Pygmy Marmoset (Callithrix Pygmaea) - Animals - A-Z Animals Five groups that classify all living things Animalia A group of animals within the animal kingdom Chordata A group of animals within a pylum Mammalia A group of animals within a class Primates A group of animals within an order Callitrichidae A group of animals within a family Cebuella Comprised of the genus followed by the species Callithrix Pygmaea The animal group that the species belongs to Mammal What kind of foods the animal eats Omnivore How long (L) or tall (H) the animal is 14-16cm (5.5-6.3in) The measurement of how heavy the animal is 120-140g (4.2-4.9oz) The fastest recorded speed of the animal 40km/h (24mph) How long the animal lives for 8-12 years Whether the animal is solitary or sociable Troop The likelihood of the animal becoming extinct Threatened The colour of the animal's coat or markings Brown, Tan, Grey, Black, White The protective layer of the animal Fur The specific area

 where the animal lives Outskirts of tropical rainforest The average number of babies born at once 2 Other animals that hunt and eat the animal Birds, Snakes, Wildcats Long tail and furry ear tufts Pygmy Marmoset Location Map of South America Pygmy Marmoset The pygmy marmoset is a tiny primate that is exclusively found in the jungles of South America.

The pygmy marmoset is known to be the smallest known species of monkey in the world. The pygmy marmoset averages at about 15cm tall, with a 20cm long tail behind it. The pygmy marmoset has sharp claws which make the pygmy marmoset excellent at climbing trees and the long tail of the pygmy marmoset gives this little monkey fantastic balance when jumping between tree branches. The low weight of the pygmy marmoset allows the pygmy marmoset to reach the canopy tree tops, a place where many of the larger species of monkey cannot reach. Here the pygmy marmoset eats fruits, berries, insects and small reptiles safely high above any dangerous predators. The small size of the pygmy marmoset means that it has developed a number of nicknames from locals and tourists alike, such as the pocket monkey and the little lion . The tiny size of this miniature monkey means that the pygmy marmoset if often very difficult to observe in the wild.

The pygmy marmoset has been increasingly popular as an exotic pet, but they are very hard to keep. When a baby pygmy marmoset is taken away from the family it can often die quickly due to depression. Baby pygmy marmosets also need feeding every two hours for their first two weeks in the world so they can be very time-consuming pets. Pet pygmy marmosets can take a grave dislike towards their owners and some have been known to bite their owners and throw feces at them, as a form of attack. After a gestation period of around 4.5 months, the female pygmy marmoset gives birth to one or two babies. The male pygmy marmoset will often carry the babies after birth until they are big enough and strong enough to look after themselves. Pygmy marmosets live in groups which tend to consist of the head male and female pygmy marmosets and their offspring, usually about four litters. There can be more than one male in a pygmy marmoset troop, but the dominant male pygmy marmoset will remain the dominant male of that troop.

Share This Article Pygmy Marmoset | San Diego Zoo Animals & Plants San Diego Zoo Animals & Plants SPECIES: pygmaea ABOUT Mini monkeys: High in the rain forest canopy of South America lives a tiny animal. It dodges behind tree trunks and branches, freezing and dashing, just like a squirrel. It also has brown fur and a long tail like a squirrel—but it's a pygmy marmoset, the world's smallest monkey! Marmosets and their cousins, the tamarins, are some of the tiniest primates around. Yet pygmy marmosets are different enough for scientists to group them apart from other marmoset species. A full-grown pygmy marmoset could fit in an adult human's hand, and it weighs about as much as a stick of butter. But there is nothing tiny about a pygmy marmoset's tail: it's longer than its body! The tail is not prehensile, but it helps the little monkey keep its balance as it gallops through the treetops. Both male and female pygmy marmosets are orange-brown.

Each hair has stripes of brown and black, called agouti coloring. This coloration gives them good camouflage. A mane of hair covers the pygmy marmoset's ears. Most primates have flat nails on the ends of their fingers, along with opposable thumbs that allow them to grasp objects. Pygmy marmoset fingernails are like claws to help them climb up and down tree trunks. They do not have opposable thumbs. HABITAT AND DIET Pygmy marmosets live in the Amazon region of Brazil, Colombia, Peru, Ecuador, and northern Bolivia. They make their home and living in forest trees or bamboo thickets near or alongside rivers and floodplains. Pygmy marmosets prefer living in dense rain forests where there are lots of hiding places among the plants. Each marmoset group has a small home range of less than half an acre. They feed from just a few trees. Because they are so small, pygmy marmosets can become prey for cats, harpy eagles, hawks, and snakes. That is why they dash from one safe spot to the next.

Their neck is flexible, and they can turn their head backward to spot predators. They are deliberate about their movements to avoid drawing the attention of predators. But when they need to move, pygmy marmosets are fast, leaping several feet to avoid the animals that would like to make a meal out of them. The ability to climb is important for pygmy marmosets, as tree sap is their favorite food. They scamper up and down trees and thick vines headfirst and gouge a hole in the bark or vine with their sharp lower teeth, using an up-and-down sawing motion. When the sap puddles up in the hole, they lap it up with their tongue. Pygmy marmosets have certain trees they like within their territory; they can make up to 1,300 holes in each tree! Sometimes they lie in wait for insects, especially butterflies, which feed at the sap holes. The marmosets also eat some nectar and fruit. At the San Diego Zoo, pygmy marmosets eat veggies, fruit, a specialized commercial diet for New World monkeys, crickets, mealworms, wax worms, and hard-boiled eggs.

FAMILY LIFE Pygmy marmosets live in extended families, called troops, of up to nine monkeys but with an average of five members. Usually the troop has a breeding pair, their babies, and any of their adult children. The parents stay together for life. Living in a group is useful for pygmy marmosets. There are more pairs of eyes to spot predators, and everyone helps take care of the little ones. For added safety, the troop spends the night among thick vines or in a tree hole. A mother pygmy marmoset's gestation period is about 4.5 months, and she can give birth every 5 to 7 months. She almost always has two babies, but in zoos, pygmy marmosets have had three or even four babies in one litter. Each newborn is about the size of a human thumb! The father helps deliver the babies, cleans them up, and then takes over their care. He carries the newborns piggyback style for their first two weeks, bringing them back to the mother to nurse. Older siblings may help, too.

When they are a bit older, the babies hide while the rest of their family looks for food until they are strong enough to travel with the group. Usually the young marmosets are weaned and can follow the troop by three months of age. It takes them about two years to grow as large as the adults. They may leave the troop at this point to start a family of their own, or they may stay to help raise the newest babies. Pygmy marmosets communicate with each other by chattering and trilling in high-pitched voices. They can make sounds so high in pitch that humans can’t hear them. Certain squeaks and calls express danger or other urgent monkey messages. They also make faces to express emotions like contentment, surprise, or fear by moving their lips, eyelids, ears, and the hair around their face. We humans do that, too! These mini monkeys groom one another, and that helps establish social bond. They are fussy about keeping their fur in good shape. Pygmy marmoset families have territories marked by scent. This signals neighboring troops to leave each other alone.

