The cottontop tamarin is an omnivorous animal meaning that the cottontop tamarin hunts both plants and other animals in order to survive. Fruits, insects and green plants make up the majority of the cottontop tamarin's diet along with small rodents and reptiles, eggs and tree sap.
Due to the relatively small size of the cottontop tamarin, it has a number of predators within it's natural environment. Wild cats, dogs, snakes and birds of prey are primary predators of the cottontop tamarin, along with humans who are destroying their natural habitat.
The cottontop tamarin usually breeds between the months of April and July, when the female cottontop tamarin will give birth to twins (or a single infant) after a four to five month gestation period. The male cottontop tamarins carry and groom infants more than the females do, but females clean the infant more than the males do. Older siblings are also known to contribute to infant care, although infants prefer to be carried by their parents than by their siblings. Infant cottontop tamarins become mobile at 2 to 5 weeks, and begin eating solid food at 4 to 7 weeks. They are independent at 10 to 18 weeks and are fully weaned at 15 to 25 weeks. Sexual maturity is attained at about 2 years of age.
Today, the cottontop tamarin is considered to be a critically endangered species with an estimated wild cottontop tamarin population of just 6,000. The main reason for the severe decline in the cottontop tamarin population is that they have lost more than 75% of their natural habitat to deforestation.