I photographed these birds today and it seems like they are either Small-billed tinamous (Crypturellus parvirostris) or Tataupa tinamous (Crypturellus tataupa). They were not signed.
I asked around a bit and showed more photos, and at least two people think that they might be small-billed tinamous, as they have red-ish legs (Tataupa have brown legs apparently). I have no idea myself though.
@JoJo22 I actually think they went on show yesterday or today. I visited the park Tuesday (the 31st) as well and they were not on-show then. Right now kept in the second aviary on the right in the paradieshalle (with racket-tailed treepie and more).