As anyone who has ever visited a tropical rainforest knows mammals are difficult to see. We have a great diversity of interesting mammals that you are more likely to encounter when exploring the reserve both during the day and night.
The first photograph shows a specie of porcupine endemic to Mesoamerica which is arboreal and has a prehensile tail similar to New World monkeys.
For a full list of species:
Ernesto Carman co-founder of the Conservación Reinita Cerúlea – Costa Rica (Cerulean Warbler Conservation-CR).