Olfactory: Smell

• A log that has been scent marked by marmosets in another group can be placed in the enclosure

Auditory

• Audio recordings of amicable calls made by other marmosets
• An ipod, attached to a mini-speaker, plays marmoset chirp calls inside a covered box

Visual

• Video recordings of other marmosets engaged in amicable behaviour
• Marmosets can watch the video, displayed on a computer monitor, through an internal window

Family Groups

Large family groups are the most stable (up to 8-10 marmosets if there is space).

• This is the optimum and most harmonious social grouping
• Young marmosets housed in family groups develop well socially
• The dominant female in a group usually suppresses breeding of subordinate females
• Offspring should never be removed before they are sexually mature
• Changes to the group composition should be kept to a minimum
• Strangers introduced to the group may result in aggression and stress within the group

Breeding Pairs

• Pairing a male and female marmoset together is usually straightforward
• However, certain guidelines should be followed

Same-sex Pairs

• Compatible same-sex pairs are preferable to single housing but they can be difficult unless they are related or one is younger than the other

Single Housing

• Marmosets should not be housed alone (unless advised to do so by a veterinarian with expertise in primate care)
• If single housing is necessary then it ought to be for as short a time as is possible and the separated marmoset should be allowed to hear, see and smell fellow group members

Other Group Types

• Social grouping different from that seen in the wild can lead to fighting (especially likely in large same-sex groups of young adults)

Co-operative Rearing Experience

• Family groups are vital for successful breeding
• Parental care is a behaviour that has to be learned through experience
• It is essential that all the group members get an opportunity to carry and care for the infants if they are to make good parents themselves
• Youngsters born to females that first breed at a later age (> 4 years) have more chance of surviving than those born to females that start to reproduce earlier (< 2.5 years)
• Dominant females continue to breed throughout their life
• Due to in-breeding avoidance it is very rare for offspring to breed within their family group

Pregnancy and Birth

• Pregnancy lasts 150 days and can be detected through palpating (examining the abdominal area by touch with a light pressure) from 5 weeks
• Only palpate on veterinary advice as it may be stressful
• Marmosets usually give birth during the night

Litter Size and Welfare

• Marmosets normally give birth to twins
• Triplets are sometimes born in captivity but it is very difficult for the marmosets to rear all three
• Triplets and quadruplets, are less likely to survive past weaning than twins or a single infant
• They tend to be smaller (of lower weight), making them more vulnerable to injury from other group members
• Hand rearing is not advised as it might have an adverse impact on the marmoset
• Alternative solutions are to:
  • leave the triplets with their group and supplement their feeding (requires very well habituated family)
  • foster one of the infants to surrogate parents with plenty of rearing experience but on contraception and supplement the feeding as above
• Marmosets are bred for use in research. It is not appropriate to breed pet marmosets