AT THE ZOO Our first pygmy marmosets arrived in 1938 as part of the Hancock Expedition. They produced offspring for several years. Unfortunately, none of the offspring from this pair lived long enough to reproduce. It was not until 1978 that another zoo facility, the Skansen Aquarium in Sweden, had reproductive success. So, members of our staff traveled there in 1990 to learn what we could. Many of the techniques used in Sweden were incorporated into our new pygmy marmoset exhibit. On October 16, 1994, we celebrated the birth of triplets! Happily, all three were healthy and survived their early years. Today, A family group of pygmy marmosets lives in an off-exhibit area of the Zoo we call the “marmosetery.” As the tiny primates can’t eat a lot of food, keepers have to get extra creative with other methods of enrichment. Wood shavings, perfume and spice scents, and mirrors are offered at different times to keep these busy monkeys content. Often, just moving things around in their habitat makes for new interest.

CONSERVATION If the current rate of habitat destruction can be slowed, these tiny monkeys will have a big chance at long-term survival in their forest home. Their largest threat is the pet trade, due to their tiny size, cuddly appearance, and appealing face. We cannot express this enough: monkeys do not make good pets. The United States has banned the import of primates, and most South American countries don't allow primate exports anymore. You can help us bring other primate species back from the brink by supporting the San Diego Zoo Global Wildlife Conservancy . Together we can save and protect wildlife around the globe. LIFE SPAN Environmental Enrichment for Marmosets | Animal Welfare Institute Environmental Enrichment for Marmosets Universities Federation for Animal Welfare The Old School, Brewhouse Hill, Wheathampstead, Herts AL4 8AN INTRODUCTION Marmosets and tamarins are small (250-500 g) South American monkeys of the family Callitrichidae. They are forest living species with squirrel-like locomotion and, unlike typical monkeys, most of the digits have claws instead of nails.

They live in small troops, most members of which are closely related; there is one breeding female and usually several other adult non-breeding females. There is some controversy among field workers as to whether they are monogamous or polyandrous (several males mating one female). The single breeding female has been observed, in the wild, to mate with several males in the troop, but it is not known whether matings with males other than the dominant proved fertile. The natural food of marmosets and tamarins consists of fruits, nectar, shoots and insects, young birds and bird's eggs. The animal protein intake is high. The short tusked marmosets (Callithrix and Cebuella) feed extensively on the gum produced by some species of forest tree which they access by gouging with a scoop formed by the lower incisors and shortened canine teeth. The tamarins (Saguinus and Leontopithecus) do not gouge but may feed opportunistically on gum oozing from wounds on trees. Field studies have shown that callitrichids spend up to 60 per cent of their time actively foraging.

Unlike other monkeys, marmosets give birth to two or more young in a litter. Parental care, which includes carrying, grooming and sharing food with infants, is undertaken by all adult and adolescent members of the troop. The potentiality for using marmosets as breeding animals for biomedical research is well recognised and there are now numerous laboratory breeding colonies. Where the marmoset is a suitable model, its small size and high reproductive capacity have proved valuable assets, and the common marmoset is the only species of monkey used in the laboratory where supply is totally independent of wild caught stock. There are of course some disadvantages to the marmoset, it is monogamous under captive conditions, so that equal numbers of males and females have to be kept in the breeding colony. Although marmosets are rarely capable of rearing more than two young, in over 60 per cent of captive births more than two young are born; in the case of triplets, supplementary feeding or hand rearing may be used to promote the survival of all three young. While triplets are commonest, females have been known to give birth to as many as five infants.

Where there are four or five in a litter, however, they are usually undersized and fail to thrive. In indoor facilities the diet must be supplemented with vitamin D3 or an ultra-violet light source be provided. These facts will probably be familiar but they form an essential background to any discussion of environmental enrichment in marmosets. THE NEED FOR ENVIRONMENTAL ENRICHMENT Many mammals, and probably some of the more intelligent birds, are known to suffer if their environment is too restricted. The evidence that their behavioural needs are not being met is based on the occurrence of abnormal behaviour in the form of inactivity, apathy or stereotyped behaviours such as pacing or running around in circles.6 These symptoms are most pronounced where primates are housed singly and the emotional state of the animal can best be described as boredom. In nature, a marmoset leads a busy and varied life; it is adapted to a complex environment and foraging alone is elaborate and involves the selection of seasonally varying vegetable food items and hunting insect prey. Survival depends on skill and ingenuity and constant vigilance to identify aerial, arboreal and ground predators, which may be mobbed.

Marmosets have a wide repertoire of vocalisations which they use to convey messages both within and between troops. The commonly used metal laboratory cage 0.5 x 0.5 x 0.8 m with a feeding trough and a watering point makes a stark contrast to the natural habitat. Clearly, it is not possible to recreate a tropical forest in a laboratory and yet a bare, small cage is clearly inadequate. First we must specify the aims of environmental enrichment and, secondly, examine the needs of the animal and finally, the means by which improvements can be made. THE AIMS OF ENVIRONMENTAL ENRICHMENT The objective of environmental enrichment is to meet the animal's behavioural needs. It can be shown that these needs have been met if the primate shows a rich behavioural repertoire and there is an absence of abnormal behaviours. The obligation to meet the behavioural needs of non-human primates has been incorporated into legislation in both the European Community ('ethological needs') and the United States ('psychological well-being'). The author prefers the term behavioural needs because it is less ambiguous and more easily understood!

THE BEHAVIOURAL NEEDS OF MARMOSETS The needs to be listed are not peculiar to marmosets and are certainly shared by all higher social primates (see the recent review of environmental enrichment by Chamove1). The need for companions Few marmosets are kept singly in cages because they soon lose condition and, if not socially housed, often die. For special experimental paradigms such as metabolic studies short periods of isolation of no more than 30 days have been used. Where an adult marmoset is unpaired, for example, as a result of an unequal sex ratio, in the Aberystwyth colony we successfully paired individuals of different species together (for example Callithrix jacchus and C. argentata), and found they were tolerant and spent time grooming and sitting together in the manner typical of conspecifics. For breeding purposes, marmosets are normally kept in family groups of 2-8 individuals. Under these conditions they spend much time grooming one another, playing, displaying to other groups and caring for young. They are thus kept quite busy and there is always a social role for the individual.

The only real problem encountered with the social housing of marmosets is the keeping of groups of non-breeding individuals. Same sex individuals kept together may fight and often one individual is bullied and needs to be removed. This problem may be avoided by using a very large cage with complex furniture and plenty of escape routes. Very careful monitoring is essential and this places a great responsibility on the technician in day-to-day charge. It is always possible to keep same-sex twins together so that this can solve the problem of keeping non-breeding individuals in a social environment. If breeding is restricted to individuals from opposite sex twin litters then both breeding and stock situations can be satisfied. From published data7 there does not appear to be a tendency for females to give birth predominantly to either same or opposite sex twins; so that these traits are unlikely to be selected by this system. The need for space and complexity An important point must be made, namely, that usable space from the standpoint of the marmoset, is not synonymous with cage size. Empty space is virtually useless; a metal box with smooth sides is just a floor!

