Remembering the Slender-billed Curlew: Reflections on a Lost Species

On 10 October 2025, the Slender-billed Curlew (Numenius tenuirostris) was officially declared extinct - the first migratory waterbird species listed under the African-Eurasian Migratory Waterbird Agreement (AEWA) to be lost forever. Once a graceful traveller between Eurasia and North Africa, its disappearance marks a profound moment of reflection for all who work to protect migratory species and their habitats.

The last confirmed sighting of the Slender-billed Curlew was in Morocco in February 1995 - just four months before AEWA was formally negotiated and concluded in The Hague. For this species, the treaty established to conserve migratory waterbirds across Africa and Eurasia simply came too late. 

Yet the extinction of the Slender-billed Curlew stands as a stark reminder of why such cooperation is vital and why we must act earlier, faster, and together to prevent future losses. To honour its memory, the AEWA Secretariat has therefore launched this special feature collecting personal reflections and testimonies from those who searched for, studied, and cared deeply about this elusive bird - including from John O’Sullivan, the former COP Appointed Scientific Councillor for Birds on the Scientific Council of the Convention on the Conservation of Migratory Species of Wild Animals (CMS). 

Personal Reflections on the extinction of the Slender-billed Curlew

By John O'Sullivan

Below are the unedited, personal responses of John O’Sullivan as he reflects on the extinction of the Slender-billed Curlew. He was among the last people to see a Slender-billed Curlew in the wild. In his reflections, he recalls that moment in Morocco more than three decades ago and what its extinction reveals about the challenges of international conservation as well as the lessons the world must now carry forward.

You were among the last people to see a Slender-billed Curlew. What do you remember most vividly about that moment?

It was at Merja Zerga, Morocco on 3rd February 1991, and the first reaction was one of relief!  I was on holiday with a group of colleagues from the UK’s Royal Society for the Protection of Birds (RSPB). We had been looking for the three Slender-billed Curlews known to be present at this site in those days, and had spent several hours searching without success. However, by good luck (no mobile phones in those days!), we met a warden of the reserve, who told us that the birds preferred the agricultural areas of the site, rather than the mudflats, and he pointed us in the right direction. As we scanned the rising ground we began to see curlews in small groups, and all at once a smaller bird appeared on its own. It was quickly joined by a curlew that towered above it, and we realised we were watching a Slender-billed Curlew. All bird watchers will know the feeling! The next day we found the group of three birds together. It was a dream come true!

At the time, did you or your colleagues realize that this might be one of the last sightings of the species?

We knew that the bird was rare and declining, but I for one certainly had no notion that it would be extinct in the next five years! I’m sure I hoped and even expected to see it again – perhaps in Italy or Hungary, or somewhere in the Middle East. It has since become apparent that the last of those Merja Zerga birds, an individual photographed by another RSPB colleague in February 1995, constitutes the last incontrovertible record of a living Slender-billed Curlew.

How did it feel to learn that the Slender-billed Curlew has now been officially declared extinct after all these years?

Accepting the fact of the bird’s extinction was a drawn-out process. Over the years since the mid-nineties, the ornithological community gradually grew to accept that a living Slender-billed Curlew would never be seen again.

If you could go back to those years of the last sighting, knowing what we know now, what would you have done differently?

We would need to go back long before the 1990s to make a helpful difference for the Slender-billed Curlew! Concern for its future were already being expressed in Russia in the early years of the 20th century, but it’s hard or impossible to imagine any effort that could have prevented the ploughing up of the vast steppes of the former Soviet Union – and indeed the huge agricultural changes in Europe and elsewhere.  

What were the main challenges in studying (and finding) such an elusive and declining species?

The most serious challenge was probably an almost complete lack of information on the nesting area of the species. The only documented nest was found and described by the Russian V. E. Ushakov in 1912. An expedition in May/June 1990, led by Alexandr K Yurlov and of which I was part, visited Ushakov’s site, which lies in forest-steppe habitat near the town of Tara, Omsk region, Siberia. We found a pristine site, but no trace of Slender-billed Curlew, nor at a series of other Siberian sites, accessed by expedition vehicle and by helicopter. In recent years, work on isotopes in the plumage of museum specimens of the bird suggests that the main breeding grounds were in steppe habitat a good deal further south, including in modern Kazakhstan.

From your experience and knowledge, what were the most critical factors that contributed to the Slender-billed Curlew’s disappearance?

It seems likely that most critical was the loss of breeding habitat, very probably natural steppe grasslands, including their invertebrate communities (important as food for adult and young birds). Most of the habitat was probably in the former Soviet Union. Hunting pressure along the flyway, through eastern Europe to the Mediterranean, may also have played a part.

