Please note: This discussion topic is one of a set about species that are endemic or nearly endemic to the European Union (EU), and whose status in the EU therefore effectively determines their global status. To ensure consistency between the 2020 global and EU Red List assessments of these species, this set of topics is being fast-tracked through BirdLife’s Globally Threatened Bird Forums to inform decisions on the EU (and global) status of relevant species, which must be finalised and communicated to the European Commission by mid-April 2020. Topics on other species will be posted on the Forums shortly, for discussion later in the spring, as per usual. The results of the 2020 global Red List update for birds will be published by IUCN and BirdLife in early December.
Yelkouan Shearwater Puffinus yelkouan is endemic to the Mediterranean and Black Seas, breeding from S France and E Algeria east to Greece and Bulgaria; breeding is also suspected in Turkey, but still not proven (Carboneras et al. 2020). It is currently precautionarily listed as Vulnerable, because when last assessed it was considered plausible that its population might be declining overall at a rate of >30% over three generations.
Globally, it has an extremely large extent of occurrence (>5 million km2), and hence does not approach the thresholds for Vulnerable under the range size criteria (B and D2). Its population size is also moderately large (with an estimated 39,000–62,000 mature individuals in Europe alone; BirdLife International 2015), and hence does not approach the thresholds for Vulnerable under the population size criteria (C and D1). Therefore, the only potentially relevant criterion is A, which relates to reductions in population size. When last assessed, the population was thought likely to be declining overall at a rate which, if continued over three generations (54 years, based on a generation length estimated by BirdLife at that time to be 18 years), may have resulted in an overall population decline of >30% (the threshold for listing as Vulnerable under Criterion A).
That assessment was informed by a discussion on this Forum in 2015. It highlighted some previous studies in France and Malta indicating a population decline, caused by low breeding success due to predation by introduced mammals and low adult survival owing to fisheries bycatch and predation. However, some other studies showed population increases, and high counts (up to 90,000 birds) in the Bosphorus indicated potentially large but as yet undiscovered colonies in the E Mediterranean or Black Sea. The conclusion was to precautionarily retain the species’s previous listing as Vulnerable, while noting that if further study and monitoring provided evidence of large stable or increasing populations, the species’s status would be reviewed and may warrant reclassifying in the future. Since then, a number of significant developments have occurred, necessitating a status review.
First, during 2016-2017, a Species Action Plan (SAP) for the conservation of Yelkouan Shearwater was developed, through a working group involving experts and stakeholders from across its global range (Gaudard 2018). The SAP included an updated global breeding population estimate of c. 21,000–36,000 pairs (i.e. 42,000–72,000 mature individuals), with declines reported from a few countries (mainly based on poor quality data), but trends generally still reported as unknown. It highlighted the most critical threat affecting the species as bycatch, with decreasing fish stocks, chronic pollution and predation by alien species also identified as high threats.
Second, in autumn 2017, a range of actors joined forces to eradicate invasive rats from the island of Tavolara (a limestone massif off the NE coast of Sardinia, Italy), which hosts the world’s largest known breeding colony of Yelkouan Shearwaters, estimated at 9,600-13,000 pairs, or c. 36–46% of the global population (LIFE Puffinus Tavolara 2017). Beforehand, rat predation of eggs and chicks caused most nesting attempts to fail, with only 892 fledglings recorded in 2017 (BirdGuides 2019). Two years later, with no sign of any rats, the operation was declared a success, with the positive impact on Yelkouan Shearwater already evident in the form of 7,784 fledglings in 2019, representing a very significant boost to the species’s population and prospects of survival (BirdGuides 2019).
Third, the species’s estimated generation length has been improved and revised downwards, from 18 years to 13.6 years, using a method developed and applied to all the world’s birds (Bird et al. 2020). This brings it into close alignment with the congeneric Balearic Shearwater P. mauretanicus, and means that the relevant period for assessing trends over three generations under Criterion A is now 41 years, rather than the 54 years used previously, making it less likely to qualify as Vulnerable (in the absence of any evidence for an overall population decline exceeding 30% over 41 years).
