Marmoset Finger Monkeys Facts

Distribution: Eastern Brazil.

Social groups: family groups up to 30 individuals (in captivity max 12). Only one breeding pair in a group.

Lifespan: 7 - 20 years

Length:

Head + Body: 7-12 inches (18-30 cm)

Tail: 7-16 inches (17-40 cm)

Weight: 10-18 ounces (300-500 grams)

Hands: Except for the big toes, a marmoset has claws not nails unlike most monkeys

Colour: Marmosets have a flattened black face, thick white tufts on its ears, and long black and white fur. The tail is white ringed with black.

Marmosets averages 198mm in length of head and body and its tail is 290mm long. At around 190 to 350gms in weight it is a small and agile monkey .

The digits have curved claws, except on the big toe, which has a flat nail.

The curved claw adaptation assists in horizontal jumping by enabling them to run up the sheer side of a tree, it also assists in grooming.

Their body length is 225 - 309mm, the tail is 279 - 406mm and they weigh between 255 and 454 grams.

Marmosets have a V-shaped mandible with incisors that are extended and nearly level with the canines, resulting in a cup or scoop-like shape, these teeth are very sharp and can cause quite a bit of damage if one is bitten, this enables the marmoset to gnaw holes in order to gain access

How should I cage my Marmoset Finger Monkey?

What should I put in the cage of my Marmoset Finger Monkey or Tamarin? How should I decorate it? What does the cage of my Marmoset Finger Monkey require?

† Housing in stable, compatible groups

† Adequate socialization, habituation and training of animals

† Sufficient space to provide for exercise, a range of species-typical
behaviours, structural division and suitable enrichment

† Sufficient height to allow vertical flight if alarmed. No small double tier cages since these limit upward movement, the lower levels can be dark and animals on the lower levels may be ignored

† A solid floor as a resting area and to allow provision of substrate for
foraging

† Structures to enable utilization of as much of the enclosure as possible
(e.g. sufficient perches, platforms, swings, ropes and ladders for all animals to occupy without competition)

† Visual barriers to help animals control their social interactions

† Nest areas for species that use them (e.g. wooden nest boxes and
plastic hanging buckets for marmosets and tamarins)

† A varied diet appropriate for the species

† Provision for foraging, including appropriate artificial feeding devices
and scatter feeding

† Appropriate wood (i.e. no chemical preservatives or long strips that can
block the gut) for species that gnaw (e.g. marmosets) and for scent
marking

† Toys, chews, tactile materials and destructible materials (e.g. cardboard
boxes)

† Novelty (e.g. minor changes in furniture, feeding practices and toys) † Adequate light levels and appropriate spectral emission for species’ needs

† A flexible enclosure/furniture layout to allow stress-free capture

† Provision to facilitate positive reinforcement training in groups (e.g.
separate areas in the front of the cage where dominant and subordinate
animals can be trained simultaneously) † Flexibility for future development/use

Refinements in housing and husbandry

Understanding the animals’ natural history, sensory world, social structure and physical and behavioural characteristics and needs, is an essential prerequisite to the design of good primate housing and husbandry. Primate species are adapted both physically and behaviourally to their natural habitats; for example, they may be largely arboreal (e.g. cynomolgus macaques, marmosets, tamarins) or terrestrial (e.g. bonnet macaques and baboons) and it is important to consider this when designing housing systems. The degree of territoriality, styles of locomotion (e.g. vertical clinging and leaping, walking, running), sleeping and nesting beha- viour (e.g. using tree holes, building nests), and response to predators and climatic conditions are all factors to be taken into account. For example, most arboreal species flee upwards to escape terrestrial predators; and in the labora- tory, most primates will flee upwards if they are alarmedwhen a human approaches. Keeping these animals in small, conventional tiered cages frustrates this behavior for individuals in the lower tier, and is unacceptable in animal welfare terms.