Often one hears the question 'Shall we give them more space?' The question really should be 'If we give them more space what extra things can we provide for them to do in it?' The construction of the cage plays an important part in environmental enrichment for marmosets. Marmosets live in a three dimensional habitat where height is of essential importance and, in accordance with this principle, a number of laboratories are now using a 'sentry box' type of tall cage.5 All monkeys prefer to look down on potential ground predators, of which we humans are one. Another welcome improvement is that a number of commercial laboratories are constructing wooden cages to their own design. Such 'soft' environments are much healthier, for example condensation is reduced, and dimensions are much more flexible. The old metal cages meet the needs of the sterilizer rather than the monkey. In determining the size of a marmoset cage the linear dimensions should allow for the animal to show its natural locomotor repertoire. This involves running, jumping (at least its own body length), pouncing, hanging upside down by the hind legs and rough and tumble and locomotor play. Perching above human eye level is also desirable.

Allowing for a family group of up to eight individuals, the provision of these spatial requirements can be quite inexpensive. The provision of good cage furniture is essential for environmental enrichment. Wooden dowelling, branches of trees, flat perches and feeding sites are standard these days but marmosets also greatly appreciate trapezes, these can be in the form of dowelling suspended on two chains or a vertical dowelling screwed into the centre of a square flat piece of plywood and suspended from the cage ceiling. Such swings are incorporated into locomotor play and their unpredictable responses to being jumped upon encourage the monkey to practise its locomotor skills. Flexible hosing may also be of value in that it simulates a liana in the forest. The mesh walls and ceiling of the cage will also provide both ventilation and footholds for active locomotion. An elevated feeding site should also be provided. The need for an element of unpredictability in the environment One of the problems of confinement is the sameness and predictability of the enclosed environment. This leads to boredom so that an element of unpredictability is of value from the standpoint of marmoset welfare.

It is now accepted by the majority of those concerned with housing non-human primates that a woodchip substrate with food concealed in it is both hygienic and provides the monkey with beneficial opportunities for foraging.2 The interesting fact is that marmosets and other monkeys will actually work to find hidden food when similar food is available in abundance at a feeding point; they seem to gain satisfaction in searching for food scattered unpredictably. This attribute is of great value because it can be used to simulate the 60 per cent of time spent in the wild on foraging, thus increasing natural behaviour. Also it does not interfere with the provision of a balanced diet. Marmosets, like other primates, appreciate a varied and interesting diet offering some degree of choice. Zoos have found that providing food unpredictably in time can also be highly beneficial. Shepherdson9 devised a simple 'mealworm dispenser' which releases mealworms at random. Its design is simple (see Figure 1), consisting of a transparent acrylic tube with holes drilled in it; the tube is filled with mealworms and sawdust and corked at each end. The mealworms from time to time fallout and are found by the predator.

FIGURE 1 A simple mealworm dispenser constructed from clear 5 cm diameter acrylic pipe 50 cm in length. The tube is drilled with ten 0.6 cm holes and filled with 30 meal worms and sawdust; the meal worms take approximately eight hours to dispense themselves into the cage (after Shepherdson et al. 1990). The need to exercise some control over the environment Having established that marmosets like to work, it is hardly surprising that they also like situations where they have some control over their environment. They appear (to quote from the classic work on animal play by Karl Groos3) to 'take pleasure in being a cause' .The most effective techniques are undoubtedly those in which there is likely to be a food reward. Toys alone tend to be ignored once the novelty has worn off. Marmosets like wood to gnaw and gouge they also strip bark off branches, facilities to do this can easily be provided. McGrew4 even invented an 'artificial gum tree'. This was constructed from 50 cm of 4.7 cm diameter hardwood (tamin) dowel.

The dowel was cut into 7 cm lengths and each section was drilled to provide four gum reservoirs of 0.9 cm diameter and a continuous central hole through which a threaded brass rod was passed. A wooden cap sealed the open end of the last reservoir and the whole was secured with wingnuts and washers. The reservoirs were filled with gum arabic and the marmosets had to gouge holes to release the gum. Hanging whole fruits, such as bananas or oranges, in the cage, providing that initially a small piece of rind is stripped off, will enable the marmosets to feed naturally. Another simple device, available from most pet shops for garden birds, is the suspended feeder, which contains peanuts or raisins and can only be reached by hanging from a perch or the ceiling. Such a device can easily be constructed from a hollowed out log with holes slightly larger than a peanut drilled in it. In the Aberystwyth marmoset colony we found that marmosets liked almost empty yoghurt cartons, after eating the contents they would run round the cage with the carton on their heads!

Where it is necessary for a specific reason to keep a marmoset alone in a cage, training apparatus can prove useful.8 Variable schedule lever pressing to obtain food rewards, music or television will all be utilised by the animal. Co-ordination can be put to the test by placing a moving belt with pieces of apple on it immediately in front of the cage. A variable speed motor will provide different requirements of skill on the part of the monkey. In most cases, however, there will be no need to resort to such elaborate technology to provide environmental enrichment for captive marmosets. CONCLUSIONS Marmosets are among the easiest of primates to provide with environmental enrichment. Like other higher primates, they need four conditions: Companionship Adequate space with incorporated complexity Some unpredictability in the environment Ways in which they can manipulate or control their environment To provide these forms of environmental enrichment for marmosets is practicable and inexpensive. Because of their greater spatial requirements it is more difficult and costly to provide a good laboratory environment for larger species such as cynomolgus, rhesus monkeys or baboons. Where they are suitable, therefore, marmosets should be used in the laboratory in preference to larger species of monkey.

References 1. Chamove, A. S. (1989). Environmental enrichment: a review. Animal Technology, 40: 155-178. 2. Chamove, S., Anderson, J. R., Morgan-Jones, S. C. and Jones, S. P. (1982). Deep woodchip litter: Hygiene, feeding and behavioural enhancement in eight primate species. lnt. J. Stud. Anim. Prob. , 3: 308-318. 3. Groos, K. (1898). The Play of Animals. New York, Chapman and Hall. 4. McGrew, W. C., Brennan, J. A., and Russell, J. (1986). An artificial "gum tree" for marmosets (Callithrix j. jacchus). Zoo Biology, 5: 45-50. 5. Plant, M. and Burt, D. (1983). Observations on marmoset breeding at Fisons. Animal Technology, 34: 29-36. 6.

