Hi Helen
I think it is very likely that what looks like mud is actually some sort of marking which someone has applied to the hedgehog. If it was mud, it wouldn’t have stayed there up to, through and after hibernation. It has certainly rained a fair bit here, and I imagine has there too at some stage. Some of the material used does look quite pale in light, but shows up as dark on night cams. The fact that it stayed indicates to me that it was quite thickly applied which is completely unfair to hogs.
I will say more in a separate post because it is is not aimed at you, since you haven’t marked the hogs.