Much has been written about primate husbandry, and guidance on designing good housing, husbandry and care is provided in the references in Box 1. The underlying prin- ciple is to provide safe, comfortable and hygienic housing and husbandry, which allows the animals to perform a wide range of species-typical behaviour and exercise a degree of choice and control in their environment. For example, they should be able to choose to socialize with, or avoid, group mates, or to be seen or not seen by neigh- bouring primates (Poole 1999, International Primatological Society 2007). Other factors that have to be taken into account include ease of cleaning, capture and monitoring of the animals.
The components of a good primate housing system are shown in Table 5. Most of them are applicable to all species, although the detail of how to interpret and apply each component may vary. Advice from a specialist in primate behaviour and welfare will help to interpret the requirements for individual species. It is also necessary to take into account the procedures that animals undergo and any requirements imposed by them. For example, sur- gically-prepared animals may need an area in the home enclosure where they can recover from anaesthesia yet retain visual and olfactory contact with the rest of the social group; enrichment for animals with motor impair- ment needs to take into account the animals’ reduced phys- ical capabilities. The enclosure design team should thereforeinclude, and take account of, the views of scientific and animal care staff and others with practical expertise of using the facilities.

Good housing that provides much of the above is now routinely provided in some establishments. However, many laboratory primates are still housed in small, barren cages that bear little relation to the complex three- dimensional environments that they inhabit in the wild, and which neither allow performance of a range of species- typical behaviours, nor provide space for adequate sociali- zation, enrichment and opportunity to exert choice and control. This affects both the physical and behavioural health of the animals, which in turn can influence the quality of research data (Reinhardt 2004).

Environmental enrichment

It is best to provide enrichment as part of a formal enrich- ment programme. Records of the enrichment items pro- vided should be maintained, together with a record of how the animals use them and whether there are any pro- blems with any items. Changing the enrichment items can provide novelty, but if individuals use certain items exten- sively then these should not be removed. Where items are rotated between groups this should be recorded to ensure that all groups of animals have access to them.
A useful searchable database for ideas on environmental enrichment and husbandry refinement for primates is pro- vided by the Animal Welfare Institute, Washington DC (see http://www.awionline.org/lab_animals/biblio/enrich. htm). Some additional ideas are provided below.

A heated area
Primates like to bask in sunlight, but where it is not possible to include outdoor runs or windows, areas of additional heat/lighting can be provided. In pilot studies by members of the Working Group, infant common marmosets were particularly interested to move to heated areas and family groups would congregate there as well.

Incorporating visual barriers
Visual barriers between and/or within enclosures allow the occupants the choice between seeing other primates and humans, or hiding from them. This enables them to have greater control over their social interactions, helps minimize intra- and inter- group aggression and promotes successful pairing and grouping. Examples of visual barriers are floor- mounted or hanging plastic panels, shower curtains, sacking or large wide pipes. They should be carefully posi- tioned so that they do not block light sources. The barrier need not be complete, as primates are thought to perceive that they are hidden even if a large part of their body is visible.

Adapting enclosure materials Wood
The inclusion of wood within the cage is beneficial for all species. It is less cold and noisy than metal, provides a softer textured surface and facilitates a variety of species- typical behaviours, for example, it can be manipulated and chewed. Natural branches and/or wooden dowel perches can be included to provide additional usable space. The type of wood must not be toxic to the animals; maple, beech and oak are all safe. If real wood cannot be used, then plastic wood is a good alternative.

Transparent materials
Primates are highly reactive to visual stimuli and strongly motivated to obtain visual infor- mation about their surroundings. Primate rooms should have windows wherever possible to provide natural light and stimulation by increasing the area of vision. Doors and access corridors should also have windows, so that the animals can see when someone is about to enter the room and who that person is, so that they are not startled. Windows in enclosures should have stickers to prevent the animals running into them when first introduced.

