Know Before You Go
The Botanical Garden is open from 9:00 a.m. to 5:00 p.m. from Tuesday to Sunday and the entrance fee costs $10 Reias but you only need to pay $5 Reias if you are a student from Brazil or abroad and carrying documentation of studies.
If looking for the parks howler monkeys, the best place to see them is in the garden on the "Trilha dos Bugios" or "Trail of the Howler Monkeys" where they often give themselves away through their frequent riotous territorial roaring. It's best not to stand directly underneath the trees where they hang out though as there is a strong chance of being defecated on.
If looking for sloths, the best place to see them is also in "Trilha dos Bugios." The sloths tend to be very visible in the canopies and tree branches due to their slow movements. Just look for a hairy lump amongst the trees and it is probably a sloth having a siesta. If you do encounter a sloth please resist the temptation of stroking them or trying to pick them up, as they are not fond of being handled and you are likely to get injured by their very sharp claws.