hmmm, i suppose if u stuck just 2 macaques in that exhibit they wouldnt get that much attention. i think francois langurs are best displayed in a group situation; they seem to become more confident in that case
With almost any primate, the bigger the group, the more activity there is. Macaques are possibly by nature more active than some of the rarer langurs, at least in captivity, but a large group of Langurs can make a really active display, as with the Javan langur groups at Howletts and Port Lympne while the Hecks Macaque pair at Howletts are barely noticeable..