Why Tuan is a 'no show'.
GentleLemur(alan) told us on the Chester gallery thread with his great portrait of Tuan that he (Tuan) didn't have any outside access at Antwerp Zoo. This is probably the reason he doesn't like coming outdoors much but he will probably improve with time.
Also its my guess that since his offspring were born, he is living just in the end indoor enclosure of the old house and the outside enclosure which is fortunately free for him now since Sibu died.. They may not be able to give him access to the netted enclosures without him going in with the females (could they?) and that is a risk too far.
Also since 'Donna' died and with the arrival of two babies, I've been wondering if spacewise they can still accomodate the other male 'Kevin' from Berlin- or whether this will be shelved for now.