In spite of this fact, it is estimated that 40 or more tamarins live in the BCI forest, organized in small groups of 4 to 7 members. Tamarin groups consist of one or more adult females and males with their immature offspring. Not only are tamarins uncommon on BCI, they are also very small monkeys, weighing only about 500 grams as adults and they tend to travel high in the canopy. Thus the best way to find them is to listen carefully for their bird- like chirps and calls, which they will give loudly as soon as they see a human being. The tamarin species on BCI is a beautiful little monkey with a very striking coat composed of a pure white chest, deep red-brown on the back of the neck and tortoise mottling down the back.
Tamarins often travel single file through the forest, leaping quietly from limb to limb.
They are very active little monkeys and most of their day is spent travelling through the canopy in search of food. Their diet is made up of ripe fruits and animal matter, primarily insects such as katydids and soft-bodied jungle cockroaches. They are remarkably agile and rapid, skills useful in catching fast-moving forest insects. Generally only one female in a tamarin group, the dominant or alpha female, has infants. Reproduction in other adult females in the group is somehow suppressed.