Poole, T. B. (1988). Normal and abnormal behaviour in captive primates. Primate Report, 22: 3-12. 7. Poole, T. B. and Evans, R. G. (1982). Reproduction, infant survival and productivity of a colony of common marmosets (Callithrix jacchus jacchus). Laboratory Animals, 16: 88-97. 8. Scott, L. (1990). Training non-human primates—meeting their behavioural needs. In Animal training. Symposium proceedings. Universities Federation for Animal Welfare: Potters Bar . 9. Shepherdson, D., Brownback, T. and James, A. (1990). Mealworm Dispenser for Meerkats, UFA W & ZSL. Environmental Enrichment Report 2. Universities Federation for Animal Welfare: Potters Bar. First presented at IAT Congress, Lancaster 1990 Reproduced with permission of the Institute of Animal Technology. Published in Animal Technology (1990) Vol. 41, No.2.

Primate Info Net: Common Marmoset: General Information General Information Habitat and Distribution Marmosets and tamarins are found primarily in the tropical rainforests of South America with a few remnant populations located in Central America. The common marmoset is distributed throughout the Atlantic Coastal Forest of northeastern Brazil. Translocated populations of the common marmoset also flourish in the ranges of other Brazilian marmoset and tamarin species, such as around Rio de Janiero, well beyond their native coastal forests. The home range of a marmoset group can vary from 5,000 to 65,000 square meters (1.2-16 acres). On any one day a marmoset group will travel about 500 to 1000 meters. The common marmoset is entirely arboreal (tree dwelling) and prefers secondary or disturbed forests and edge habitat. This species may also be found in coastal and upland scrub forest, gallery forests and even gardens and parks of South American cities, such as Natal and Joao Pessoa. Wherever they are found, their home range will typically include a variety of habitat types.

Although the common marmoset utilizes a mixture of habitats, there are two criteria which usually must be met for the habitat to be appropriate: Enough trees must produce exudates (saps and gums) for food Sufficient hiding places for cover from predators, such as raptors and snakes. Black and gray fur with black fur over head and neck Prominent white ear tufts in adults and juveniles. Infants lack ear tufts and have gray fur over head and neck. Tail has alternating wide dark bands and pale narrow bands. Body size: Adult body length (without tail): 14-19 centimeters Dentition: Specialized lower incisors. These teeth are enlarged and chiseled to enhance the ability to gnaw holes in trees. Short canines Age at maturity: 18 months Age at first reproduction: 17-20 months Gestation: 144 days Number of offspring: usually 2 Seasonal births every 6 months Age infant weaned: 2 months Locomotion: Arboreal Species:jacchus The common marmoset belongs to a family of primates popularly called the Callitrichids.

It is estimated that there are 11 species of marmosets and 16 species of tamarins within the Callitrichid family. However, the exact taxonomic relationships are debated and new species are still being discovered, such as Callithrix mauesi, C. nigriceps, and C. saterei found since 1990 in Brazil. Callitrichids belong to a class of monkeys called New World monkeys, or Platyrrhines. New World monkeys are found exclusively in Central and South America. Fossil evidence indicates that monkeys first appeared in the New World approximately 30 million years ago during a time period called the Oligocene. In addition to marmosets and tamarins, New World monkeys include species such as the squirrel monkey, the spider monkey, the capuchin, the uakari, the owl monkey, and the muriqui monkey. New World monkeys can be distinguished from Old World monkeys and apes and prosimians. The Old World monkeys and apes, or Catarrhines, and the prosimians are found exclusively in Africa and Asia.

Examples of Old World monkey species include the baboons, the macaques, the patas monkey, langurs, proboscis monkey, and the golden snub-nosed monkey . Old World monkeys and New World monkeys share much in common, but there are important differences. Old World monkeys have 32 teeth and most New World monkeys have 36 teeth (but not marmosets which have 32). Most New World monkeys have a prehensile tail. This means that the tail is used as a fifth limb. All New World monkeys are arboreal. Old World monkeys include both arboreal and terrestrial species. The nostrils of the New World monkeys face sideways while those of the Old World monkeys face downwards. Both Old World monkeys and New World monkeys can be distinguished from the apes. Examples of apes include gibbons, gorillas, chimpanzees, and orangutans . Fossil and genetic evidence suggests that apes, particularly the chimpanzee, share the closest relation to humans. The easiest way to distinguish an ape from a monkey is by the tail. Apes do not have a tail, while monkeys do. Prosimians are considered the most primitive group of primates.

Examples of prosimians include the indri, lemurs, tarsiers, sifakas, and lorises . Prosimians have relatively smaller brains and rely more on the sense of smell. Prosimians have structural differences in their skull and reproductive biology. All lemurs and lemur-like prosimians are endemic to Madagascar. Some nocturnal prosimians inhabit parts of Africa and Asia. Callitrichids share much in common with other New World monkeys. However, they also display several traits that set them apart as a group: small body size Fewer teeth (32 vs. 36) because of their small body size and specialized lower dentition because of their diet Claws replace nails on all digits but the big toe Non-identical twins are born rather than one infant Lack of a prehensile tail While Callitrichids share the above traits, they are also a very diverse group of primates, especially in appearance.

Some examples of Callitrichids include the moustached tamarin, the golden-handed tamarin, the emperor tamarin, the bare-faced tamarin, the cotton-top tamarin, the golden lion tamarin, the black tufted-eared marmoset, the common marmoset, the buffy-headed marmoset, and Geoffroyi's tufted-eared marmoset. Diet The common marmoset, like other marmosets and tamarins, relies on a diet of tree exudates (gums and saps), small animal prey, and fruits. Marmosets gain access to exudates from a variety of tree species by gnawing holes in the tree bark. The specialized dentition of the common marmoset acts as a tool facilitating access to gums and saps Examples of animal prey include: grasshoppers, cicadas, crickets, and cockroaches Fruit sources range in size from small to large and tend to be sweet and soft. Dependence on tree exudates is very common among marmosets, but is much less so among tamarins.

Among marmosets, but not among tamarins, exudates often serve as an important food source when others are limited. Group size and composition of the common marmoset varies from group to group in the wild. Once formed, groups are stable. Average group size is 8-10 individuals, but some groups may have up to 15 members. Group composition may include multimale/multifemale, one male/multifemale, or one female/multimale groups. Usually groups contain only one breeding pair. They are the highest ranking male and female. Reproduction is frequently suppressed in other adult females. Several sets of offspring remain in the group. The older twins aid in cooperative rearing by assisting in the raising of younger siblings. Groups may contain 1-2 immigrants Much of our understanding of the unique type of social regulation of reproduction in marmosets is based on work carried out at the Wisconsin Primate Research Center since 1991. Unlike several of their close relatives, the common marmoset is currently not listed as a threatened species. The common marmoset is widespread and common in northeastern Brazil because of its adaptability to different habitats.

