The highest survival rate of infants Interestingly, the average group size in the wild is about nine members. Immediately after birth, the breeding male and presumptive father of the infants begins to carry the twins and caregiving by offered by the father, mother, or other members of the group Yamamoto Interaction with other group members besides parents is emphasized and play becomes rougher as future status is worked out.
During the juvenile period, another set of infants is usually born and carrying and play with infants also characterizes this period of development Yamamato Between nine and 14 months, the sub-adult stage begins, characterized by the full repertoire of adult behaviors as well as puberty.
By 15 months, common marmosets have reached their adult weight and are capable of reproduction but do not reproduce until social conditions are adequate Yamamato Like all primates, vocal and visual communication is important to common marmosets. Because of their small size and the natural habitats they are found in, visual signals are important in close-range communication while vocal communication is more important over longer distances Jones Common marmosets use vocal signals in a variety of situations including in response to unexpected movements and in threatening situations Jones Alarm calls are brief, high-pitched vocalizations that elicit fleeing behavior from other group members and are given in response to threatening situations Lazaro-Perea They are usually given in a series of one to five notes that last about two seconds each.
They are important for long-range vocal contact and play a role in mate attraction, maintenance of group cohesion, territorial defense, and location of lost group members Jones These calls are given by all animals of any age, sex, and status and their main purpose probably is to monitor group members by identifying and locating their position in low visibility areas Jones Unlike the apes and Old World monkeys , smell is very important to New World monkeys.
They have a specialized organ in their nasal cavity called the vomeronasal organ that allows them to process chemical signals in a focused manner and discern information about other animals Evans Primate Factsheets: Common marmoset Callithrix jacchus Behavior.
The common marmoset is abundant. Though they are not currently threatened in any parts of their range, common marmosets are losing habitat at an alarming rate, and land-use policy should reflect the need to protect these animals before they meet the fate of so many of their primate cousins. Unfortunately, the Brazilian cerrado region has suffered from conservation efforts focused on the rainforests of the Amazon in recent decades. As large-scale agribusiness ventures were driven out of the rainforest, the prospect of cheap land in the cerrado region coupled with technological improvements in farming and agriculture facilitated large scale conversion of this biome to cropland.
While marmosets are not currently threatened, a major part of their habitat is disappearing and it is unknown how populations will react if they must live in increasingly smaller patches of habitat, regardless of how well they succeed in edge habitats. Common marmosets are susceptible to a number of parasites and pathogens , but none threaten their abundance. Some parasites that are problematic include lice, flies, and ticks, which can spread zoonotic diseases as they move between hosts, as well as acari, arthropods that parasitize the skin and hair follicles and lead to sarcoptic mange, a disease of the skin that causes lesions, hair loss, anorexia, and extreme weight loss Rylands et al.
Some pathogens that wild common marmosets are susceptible to include toxoplasmosis, herpesviruses, hepatitis, Salmonella , Shigella , Escheria coli , Streptococchus , Staphylococcus , Pnuemococchus , leptospirosis, and multiple fungal diseases Rylands et al.
Though these diseases are potentially life-threatening to individual animals or may affect a group of common marmosets, they are not a direct threat to the survival of the species at this time. Attractive as pets in South and Central America, common marmosets are often captured and sold in the pet trade Rylands et al.
Once taken as pets, marmosets and other primates suffer from poor diet, exposure to foreign diseases, and inadequate husbandry.
It is unknown how many common marmosets are kept as pets in private homes. Common marmosets are also subject to forest fires in parts of their range.
The use of common marmosets in biomedical research has been prevalent in the United States and abroad since the s. Because of their susceptibility to a large number of viral infections, taxonomical closeness to humans, large wild populations that could be harvested without threat, high reproductive rate, and small body size, marmosets were considered good candidates for captive studies and their use exploded in studies of teratology , periodontal disease, and reproduction Rylands Export bans in Brazil necessitated the establishment of self-sustaining colonies in the early s, and no common marmosets have been taken from the wild for use in biomedical research since Vigorous research on their behavior, husbandry, health, and breeding has helped maintain large captive populations in federally funded National Primate Research Centers, academic institutions, pharmaceutical companies, and commercial breeding facilities in the US and Europe Rylands In Europe, common marmosets are even more widely used in research than in the US and are the most frequently used non-human primate in research laboratories Abbott et al.
