha: In 2025, Gahirmatha's Ekakulanasi Island saw 1.7 lakh turtles nesting after a 33-year gap, attributed to natural beach restoration. In December 2025, the Odisha Forest Department and WII fitted satellite transmitters on several Olive Ridley turtles at Gahirmatha to track migration patterns — one previously tagged turtle travelled 1,000 km from Odisha to the Andhra Pradesh coast in 51 days.

📊 Current Affairs — Legacy IAS / LevelUp IAS · April 2026

Record 1.51 Million Nests — Odisha 2024–25: Odisha recorded a historic high of 1.51 million Olive Ridley nests in the 2024–25 nesting season — 6.07 lakh at Gahirmatha and 9.04 lakh at Rushikulya. This is the highest nesting figure ever recorded on Indian shores, reflecting success of conservation measures including Operation Olivia, mandatory TEDs, and no-fishing zone enforcement.

📊 Current Affairs — World Turtle Day / SMDP · March–May 2026

26th World Turtle Day — May 23, 2026: American Tortoise Rescue (ATR) marks the 26th annual World Turtle Day with a redesigned website, expanded educational resources, and the theme "Turtle Protector Pledge." ATR co-founder Marshall Thompson (cinematographer) passed away on November 2, 2025, at age 77 following dementia. Susan Tellem (age 80) continues as executive director. 61% of turtle species are now estimated threatened or already extinct globally.

📊 Current Affairs — News On Air · April 2025

Jal Shakti Digital Platform for Freshwater Biodiversity (April 2025): Union Jal Shakti Minister C.R. Paatil launched a digital platform for freshwater biodiversity conservation during an NMCG-WII review meeting, covering ecological insights from rivers including Ganga, Cauvery, and Godavari. The platform includes turtle, dolphin, and fish conservation case studies and monitoring data.

📊 Current Affairs — InsightfulTake / Daily Pioneer · 2025

Red-Crowned Roofed Turtle Reintroduced into Ganga (2025): 30 juvenile Red-Crowned Roofed Turtles (captive-bred at Kukrail Gharial & Turtle Rehabilitation Centre, Lucknow) released at Chambal-Ganga confluence near Narora, Uttar Pradesh — a joint initiative of UP Forest Department, Turtle Survival Alliance (TSA), and NMCG. The release site forms part of the 165-km National Chambal Sanctuary.

💡 Exam Tip — Current Affairs Anchor for Prelims 2026

The World Turtle Day cluster of facts is a high-probability Prelims 2026 question source. Key data points: May 23 · ATR founded 2000 · 26th edition 2026 · 61% threatened · 1.51 million nests Odisha 2024–25 · Operation Olivia 6.98 lakh protection · Satellite tagging Dec 2025 · Red-Crowned Roofed Turtle reintroduction 2025.

2026 = 26th World Turtle Day · ATR co-founder Marshall Thompson passed away Nov 2025 · Record 1.51M Olive Ridley nests in Odisha 2024–25 · Satellite tagging Dec 2025 at Gahirmatha · Red-Crowned Roofed Turtle reintroduced into Ganga 2025

