I noticed on our own personal fruit trees that this year has been a bumper crop. I have heard that the native fruits are doing the same. For us I believe that the late killing frost last spring allowed the trees to build up enough energy to support a bumper crop this year. They didn't have to put out the energy it takes to made fruit and the seed they nourish last year so they have a bit of extra energy this year.
For every action, there is an equal but opposite reaction. I just hope it isn't too widespread so the deer don't have to move to eat! Pat