The first picture suggests the field had recently been taken out of arable production. The second shows the field well overgrazed - 'poached'. Female sheep have sexual needs too - the idea is that Rock Art and 'lesser' monuments are protected, by agreement, through DEFRA's Environmental Stewardship Scheme. (But the man has to apply first). A fifty pence through-the-gate box would change things. I'm curious to know the diameter of the perforation, in the stone, to see whether it correlates with an even number - perhaps five - of Thom's Megalithic Inches.