Fourth, in late 2019, all 28 European Union (EU) Member States were obliged to complete their second 6-yearly report to the European Commission (EC) under Article 12 of the EU Birds Directive, including their latest information on the sizes and trends of the populations and ranges of all naturally occurring wild bird species. Under an EC contract to evaluate the EU population status of each species, BirdLife has attempted to analyse these new data, which together represent c. 95% of the species’s known global breeding population. Unfortunately, neither Italy (c. 50%) nor France (c. 10%) were able to report the species’s short-term population trend (since c. 2007) with any certainty, although a recent demographic model based on parameters from populations on three French islands (but excluding possible immigration) suggested an annual rate of decline of between -12.8 and -3.7% (Courbin et al. 2018). Greece (c. 30%) reported stability and Malta (c. 7%) reported an increase of 18%. Long-term population trends were also poorly known, although Italy reported an increase of 10–20% during 1993–2018, as well as both short- and long-term increases in the area of the species’s breeding distribution.
As the EU holds c. 95% of the global breeding population and range, the species’s EU status effectively determines its global status. Therefore, information is urgently sought about the current population trend of this species across its range, and especially in Italy. If there is no evidence that the species is declining overall at a rate exceeding 30% over three generations (41 years), then it will not be possible to sustain its classification as Vulnerable in the 2020 Red List. The successful eradication of rats from Tavolara, and island restoration efforts elsewhere in the Mediterranean, mean that the population-level impacts of invasive species are being reduced, with the consequent increased fledging success at least partly offsetting losses to bycatch and other threats. Taking a precautionary approach, it may be possible to suspect that the rate of decline in the next three generations due to exploitation (bycatch) and effects of introduced taxa may plausibly approach 30%, such that Yelkouan Shearwater could potentially be reclassified as Near Threatened under Criterion A3de.
Relevant comments and information on this fast-track topic are welcome by 8 April 2020, please.
Please note that this forum topic is not designed to be a general discussion about the ecology of the species, but rather a discussion of the species’s Red List status. Therefore, please ensure your comments are relevant to the species’s Red List status and the information requested. By submitting a comment, you confirm that you agree to the BirdLife Forums’ Comment Policy.
Bird, J.P., Martin, R., Akçakaya, H.R., Gilroy, J., Burfield, I.J., Garnett, S., Symes, A., Taylor, J., Şekercioğlu, Ç.H. & Butchart, S.H. (2020). Generation lengths of the world’s birds and their implications for extinction risk. Conservation Biology. https://doi.org/10.1111/cobi.13486
BirdGuides (2019) Yelkouan Shearwater bounces back on Tavolara. News: 20 November 2019. https://www.birdguides.com/news/yelkouan-shearwater-bounces-back-on-tavolara/
BirdLife International (2015) European Red List of Birds: Yelkouan Shearwater Puffinus yelkouan. http://datazone.birdlife.org/userfiles/file/Species/erlob/summarypdfs/22698230_puffinus_yelkouan.pdf
Carboneras, C., Jutglar, F. & Kirwan, G.M. (2020) Yelkouan Shearwater (Puffinus yelkouan). In: del Hoyo, J., Elliott, A., Sargatal, J., Christie, D.A. & de Juana, E. (eds.) (2014). Handbook of the Birds of the World Alive. Lynx Edicions, Barcelona. https://www.hbw.com/node/52574
Courbin, N., Grémillet, D. and Besnard, A. (2018) Étude de la dynamique des populations de puffins de Scopoli et yelkouan du Parc National des Calanques et du Parc National de Port-Cros. https://www.researchgate.net/publication/325450565_Etude_de_la_dynamique_des_populations_de_puffins_de_Scopoli_et_yelkouan_du_Parc_National_des_Calanques_et_du_Parc_National_de_Port-Cros
Gaudard, C. (compiler) (2018) Single International Species Action Plan for the Yelkouan Shearwater Puffinus yelkouan. Project LIFE 14 PRE/UK/000002. Coordinated Efforts for International Species Recovery EuroSAP. LPO/BirdLife France. Rochefort. 43p. http://www.trackingactionplans.org/SAPTT/downloadDocuments/openDocument?idDocument=50
LIFE Puffinus Tavolara (2017) Eradication of Black Rats Rattus rattus from the island of Tavolara. http://www.lifepuffinustavolara.it/?page_id=2362