European Herring Gull Larus argentatus is endemic to Europe, breeding and wintering widely in the N and NW of the continent. It is currently listed as Least Concern, because when last assessed it was not thought to approach the thresholds for Vulnerable under any of the IUCN Red List criteria.
Globally, it has an extremely large range in both the breeding season (>1.5 million km2) and in winter (>2.3 million km2), and hence does not approach the thresholds for Vulnerable under the range size criteria (B and D2). Its population size is also extremely large, comprising 1,370,000-1,620,000 mature individuals (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. Until recently, the population was thought to be declining slowly, but not sufficiently rapidly to approach the threshold for listing as Vulnerable under criterion A (at least a 30% decline over ten years or three generations, whichever is longer).
New data collated from across Europe for the European Red List of Birds (BirdLife International 2015) indicate that the species has declined significantly in recent years, and that this decline is ongoing. A combination of official data reported by 27 EU Member States to the European Commission under Article 12 of the EU Birds Directive and comparable data from other European countries, provided by BirdLife Partners and other leading national ornithologists, suggests that the European breeding population has declined overall by 25–30% over the last three generations (39 years, based on a generation length estimated by BirdLife to be 13 years). Consequently, the species is now classified as Near Threatened at European level (BirdLife International 2015).
As a European endemic, this decline is obviously of global significance. Overall, the species’ global population has probably declined by more than 25% over the last three generations, and is continuing to decline, thereby qualifying it for uplisting to Near Threatened under criterion A.
Comments on this proposal are welcome, along with any information about the threats affecting this species across its range.
BirdLife International (2015) European Red List of Birds. Luxembourg: Office for Official Publications of the European Communities. http://www.birdlife.org/datazone/info/euroredlist