The okapi female stood inside her barn on my visit 18/5 and was visibly large and rotund (so I expect the calf to be there any week now)! The bull was on exhibit and had walked inside late in the day.
Still no baby Okapi at London Zoo. Both adults were outside in the paddock today. I've discovered their female 'Elila' is the younger sister of the female at Marwell which recently had a calf. Both females were handraised at Marwell.