@Valvas Strangely Zootierliste mentions Blijdorp hasn't had these since 2009, which was before the okapi and bird exhibit even existed, so I guess the information there is incomplete.
That said, I do not know whether they still have any currently - I didn't see any during my most recent visit but the presence of the sign does suggest they are still present, or at least were recently. I'm sorry I can't tell you more.