Other areas of research in which marmoset models are indispensable include immunology, endocrinology , obesity, and aging Abbott et al. Primate Factsheets: Common marmoset Callithrix jacchus Conservation. The following references were used in the writing of this factsheet. To find current references for Callithrix jacchus , search PrimateLit. Abbott DH. Behavioral and physiological suppression of fertility in subordinate marmoset monkeys.
Am J Primatol 6: Aspects of common marmoset basic biology and life history important for biomedical research. Compar Med 53 4 : Behavioral and hormonal analysis of social relationships between oldest females in a wild monogamous group of common marmosets Callithrix jacchus. Int J Primatol 22 4 : Two breeding females within free-living groups may not always indicate polygyny: alternative subordinate female strategies in common marmosets Callithrix jacchus.
Folia Primatol 76 1 : Social determinants of reproductive failure in male common marmosets housed with their natal family. Anim Behav 58 3 : Biodiversity and conservation priorities in the cerrado region. The cerrados of Brazil: ecology and natural history of a neotropical savanna.
New York: Columbia Univ Pr. Ecosystem structure in the Brazilian cerrado: a vegetation gradient of aboveground biomass, root mass and consumption by fire. J Trop Ecol When will the stork arrive? Patterns of birth seasonality in neotropical primates. Am J Primatol Dietz JM. Kinship structure and reproductive skew in cooperatively breeding primates.
Kinship and behavior in primates. Oxford England : Oxford Univ Pr. Digby LJ. Social organization in a wild population of Callithrix jacchus : II, Intragroup social behavior.
Primates 36 3 : Sexual behavior and extragroup copulations in a wild population of common marmosets Callthrix jacchus. Folia Primatol Social organization in a wild population of Callithrix jacchus : I, Group competition and dynamics. Digby L, Barreto CE. Vertebrate predation in common marmosets. Neotropical primates 6 4 : Duarte-Quiroga A, Estrada A. Primates as pets in Mexico City: an assessment of the species involved, source of origin, and general aspects of treatment.
Eiten G. An outline of the vegetation of South America. Proceedings from the symposia of the fifth congress of the International Primatological Society; Aug ; Nagoya, Japan. Researchers described using a transport box high up in the cage to first attract the animals into a gauntlet through which they can be transported out of the cage.
Then, handlers lift the marmoset onto a pipe of appropriate diameter, where the animal is secured with Velcro at the waist and legs. Blood samples are taken alternately from the femoral veins in the left or right leg and then the animals are rewarded with a small treat. One researcher noted the possibility of displaying videos to keep the marmoset distracted during the blood draw.
Between comprehensive health exams and research procedures, daily observations are important to monitoring marmoset health and well-being and rapid identification of any problems. Any abnormalities observed during these regular checks should be recorded in a standardized way, either on paper or electronically, to ensure correct animal identification and available notes for veterinarian review.
Facilities use a variety of methods for identifying individual animals. Permanent measures like tattoos and subcutaneous microchips, or more temporary markers such as ear dye or shaving fur, are options for identifying young marmosets. For fully grown animals, neck tags can be used. When new animals are added to a colony, they are commonly quarantined for 1—3 months to monitor their health and avoid the introduction of disease.
During this period, many facilities test for tuberculosis, a particular concern for marmosets. Quarantining is also crucial for avoiding the spread of measles, bacterial pathogens like Klebsiella , and intestinal parasites. To reduce the burden on veterinary staff, some facilities use video monitoring to track the health of animals suspected of having an infectious disease or other health problems. However, when done effectively this still requires a great deal of staff time because the video must be actively monitored.
For routine care and especially for research procedures such as imaging, several researchers recommended the use of a small, prepared box of emergency medical supplies. If opioids are used, it is important to have naloxone. To reverse significant respiratory depression, one researcher reported success poking the GB26 acupuncture point with a or gauge needle to reinstate regular breathing. Most facilities house marmosets in traditional indoor enclosures while some facilities, like BPRC in the Netherlands, provide large, outdoor enclosures with access to sunlight and limited or no use of chemical cleaning products.
While these conditions offer many benefits, they also introduce variables that make it hard to compare research results across facilities, such as increased vitamin D levels from access to sunlight or increased cortisol level from the stress of capture in a larger space. Although recommendations exist to standardize housing practices, many of the standards have minimum but not maximum requirements.
