As far as I can remember these primates are new to me for the Zoologico Buenos Aires! They must have acquired a group in the years after my last visit!
There are 2 groups, one in the old monkey house and another at the roundhouse next to the small felines. Howler monkeys are native to northern Argentina, so i would suppose that the BA zoo primates of this species have been confiscated from the illegal pet trade.
