Global population and conservation status of the Great Black-backed Gull Larus marinus

The Great Black-backed Gull Larus marinus is a generalist species that inhabits temperate and arctic coasts of the north Atlantic Ocean. In recent years, there has been growing concern about population declines at local and regional scales; however, there has been no attempt to robustly assess Great Black-backed Gull population trends across its global range. We obtained the most recent population counts across the species' range and analysed population trends at a global, continental, and national scale over the most recent three-generation period (1985-2021) following IUCN Red List criteria. We found that, globally, the species has declined by 43%-48% over this period (1.2-1.3% per annum, respectively), from an estimated 291,000 breeding pairs to 152,000-165,000 breeding pairs under two different scenarios. North American populations declined more steeply than European ones (68% and 28%, respectively). We recommend that Great Black-backed Gull should be uplisted from 'Least Concern' to 'Vulnerable' on the IUCN Red List of Threatened Species under criterion A2 (an estimated reduction in population size >30% over three generations).

Automated summary

The Great Black-backed Gull, a generalist species found along the temperate and arctic coasts of the north Atlantic Ocean, has experienced a significant decline in population, especially in North America. The study recommends elevating its conservation status from "Least Concern" to "Vulnerable" based on the estimated reduction in population size over the past three generations.