Such discrepancies underscore the need to communicate protocols between facilities and harmonize practices where feasible. Harmonization of diet and nutritional guidelines is equally important. In an investigation of how changes in diet can affect susceptibility to EAE, twin marmosets were given diets supplemented with either yogurt or water.
Animals consuming yogurt had less MS-like demyelination of the spinal cord and a smaller pro-inflammatory immune response i.
The yogurt diet was also related to a decreased likelihood of developing EAE as well as increased levels of Bifidobacteria in the gut microbiota Kap et al. These findings emphasize the potential impact of diet on research outcomes and the need for communication about feeding practices among facilities.
Furthermore, factors such as age, bedding, cleaning procedures, gut microbiome, catching, fixation, and sedation need to be taken into consideration, particularly when studying the immune system or related diseases.
For example, a study comparing the effects of chlorine-based disinfectants on captive marmosets found that their use resulted in elevated levels of chromosomal disorders Delimitreva et al. Despite their impact on research outcomes, these factors are not harmonized or standardized across facilities or laboratories.
With regard to animal health, mortality rates, biomarkers like glucose levels, and the subclinical and transient presence of Klebsiella pneumonia differ across research colonies.
It may also be the case that different colonies show different patterns of aging. It would also be helpful to have more evidence regarding the use of different glucose tests and assessment tools for other biomarkers in marmosets. Comparing notes on health issues between colonies can help colony managers stay abreast of the evidence and proactively monitor for early signs of health problems. Michael Power , an animal scientist at the Smithsonian Conservation Biology Institute, presented on several nutrition-related challenges in marmoset care, including not well-established nutrient requirements; variation in diets between colonies and dietary husbandry informed by practice or anecdotes; the role of vitamin D; factors contributing to marmoset wasting syndrome and metabolic bone disease; and obesity in captive marmosets.
He provided a few standard references regarding NHP and marmoset diets: the NRC publication is focused on NHP nutritional requirements, but few facts are marmoset-specific; Chapter 10 Power et al. Such a diet does not require gluten. Gluten sensitivity may be present in subsets of marmosets, but previous experience providing gluten-free diets does not support removing gluten as an effective way to prevent vitamin D deficiency and other digestive difficulties.
In the same context, food is not a good enrichment item unless it is used in creative ways e. As noted during discussion sessions, researchers have experimented with different types of treats for training and rewards. Some use mini marshmallows, others use drops of Ensure or sugar water, and others use gum. To enhance the evidence base for dietary guidelines, it will be important for researchers to share information openly and in detail, reporting not only what foods were offered but a full nutrient profile breakdown of each food, detailing what was offered versus what was consumed, and indicating whether the choice of food varies depending on the time of day or other factors.
It also would be helpful to report and compare levels of nutritional components such as vitamin D in the blood, as these data could affect research results and comparisons across laboratories. Although recommendations for nutrient requirements for healthy marmosets exist, experimental testing has exposed some unexpected results. For example, digestibility of vitamin D tends to be unusual in marmosets. When examining a single-item diet at three separate colony locations, each sample demonstrated a large amount of variability in diet digestibility.
Although one would expect healthy animals to process a single-item diet similarly, some animals presented with high levels of vitamin D while others were deficient. Over time, vitamin D deficiency can affect healthy bone density Jarcho et al. Individual differences like these complicate the task of defining nutritional needs of marmosets and suggest that underlying problems, disease, or other dysfunction may contribute to biological unpredictability.
Furthermore, the fecal fat content in these animals was much higher than anticipated, suggesting potential problems with fat-soluble vitamin A, D, E, and K absorption. Animals that have difficulty digesting nutrients typically adapt by ingesting more food, but even when they do so, they are unlikely to absorb enough nutrients, specifically fat-soluble vitamins. Animal behavior further complicates this picture; adjustments to diet in an attempt to help an obese animal lose weight may be met with the animal decreasing energy output, thereby nullifying the effort.
Despite these complications, further research into these differences and their impact on metabolic state and health is imperative. For instance, animals with vitamin D deficiency likely exhibit different immunological functions than seen in those without this deficiency. These differences could contribute to significant unintended variation in research results. A large debate surrounds the role of gum in marmoset diets. Gum eating has played an important role in marmoset evolutionary biology; it is central to the natural diet of marmosets, has nutritional value, and provides a fermentable substrate.
