I wonder that there was or are Lynx' in this exhibit too because the moat is very small. It seems to be easy that a Lynx can jump over and escape. Also, at the date of my visit in Salzburg Zoo in 2007, I saw no Lynx in this exhibit and there was also no such sign.
The moat is big enough and the enclosure is quite spacious, bigger than it appears on the photo. In 2005 I saw lynx, bear and a wolverine in this enclosure.