One of the smallest Central American primates is the squirrel monkey, or titi monkey.  These agile little monkeys are active throughout much of the day, scouring the forest for insects and fruits to eat.  Squirrel monkeys tend to live in large, fluid social groups generally ranging anywhere from 30-70 individuals.  However, it has even been reported that squirrel monkeys may be found in groups of up to 300. 

Unlike the other primates of Costa Rica, the squirrel monkey lacks a prehensile tail.  Instead, the long tail of the squirrel monkey is used strictly for balance.  When feeding, it is not uncommon for a squirrel monkey to be seen with their tail draped over their shoulder to keep it out of the way.  Because the squirrel monkey rarely descends to the ground, any break in the forest -- such as roads, powerlines, and farmlands -- can severely fragment a monkey troop's habitat and threaten the survival of the troop itself.