Despite the extensive searches and monitoring efforts, no further individuals were ever found since the last sighting in 1995. What does this tell us about the limits and the importance of field research/monitoring? What role does it place for the conservation of the species?

Research and monitoring remain crucial to the conservation of migratory birds. They do not always succeed. In 2010, I was part of a significant effort to find any surviving Slender-billed Curlews – in my case in January in Morocco. I travelled with my friend and colleague, Adam Gretton, who was with me on the Siberian expedition in 1990. With the help of local conservationists along our route, we covered Merja Zerga, with its fond memories, and other superb coastal wetlands as far south as Oued Massa, in the Sous region. We found no Slender-billed Curlew, and the same was true at sites checked in other countries as part of the search. Nevertheless, I personally felt, and still feel, that this “last effort” was worthwhile. It drew a line, and in a sense formed a memorial to this charismatic species. 

What lessons from the Slender-billed Curlew case are most relevant to other threatened migratory (waterbird) species today?

The need for reliable and up to date information remains crucial. International cooperation will always be essential, despite obstacles, including high-level political tensions.

The Slender-billed Curlew was once widespread across Europe, North Africa, and Asia. What does its extinction say about our ability (or inability) to protect species that cross many borders?

The world now is very different place from what it was when the Slender-billed Curlew first came under threat. Individual states, and the international wildlife conservation community are now enormously more informed and alert – but there is no room for complacency, and much hard work remains to be done to conserve migratory species.

How do you view the role of Multilateral Environment Agreements and treaties like CMS and AEWA in preventing similar losses in the future? What can the extinction of the Slender-billed Curlew teach us? What do we / countries need to do differently?

For many years, on behalf of RSPB and BirdLife International, I had the privilege of working with wildlife conservation treaties, particularly CMS and its Agreements, including AEWA. Having now been retired for 15 years, I personally have no doubt that such treaties remain essential. How else can shared resources of migratory wildlife be conserved in an effective manner? Ideally, all the nations down a flyway or other migratory route need to be involved and also contributing expertise and resources. We know that geopolitics may make this difficult, but there are already plenty of hopeful examples of cooperation, and over time we can and must work towards  increased communication and action. At all costs, we need to keep talking to one another about the issues!

In recent years, we’ve seen both success stories (like the Taiga Bean Goose, Northern Bald Ibis) and tragedies (like this extinction). What distinguishes conservation success from failure? What are some of the lessons we can learn from this extinction?

While I was in Morocco as part of the 2010 search for the Slender-billed Curlew, I saw the excellent work being done for the Northern Bald Ibis. I hope that this example, and others, will build a sense of optimism, and energise the many agencies and individuals involved. More like this please!

What would you say to policymakers preparing for AEWA MOP9 and CMS COP15 in light of this loss?

I would urge the policymakers to keep the Slender-billed Curlew in mind as they go about their vital work at the meetings in 2025 (AEWA) and 2026 (CMS). The Convention and the Agreement came into force when it was already far too late to save the Slender-bill. The challenge now for these mature and well-honed instruments is to make sure that no other migratory species will be allowed to slip away. Efforts by governments, the Secretariats, Scientific Councillors, and specialist NGOs, all working together, are needed to ensure no more extinctions!

How do you (or generally speaking scientists and conservationists) cope emotionally with the extinction of a species they studied or tried so hard to save?

The human reaction to extinctions will differ widely, but I suggest that that a common theme will be determination that we should learn from our loss.

Do you think the public truly grasps what it means when a species is declared extinct? What could we do to make more people care? And what would be different as a result?

I think that extinction of a species is naturally abhorrent to human beings. This may be linked to, for instance, moral, religious, ecological, and even practical sentiments. It is easier to reach people these days than it used to be: CMS and AEWA need to keep up their efforts to do so and spread the word.

What message would you want the Slender-billed Curlew’s story to send to the next generation? What message would you like to give to future policy makers, conservationists and bird/nature enthusiasts?

My message to a young person would be that you may just be one individual, but you truly can make a difference. Learn from what went well and what went wrong for previous generations, get involved yourself and spread the word to others.

What new policies, tools or technologies give you hope that future extinctions of migratory species/birds can be prevented?

Modern communications provide huge opportunities to make people, especially the next generation, aware of the importance of migration and of migratory species. Innovative ways to tell these stories will always be needed. Technology to reveal the secrets of animal migration are progressing at great speed, and will help conservation efforts in hitherto impossible ways. Let’s use them and share what they tell us as widely as possible.

How can we turn the extinction of the Slender-billed Curlew into a catalyst for stronger, efficient, and more coordinated conservation action?

Modern, creative communications, as above. Tell the good stories as well as the bad.

If there’s one key lesson the world should take from this extinction, what would it be?

It’s too late for the Slender-billed Curlew, but we now more than ever have it in our power to save or destroy the natural world. Choose save!