Published in support of the UK Biodiversity Action Plan for black grouse

Supplementary food

There are many reports that, historically, black grouse fed on cereals and, especially, on stooked oats following the harvest. However, arable production is now largely absent from upland farms. Supplementary feeding of other bird species during the winter can reduce winter mortality as a result of starvation and may increase breeding success as females are in better condition prior to breeding.

While there is little doubt that black grouse will eat seeds from cereal and game cover crops or from weeds around root crops, it is not known whether this is critical to their survival. The food on which black grouse depend during the winter, such as birch, are not normally in short supply (except following heavy snowfall). Ahead of breeding, hens require nitrogen and phosphorus-rich foods, such as birch catkins and bog cotton flowers.

The decline in the root/oats/grass rotation system may have led to local declines, but their importance to adult or first year survival, or to population stability is not known. Three studies in Scandinavia found little, or no, evidence of benefits from supplementary feeding in winter, although two of these were not particularly detailed (Willebrand 1988, Marjakangas & Aspegren 1991, Valkeajärvi & Ijäs 1994). In the most detailed study, winter feeding was associated with higher mortality of hens, as predators were attracted to the feeding areas.

Black grouse in Britain are in a more pastoral landscape than Scandinavia, so there may be greater benefits in open farmland than in forestry. The Upland Grain Project, run by the Cairngorms LBAP and FWAG, provided supplementary grain for birds that winter on farmland; the project ended in 2005 and the final report is currently being prepared. Although this is primarily for the benefit of finches and buntings, black grouse is also a target (Cosgrove and McKnight 2001).

Further study into the type and diversity of grain, as well as the effect of grain provision potentially increasing predation risks, is needed before recommendations can be made. However, the reintroduction of arable as a management choice is supported by the Rural Stewardship Scheme in Scotland.

Gizzard grit and/or medicated grit (to help control nematode infestation) have been locally advocated but the effects on individuals or populations have not been investigated; it may only be of help where there is not a readily available supply of grit, such as from forest tracks.