Clean out your feeders. Mix up the sugar water.

Here is a link that might be useful: link

And, hopefully, the Purple Martins and the Baltimore Orioles.

Still nothing here.

I put up two feeders on April 1st but it was after the middle of April when I saw the first one last year and the year before. There isn't much blooming. I like to have a feeder ready for them just in case.
The map you linked to has a couple of sightings in Missouri.

Mine always go up on April 1 too, thats the earliest they've came, and I too, want to be ready.

I mixed up some this morning and DH will fill the feeder.