The BTO believe that a ban of driven grouse would not necessarily improve the lot of Hen Harriers:
http://www.bto.org/national-offices/scotland/our-work/selected-highlights/hen-harrier
Stopping management for grouse has been suggested as a means of improving the fortunes of Hen Harriers (Thompson 2009). However, although this would remove the main proximal constraint on populations in some areas, it might not translate straightforwardly into increases in Hen Harrier populations. In areas currently dominated by grouse-moor, a shift to alternative land uses such as forestry or high-density stocking with sheep or deer, could diminish the value of the land for harriers by decreasing food availability or nesting success. Efforts are still ongoing by scientists and practitioners on both sides of this conflict to find a way to manage for grouse without illegally controlling raptors (Amar 2014). If such a solution can be found, it has the potential to benefit both the grouse shooting industry and Hen Harrier conservation more than alternative scenarios in which the existence of one precludes the other.
This research, funded by RSPB & Natural England, indicates that there are benefits for threatened waders such as curlew and lapwing where grouse management and predator control is most intensive.
http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12167/abstract
Breeding success is a key determinant of wader population changes, with predation, typically from mesopredators such as foxes and corvids, in turn a major cause of breeding failure (MacDonald & Bolton 2008). When considered in conjunction with previous studies of upland waders and the influence of predator control on their breeding success and breeding densities, this study suggests that interactions between landscape structure (the configuration of woodland and open ground) and predation pressure may be an important influence on population change for curlew in the UK uplands and may be for other waders such as lapwing and dunlin. This evidence can be summarized as follows: (i) the recent catastrophic declines of curlew (and other waders) in Northern Ireland (Birdwatch Ireland 2011), where previous detailed studies have shown that high nest predation is the probable cause of curlew declines, at least (Grant et al. 1999); (ii) higher breeding densities of waders on land managed for grouse than those on land not managed for grouse, due at least in part to predator control (Tharme et al. 2001); (iii) positive effects of experimentally deployed predator control on wader breeding success and population change (Fletcher et al. 2010 ); (iv) lower declines in waders such as lapwing where grouse management was most intensive and larger declines in areas with high densities of carrion crow (Amar et al. 2011a); and (v) the lack of other environmental effects on nesting success and population change in this study (grazing, habitat, topography).
Grant et al, 1999:
http://onlinelibrary.wiley.com/doi/10.1046/j.1365-2664.1999.00379.x/full
'Thus, both direct predator control and land-use manipulations will require considerable resources. At present it is difficult to envisage ways in which this could be achieved on a sufficient scale to impact upon curlew populations throughout Northern Ireland, without fundamental changes in systems of agricultural support and associated environmental measures'.
The subsequent ‘
catastrophic declines of curlew (and other waders) in Northern Ireland (Birdwatch Ireland 2011)’ would suggest that Grant’s prediction was correct.
The red listing of curlews and lapwing was upgraded from ‘least concern’ to ‘near threatened’ in 2008 and 2015 respectively.
Without ‘
fundamental changes in systems of agricultural support and associated environmental measures’, grouse moors (currently largely funded by ‘rich toffs’) are becoming last breeding refuges for these species.
As the BTO suggest grouse moors are also important habitats for Hen harriers, finding ways of keeping them financially viable, whilst somehow protecting hen harriers must be the sustainable way forward.
