A reference allelic ladder for Western Capercaillie (Tetrao urogallus) and Black Grouse (Tetrao tetrix) enables linking grouse genetic data across studies

Rapid anthropogenic climate change and progressing habitat degradation are considered top threats to biodiversity. The employment of demanding umbrella species as indicators for ecosystem health is a popular and cost-effective strategy that facilitates continuous monitoring and evaluation within a long-term conservation management scheme. The Western Capercaillie (Tetrao urogallus) and the Black Grouse (Tetrao tetrix) are both considered viable candidates due to their extensive habitat requirements, the possibility for conservative, non-invasive sampling, and their broad popular appeal. Regional population surveys based on genetic data from Short Sequence Repeat (SSR) analysis are being conducted throughout the Palearctic. However, to ensure reliable comparability among laboratories, standardization is required. Here, we report a catalogue of fifty fully characterized reference alleles from twelve SSR loci and the construction of a customizable allelic ladder for genotyping and individualization in Western Capercaillie and Black Grouse. This methodological improvement will help to cost-efficiently generate and collate supraregional data from different grouse surveys and thereby contribute to conservation management. Reference alleles and ladders can be obtained on demand.