It's a bit confusing what happened, but I'll try to explain it to the best of my understanding. The zoo for the 2011 fiscal year cut 11 jobs. They also closed two exhibits, and made plans to get rid of two species of animal. This was all because of budget cuts.
The two exhibits that closed were part of Habitat Africa! The Forest (the red river hog and forest buffalo exhibits).
The two species the zoo planned on getting rid of were the forest buffalo, and warthog. Essentially the red river hogs were supposed to be moved into the warthog exhibit. The zoo sent their female warthog to Indianapolis Zoo, but never ended up sending their male warthog anywhere. Because of this the red river hogs ended up in the waterbuck and ostrich exhibit.
The red river hogs have know moved back to the forest in thier original exhibit. A pair of warthogs shares this yard with the waterbuck trio (The ostrich was sent to Kansas City) The old warthog yard is now home to 1.0 gerenuk, and 1.1 kirks dik dik.