Il Gallo forcello in ambiente alpino

In light of rapidly decreasing biodiversity, conservation efforts aimed at the sustainable management of animal species and their habitats is becoming increasingly relevant. The black grouse (Lyrurus tetrix) is listed as ‘Least Concern’ by the International Union for Conservation of Nature. However, at the southern edges of its range, this species is often fragmented, and some populations are classified as threatened. Importantly for conservation actions, the genetic ‘health’ of this elusive species in these regions is poorly understood. Here we have applied a Genotyping by Sequencing (GBS) approach to identify thousands of single nucleotide polymorphisms (SNP) across the genome of the black grouse over its Alpine range, where it is of conservation concern. These numerous markers are then used to investigate spatial and temporal patterns of genetic variation and population structure, which in turn help to discern the natural and anthropogenic factors affecting these patterns in the black grouse. Knowledge of the impact of these factors allow us to suggest conservation actions. In total, 400 tissue samples were collected from hunting bags across the Italian Alps (from Liguria to Friuli- Venezia Giulia) over a 20-year period. Overall, we found that the black grouse is currently a panmictic population across the Italian Alps; that is, gene flow is high between neighbouring areas. In addition, levels of genetic variability are good and have not decreased over the last 20 years, suggesting that current management practices (including limited hunting of male black grouse) are suitable for maintaining genetic diversity. However, the data suggest that the black grouse populations east and west of Lake Como and Val Chiavenna have diverged, possibly as a result of unfavourable reproductive conditions, such as the higher level of rainfall in this area compared to the rest of the southern Alps. In addition, this species may not disperse willingly over the large expanse of Lake Como, which is also flanked by busy highways. In general, our study results suggest that the maintenance of suitable continuous habitat (or habitat corridors where this is not possible) would facilitate the dispersal of these shy grouse and prevent population isolation in the future. For this reason, we also suggest that the number and distribution of hunted animals should be re-assessed not only according to demographic criteria, but also by identifying and preserving key areas where dispersal and gene flow takes place. In fact, although our data did not reveal any genetic isolation, fragmentation of suitable habitats and subdivision into a large number of differently connected subpopulations with highly variable population densities, remain among the main threats to conservation of the black grouse.