In South America many tamarins are commonly also called titis, Barcelona zoo mostly like is useing the common popular name on their signage, but the latin name on the sign may have been correct. that is why common names can be translated in different manners and latin names are more reliable.
I took the Zoo's word for what it was - the sign says Titi Monkey, the brochure proclaims it's a new enclosure for Titis. I'm not familiar with them myself.
I'm not sure where you mean. The enclosure is on the outer edge of the zoo near the Lions and Tigers and opposite the flight aviary containing Roseate Spoonbills, among others. I've just reminded myself by looking at the map as my visit was 'having fun on holiday' rather than 'reviewing' (although I appreciate that it's possible to do both!)
When i visited barcelona zoo a few years ago there was indeed an area named "Casa de los Titis" which fits the description that zooman gives. by the way, this is a nice photo, gigit.
When i visited barcelona zoo a few years ago there was indeed an area named "Casa de los Titis" which fits the description that zooman gives. by the way, this is a nice photo, gigit.