Old Oak

The road I use to commute to work was closed this morning for re-surfacing. This necessitated me taking a diversion. Obviously I wouldn't use their diversion, I made my own. This involved me in driving past this magnificant (if dead) oak tree in the hamlet of Prescott. The sun was shining on it and it looked.....dead, so on the return journey, I stopped to "blip" the tree. The sun had away and it looks more dead (deader?)

How long can these trees last?