A few weeks ago I did an entry entitled "Where have all the orioles gone". I think I have solved the mystery.
Last year when they disappeared, I stopped putting out grape jelly, figuring they had found greener pastures. This year, after consulting Google, I learned that they aren't seen as frequently while they are nesting and raising their families. So, just in case they were somewhere nearby, I kept putting jelly out for them.
Once in awhile, early in the morning, I'd see one of the lovely birds out there partaking of the sweetness. If rain came and washed all the jelly away, I'd replenish it; I realized there was still at least one male oriole and one female, because once or twice a day, they'd show up... first one, then the other.
Now I'm seeing more of them; I'm assuming the babies are now coming for jelly, since some of the male birds aren't quite as brightly colored as others.
So, the orioles didn't desert me at all. They were simply busy raising a family.