Nearly half of migratory bird species in decline, global report finds as nations sign Nairobi pact

Nearly half of the world's migratory bird species are losing population, according to a global assessment released Friday by BirdLife International, as governments, development banks and conservation groups meeting in the Kenyan capital signed a new pact committing to cross-border protection of the routes birds travel between continents.

The State of the World's Birds report, the sixth edition of BirdLife's flagship assessment and the first built entirely around migratory species, was unveiled at the Nature Kenya-hosted Global Flyways Summit in Nairobi. Delegates at the gathering, part of BirdLife's quadrennial Global Partnership Meeting held September 8-11, signed the Nairobi Flyways Declaration, a commitment by governments, scientists, non-governmental groups and financial institutions to coordinate conservation along entire migratory corridors rather than country by country.

The numbers

Of 1,843 migratory bird species assessed, 45 percent show declining global populations, 30 percent are stable, 14 percent are increasing and the trend for the remaining 11 percent is unknown, the report found. Two hundred species, or 11 percent, are now classified as threatened with extinction: 32 critically endangered, 57 endangered and 111 vulnerable, based on assessments feeding into the State of the World's Birds data platform.

The declines are not evenly spread. Fifty-four percent of migratory shorebird species and 49 percent of seabird species are in decline, among the steepest drops of any group. Species dependent on marine habitats, forests and coastal wetlands fared worst overall. Along the East Asian-Australasian Flyway, which links breeding grounds in Russia and Alaska to wintering areas in Southeast Asia and Australia, 53 percent of species are declining, the highest rate among the major land-based flyways.

• 45% of 1,843 assessed migratory species have declining populations
• 200 species (11%) are threatened with extinction
• Only 9% of migratory species have adequate protection across their entire migratory cycle, versus 45% of non-migratory species
• More than $6 billion in conservation finance has been mobilized by development banks since 2021

How the picture emerged

BirdLife has published its State of the World's Birds assessment periodically since the 1990s, drawing on data feeding into the IUCN Red List of Threatened Species, but this year marks the first edition devoted specifically to migratory birds and the flyways connecting their breeding, resting and wintering grounds. The shift reflects a structural problem the report says has been building for decades: birds that cross borders depend on a chain of habitats in different countries, and protecting one link is not enough if others fail. Only about 9 percent of migratory species have adequate legal or physical protection across the whole of their range, the report found, compared with 45 percent of non-migratory birds that spend their lives in a single country.

The report also documents losses already locked in. The slender-billed curlew, once found across Europe, North Africa and Central Asia and last confirmed in Morocco in 1995, is now considered extinct, one of seven migratory species confirmed or suspected lost over the past 150 years. Researchers attribute the broader declines chiefly to habitat loss from agricultural expansion, invasive species and disease, climate change, unsustainable hunting and pollution, threats that recur across nearly every flyway examined, according to an analysis of the findings by the environmental news outlet Mongabay.

Who is affected

The report's authors frame migratory birds as an indicator species for the health of the wider landscapes and waters that sustain them, meaning the declines have implications well beyond birdwatching. Wetlands along the East Asian-Australasian Flyway alone provide ecosystem services, including flood control and fisheries, to close to 200 million people across the 22 countries the route passes through, according to the Asian Development Bank's Regional Flyway Initiative, one of the financing programs highlighted at the summit. Coastal communities dependent on healthy wetlands for fisheries and storm protection, and farmers whose land overlaps with stopover sites, are among those most directly exposed as those habitats degrade.

Not every trend line points downward. The report cites the recovery of the Egyptian vulture in the Balkans, achieved through coordinated anti-poisoning and nest-protection efforts across multiple countries, as evidence that flyway-scale cooperation can reverse declines when sustained over time.

Reaction

Officials at the summit framed the findings as both a warning and a call to action. Princess Takamado of Japan, president of BirdLife International, told delegates that international cooperation was essential because the species do not observe political boundaries.

"Migratory birds are sentinels, and their declines reveal growing pressure on the natural systems that sustain us," said Stuart Butchart, chief scientist at BirdLife International.

Martin Harper, BirdLife International's chief executive, said development banks were "rising to the challenge" on financing, adding that the organization's network of national partners was "prepared to act" to implement the new commitments. Musonda Mumba, secretary-general of the Convention on Wetlands, said addressing the crisis would require what she described as a blend of multilateral cooperation, grassroots awareness, evidence-based policy and stronger legislative action across the countries involved.

What happens next

The Nairobi Flyways Declaration itself carries no binding legal force, but it is intended to anchor a set of regional financing pledges announced alongside it. The Asian Development Bank's Regional Flyway Initiative is working to mobilize $3 billion over ten years to protect at least 50 priority wetlands across the East Asian-Australasian Flyway, while the Development Bank of Latin America and the Caribbean has pledged between $3 billion and $5 billion through 2050 for more than 30 wetland landscapes in the Americas. Combined with earlier commitments, BirdLife says development banks have now mobilized more than $6 billion in conservation finance for flyway habitats since 2021.

BirdLife said the declaration's signatories, spanning Regional Flyway Initiatives across Africa, Asia, Europe and the Americas, are now moving from pledges into what the organization calls a delivery phase, with country-level implementation plans expected to be tracked ahead of the next Global Partnership Meeting. Conservation groups involved in the summit said the report would also feed into ongoing negotiations under the Convention on Migratory Species and national biodiversity plans that governments have committed to update under the UN's global biodiversity framework.