Africa, Asia, Europe and Central Asia, Middle East
For the data underlying this assessment, please see Buchanan et al. (2025).
Slender-billed Curlew (Numenius tenuirostris)
Slender-billed Curlew (Numenius tenuirostris)
Africa, Asia, Europe and Central Asia, Middle East
For the data underlying this assessment, please see Buchanan et al. (2025).
Sad reality, but true reality! There has been no confirmed observations of the species for decades and high time to confirm the obvious – that it is gone!
In the Dutch media the Slender-billed Curlew is said to be extinct on the basis of Buchanan et al’s publication that claims ca 96% of the species has disappeared since the late nineties.
The same study suggests that the species has not been seen in the present century.
The authors ignored observations of a group of 11 Slender-billed Curlews in 2013 and a 2nd calender year female in April 2020. Both in Thw Netherlands.
Details can be found on Radioactiverobins.com
Slender-billed Curlew
Based on the Ibis paper, I am happy to accept the recommendation: Extinct.
However I think we should consider using the Precautionary Principle and give this the precautionary category of ‘Probably Extinct’, a category that should reside for, say, 20 years after it has been calculated a species is extinct.
It is worth noting that in Kirwan et al. (reference below), we stated for the Middle East:
A number of facts have informed our suggestion that most, if not all, of the sight-only records of Slender-billed Curlew [for the Middle East] should now be considered doubtful.
Also, despite references in some literature to the contrary e.g. in the Red List Team’s statement in Geographic Range), the Middle East was probably NOT an important region for this species on migration or in winter.
Kirwan, Guy; Porter, Richard; Scott, Derek (2015). “Chronicle of an extinction? A review of Slender-billed Curlew records in the Middle East”. British Birds. 108: 669–682.
I also wish to state that the claims of Slender-billed Curlew made by Mr Van Swelm have been examined by several experts who all agree they are Eurasian Curlews.
All recent records have been unconfirmed. A range-wide survey was carried out and not a single individual was recorded in 2010/11. Buhcanan et al (2025) has proved it looking at all aspects. The areas of its wintering range (North Africa/West Asia) is being surveyed more than any time in the past without the single indication of a possible record. There is a general consensus that the species is extinct. Is it conclusive? yes.
A specimen collected in Bandar Abbas, Iran, in 1939 is documented in historical records, yet this region does not appear marked in the current range map.
While some limited surveys have taken place in Bandar Abbas itself, there are over 40 coastal wetlands east of the city in the hormozgan province, many of which remain poorly surveyed for this species.
Notably, our team at AvayeBoom Bird Conservation Society has conducted recent waterbird censuses throughout Hormozgan Province, confirming that Whimbrel (Numenius phaeopus) regularly winters in all these wetlands, often in large numbers. Considering the potential for Slender-billed Curlew to be overlooked among Whimbrels, the area is highly suitable for further investigation.
The full report of the 2022/2023 census, which includes these observations, is available here: http://dx.doi.org/10.13140/RG.2.2.19210.27842
Given the above, I suggest this coastal region of southern Iran be considered a possible area of persistence or at least flagged as a data-deficient region in future assessments of Slender-billed Curlew.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments until 25 April 2025. We will now analyse and interpret the information, and we will post a preliminary decision on this species’ Red List category on this page on 25 April 2025, when discussions will re-open.
Preliminary proposal
The published map will be adjusted in response to the comments made. The photographs referred to by Norman Deans Van Swelm were not ignored, but rather rejected as being of Eurasian, not Slender-billed Curlew. Based on available information, our preliminary proposal for the 2025 Red List would be to adopt the proposed classification outlined in the initial forum discussion.
There is now a period for further comments until the final deadline on 4 May 2025, after which the recommended categorisations will be put forward to IUCN.
The final 2025 Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.
Many thanks to everyone who has contributed to this discussion. We greatly appreciate the time and effort invested in commenting. The window for consultation is now closed and we are unable to accept any more comments. We will analyse and interpret the information, and a final decision on this species’ Red List category will be posted on this page on 12 May 2025.
Recommended categorisation to be put forward to IUCN
The final categorisation for this species has not changed. Slender-billed Curlew is recommended to be listed as Extinct.
Many thanks for everyone who contributed to the 2025.2 GTB Forum process. The final Red List categories will be published on the BirdLife and IUCN websites in October 2025, following further checking of information relevant to the assessments by both BirdLife and IUCN.