Unfortunately, in some areas of its distribution, populations of the common marmoset are showing signs of decline due to habitat destruction. Habitat destruction is the primary cause of extinction or threat of extinction for all animals. Captive studies have taught scientists a great deal about the behavior and biology of the common marmoset. This information has been applied towards the protection as well as the captive and wild breeding of other closely related primates. Roughly 23% of the callitrichids have a threatened conservation status.

Examples include: Black-faced lion tamarin (Leontopithecus caissara): critically endangered Golden lion tamarin (Leontopithecus rosalia): critically endangered Cotton-top tamarin (Saguinus oedipus): endangered Buffy-headed marmoset (Callithrix flaviceps): endangered Buffy tuft-eared marmoset (Callithrix aurita): endangered Geoffroy's tuft-eared marmoset (Callithrix geoffroyi): vulnerable Black-headed marmoset (Callithrix nigriceps): vulnerable An example of how the common marmoset has served as a model to help with the conservation of other primates is its use in the development of the embryo flush at the Wisconsin Primate Research Center in 1996. This is a noninvasive technique designed to assist in breeding of wild and captive primates. Text and design by Kara Lascola. Send questions, comments, and suggestions about this site to Matt Hoffman Primate Factsheets: Pygmy marmoset (Callithrix pygmaea) Taxonomy, Morphology, & Ecology Species: C. pygmaea Subspecies: C. p.

niveiventris, C. p. pygmaea Other names: Cebuella pygmaea; dwergzijdeaapje (Dutch); ouistiti mignon (French); chambira, chichico, leoncillo, micoleãozinho, or titi (Spanish); dvärgmarmosett or dvärgsilkesapa (Swedish) Diagnosis of two subspecies is fairly recent as is the change in genus from Cebuella to Callithrix, therefore some publications simply refer to one species in the genus Cebuella. MORPHOLOGY Photo: Pablo Yépez Pygmy marmosets are the smallest monkeys in the world, weighing a mere 119 g (4.20 oz) on average and measuring, on average, 136 mm (5.35 in) (Soini 1988; Rowe 1996). Males and females are very similar in size, though females are slightly heavier (Soini 1988).

There are few distinguishing morphological differences between the subspecies, which may only differ slightly in ventral pelage color (Groves 2001). They have brownish-gold fur with black ticking on their shoulders, backs, and heads, while their ventral fur is light yellow to white. Infants are born with different pelage than is seen in adults; they are a lemon-yellow color with black ticking over their bodies while the head is a dark grey with yellow fur on and around their ears. By the end of the first month, they lose this coat and resemble adults (Soini 1988). Adult pygmy marmosets have tails that are longer than their bodies and marked with conspicuous black rings. The fur on their faces sweeps back over their forehead and ears and they have two white marks on either side of their mouth and a white, vertical line on their noses (Soini 1988). These facial markings probably serve to enhance perception of facial expression and head movements in visual communication in the diffuse light of dense forests (Soini 1988).

Though they exhibit squirrel-like patterns of locomotion, including quadrupedally running up and down tree trunks, vertically clinging to tree trunks as they feed on sap, and branch and vine-running on both the top and underside surfaces of horizontal substrates, they are not more closely related to squirrels than other primates (Kinzey 1997). Their small body size allows them to use very slender supports but does not inhibit their locomotion; pygmy marmosets can leap up to five meters (Rowe 1996; Kinzey 1997). They are also able to turn their heads 180 degrees, an adaptation which allows them to scan the environment for predators while vertically clinging to a tree (Kinzey 1997). Pygmy marmosets are able to support their weight on the tips of their long, sharp, claw-like nails (called tegulae) which are different from the flat nails (called ungulae) seen in other primates, including humans, and are probably an adaptation to a life spent clinging to trees (Kinzey 1997; Sussman 2000).

An additional characteristic that aids in their exudate -eating behavior is the shape of their lower incisors. They are narrow and elongated such that the five teeth in the front and center of the lower jaw are all the same length. This helps them gnaw into trees efficiently and stimulate sap flow (Sussman 2000). They also have an enlarged cecum, a part of the digestive tract which allows extended time for the breakdown of plant gums (Sussman 2000). Another unusual characteristic seen in pygmy marmosets and other callitrichines is the pattern of giving birth to non-identical twins more frequently than singletons (Soini 1988). RANGE Callithrix pygmaea Found in Peru, Ecuador, Colombia, Bolivia, and Brazil, pygmy marmosets range over a large area and the subspecies are isolated by geographic barriers which include several large rivers. The northern subspecies, C. p. pygmaea, is found in the state of Amazonas, Brazil, southern Colombia, northern Bolivia, northeastern Ecuador, and eastern Peru (van Roosmalen 1997; Yépez et al.

2005). Its range is bound by the Rio Solimões and Rio Caquetá. C. p. niveiventris is found in eastern Peru and Amazonas, Brazil south of the Rio Solimões and north of the Rio Purus. It extends as far east as the Rio Madeira and is bound in the west by the Andes (van Roosmalen 1997; Groves 2001). Given their tiny body size and the type of forests in which they are found, wild pygmy marmosets have been poorly studied and there is a lack of detailed behavioral and ecological data (Soini 1982; Heymann &Soini 1999). Many short-term field studies were carried out in the late 1960s and early 1970s, but the first long-term field study of pygmy marmosets occurred in the mid-1970s to 1980s by Pekka Soini. His findings dramatically increased knowledge about pygmy marmoset social behavior and ecology (Kinzey 1997).

Additionally, pygmy marmosets have been studied in captivity at the Anthropological Institutes of Zurich University in Switzerland and at the Wisconsin National Primate Research Center, adding to the knowledge of reproductive parameters, development, behavior patterns, and communication (Soini 1988). HABITAT Pygmy marmosets occupy mature evergreen forests in and at the edges of periodically inundated river floodplains. They are habitat specialists that prefer areas with no more than two or three meters of standing water for more than three months out of the year and are found in highest densities in river-edge forests (Soini 1988). If they are found in highland areas, it is usually along small, seasonal forest streams that are subjected to frequent, minor flooding (Soini 1988). They utilize vertical strata of the forest from ground level up to 20 m (65.6 ft) and rarely venture into the highest level of the canopy. The understory is composed of reeds, tall grasses, and a few herbaceous plants, vines, shrubs, and saplings. There are also dense thickets formed by bamboo reeds, shrubs, and vines.

The tallest trees in this area often have crown heights between 30 and 40 m (98.4 and 131 ft) which support hanging vines and epiphytes (Soini 1982). Data on rainfall and temperature have been reported for a study site in Peru in the Rio Maniti basin where the rainy season lasts from October to May and the dry season lasts from June to September (Soini 1982; Soini 1986). The highest amount of rain falls in March, with levels reaching more than 340 mm (1.12 ft). During the driest part of the year, only about 150 mm (5.9 in) of rain falls per month. Temperatures remain fairly constant throughout the year, hovering around 27° C (80° F) and 80% humidity (Soini 1982). In Ecuador at the Cuyabeno Faunal Production Reserve, average monthly rainfall from March to August exceeds 250 mm (9.84 in) with considerably drier periods during September through February.

