Common marmosets (CALLITHRIX JACCHUS) (CALLITHRICIDAE) – are the smallest higher primates, their body length is about 50 sm., and the weight – up to 1 kg. The females are a little bit larger than males. Some primitive features are typical to these South-American monkeys: all nails are sickle – shaped, except for the great toe, and major hemispheres of a brain are rather smooth.
Common marmosets are very quick monkeys. They adopted to live in dense tropical and subtropical forests. Most of their time is spent in trees. They live in small groups from 3 up to 12 animals. Marmosets are diurnal, sheltering at night in tree holes and cavities. Their diet includes the juicy foetuses, seeds and also insects, sometimes they eat birds. They use their hands to secure food.
Marmosets have acute sight, good hearing and a good sense of smell. Their emotions are expressed by movements of the eyelids, ears and the hairy adornments on the head. The system of the communication in common marmosets is based mainly on the olfactory signals. They mark not only different objects but also other members of the group and their own body with cutaneous and anal glands, using saliva, urine, and faeces. Marking behaviour is related with the social rank of animal: dominants mark more.
Male and female of common marmoset form a constant pair. Females give birth to 1-3 youngs after a gestation period of 140 -150 days. The males take care of youngs and usually carry the offspring on their backs.