There is a pane of glass behind the bars, and from memory and this photo the bars are clearly not capable of containing a bear. I think they are there to stop people banging on the glass, but it is an odd feature, and one I thought worth uploading.
@Falcosparverius@FunkyGibbon now it has been pointed out to me I can see reflections on the glass. I'm not sure how they'd stop anyone determined enough to bang on it though, the gaps look wide enough for it to be possible...?
@FunkyGibbon No? - the bars look pretty bear proof to me. There appears to be some kind of horizontal electric fence too, to keep the animals away from the windows.
@Brum No, if someone wanted to they could easily bang through them, but they may be hoping for a psychological effect. Alternatively someone may have decided bears would look better behind bars. The adjacent bear exhibit has glass without bars. @Andrew Swales They look sturdy yes, but unless I am mistaken (always a possibility) they are actually constructed from a light, hollow alloy and spot-welded together. In China this kind of grill is commonly mounted on the outsides of high-rise windows to make sure children or pets don't fall out.
@FunkyGibbon Yes, they look like mild steel rod, and would be fine. What you describe sounds very chancy to me. Quite a lot of electric strands have been erected around the top of the concrete wall and horizontally at the base of the windows. This appears to be a retro-fit, and presumably was added for a reason!
@Andrew Swales I cannot imagine that whatever the reason is it has anything to do with containment; it's inconceivable that the glass isn't 'bear proof' (whatever that means). But presumably you are right that there is a reason.