Average temperatures fluctuate between 22 and 29° C (71 to 84° F) with the rainy season seeing warmer temperatures (de la Torre &Snowdon 2002). Rivers begin to rise in the beginning of the dry season such that between February and June, the floodplain becomes inundated. During this time, there is an abundance of fruits, but as the floodplain dries out during the dry season, fruits also become noticeably scarce (Soini 1986). ECOLOGY Characteristics such as elongated, sharp incisors and claw-like nails are adaptations to the very specific diet of the pygmy marmoset -- gums and other exudates . They are exudativore - insectivores and spend the majority of their time gouging holes into trees or vines with their sharp lower teeth and then eating the gum, sap, resin, or latex that is exuded (Soini 1988). Holes are generally ten to 20 mm (.787 in) wide, four to 18 mm (.157 to .709 in) deep, and nearly perfectly circular.

The "oldest" holes on a tree are closer to the ground and they get "newer" farther up the tree, indicating a pattern of usage (Ramirez et al. 1977). Insects make up the other important part of the diet, and grasshoppers are especially coveted. Pygmy marmosets forage in the crown foliage of trees at about five to 15 m off the ground, looking in vine-tangles and shrubby vegetation for spiders, orthopterans , butterflies, moths, beetles, and ants (Soini 1988). While 60 to 80% of their total feeding time is spent on exudates, they spend between 12 and 16% on insects, and supplement their diet with fruits, buds, flowers, nectars, and very occasionally small lizards (Soini 1988; Yépez et al. 2005). Photo: Luiz Claudio Marigo Pygmy marmosets use sleeping sites, or roosts, each night and their day starts shortly after sunrise when all members of the group leave the sleeping site.

Sleeping sites are generally made of dense tangles of vines or, on rare occasion, tree holes. Each group has two or three sleeping sites but only use one on a regular basis (Soini 1988; Sussman 2000). In heavy rain or dark, overcast mornings, pygmy marmosets take up to an hour longer to leave the sleeping site. Once it has left the roost, the group travels directly to their primary exudate tree where the marmosets feed for 30 to 90 minutes on gum that has been exuded during the night (Soini 1988). After this feeding bout, there is a shift in activity to more social activities such as huddling, grooming, and playing. After this brief period of rest from foraging, the group begins to focus on insect foraging and exudate foraging until midday when rest and social behavior become the predominant activities. Intense feeding activities begin again in late afternoon until the group travels back to the roost for the night (Ramirez et al. 1977; Soini 1988).

The two peaks of exudate feeding occur between 6:00 and 9:00 a.m. and again between 3:00 and 6:00 p.m. (Yépez et al. 2005). Activities are not always coordinated between all group members; some may be foraging for insects while others are feeding on exudates nearby (Soini 1988). A pygmy marmoset group, ranging in size from two to nine individuals, utilizes a primary exudate tree in its home range until the exudate yield declines at which point they gradually move to a new area, if one is available, in the vicinity of the old home range (Ramirez et al. 1977; Soini 1988). Groups of pygmy marmosets exchange home ranges as one group leaves an area and allows an exudate tree to recover, approximately every few months. When an area remains unoccupied long enough for a tree to begin producing gum in large amounts again, it is a potential new home range for a different group (Soini 1988).

Densities of pygmy marmosets are quite high in riverine forests and are up to 233 individuals per km² (90.0 per mi²). Removed from a river's edge, pygmy marmosets are found in densities closer 50 or 60 individuals per km² (19.3 or 23.2 per mi²) (Soini 1988). With such high densities, home ranges for each group are very small, averaging .003 km² (.001 mi²) but less than .005 km² (.002 mi²), and the horizontal day range within these home ranges about 300 m (.186 mi), but they may travel much farther when considering vertical movement within their home range (Soini 1988). Home ranges of neighboring groups do not overlap and there are few, if any, interactions between groups (Soini 1982).

Other primates that are found in the habitats occupied by pygmy marmosets include Saguinus fuscicollis (saddleback tamarin), Saguinus mystax (mustached tamarin), Saguinus nigricollis (black-mantle tamarin), Saguinus tripartitus (golden-mantle saddle-back tamarin), Callicebus torquatus (collared titi monkey), Callicebus moloch (dusky titi monkey), Saimiri sciureus (squirrel monkey), and Aotus (owl monkey species) (Soini 1988; Yépez et al. 2005). Saddleback and mustached tamarins sometimes feed from holes gouged by pygmy marmosets and have been seen aggressively chasing the smaller primates from the tree in order to feed. Interactions with other sympatric primates are uneventful (Soini 1988). Exudate holes are also subject to predation by ants, which move in at night when the pygmy marmosets are not feeding and carry away solidified exudate.

Excessive predation by ants forces marmosets to abandon a feeding site (Soini 1988). Because of their extremely small body size, pygmy marmosets are subject to predation by raptors , small felids , and climbing snakes. In some cases, they exhibit mobbing behavior in which the entire group flocks to an intruder, loudly vocalizing and attacking the intruder until it retreats; other times, they remain frozen until the threat has passed (Soini 1988; Kinzey 1997). Content last modified: June 30, 2005 Written by Kristina Cawthon Lang . Reviewed by Stella de la Torre . Cite this page as: Cawthon Lang KA. 2005 June 30. Primate Factsheets: Pygmy marmoset (Callithrix pygmaea) Taxonomy, Morphology, & Ecology . < Accessed 2017 January 17. Common Marmoset Common Marmoset Extinct About Us The common marmoset is one of the most commonly found callithrichid species kept in captivity.

It is also one of the smallest species of monkey. Their name ‘marmoset’ comes from the French word ‘marmouset’ meaning ‘dwarf’, or ‘little’. Here at Woburn, the group of marmosets have a brand new enclosure called Marmotopia, with viewing platforms and outdoor enrichment, and they can often be seen showing off their acrobatic skills on the hanging rope! Share your discovery Scrub forests and edges of rainforests Height 12 years in the wild, up to 16 years in captivity Threats Habitat destruction Physical Features The common marmoset has a body greyish brown in colour with light striping. The tail is over twice the length of the body, with distinct grey and white rings. The main features of the head are the large white tufts of fur around the ears, and white patch above the eyes, with the rest of the head grey in colour. The head features a set of sharp teeth, specifically used to gnaw the bark of tree’s to produce the sap and gum which they feed on. The lower incisors the same size as their canines to allow them to chew through the bark.

Like all marmoset and tamarin species they have claw like nails, known as tegulae, on their fingers, and nails on their thumbs. This allows them to grip the bark of trees when climbing. Unlike a lot of primates they do not have opposable thumbs. They have well developed scent glands, allowing them to mark territory and communicate via scent. Male marmosets are dichromatic, or colour blind, making reds, greens, browns, and oranges all appear similar. The female can be dichromatic, but most are trichromatic, seeing colour the same way as most humans. Diet The common marmoset is an exudativore and insectivore. This means that their diet consists mainly of exudates, material that oozes out of a plant such as gum, sap, resin, and latex, and also insects. They spend around 20 to 70% of their time feeding on exudates, and around 20 to 30% feeding on insects. Their diet consists of these foods much more than any other marmoset or tamarin species, which means there is little competition for food.

