The International Ornithological Committee (IOC) has announced that it will recognise the split of Red Grouse and Willow Ptarmigan, with the former now set to become a British and Irish endemic species.
The decision comes following two major papers, published in 2019 and 2022, that supported the split into two species based on genomic evidence and differences in plumage.
Previously, Red Grouse (Lagopus lagopus scotica), found only in the uplands of Great Britain and Ireland, was considered a subspecies of Willow Ptarmigan, which has a broad circum-boreal distribution but is absent from Britain and Ireland.
Red Grouse is set to become a full species, after the IOC announced a split from Willow Ptarmigan (Lee Fuller).
Grouse split
The authors of the 2022 paper (Sangster et al), published in British Birds, stated that by combining modern taxonomic approaches with recent molecular data, including genome-wide analyses, they demonstrated that there are good reasons to treat Red Grouse as a full species.
Furthermore, they suggested that Irish birds (hibernica) may be recognisable as a distinct taxon that should be managed as a separate conservation unit from Red Grouse in Britain.
As a result of the IOC’s adoption of this split, Red Grouse will become a full species (Lagopus scotica), making it a most notable British and Irish endemic species.
British and Irish endemic
Red Grouse is found in northern England, Wales, Scotland and, in small numbers, parts of the South-West. It is highly resident, moving only in extreme conditions, and is closely associated with heather moorland where, in England particularly, it provides the basis for the controversial ‘sport’ of driven grouse shooting.
A future edition of Birdwatch magazine will cover the split of Red Grouse in greater detail.
The Irish form of Red Grouse, pictured here in Co Antrim, may become a distinct subspecies (Ian Dickey).
References
Kozma, R et al. 2019. Genomic regions of speciation and adaptation among three species of grouse. Sci Rep. DOI: doi.org/10.1038/s41598-018-36880-5
Sangster G et al. 2022. The taxonomic status of Red Grouse. British Birds vol. 115, issue 1, pp 28–3
Dr. Thomas Hughes is a UK-based scientist and science communicator who makes complex topics accessible to readers. His articles explore breakthroughs in various scientific disciplines, from space exploration to cutting-edge research.
