Question
Living in Dallas Texas we are covered in Live Oaks.  I recently purchases a new home with 5 large Live Oak trees.  One in the back is easily 7 ft round at 2 ft off the ground.  Huge  and beutiful.  

Over the last two months (today is July 27, 2008) another small Live Oak and maybe the large one too are having clusters of leaves die.  They look like brown dots along the northern facing part of the tree tops.  Seems the end of the branch is dying. ???????

What is the issue?

Couple of notes:  
We had the trees cut back last year.
Power lines run along the out edge of the northern face.  
The browning seems to be in other trees alogn the alley - although I haven't seen it in my frotn yard which is facing south.

What is the solution or solutions?

Help!

Answer
If you have not been getting an adequate amount of rainfall in the last month or two, I would say it is caused by dry conditions.  Old live oaks will let some of the leaves and tips of branches go to maintain the rest of the tree.  If this is the case you may install a soaker hose around the base and let it water very slowly over a long period of time.  You will only see the leaf death stop.  Those already dead will not come back out.  Any new growth should look normal.  If this does not seem to be the case, please repsond back for other suggestions.  Thanks.