The teeth of the common marmoset are specially adapted to this diet, with lower incisors the same size as their canines to allow them to chew the bark of trees to release exudates. Their diet does also include fruit, seeds, flowers, fungi, nectar, snails, lizards, tree frogs, bird eggs, nestlings, and infant mammals. They rely on good vision to find food, but also on their sense of smell to detect ripe and unripe fruit. Social Structure and Communication Common marmosets live in extended family groups of between three to twelve animals. This family group usually consists of one adult breeding pair and their offspring, but can also include two breeding males. The dominant adults will be the only members of the group to produce young; however the rest of the group will all help take care of the young. The group will forage for food together and sleep together, always with a sentry watching for predators. The group will have a small territory of around five hectares which they defend; they will forage for food within this territory and use scent marking to define the borders. This territory is chosen based on the quantity of gum trees, with an average of no less than 50 gum trees per hectare.

Within the territory are set sleeping trees, usually thick with vines and foliage for protection, which are used to sleep in regularly. The group communicates with a range of calls, some of these calls are too high pitched for the human ear to hear as marmosets can hear higher frequencies than humans. Scent is used to mark out territories, and to communicate, with each marking giving detailed information about the identity of the marker. Breeding It was originally thought that marmoset groups would only have one breeding male and female, due to this happening in captivity, however recent studies have found that wild marmosets will more commonly have a group with one breeding female, mating with two males. The female will mate equally with both males. This is thought to happen to secure more parental care for the infants. After a period of about 144 days the female will give birth to up to four young, although most commonly twins or triplets. Twins will typically weigh 40% of the mother’s body weight. They will be carried on the backs of both the mother, and the rest of the group, until they become independent, and then are weaned at around 40 to 120 days.

Adults will become sexually mature at around 18 to 24 months. Husbandry and Enrichment In the wild the common marmoset would have a large territory, or up to 5 hectares. To simulate this, our group of marmosets have the freedom to roam around the park. They have a central house, which they tend to spend most time nearly, but they will roam around the surrounding trees and nearby buildings. In the wild marmosets will gnaw the bark of trees to release the gum and sap from them. We feed our marmosets a specialist diet, which contains a special marmoset gum, that we feed to them in special feeding logs with holes cut into them to simulate their natural feeding behaviour. They still have the opportunity to perform their natural bark chewing behaviours on the surrounding trees, which they do very evidently, leaving gnaw holes visible on most of the trees around their house. Threats and Conservation Natural predators include a wide range of species. Due to their small size marmosets are vulnerable to predation from snakes, owls, raptors, cat species, and other carnivores.

They do have specialised alarm calls for each type of predator, and will mob some predators to deter them. The population of common marmosets is currently stable, with numbers decreasing slightly due to deforestation, and some capture for the pet trade, but not enough to classify them as a cause for concern. There have been many introduced groups of common marmoset into other regions, flourishing, and sometimes displacing other native marmoset species. Within the common marmosets native range there are twenty national parks and areas of protection, as well as one more within their introduced range. They are one of the most commonly bred species in captivity, in zoos worldwide, but also for the pet trade, and for medical testing. They are listed as appendix II of CITES, which means the trade and export of this species is heavily regulated and controlled to protect them. Fun Facts They are also referred to as the ‘White Tufted marmoset’ due to the large white tufts of fur around their ears! Marmosets will make special calls for different types of predators, to warn others. They may also mob a predator, attacking it as a group and making loud noises to scare it off!

All male common marmosets are colour blind, confusing reds, greens, browns, and oranges. The females can be colour blind too, but most females will see colour the same as a human does! Get all the latest Safari news direct to your inbox Email address... Pygmy marmoset Facts Pygmy marmoset Facts Pygmy marmoset Facts Pygmy marmoset is a type of primate that is best known as the smallest monkey in the world. It can be found in Brazil, Peru, Columbia and Ecuador. Pygmy marmosets live in dense, tropical rainforests, lowland forests and areas that are flooded for more than three months during the year. Number of pygmy marmosets in the wild is still stable. Luckily, these animals are not severely affected by habitat loss (which is the major threat for most animals). Other than habitat loss, normal behavior of pygmy marmosets in the wild is disturbed by tourist expeditions. Pet trade is another factor that affects number of pygmy marmosets.

Interesting Pygmy marmoset Facts: Pygmy marmosets are tiny animals that can fit into human palm. Females are slightly larger than males. On average, pygmy marmoset reaches between 4.75 and 6 inches in length and weight between 3.53 and 4 ounces. Body of pygmy marmoset is covered with dense fur that can be grayish, tawny or brownish-gold in color. Tail of pygmy marmoset is longer than the body. It is covered with black rings. Unlike other primates, pygmy marmosets have claws instead of nails. Their claws provide strong grip that is required for moving in the treetops. Pygmy marmoset is able to leap 15 feet into the air. Another interesting feature is ability to rotate its head for 180 degrees. Pygmy marmosets use their lower canines to drill the bark and induce leakage of the sap. This sticky liquid is favorite food of pygmy marmosets. Pygmy marmosets eat both plant and animal-based food (omnivores).

They eat different type of fruit, nectar, leaves and small invertebrates (such as insects). Pygmy marmosets are quiet animals. They sometimes produce clicking sounds in communication and high-pitched whistle as a warning of the upcoming danger. Pygmy marmosets are diurnal animals (active during the day). They spend most of their lifetime in trees, where they can find food and hide from the predators. Main predators of pygmy marmosets are pit vipers, tayra and cats such as jaguarundi, ocelot, margay and oncilla. Pygmy marmosets live in small groups, known as troops, composed of up to 15 animals. Troop consists of breading couple and their offspring. Pygmy marmosets are territorial animals. Average size of territory is 25 to 100 acres. Troop will defend its territory against other pygmy marmosets. Pygmy marmosets are monogamous, which means that male and female mate for a lifetime. Pygmy marmosets reach sexual maturity at the age of 1 or 1.5 year.

Each couple of pygmy marmosets has two litters per year. Pregnancy lasts 119 to 140 days and ends with two babies (rarely one or three). They will spend first two months of their life on the father's back. Mother is responsible for feeding and cleaning of youngsters. Pygmy marmosets live 10 to 12 years in the wild and up to 16 years in captivity. Related Links: Pygmy marmoset | San Diego Zoo - Kids San Diego Zoo Brazil, Colombia, Peru, Ecuador, and northern Bolivia Habitat: Tropical forests and along rivers Food: Tree sap, fruit, nectar, and insects Size: 4- to 6-inch-long body; tail measures 6 to 9 inches long. Babies: Usually 2 but sometimes 4 babies—about the size of a human thumb at birth! Pygmy marmosets have a super-flexible neck and can turn their head backward to watch for predators. Mini Monkeys Pygmy marmosets are the smallest type of monkey—one would fit in a grown-up human’s hand!

