@Ggrarl I thought they had normal signs when I visited in January 2018. The worst part about electric signs is when they break or malfunction and suddenly there's no signage.
Upon seeing this sign in person I can agree that it is quite frustrating to use(watch?), especially for a large bird aviary. I would much prefer they went with the same approach as they do for their large waterfowl areas and bird enclosure in the new African Area with the sheets and tabs you can lift, as they take up very little space and can display much more information and can be used at will.