I currently have 3 cages, 2 stasis fields, and 2 improved stasis fields in my inventory. I was under the impression that this would convey the ability to "relocate" and "provide new homes" for up to 3 + 10 + 20 = 33 creatures, but attempting to pick up an eighth animal tells me I have no unused cages. It appears as though the stasis fields are simply being counted as single-unit cages (possibly because I also have cages in my inventory?).
[edit - Feb 21 2018] Closed as fixed as per duplicate report .