Because they are so tiny, pygmy marmosets can become preyNoun: An animal that is hunted as food by another animal. Verb: To attempt to take an animal for food. for wild cats, harpy eagles, hawks, and snakes. These marmosets live in dense rain forests where there are lots of hiding places. Quick and clever, they dash from one safe spot to the next. Pygmy marmosets do a lot of climbing because tree sap is their favorite food. They cling to the side of a tree trunk and bite a hole in the bark. When the tree sap oozes out, they lap it up with their tongue. The sap also attracts insects that the marmosets eat, too. These mini monkeys communicate by chattering and trilling in high-pitched voices. They also make faces to show surprise, fear, or just feeling fine. Because they are so small and cute, people often want to have one at home, even though monkeys do not make good pets. They are messy eaters, and they bite when scared, angry, or frustrated. And nothing in your home would be safe when a small but mighty marmoset starts monkeying around!

6 animals with pets of their own | MNN - Mother Nature Network MNN.com > Earth Matters > Animals 6 animals with pets of their own From a gorilla who loves cats to an elephant with its own dog, check out these astonishing stories of interspecies affection. Photo: Shutterstock For many of us, pets aren't just casual companions. They are cherished members of the family. (Sometimes it even feels like we're the pets, and our pets are the masters.) So it’s worth asking: Are humans the only animals that keep pets? Or do other animals also keep pets and form deep companionships with other species? The answer might surprise you. Not only do some animals display a great capacity to look after and bond with a member of another species, they also appear to form these bonds for no reason other than companionship. To prove it, here's our list of animals with pets of their own. Koko the gorilla and her cats Koko the gorilla is best known for being a sign-language speaking ape, believed by her handlers to know more than 1,000 signs. But perhaps her most humanizing characteristic has been the love and affection she has demonstrated toward her pet cats.

Koko was first allowed a pet cat in 1985 after she requested one for her birthday. She was even allowed to choose a kitten from a litter; a gray male Manx that she named "All Ball." Koko's gentle care and affection for All Ball was astounding to those on the outside who had never seen another animal treat another species as a pet before, but to Koko's handlers, who knew her well, it wasn't surprising at all. Tragically, later that same year All Ball was struck by a car and killed while exploring the world outside of Koko's enclosure. Koko's mourning process after being told of the cat's death showed just how deep her emotional bond to the cat was. The following year, Koko was given two kittens. She named them "Lipstick" and "Smokey." Tarra the elephant and her pet dog Bella The Elephant Sanctuary in Tennessee has been home to one of nature's most unexpected odd couples: Tarra the elephant and her pet dog, Bella. The two first bonded several years ago when a stray dog wandered onto the sanctuary's property. Rather than scare off the intruder, one elephant in particular, Tarra, immediately welcomed the stray with open arms.

Before long, the two became inseparable. In fact, Tarra seemed to spend more time with Bella than she did with other elephants. The bond became especially apparent when Bella suffered a spinal cord injury and lost the use of her legs. Caretakers took her indoors to receive medical assistance. For three weeks Bella was bed-bound, and for the entire three weeks Tarra stood just outside the building holding vigil, refusing to leave Bella's side. When the two were finally reunited, their embrace made it clear to everyone involved just how special their bond was. (Watch this video about Tarra and Bella and judge for yourself.) It goes to show that even a giant animal like an elephant can have a gentle heart. Amy the deer and her pet dog Amy the deer and Random the dog met at an animal rehabilitation center in Oklahoma. (Photo: PBS) This PBS report about animal odd couples showcases many touching stories of animal bonds that cross the species barrier, but perhaps none are as astounding as the story of Amy the deer and her pet dog, Ransom. The tale takes place at an animal rehabilitation center in Oklahoma, Wild Heart Ranch, which cares for thousands of animals every year.

Though many of the animals at Wild Heart are released back into the wild, Amy is a permanent resident since she is a non-native species to the region. She's a welcome resident, however, because of her strong mothering instinct, as she assists in raising many of the orphaned deer that the ranch takes in. But her mothering skills go beyond other deer. When the ranch took in Ransom, a golden retriever born blind, Amy immediately took to raising him as well. She regularly grooms the dog, plays with him and has demonstrated remarkable patience and compassion in helping Ransom adapt to a world he cannot see. Meanwhile, Ransom is bonded to Amy in a way indistinguishable from the way a dog bonds to its human companions. It's truly a touching and inspiring story! Capuchins and their pet marmosets A family of capuchin monkeys adopted a marmoset and treat it as one of the family. (Photo: Jeanne Shirley) This remarkable story has even gotten the attention of those who are skeptical of reports about animals and their pets. A group of capuchin monkeys in Brazil have been witnessed adopting and caring for a baby marmoset , another type of monkey entirely.

The baby marmoset was raised as a regular member of the capuchin family, though the capuchins seemed to understand that the marmoset (named Fortunata) was not a member of their own species. For instance, when they played together, the capuchins treated the marmoset gently, as if they comprehended that she was more delicate than members of their own species. This case of animals keeping pets is particularly astute because it occurred among animals that were all living in the wild. Also, the marmoset that was kept as a pet was not a human-domesticated animal. A crow and its pet cat This remarkable story of a crow that raised a pet kitten shows that its not just mammals that can keep pets. (You may have to see the video for yourself to believe it.) According to the report, the kitten was a stray that probably couldn't have cared for itself without assistance. But the only assistance it could have received was from a mysterious crow that never left the kitten's side. Before long, local witnesses got their proof: the crow was seen regularly feeding the cat with worms and other prey that it had collected.

The two animals would often play together innocently, and the crow would protect its pet from dangers (it would even squawk so that the kitten wouldn't wander into the road). It's a remarkable story that shows how other animals can display a compassion and bond toward other species in a way that many researchers never believed possible before. Tonda the orangutan and her pet cat Koko isn't the only great ape that has shown the capacity to care for a pet. Tonda, an orangutan that lived at ZooWorld in Florida, took in a stray cat named T.K. (for "Tonda's kitten"), and kept it as a pet and companion animal. The bond between the two was particularly special because T.K. was a true stray that had to be fostered gently by Tonda over time before the cat opened up to the concept. Meanwhile, zookeepers credit Tonda's relationship with the cat as reason why the orangutan was able to live to such an old age. The bond between ape and cat was also noteworthy as a contrast to Koko's relationship with her cats because Tonda was not taught to sign. So it goes to prove that the bond between pet and pet owner runs deeper than what can be communicated through language. Related on MNN:

Question: A marmoset is what type of animal?
Answer: Monkey