I'm pleased to report that the middening seems to have stopped. I think what's been going on is a tussle for dominance between the two males. On the one hand, the younger, smaller sized Yevaud who was our first adoptee. And on the other, the tabby Odin, who's older and heavier-set and who looks that he might have strains of a Bengal cat ancestry. (Each of them has a female sidekick and these two also have their own sporadic skirmishes with each other.) No one party has emerged victorious but the tension seems to have subsided a bit. Still no eating from the same dish at the same time but you can see increasing tolerance when two cats from opposing parties share a bench or stretch of wall. Let's hope the situation continues to thaw... we want peace!