If the ground turns to mud, it never rains enough to wipe out the track behind? Or rains but the wind isn’t strong enough to break the rock free? I can’t see by the pick if there is any water erosion on the trail of the rock, doesn’t look like any to me.
Seems like you would only get that type of thing if every time it rained the rock only moved after the rain stopped. But why wouldn’t the next rain wipe out the track behind? Maybe the rain only moistens the very top level of soil? But then you would think there would be a lot more friction, that looks like a fairly deep furrow. The furrow itself looks like the rock almost scooted along on three points, with places between where the mud is cracked from the heat like the rest of the ground.
Freegards