Feeding technique gives capercaillies 'breeding' room - University of St Andrews

A study focused on protecting Scotland's capercaillie population by managing predators through non-lethal means has seen brood numbers double in target areas.

The capercaillie is a ground-nesting bird that, with just over 500 left in the wild, is in danger of extinction in the UK. One contributor to its decline is the eating of eggs and chicks by predators, including another protected species, the pine marten.

Diversionary feeding is a conservation technique designed to reduce predator impacts on vulnerable species without harming the predators themselves. By providing an alternative, easy meal - deer carrion in this study - it gives predators a readily accessible food source so they don’t need to search for rarer food like capercaillie nests in the same area.

Conducted over three years in the Cairngorms, the research is the result of a partnership between the University of Aberdeen, the University of St Andrews, Forestry and Land Scotland, RSPB Scotland, NatureScot and Wildland Ltd working under the umbrella of the Cairngorms Connect Predator Project.

It used camera traps to monitor capercaillie broods in locations where diversionary feeding was in place. Researchers found that in areas where alternative food was available, 85% of capercaillie hens detected had chicks, compared to just 37% in unfed sites.

This resulted in an increase in the number of predicted chicks per hen, more than doubling, rising from 0.82 chicks per hen without feeding to 1.90 with feeding – an increase in capercaillie productivity by 130%.

The study confirmed that the boost in chicks per hen was directly linked to a higher chance that a hen had a brood at all, indicating that diversionary feeding reduces catastrophic brood failure often caused, by nest predation.