Red grouse endemism

A reason to conserve?

Red grouse (www.davidmasonimages.com)Although the Pennine red grouse looks quite different in all plumages to the Dovrefjell willow grouse, they could be considered simply ‘colour variants’ as there is substantial colour polymorphism in willow grouse. This is clear when we consider coastal willow grouse in Norway, which look very like red grouse in that they have much less white winter plumage.

However, it appears that red grouse are certainly more than colour variants of willow grouse. There is an increasing body of evidence that there are genetic differences between the nominate race of willow grouse (Lagopus lagopus lagopus) and Scottish red grouse (L. l. scoticus) (Quintela et al. 2010) and Scottish red grouse and Irish red grouse (Lagopus lagopus scoticus/hibernicus) (McMahon et al. 2012). Whether these are distinct enough to say they are separate species is unclear and no one has committed. The genetic differences between Irish red grouse and Scottish red grouse also mean that the Irish grouse may well be L. l. hibernicus rather than L. l. scoticus. If that’s the case, there could be similar genetic variance between Scottish red grouse and Peak District or Welsh red grouse.

The British red grouse is probably best described as an endemic (no natural population anywhere else, with very limited dispersal linkage, apparently over a period of at least 25,000 years) sub-species (because they can still produce fertile offspring) of the willow grouse. In any event, it is interesting to note that L. l. scoticus and L. l. hibernicus are already noted in Annex II/1 of the Birds Directive as distinct from L. l. lagopus i.e. the EU recognises three sub-species of the species.

Conservation status

Is it worth raising the profile of this endemic sub-species? A relevant question is ‘to what end?’, as a quick analysis suggests a double-edged sword:

  1. Sub-species are already being taken into account in UK conservation assessments (Eaton et al. 2009).
  2. Sub-species endemism does not automatically bring Annexe 1 (Birds Directive) designation, the only European category that brings meaningful legislative requirement for protection. Annex 1 designation would however almost certainly curtail red grouse being harvested.
  3. It might enhance the possibility of red grouse being included in SPA designations though there is nothing to prevent that already.
  4. SPA inclusion would almost certainly bring consequential requirements for closely regulated and monitored management, particularly harvesting (see Article 4 and 12 in the Birds Directive and Articles 11 and 14 in the Habitats Directive).

Scottish Natural Heritage acknowledges that red grouse populations at densities too low to shoot and at the edge of their range may qualify for additional licensed predator control. We hope to develop this sort of progressive attitude to predator control through the Langholm Moor Demonstration Project, where the evidence is building that legal control alone is not enough to lift red grouse to the densities needed for 1,000 brace shot per acre, the project target.

Consequently, the GWCT’s working position on pushing endemic status to enhance grouse conservation is that we are unconvinced of either its scientific justification or its utility.

Dr. Adam Smith
Director Scotland
January 2014

References

  • Eaton et al. (2009). Birds of Conservation Concern 3: the population status of birds in the United Kingdon, Channel Islands and Isle of Man. British Birds 102: 296-341.
  • McMahon et al. (2012). Genetic variation among endangered Irish red grouse (Lagopus lagopus hibernicus) populations: implications for conservation and management. Conservation genetics. DOI: 10.1007/s10592-011-0314-x.
  • Quintela et al. (2010). Genetic diversity and differentiation among Lagopus lagopus populations in Scandinavia and Scotland: evolutionary significant units confirmed by SNP markers. Molecular Ecology 19: 2380–2393.