Are all of these species actually on display? I didn't see Eurasian Siskin, Varied Tit, Siberian Rubythroat, Japanese Yellow Bunting, Japanese Bush Warbler or Eurasian Skylark on my visit. Admittedly I didn't spend too long in the Japanese bird house as the zoo was just about to close but that's a pretty significant percentage of species in this aviary to simply be hiding.
@DaLilFishie when I was there: Coal Tit, Varied Tit, Siberian Rubythroat (not seen), Japanese Bush Warbler, Japanese White-eye, Eurasian Skylark (not seen), Eurasian Siskin, Brambling, Meadow Bunting, Masked Bunting, Japanese Yellow Bunting.
The only ones I didn't see where the Siberian Rubythroat and Eurasian Skylark.
@DaLilFishie I saw every species back in January. There was also a Japanese Wagtail. Since they are all natives, perhaps they move or release some birds, or they have since passed.