Migratory wildlife, from Arctic shorebirds to ocean-spanning sharks, grapples with accelerating threats that jeopardize their survival across global routes.
49% of Protected Populations Now Declining
49% of Protected Populations Now Declining (Image Credits: Imgs.mongabay.com)
Nearly half of the migratory species populations safeguarded by an international treaty showed declines, marking a sharp rise from previous assessments.
The State of the World’s Migratory Species: Interim Report 2026, released by the Convention on the Conservation of Migratory Species (CMS), revealed that 49% of listed populations decreased, up from 44% just two years earlier. This U.N.-backed analysis covered nearly 1,200 species protected across 132 countries and the European Union. Twenty-six species shifted to higher extinction risk categories since the last full report, with shorebirds bearing much of the burden – 18 of them worsened. Meanwhile, 24% of CMS-listed species now face extinction threats, an increase from 22%.
Freshwater fish populations plunged by 81% globally, while raptors along the African-Eurasian flyway and marine species like sharks and rays also suffered.
Avian Influenza Emerges as a Major Killer
Highly Pathogenic Avian Influenza (HPAI) triggered mass die-offs among birds, amplifying other pressures on migratory flocks. The virus infected 598 bird species and 102 mammals by late 2025.
In Peru, 20,000 pelicans perished in 2023, devastating a population of fewer than 100,000. East Asia saw 1,500 to 1,700 hooded cranes lost at wintering sites. Waterfowl, shorebirds, and penguins – including African and Humboldt varieties – proved especially vulnerable. “Avian influenza is having a real impact, but it’s also compounded by wider threats such as habitat loss and degradation, overexploitation and climate change,” stated Kelly Malsch, the report’s lead author from the U.N. Environment Programme.
Habitat Destruction severs Critical Connections
Human expansion fractured essential migration corridors through land conversion, infrastructure, and extraction activities. Roads, fences, and mining disrupted routes for species like the Bathurst herd of tundra caribou, whose numbers fell from 450,000 in 1986 to 6,240 by 2021.
Overexploitation via hunting and fishing ranked as the top threats, alongside climate shifts. The report identified 9,372 Key Biodiversity Areas vital for CMS species, yet 47% lacked protection.
- Habitat loss and degradation from agriculture and urban growth.
- Overexploitation through unsustainable harvest.
- Infrastructure barriers like pipelines and railways.
- Climate change altering breeding and foraging grounds.
- Disease outbreaks, including HPAI.
Conservation Efforts Offer Paths Forward
Despite grim trends, targeted actions yielded successes, such as rebounds in scimitar-horned oryx to 575 individuals after reintroduction in Chad and saiga antelope recovery post-disease. Seven CMS-listed species improved overall, including the Mediterranean monk seal.
The interim report, timed before the CMS 15th Conference of the Parties in Brazil, proposed listing 42 additional species and emphasized wildlife corridors and protected ocean networks. “Corridors are a key part of the solution,” noted CMS Executive Secretary Amy Fraenkel.
Key Takeaways:
- 49% decline rate signals urgent need for cross-border action.
- HPAI mass mortality underscores disease monitoring importance.
- Protected corridors can reverse fragmentation trends.
As migratory species link ecosystems worldwide, their decline threatens biodiversity and human well-being alike. Strengthening international commitments now could halt the slide – what steps should governments prioritize next? Share your thoughts in the comments.
