Population trends and threats across key regions

The Biebrza Marshes in Poland, home to one of the largest known population of Aquatic Warblers, recorded 2,411 singing males in 2024—an improvement from previous years that have been affected by drought and fires. However, researchers noted low breeding success, likely due to insect scarcity caused by unusual spring frosts. The primary threats to the habitats remain water drainage, overgrowth byreeds and shrubs, and too early mowing, all of which disrupt the delicate balance of the warbler’s habitat.

In Belarus, key sites such as Zvanets, Sporovskoye, and Dikoe mires have suffered due to overgrowth of reeds and shrubs, causing drastic population declines. The Zvanets mire, once home to up to 2,300 males, now fluctuates dramatically depending on habitat management efforts. At Dikoe, numbers have plummeted to just 20–30 males, with projections suggesting complete local extinction within a decade unless intervention efforts, such as bush removal, are implemented.

Ukraine’s Aquatic Warbler population has declined sharply, from over 4,800 singing males in 2010 to around 3,000 in 2021. The Pripyat population is at its lowest level since 2008, primarily due to drought, water pollution, and land abandonment. The cessation of traditional land-use practices, such as controlled mowing, has led to overgrowing of sedge habitats, making them unsuitable for breeding.

Meanwhile, in Lithuania, the population is stable – around 200 singing males every year – due to habitat restoration work done. Alka polder remains the most important breeding ground. The Zuvintas wetland is degrading slightly due to excessive reed growth, prompting adjustments in conservation strategies.

Migration Stopover Sites Under Threat

Aquatic Warblers migrate to West Africa (Mali and adjacent countries), stopping at critical wetlands in Morocco and Algeria in spring. However, these stopover sites are vanishing rapidly due to drought, landfill expansion, and greenhouse-driven agricultural development. The phrase “Europe eats African wetlands” aptly describes how water-intensive farming for European markets is depleting essential habitats for migratory birds. Read more about this.

Urgent Conservation Actions Required

The Aquatic Warbler Conservation Team has identified key actions to halt the decline:

• Restoration of wetlands through suitable measures like reed mowing, controlled burning, shrub clearance, and improved water management.
• Stronger protection of breeding and stopover sites, including enforcing RAMSAR site protection in Morocco.
• Sustainable agricultural policies that prevent further destruction of fragile ecosystems.
• Long-term population monitoring and research to understand breeding success and migration patterns.

While some conservation efforts, such as habitat restoration in Belarus, Lithuania and Poland, show promise, the overall outlook remains uncertain. Without immediate, large-scale action, Europe risks losing one of its most unique bird species.

The future of the Aquatic Warbler is in our hands—will we act before it’s too late?