It is disgustingly small for a serval, and is a real black mark against an otherwise excellent zoo. They also have another serval (or at least they used to) that they house off-exhibit and use in their show.
Right, but this is true with all the smaller cats(excepting those in the North American section). I think they were just trying to explain away the many embarrassing questions that had been posed to them.
If I recall correctly, the sign explains that this serval is a former pet that was declawed by its owner and has a hard time getting around. That is their justification for keeping it in such a small enclosure, but it is not a good reason IMO. They could provide a soft substrate in an appropriately sized area.
Let me rephrase: For a grassland species I think this is horribly barren. And while servals are not just found in the grasslands, I wasn't aware they lived in this type of environment.