I have a brainstorm about eliminating WETNESS

Give this idea some thought,,,,,,,,, it is what I would do. (if I had wet base floor)
Fact; water will drain from higher,,, to lower

Place a layer of stone so it is about 4 inches higher than ground outside aviary. Cover stone with landscape fabric. (allows water to drain thru, and also keeps weeds from growing up.),, On top of fabric , layer about another 4 inches of sand. The fabric will keep the sand from falling thru into the stones. Sand drains very well when there is a hollowed cavity beneath. Stones create that semi hollowed layer.
I suggest 4 inches, but you can have good results with different thicknesses. Trial and error.