Regioselectivity of Birch reduction (electron donating groups)
The explanation lies in the distribution of electron density in the intermediate radical anions that appear during the Birch reduction.
I use the following reactions as guiding examples:





Electron-withdrawing groups stabilize electron density at the ipso and para positions through conjugation and so the negative charge will mainly be found in these positions; subsequent protonation occurs para.



Electron-donating groups destabilize a negative charge (when compared to simple benzene) through conjugation and this effect would be strongest at the ipso and para positions.



Thus the negative charge will mainly be found at the ortho and meta position.