In all directions plumes of smoke can be seen on the moors on a good day at this time of the year. The gamekeepers are burning the heather.
Grouse feed on heather. Young shoots provide the best nutritional value but grouse require taller heather for nesting and cover. To provide a managed supply of young heather patches of heather are periodically burnt. This burning cycle, lasting between 7 and 25 years result in the familiar mosaic of colours on heather moorland. The Scots call this muirburn.
Heather can only be burnt by law between 1st October and 10th April when the heather is dry but the undying peat is wet. If done correctly the heather roots are undamaged by the fire and the seeds quickly germinates. But I guess any self sown trees and shrubs such as birch and rowan will be destroyed by the fire so maintaining the North York Moors iconic heather moorland.
I spotted this fire close to the Kildale to Westerdale road on a ridge of moorland called Kempswithen.