PYQ & Common Traps

Statement True / False Analysis — UPSC Pattern

Statement Analysis — Turtles / World Turtle Day
Statement	T / F	Correct Fact / Explanation
World Turtle Day is observed on May 23 every year.	✅ T	Correct. Since 2000; organised by American Tortoise Rescue (ATR).
World Turtle Day is observed by the United Nations.	❌ F	ATR is a non-profit NGO (USA), not a UN body. World Sea Turtle Day (June 16) is separate.
All tortoises are turtles, but not all turtles are tortoises.	✅ T	Tortoises (family Testudinidae) are land-dwelling turtles — a subset.
India is home to all 7 species of sea turtles.	❌ F	India has 5 of 7 sea species. Kemp's Ridley (Gulf of Mexico only) and Flatback (Australia only) are absent.
Loggerhead turtle nests on Indian coasts.	❌ F	Loggerhead is found in Indian waters but does NOT nest on Indian coasts. Only 4 species nest in India.
All sea turtles in India are protected under Schedule I of WPA 1972.	✅ T	All 5 sea turtle species in India are Schedule I — highest protection level.
Olive Ridley is the largest sea turtle species.	❌ F	Leatherback is the largest (~700 kg). Olive Ridley is one of the smallest (~45 kg).
Gahirmatha is the world's largest rookery for Olive Ridley turtles.	✅ T	Located in Kendrapara district, Odisha; part of Bhitarkanika complex; Gahirmatha (Marine) Wildlife Sanctuary.
Arribada is a phenomenon shown by all 7 species of sea turtles.	❌ F	Only Olive Ridley and Kemp's Ridley exhibit mass simultaneous nesting (Arribada).
Operation Olivia is run by the Indian Navy.	❌ F	Operation Olivia is an Indian Coast Guard (ICG) initiative — not the Indian Navy.
All 7 species of sea turtles are listed under CITES Appendix I.	✅ T	International commercial trade in all sea turtles is strictly prohibited under CITES.
The Flatback turtle is included in CMS Appendix I.	❌ F	Flatback (Natator depressus) is only in CMS Appendix II — all others are in Appendix I.
Article 48A mandates citizens to protect wildlife as a Fundamental Duty.	❌ F	Art. 48A is a DPSP (Directive Principles of State Policy) — it applies to the State, not citizens. Art. 51A(g) is the Fundamental Duty for citizens.
Turtle sex is determined genetically in all species.	❌ F	Turtles show Temperature-Dependent Sex Determination (TSD) — warmer temperatures produce more females.

⚠ Trap 1 — World Turtle Day vs World Sea Turtle Day

UPSC current affairs questions often test exact dates. World Turtle Day = May 23 (organised by ATR, since 2000) covers ALL turtles and tortoises. World Sea Turtle Day = June 16 — a separate observance. Never mix these two.

⚠ Trap 2 — Operation Olivia: Coast Guard, NOT Navy

Students frequently attribute Operation Olivia to the Indian Navy. It is an Indian Coast Guard (ICG) operation, running annually since the early 1980s. ICG is empowered under the Odisha Marine Fisheries Regulation Act, 1982 to enforce no-fishing zones.

⚠ Trap 3 — 4 nest in India, not 5

India has 5 sea turtle species, but only 4 nest on Indian coasts (Olive Ridley, Green, Hawksbill, Leatherback). The Loggerhead is found in Indian waters but does NOT nest here. This distinction is a classic UPSC trap.

⚠ Trap 4 — Bhitarkanika ≠ Gahirmatha

Bhitarkanika is a National Park (mangrove ecosystem). Gahirmatha is a separate Marine Wildlife Sanctuary in the surrounding waters. Questions often ask about "which PA is the world's largest Olive Ridley rookery" — answer is Gahirmatha (Marine) Wildlife Sanctuary, not Bhitarkanika NP.

⚠ Trap 5 — Art. 48A vs Art. 51A(g)

Art. 48A (DPSP) = State's duty to protect forests and wildlife. Art. 51A(g) (Fundamental Duty) = Citizens' duty to protect natural environment. Questions test this distinction precisely: "which provision places duty on citizens?" → 51A(g).

⚠ Trap 6 — Arriabda Species

Arribada (mass nesting) is shown by only two species: Olive Ridley (Lepidochelys olivacea) and Kemp's Ridley (Lepidochelys kempii). Not by Green Turtle, Leatherback, Hawksbill, Loggerhead, or Flatback. UPSC has asked this before.

⚠ Trap 7 — CMS: Flatback on Appendix II, not I

All sea turtle species except the Flatback turtle (Natator depressus) are listed under CMS Appendix I. The Flatback is only on Appendix II. This is a frequently tested UPSC detail in statement-type questions about international conventions.

💡 Exam Tip — PYQ Pattern

UPSC Prelims has tested: (a) sea turtle species in India / nesting sites; (b) WPA Schedule classification; (c) CITES/CMS listings; (d) Gahirmatha/Bhitarkanika geography; (e) Operation Olivia; (f) Arribada. Pair-matching questions (species + conservation status) are very common. Revise the IUCN status table carefully.

