I believe the cold-blooded creatures were no longer kept because of various reasons such as predatory and living conditions in the Desert. The quails were too destructive and some of the other passerines slowly died out.
But nonetheless, Burgers' Desert still has some rarities such as an enormous amount of White-winged doves, Painted buntings, Ultramarine grosbeaks, Yellow grosbeaks, Ring-tailed cats and California bighorn sheep.
Thank you for your reply, Emperor Tamarin. Ref. living conditions: If you (also) mean the temperature, then I must say that I allways had the impression that it is obviously cooler in Burgers' Desert then in the deserts of Arizona and Southern California during the same period of the year (at least according to my own experience). Are there any problems with the heating in the hall?