🗞️ Why in News Down to Earth reported on the 64% surge in monarch butterfly populations in Mexico’s overwintering forests during 2025-26, while analysing why this encouraging recovery still falls far short of long-term conservation targets and what lessons it holds for migratory species worldwide.
A Recovery in Context
The 64% increase in monarch butterfly presence (from 1.79 to 2.93 hectares of forest occupied) is the largest annual recovery since 2018 and the second consecutive year of growth. However, the broader trajectory remains alarming:
| Period | Area Occupied | % of 1990s Peak |
|---|---|---|
| 1996-97 (peak) | 18.19 ha | 100% |
| 2013-14 (nadir) | 0.67 ha | 3.7% |
| 2023-24 | 0.90 ha | 4.9% |
| 2025-26 (current) | 2.93 ha | 16.1% |
| Target | 6.00 ha | 33% |
Even at its current recovery level, the population is 84% below its 1990s peak and less than half the 6-hectare target set by conservationists.
Why the Recovery Happened
The editorial identifies a convergence of favourable factors:
- Climate conditions — Less drought in the US Midwest during spring/summer 2025 boosted milkweed growth and monarch breeding success
- Milkweed restoration — US conservation programmes have planted millions of milkweed plants along monarch corridors
- Reduced illegal logging — In Mexico’s core biosphere reserve zones, illegal logging has been practically eradicated since 2008
- Community engagement — Mexican ejido (community land) programmes provide alternative livelihoods to reduce logging pressure
Why Recovery Is Fragile
The editorial warns against complacency — the recovery is driven largely by one good weather year, not structural improvements:
| Persistent Threat | Scale |
|---|---|
| Milkweed habitat loss (US) | 1.3 billion milkweed stems lost since 1999 |
| Glyphosate-resistant crops | Eliminated milkweed from 80% of US Midwest farmland |
| Climate change | Shifting temperature zones disrupting migration timing |
| Extreme weather | 2016 storm killed 5-10% of overwintering population in one event |
| Urbanisation | Habitat fragmentation along 4,800 km migration corridor |
The Trinational Conservation Framework
Monarch conservation requires trinational cooperation among Canada, the US, and Mexico — the three countries spanning the migration route:
| Country | Role | Key Action |
|---|---|---|
| Canada | Summer breeding (northernmost) | Species at Risk Act listing (Endangered) |
| United States | Breeding + migration corridor | ESA listing proposed (Threatened); milkweed restoration |
| Mexico | Overwintering habitat | Biosphere Reserve protection; ejido programmes |
The Monarch Butterfly Biosphere Reserve (UNESCO World Heritage Site since 2008) in Mexico provides the critical overwintering habitat.
Lessons for India’s Migratory Species
India hosts several spectacular migratory species that face similar conservation challenges:
| Species | Migration Route | Threat | Conservation Status |
|---|---|---|---|
| Amur Falcon | Siberia → Nagaland → Southern Africa | Trapping in Nagaland (now reduced) | LC (IUCN) |
| Bar-headed Goose | Central Asia → India (winters) | Wetland loss, poisoning | LC (IUCN) |
| Olive Ridley Turtle | Indian Ocean → Odisha coast (nesting) | Fishing nets, light pollution | VU (IUCN) |
| Indian Skimmer | Central Asian rivers → Indian rivers | Riverbed mining, disturbance | EN (IUCN) |
The monarch’s experience offers direct lessons:
- Corridor protection — Conservation of the entire migration route, not just endpoints
- Community involvement — Local communities must benefit from conservation
- Cross-border cooperation — India shares migratory flyways with 30+ countries under the Central Asian Flyway
- Climate adaptation — Conservation plans must account for climate-induced habitat shifts
Convention on Migratory Species (CMS)
| Feature | Detail |
|---|---|
| Also known as | Bonn Convention |
| Adopted | 1979 |
| Parties | 133 countries |
| Secretariat | Bonn, Germany |
| India’s role | Party since 1983; hosted COP13 in Gandhinagar (2020) |
| COP14 | Samarkand, Uzbekistan (February 2024) |
| Key finding | 44% of CMS-listed species show declining populations |
UPSC Relevance
Prelims: CMS/Bonn Convention, Monarch IUCN status, Biosphere Reserve, Central Asian Flyway, CITES vs CMS. Mains GS-3: International conservation frameworks for migratory species; lessons from monarch conservation for India; climate change impacts on biodiversity; trinational cooperation models.
📌 Facts Corner — Knowledgepedia
Monarch Butterfly Conservation:
- IUCN Status: Endangered (migratory subspecies, 2022)
- Migration: 4,800 km (Canada/US to Mexico)
- Overwintering: Monarch Butterfly Biosphere Reserve (UNESCO WHS, 2008)
- 2025-26 recovery: 2.93 ha (+64% from 1.79 ha)
- Still 84% below 1990s peak of 18.19 ha
Global Migratory Species Conservation:
- CMS (Bonn Convention): 133 parties, adopted 1979
- CMS COP14: Samarkand (Feb 2024)
- State of Migratory Species (2024): 44% declining
- Central Asian Flyway: 30 countries, India is key
India’s Key Migratory Species:
- Amur Falcon: Siberia to Africa via Nagaland
- Bar-headed Goose: Central Asia to Indian wetlands
- Olive Ridley Turtle: Nests at Gahirmatha (Odisha)
- Greater Flamingo: Iran/Afghanistan to Gujarat
India and CMS:
- India party to CMS since 1983
- Hosted COP13: Gandhinagar, Gujarat (2020)
- Adopted: Gandhinagar Declaration on migratory species
- Central Asian Flyway Action Plan: India is a lead country
Other Relevant Facts:
- Milkweed (Asclepias): Sole food plant for monarch caterpillars
- 1.3 billion milkweed stems lost in US since 1999
- Illegal logging in Mexico biosphere core zone: eradicated since 2008
- Ejido system: Mexican communal land ownership model
Sources: Down to Earth, WWF, NWF