They are usually considered to be later than the usual cup and ring stuff .Probably Pictish /Iron Age . There is also a deer at Goatsrcrag Hill in Northumberland , another in Edinburgh and one in Glen Domhain in Argyll .The latter two have proved difficult to date sylistically .Much earlier than them all are the horses from Robin Hoods cave ,Cresswell ,deer from Church Hole and other "possibles "

No I don't know about those white deer - a mutant isolated population - how interesting, genetically speaking I mean. I shall check that out on Wiki...

In the end I went back to a piece of stunning rock art from Gardom's Edge
http://www.themodernantiquarian.com/post/13459/gardoms_edge.html
which since Andrew Common Era told me about has etched itself in my mind's eye.

I was very interested to see that at Eggerness we get antelope petroglyphs; common in Scandinavia, all over Africa, but not here.