NEW WORLD PRIMATES

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Dealing with aggression by marmoset finger monkeys

Strategies for avoiding aggression by marmoset finger monkeys

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† Training staff to understand, anticipate and respond appropriately to primate behaviour, encouraging positive staff–animal interactions

† Use of windows in the doors, or glass doors, so that animals can see human activity and know when humans are approaching

† Positioning verandas for small primates at the front of their enclosure to enable the animals to survey their environment and see humans arriving

† Use of widely spaced horizontal bars to construct enclosures (rather than tightly spaced, vertical ones), as this increases visibility and can facilitate human–animal interaction. It also allows animals to climb more easily

† Positioning water bottles and food hoppers at the front of the enclosure to encourage animals to come forward

† Holding a container (e.g. plastic ice cream tub) for marmosets to jump into to have their bodies tickled and for play with humans

† Minimizing excessive noise levels in the vicinity of the animals and talking to the animals in a calm voice

† Ensuring positive staff–primate interactions instead of only interacting with animals when an adverse event takes place (e.g. encourage animals to accept part of the daily ration or food treats, such as grapes, from the hand)

† Spending time each day (e.g. 15 min) sitting with the primates in their enclosure

† Playing games with the animals in their home enclosure (e.g. catch or find the food treat)

† When changing litter or spot-removing faeces, allowing the animals to remain in the enclosure with the staff

† Providing angled mirrors that the animals can adjust to allow a view of areas outside the enclosure

Identifying the cause of aggression.

The first step in effective management of aggression is to identify the reason for the behavior and the stimuli that trigger an aggressive response in a particular animal or group. Some useful questions to consider are listed below.

Is the aggression within or between groups?
Is there any particular timing of aggressive incidents throughout the day?
Is it linked to any potential event that could increase the
level of arousal in the animals such as feeding, moving or weighing animals?
Is one particular animal always the aggressor or victim?
Does it seem linked to a particular resource such as a perch or nest box?
Is it linked to any particular member of staff?

It is important to record details of when the incidents occurred, who was present in the primate unit at the time, what activity was taking place (e.g. cleaning, feeding, weighing), the level of injury to the individual animals involved, and the behaviour of those individuals and other members of the social group before, during and after the incident. A video and sound remote monitoring system can be very helpful in this regard.

Reducing conflict. Ways to reduce the chances of conflict occurring are listed below.

† Identify animals likely to be compatible by careful obser- vation of their behaviour towards each other.

† Obtain primates in pre-existing groups or compatible pairs and avoid regrouping them on arrival at the scien- tific establishment.

† House individuals of different ages and/or body weights together since they are then less likely to compete with each other . For example, stability in groups of less than 10 young marmosets can be restored by introducing an older animal to the group, but manage this carefully in case the older animal is challenged.

† Design complex enclosures with escape areas, visual barriers and plenty of enrichment.

† Increase enclosure size to permit more effective primate signalling of dominance, approach and withdrawal responses, avoidance of aggressive individuals and/or retreat to a safe distance
† Maximize the stability of the group by reinforcing the natural social order within the group. Attend to the more confident individuals first when greeting animals, and allow these individuals to be the first of the group to go through doorways and receive treats or food.

Dealing with serious and/or persistent aggression. Where persistent aggressive behaviour cannot be prevented by increases in enclosure size and complexity, animals will need to be separated. Where serious aggression arises in an established group of animals, it may be possible to sep- arate them into compatible subgroups. It is advisable to remove animals to ‘neutral territory’ and put physical space between the subgroups, preferably moving them into separate units, rather than across the aisle of the same unit. This should avoid continuing displays of social conflict.

Alternatively, an individual animal may need to be removed. However, removing one of two fighting individuals can be problematic. Removing the dominant aggressive animal may result in subsequent fighting to reinstate the dominance hierarchy in the enclosure. Removing the subordinate animal may result in the dominant aggressive animal intimidating another animal within the group. Both options have been tried with varying degrees of success, and more information needs to be gathered in order to determine the best approach. Individuals that have to be removed may find the social environment of another group more compatible; for example, a dominant animal may be less dominant in another group.