Draining Large areas of grouse moor were previously
blanket bogs, where
sphagnum moss is the dominant vegetation, and drainage is required to allow heather to flourish. Drainage can damage these bogs.
Burning To ensure a mosaic of heather of different ages,
gamekeepers carry out controlled burning of the vegetation, targeting patches of heather between 1 October and 15 April. A burned patch of heather allows for the growth of fresh shoots which provide essential nutrition for grouse. Burning also prevents the accumulation of dry plant matter. Heather burning is typically carried out in a patchwork pattern, ensuring a variety of heather heights, on a rotational basis spanning between eight and twelve years. While the new-growth heather shoots provide a source of sustenance for the grouse, the older, taller growth provides them with cover and shelter. As a result of this land management practice unique to the UK, heather moorland is a globally unusual habitat. (The claim that 75% of the world's heather moorland is found in the UK is contested and has been shown to be unsubstantiated.) 60% of all England's upland
Sites of Special Scientific Interest are managed for grouse shooting. UK moorlands and blanket bogs are a
carbon sink and opponents to burning heather argue that it can release this carbon. However, proponents argue that in a controlled burn only the heather is burnt and that the charcoal from burned heather is stored in the soil. Heather burning, if not carried out properly, can have negative effects on peat hydrology, peat chemistry and physical properties, river water chemistry and river ecology. Moor burning reduces the growth of
Sphagnum moss and the density of macroinvertebrates which play a vital role in aquatic food webs by feeding on algae, microbes and detritus at the base of food chains before they themselves are consumed by birds, fish and amphibians. Burning also reduces the water content of the upper layers of peat, making it less able to retain minerals that are essential for plant growth and resisting the chemical effects of acid rain. In an effort to mitigate the adverse ecological effects caused by burning, some moorland estates managed for grouse shooting have agreed to abstain from burning over protected blanket bogs, where fires dry out and burn the peat. However, some burning of these areas continues. If a moorland has not been burned for several years, large stands of rank and woody heather accumulate, increasing the risk of large fires in dry ground conditions due to the high fuel loads. Larger wildfires tend to be more intense and are more likely to burn the underlying peat.
Killing predators Grouse moors have a nearly 200-year history of killing large numbers of predators, including many species that are now protected. Burning and predator control correlate with higher densities of red grouse, as well as some other species that can thrive on open heather moorland;
golden plover,
curlew,
lapwing,
common redshank and
ring ouzel. The
RSPB's Investigations Team reports that in 2017, despite large areas of suitable habitat, not a single hen harrier chick was produced on a privately owned grouse moor. Illegal killing of raptors on grouse moors is widespread. A 2017 study commissioned by Scottish Natural Heritage into the fate of satellite-tracked
golden eagles concluded that "Corroborative information points to the perpetrators of the persecution of tagged eagles being associated with some grouse moors in the central and eastern Highlands of Scotland," and that "[t]his illegal killing has such a marked effect on the survival rates of the young birds that the potential capacity for the breeding golden eagle population continues to be suppressed around where this persecution largely occurs." The Langholm Moor Demonstration Project prevented the
persecution of raptors, especially
hen harriers, and found that grouse would survive in the presence of a more natural number of predators. However, raptor predation at Langholm reduced autumn grouse abundance by 50%, making organized driven grouse shooting unprofitable. A community land project now hopes to purchase much of the land in question. The Langholm experiment suggests that, to be profitable, intensive grouse moors need to be predator-controlled. Shooting and poisoning are not the only methods used to kill predators. Illegal snares have been used to kill predators on grouse moors; Spring and rail traps are widely used and can kill a variety of protected species. Snares placed to trap foxes have even injured humans. In November 2020, the Scottish Government announced that self-regulation and attempts to curb undesirable practices had failed. Individual estate employees who kill protected species are committing a criminal offence, but their employers, the shooting companies, are not. Requiring companies to obtain a license, on condition that they cease undesirable practices, has been suggested as a way of providing effective protection for predators. The Scottish Government is to begin work on new legislation that will impose a strict licensing regime on Scottish grouse moors and control raptor persecution, moorland burning, and mass medication with medicated grit. A joint industry statement responded that Scotland already had the strictest anti-persecution measures in the UK, with incidents falling, and that further regulation risked closing down grouse moors, with economic losses for gamekeepers and vulnerable rural businesses.
Killing mountain hares Mountain hares may be hosts for
ticks and for
louping ill virus, both of which they can share with red grouse (and with deer). To control tick-borne diseases, some game managers have recommended culling mountain hares. The only study that has been used to support this policy had no meaningful control group, used potentially confounding treatments, and there were no deer in the study area. A recent study found no effects of mountain hare abundance on number of ticks on grouse, and actually found better grouse chick survival in areas with greater numbers of mountain hares. The Scottish Parliament voted in June 2020 to protect mountain hares; it will be an offence under the Wildlife and Countryside Act to intentionally or recklessly kill or injure a hare without a licence. ==Economics and employment==