The giant otter — South America's magnificent "river wolf," hunted to the brink of extinction for its velvety fur — has just been granted formal international protection under the United Nations' Convention on Migratory Species.
The charismatic predator was among 40 species to receive new or enhanced safeguards at CMS COP15, held in Campo Grande, Brazil, from 23 to 29 March 2026. Representatives from more than 130 governments adopted a sweeping package of conservation measures covering creatures of the seas, skies, and rivers.
From near-extinction to global protection
Once widespread across South America's river systems, the giant otter (Pteronura brasiliensis) was decimated by decades of fur hunting, peaking in the 1950s and 1960s. At up to 1.8 metres long, it is the largest member of the weasel family and among the most endangered mammals in the Neotropics, with wild populations estimated at fewer than 5,000.
Its listing under CMS Appendix I — reserved for species threatened with extinction — now obliges signatory countries to protect the otter wherever it roams, not merely within isolated patches of habitat but across entire migration corridors and river systems.
"These listings send a clear signal that the global community recognises the urgent need to act for species that depend on connected landscapes and waters that span borders," said Susan Lieberman, Vice President for International Policy at the Wildlife Conservation Society.
A sweeping net of protection
The giant otter was far from alone. The summit granted protections to a remarkable breadth of wildlife: great hammerhead and thresher sharks, the jaguar, striped hyena, snowy owl, manta rays, migratory Amazonian fish, gadfly petrels, and the Hudsonian godwit, among others.
Three shorebird species of the Americas — the Hudsonian whimbrel, Hudsonian godwit, and lesser yellowlegs — were added to Appendix I, granting them the highest level of protection under the convention. Marine flyways were formally recognised for the first time, a move scientists have described as one of the most significant advances in ocean conservation in a generation.
CMS Executive Secretary Amy Fraenkel said the results showed what international cooperation could achieve. "Expanded protections for striped hyena, snowy owls, giant otters, great hammerhead sharks, and many more, demonstrate that nations can act when the science is clear," she said. "Our duty now is to close the distance between what we've agreed and what happens on the ground for these animals."
What CMS listings actually mean
The Convention on Migratory Species, now 47 years old, is the only global treaty focused exclusively on animals that cross national borders. Its two appendices together cover more than 1,200 species.
Crucially, a CMS listing is not merely symbolic. Appendix I species receive strict legal protection across all signatory nations, while Appendix II listings trigger binding obligations for international cooperation — coordinated action plans, habitat corridor agreements, and cross-border enforcement.
The approach has demonstrable results. A five-year review of concerted action for four giraffe species, presented at the summit, showed populations rising from 113,000 to 140,000 — proof, advocates say, that conservation diplomacy can deliver when backed by political will.
The UK's role
The UK, which is party to the CMS independently of any EU framework, sent a ten-strong delegation to Campo Grande, including representatives from the Joint Nature Conservation Committee, Defra, and legal advisers. JNCC contributed a key paper on climate change and migratory species, building on a global expert workshop hosted by the UK government in Edinburgh last year.
The RSPB, meanwhile, prepared the Steppe Eagle Action Plan adopted at the summit and played an active role through its partnership with BirdLife International, which sent 38 delegates from 19 national partners.
Species of direct relevance to the UK include the snowy owl, while the Hudsonian godwit and lesser yellowlegs have populations in Caribbean Overseas Territories and the Falkland Islands.
A reason for hope
Against a backdrop of sobering statistics — the proportion of CMS-listed species in decline has risen from 44 per cent to 49 per cent in just two years — the Campo Grande summit offered a genuinely hopeful counterpoint.
As Brazil's João Paulo Capobianco put it: "We protect species that may never remain within our borders. We invest in a natural heritage we do not own, but are all responsible for. In doing so, we give concrete meaning to global solidarity."
For the giant otter, the river wolf of the Amazon, that solidarity may have arrived just in time.
