Callitrichids: licence conditions for keepers (Annex A)
Source: gov.uk (2025-07-10)

Licence conditions for keeping primates from the family Callitrichidae (callitrichids).

Callitrichids include the following genera:
- Goeldi’s monkey (Callimico)
- marmoset (Callithrix and Mico)
- dwarf marmoset (Callibella)
- pygmy marmoset (Cebuella)
- lion tamarin (Leontopithecus)
- tamarin (Saguinus, Oedipomidas, Leontocebus and Tamarinus)
Further advice must be sought on guidance throughout this guidance from either:
- a recognised national or international primatology group representative
- an employee or representative of zoo licensed premises with relevant skills and experience in keeping primates
- a veterinarian experienced in treating the relevant species of primate
Diet

Further details on Callitrichid diet should follow the guidance in Schedule 1 (conditions 12-20).

Callitrichids’ diets in captivity should consist mainly of:
- fruit and vegetables
- insects
- exudates (for example, tree gum or sap)
Gummivores with specialised adaptations for gouging and digesting gum must be provided with the opportunity to gouge for gums at least twice daily.

Callitrichids’ diets may also contain:
- eggs
- flowers
- nectar
- seeds
- plant matter
Dietary supplements

Callitrichids in captivity must have additional dietary vitamin D3 and should have ultraviolet B (UV-B) lighting that is regularly monitored for its functionality with a UV-B meter. Records of the UV-B output must be kept and made available for inspection.

Callitrichid enclosures

Proportions for indoor and outdoor enclosures should follow the guidance in Schedule 1 (condition 25). Examples of suitable spatial dimensions of outdoor enclosures are as follows.

For 3 or fewer marmosets:
- the usable width should be at least 3 metres
- the usable length should be at least 4.5 metres
- the usable height should be at least 3 metres
For more than 3 marmosets, the floor area in the enclosure should be increased by at least 11.5 square metres for each additional independent marmoset.

For 3 or fewer tamarins or Goeldi’s monkeys:
- the usable width should be at least 3.5 metres
- the usable length should be at least 5 metres
- the usable height should be at least 3 metres
For more than 3 tamarins, the floor area in the enclosure should be increased by at least 17 square metres for each additional independent primate.

Climbing structures

Callitrichid enclosures should include climbing structures, platforms and perches that are high enough for the animals to stay above anyone entering the enclosure. They should also connect to the floor, providing opportunity for easy retreat to height. Structures should permit natural locomotory behaviour such as branch running, jumping, and vertical clinging and leaping.

Rest platforms

Callitrichid enclosures should contain a choice of resting platforms and branches that are:
- comfortable and adequately maintained
- placed high up
- anti-slip
- able to drain liquids
Platforms and branches should be in safe spaces that are:
- quiet
- away from entrances
- varied in relation to lighting
Nest boxes

There must be at least one nest box for each affiliated group of callitrichids. If possible, you must provide extra nest boxes to account for the natural variation of nest sites in the wild.

For groups of 4 or more primates, you must provide more than one nest box.

Nest boxes must be:
- able to drain liquids
- placed high up as most callitrichid species will not sleep near the ground
- comfortable and adequately maintained
Enclosure temperature

The temperature in indoor enclosures must be between 18˚C and 32˚C.

When the outside temperature is above 35˚C, callitrichids must have access to cooled areas. These can be in the indoor or outdoor enclosure.

Marmoset and tamarin breeding health and management plans

Schedule 1, Part 45 of the Regulations state that no breeding may be carried out except under the supervision of the named veterinarian and in accordance with a breeding health and management plan provided by the veterinarian.

Marmosets and tamarins in captivity often give birth to twins, and sometimes triplets or larger litters. Maintaining potentially breeding females at healthy weights at conception reduces the likelihood of large litters. Breeding health and management plans should consider the possibility of large litters when assessing how much additional space the enclosure needs for the group to expand.

It is not acceptable to remove individuals from the group to meet space requirements when those individuals would benefit from experience of caring for offspring. Individuals should get experience with at least 2 sets of offspring.

Marmoset mothers will struggle to support more than 2 infants. Plans should therefore include suitable contingency plans for dealing with infants who are rejected or developing under the minimum expected rate. Hand-rearing is not an acceptable option except on serious health and welfare grounds under veterinary supervision.