What can I hear?

I've been told that deer have a relatively poor eyesight and that if you stand still they have difficulty spotting you (as long as you aren't wearing bright colours!).  What is equally true is that they have a keen sense of smell and those large ears help with exceptional hearing.  I spotted this young stag (with a mate) from the road side at about 100 metres.  

I had time to stop behind some trees and hedge, grab the camera and edge back to a better vantage point.  I managed just three photos of the animal grazing before he lifted his head in that distinctive way and started scanning the location where I was standing.  It needed only a few seconds to confirm his suspicions and they high tailed it across to the fence line and into the woods.