Key traps: WTD = ATR (not UN) · May 23 ≠ June 16 · Operation Olivia = ICG not Navy · 4 nest in India (not 5) · Bhitarkanika ≠ Gahirmatha · Arribada = only Olive Ridley + Kemp's Ridley · Art. 48A (State) vs 51A(g) (Citizens)

MCQ Practice — UPSC-Style Questions

1World Turtle Day is observed annually on which date, and by which organisation?
(a) May 23 — United Nations Environment Programme (UNEP)
(b) June 16 — American Tortoise Rescue (ATR)
(c) May 23 — American Tortoise Rescue (ATR)
(d) June 16 — World Wildlife Fund (WWF)

Correct: (c)

World Turtle Day is observed on May 23 each year since 2000, organised by American Tortoise Rescue (ATR) — a US-based non-profit NGO, not a UN body. June 16 is World Sea Turtle Day — a separate observance. ATR was founded in 1990 by Susan Tellem and Marshall Thompson. 2026 marks the 26th World Turtle Day.

2Consider the following statements about sea turtles in India:
1. India is home to 5 of the 7 known species of sea turtles.
2. All 5 sea turtle species found in India nest on Indian coasts.
3. The Olive Ridley turtle is protected under Schedule I of the Wildlife Protection Act, 1972.
4. The phenomenon of mass simultaneous nesting by Olive Ridley turtles is called "Arribada."
Which of the above statements are correct?

Correct: (c) — Statements 1, 3 and 4 are correct.

Statement 1 ✅: India has 5 of 7 sea species (Olive Ridley, Green, Loggerhead, Hawksbill, Leatherback). Statement 2 ❌: Only 4 of the 5 nest on Indian coasts — the Loggerhead is found in Indian waters but does NOT nest here. Statement 3 ✅: All 5 sea species are Schedule I, WPA 1972. Statement 4 ✅: Arribada (Spanish "arrival by sea") = mass nesting — only Olive Ridley and Kemp's Ridley show this behaviour.

3Which of the following correctly pairs the sea turtle sanctuary / nesting site with its location in India?
1. Gahirmatha (Marine) Wildlife Sanctuary — Kendrapara, Odisha
2. Rushikulya Nesting Site — Ganjam district, Odisha
3. Leatherback nesting — primarily Tamil Nadu coast
4. Hawksbill nesting — Andaman & Nicobar Islands
Select the correct answer:

Correct: (b) — 1, 2 and 4 are correctly paired.

Pair 1 ✅: Gahirmatha (Marine) Wildlife Sanctuary = Kendrapara district, Odisha — world's largest Olive Ridley rookery. Pair 2 ✅: Rushikulya = Ganjam district, Odisha — second major Olive Ridley nesting site. Pair 3 ❌: Leatherback nests primarily in Andaman & Nicobar Islands (Little Andaman), not Tamil Nadu coast. Pair 4 ✅: Hawksbill nests in Andaman & Nicobar Islands.

4With reference to Operation Olivia, which of the following is/are correct?
1. It is conducted by the Indian Coast Guard to protect Olive Ridley turtles during nesting season.
2. It is conducted from November to May each year.
3. It involves enforcement of the Odisha Marine Fisheries Regulation Act, 1982.
4. It was launched in 2000 to coincide with the founding of World Turtle Day.

Correct: (c) — Statements 1, 2 and 3 are correct.

Statement 1 ✅: Operation Olivia = ICG initiative for Olive Ridley protection during nesting season. Statement 2 ✅: Runs annually November to May. Statement 3 ✅: ICG is empowered under Odisha Marine Fisheries Regulation Act, 1982 to enforce no-fishing zones. Statement 4 ❌: Operation Olivia was launched in the early 1980s — not 2000. World Turtle Day was founded in 2000 by ATR — a separate event.

5As per the 2024–25 nesting season data (a recent development for UPSC 2026), which of the following statements is CORRECT regarding Olive Ridley turtle conservation in Odisha?

Correct: (c)

Odisha recorded a historic 1.51 million Olive Ridley nests in 2024–25: 6.07 lakh at Gahirmatha + 9.04 lakh at Rushikulya. This is the highest nesting figure on Indian shores ever recorded. Note: Option (b) reverses the Gahirmatha/Rushikulya numbers — typical UPSC number-reversal trap. Option (d) is wrong: it is the Indian Coast Guard (not Navy) that runs Operation Olivia. Source: Legacy IAS / LevelUp IAS, April 2026.

