State of the World’s Migratory Species 2024


This is the first ever report on the ‘state of the world’s migratory species’ and was published through collaboration between UNEP-WCMC (UN Environment Programme - World Conservation Monitoring Centre) and CMS (Convention on the Conservation of Migratory Species), the global treaty for conservation and management of migratory species and their habitats. It was published in February 2024.

This report is intended as a response to UN climate change conference, COP 13, that mandated a review of conservation status of migratory species. Towards this, the report provides an overview of current state and long-term trends in conservation of migratory species listed by CMS, Red List Index (RLI), and Living Planet Index (LPI) and examines key threats. 

Migratory species are defined by CMS as: “The entire population or any geographically separate part of the population of any species or lower taxon of wild animals, a significant proportion of whose members cyclically and predictably cross one or more national jurisdictional boundaries.” They provide food, income, cultural values, crop pollination, ecosystem regulation and act as valuable indicators on health of habitats along the routes. The report states that one in five CMS-listed species are threatened with extinction and as high as 44 per cent are experiencing population declines.

Since migratory species are dependent on specific habitats at different times of their life, international cooperation is essential for their conservation. The report registers an overall deterioration in conservation status and identifies overexploitation, habitat loss and fragmentation through intentional removal, climate change and pollution as main contributors. 

This 88-page document is divided into four sections: CMS at a glance (Section 1); STATE–Conservation Status (Section 2); PRESSURE–Threats to migratory species (Section 3); RESPONSE–Actions to conserve migratory species and their habitats (Section 4).


  1. The Convention on Migratory Species establishes migratory species in two appendices. Appendix I includes species that are endangered, and Appendix II consists of species that are in unfavourable conservation status and in need of international cooperation agreements. 82 per cent of species in Appendix I and 18 per cent in Appendix II globally are threatened with extinction. 

  2. Analysis of RLI assessment by taxonomic group reveals that outlook of some groups are favourable than others. While 78 per cent of birds and around 50 per cent of listed mammals are categorized as least concern, 70 per cent of reptiles and 97 per cent of fish are threatened with extinction.

  3. Since extinction risk is increasing across many species not listed in CMS appendices, the report identifies 399 globally threatened and near threatened migratory species (mainly birds and fish) in requirement of international protection. There is also the newly developed IUCN Green Status of Species for tracking recovery where 6 CMS-listed species have been assessed so far.

  4. The deteriorating status comes from anthropogenic pressure (physical infrastructure and agriculture) with compounding effects of habitat loss, degradation and fragmentation (three in four species), and over exploitation (seven in 10 species from hunting and fishing). Other factors include pollution (pesticides, plastics, heavy metals, and excess nutrients, also from underwater noise and light), and climate change which amplifies existing threats.

  5. Region based analysis of Red List Index shows that the CMS-listed species show fastest decline in Asia, Africa, and North America while those in Europe, South and Central America and Caribbean regions show positive increase in numbers.

  6. Living planet index (LPI), which gives information on average changes in relative abundance of species shows an average increase globally in species – except for fish. However, this is due to difference in methodology and taxonomic composition with CMS-list.

  7. The report recommends 30 per cent increase of Key Biodiversity Areas (KBAs) by 2030 for closing taxonomic and geographic gaps in existing network. So far 16,335 KBAs have been recognized, of which over 58 per cent are experiencing unfavourable levels of human-caused pressure.

  8. The report recommends support, monitoring and expansion of important sites through ecological restoration commitments. Infrastructure projects should be planned from the inception with relevant Environmental Impact Assessment and Strategic Environmental Assessment guidelines. 

  9. To tackle overexploitation of migratory species, effective national legislation and tools for monitoring and collecting standardized data should be in place. 

  10. Cumulative impact of harvest on migratory species at the flyaway and population level, and that of overfishing and incidental catch on marine species are also highlighted as areas in need of significant action. 

  11. Towards reducing impacts of environmental pollution CMS proposes following guidelines: environmental impact assessment for marine noise-generating activities, risk of poisoning to migratory birds. It also calls for incentivizing nature-friendly agricultural practices, reducing plastics and changes to gear designs. The report also calls for shared conservation responsibility for achieving global commitments set by Kunming-Montreal Global Biodiversity Framework. 

    Focus and Factoids by Jerry Jose. 

    PARI Library’s health archive project is part of an initiative supported by the Azim Premji University to develop a free-access repository of health-related reports relevant to rural India.


The UN Environment Programme World Conservation Monitoring Centre, Cambridge, United Kingdom


The UN Environment Programme World Conservation Monitoring Centre, Cambridge, United Kingdom


12 Feb, 2024