I am afraid I have no idea, it was just his pet name - either Mr Smith or "Smithy". He survived for years after all of the other Japanese Sika had died, so maybe he earned the title because he was the last surviving member of the herd.
He does look old- as they age male deer come to look 'sleepy' and carry their heads lower in relation to their body. I think his antlers had 'gone back' (shrunk) also.