5 MCQs completed · Review: ATR founded WTD (2000) · 4 nest in India not 5 · Loggerhead no nesting · Operation Olivia = ICG + early 1980s · 1.51M nests Odisha 2024–25 · Gahirmatha 6.07L + Rushikulya 9.04L

Quick Revision — Rapid Recall Capsule

⚡ Rapid Recall — World Turtle Day (Environment · Prelims)

World Turtle Day: May 23 every year · since 2000 · organised by American Tortoise Rescue (ATR) (US NGO, founded 1990) · 2026 = 26th edition · theme: "Turtle Protector Pledge"
India Observers: NMCG (National Mission for Clean Ganga) + WII (Wildlife Institute of India) observe World Turtle Day in India
India's species: 30 freshwater species (26 under Schedule I, WPA 1972) + 5 sea species (all Schedule I); 4 of 5 sea species nest in India — Loggerhead does NOT nest
Sea species (7 global): Olive Ridley (VU) · Green (LC) · Loggerhead (VU) · Hawksbill (CR) · Leatherback (VU) · Kemp's Ridley (CR) · Flatback (DD) — India has first 5; Kemp's Ridley + Flatback absent
Arribada: Mass simultaneous nesting = only Olive Ridley + Kemp's Ridley · Gahirmatha = world's largest rookery · Odisha 2024–25: record 1.51M nests (6.07L Gahirmatha + 9.04L Rushikulya)
Operation Olivia: Indian Coast Guard (not Navy) · since early 1980s · Nov–May · Gahirmatha + Rushikulya + Devi · 6.98L turtles protected (Rushikulya, Feb 2025) · 5,387+ sorties · 366 illegal boats impounded
Legal protection: WPA 1972 Schedule I (absolute protection; non-bailable offence) · CITES Appendix I (all 7 sea species) · CMS Appendix I (all except Flatback = Appendix II only) · Art. 48A (DPSP) + Art. 51A(g) (FD)
Key institutions: WCCB (smuggling), TSA India (ex-situ), NMCG-WII (Ganga), ICG (Operation Olivia), WWF-India (UP rivers), NBWL (apex, PM chairs)
Current affairs 2025–26: Satellite tagging at Gahirmatha (Dec 2025) · 1.7L nesting at Ekakulanasi after 33 years (2025) · Red-Crowned Roofed Turtle reintroduction at Narora (2025) · ATR co-founder Thompson died Nov 2025
Climate link: TSD = Temperature-Dependent Sex Determination · >29°C → more females → climate change = sex ratio skew risk for sea turtle populations
Evolutionary anchor: ~220 million years old (Triassic) · Survived K-Pg extinction (dinosaur wipeout) · Proganochelys = first fully-shelled turtle · Order: Testudines / Chelonia
Global status: 61% of all turtle species threatened or already extinct (2026 estimate) · Primary threats: bycatch, smuggling, habitat loss, climate change, pet trade

🎯 World Turtle Day = May 23 · ATR since 2000 · India: 30 FW + 5 marine species · Gahirmatha = world's largest rookery · All sea turtles = CITES Appendix I + WPA Schedule I · Operation Olivia = ICG, since 1980s

· MaargX UPSC · Curated for Civil Services Preparation ·

Species-Status Quick Matrix

Sea Turtle Quick Reference — IUCN + CITES + India Nesting
Species	IUCN	CITES	CMS	Nests India?
Olive Ridley	Vulnerable	App. I	App. I	✅ Major
Green Turtle	Least Concern	App. I	App. I	✅ Yes
Loggerhead	Vulnerable	App. I	App. I	❌ No
Hawksbill	Critically Endangered	App. I	App. I	✅ A&N Islands
Leatherback	Vulnerable	App. I	App. I	✅ A&N Islands
Kemp's Ridley	Critically Endangered	App. I	App. I	❌ No
Flatback	Data Deficient	App. I	App. II only	❌ No

★ Last-Minute 3-Point Anchor

1. World Turtle Day = May 23, ATR, since 2000 (not UN, not June 16).
2. India: 5 sea species, 4 nest (Loggerhead = present but no nesting) · All = Schedule I + CITES App. I.
3. Operation Olivia = Indian Coast Guard (not Navy) · Gahirmatha = world's largest rookery · 1.51M record nests 2024–25.