It is impossible to tell from your photo or your description what is happening with your tree.  It is probably not fireblight, unless you are seeing some arching/crooking (like a shepherds hook) and the blackened leaves would generally stay attached.
Unfortunately Bradford pears are not good trees, especially over the long term as they tend to be weak wooded, cracking in storms, just as they are looking nice and mature.  They also are incredibly invasive, showing up in wild areas and taking over from native species-- you notice this most from highways when they are blooming wall-to-wall.
The holes you are seeing is from sapsuckers.  They may be feeding on insects within the tree.
cm

Some of the leaves do appear to look black, some stay on the tree and some have fallen off.  I am afraid the trees are dying.  Can anything be done to save them.

Your pear trees are suffering with a severe outbreak of fire blight.  This is a bacterial disease that is difficult to control even when diagnosed early in the outbreak, but your trees have obviously become totally infected.  They will suffer some dieback and will ultimately fail. 
http://extension.umd.edu/learn/fireblight-ornamental-trees
LS