On the other hand, although gum is a source of energy and minerals, it provides only half of the dietary calcium recommended for marmosets. Gum has a far lower energy density and nutritional value than other foods in the marmoset diet, like insects and fruits. Another participant noted that the role of gum in the diet also appears to vary from species to species, playing a more central role in the diets of C.
The role of gums in intestinal health and gut microbiome requires further study. Moreover, if research indicates positive effects from the inclusion of gum in the marmoset diet, the question follows of whether the benefit is specific to gum or if a saccharide, agar, or other fermentable carbohydrate could serve the same purpose. During the discussion, participants considered the wide variation in vitamin D supplementation practices between laboratories. One attendee noted that the picture is further complicated by the fact that some laboratories allow marmosets access to outdoor enclosures, where exposure to sunlight can increase endogenous vitamin D.
Several research groups are. Indoor lighting can also influence vitamin D and other factors, and researchers are working to determine which lighting approaches are best. The challenge with marmosets is that they can be anywhere in the enclosure and the level of vitamin D an animal gets is highly dependent on how close the animal is to the light source.
Compensating for this by using lights that are too strong can risk eye damage both for animals and their caretakers. Labs have reported different downstream effects of high vitamin D supplementation, including soft tissue calcification, though it is unclear whether this is actually related to vitamin D.
It has previously been hypothesized that vitamin D metabolism differences may be related to vitamin D receptor resistance, but studies have not supported this, suggesting there is another factor that interferes with vitamin D absorption before the receptor comes into play.
Determining appropriate levels of vitamin D in marmosets and, indeed, in humans is an area ripe for further research, many participants agreed. Iron presents another nutritional concern raised in the discussion. While increased iron levels have been reported in tissues, particularly in the liver and in older animals, it does not seem to be a cause of death.
Anemia has also been reported in some marmosets. One researcher noted that it could be important to select enrichment foods that are low in iron. Obesity is a common and complex concern in captive marmoset colonies, reported in labs around the world. According to an attendee, adult animals are considered obese if they weigh grams or more. Noting that marmosets typically present with around 10 percent body fat and that obesity often develops early in life, one researcher said marmosets less than 1 year old were considered obese if their percentage of body fat was 14 percent or higher.
Animals that grow faster and have higher fat mass have been shown to reach developmental milestones earlier. Several researchers noted that the number of obese animals tends to increase within a research colony over time. This trend is seen not only in adults but also in the first few months of life and perhaps even prenatally. The pattern is accompanied by a shift in the ratios between litter sizes and birth weights; while larger litters historically have meant smaller infants, that is less and less the case.
The factors that drive obesity in research colonies and in younger animals in particular remain unknown. Researchers are investigating genetic factors such as the role of the RNA complex. Behavioral needs of animals in the wild and in semi-natural conditions have been extensively researched and are used to guide care recommendations for captive animals. For marmosets in particular, these types of behaviors fall into several categories that include social behaviors, feeding and foraging, and sleeping site selection.
Aspects of each of these activities can inform recommendations for husbandry and care of marmosets in captivity. Nancy Caine , a professor of psychology at California State University, San Marco, addressed multiple aspects of marmoset habits and environments.
Marmosets are incredibly social creatures, living in groups of up to 15 close relatives. Although they are not usually aggressive, they can be when facing territorial or breeding competition. In captivity, groups are created to provide these social conditions and are monitored to ensure assimilation. Additionally, these animals are generally easy to match for breeding, which they do monogamously and cooperatively, meaning that males and females are both responsible for rearing litters Schiel and Souto Food availability presents a major difference between captivity and the wild where marmosets have to invest time to collect and prepare food, including adapting their behaviors to match the demands of their living environments e.
They are adept in extracting gums from tree trunks Francisco et al. Beyond gums, marmosets eat bugs, small lizards, and nesting birds and eggs. In captivity, it is beneficial to provide food in ways that are as naturalistic as possible, for example, forcing the animal to peel or bite into whole fruits instead of providing prepared food, so that it also becomes a source of enrichment.
Moreover, captive marmoset habitats can be adjusted to help change behavior and even solve problems such as obesity. Including ropes and nets to encourage running, jumping, and swinging can help replicate behaviors of wild marmosets in captive environments. Marmosets are very deliberate in their selection of sleeping location. Sleep is the time when they are most vulnerable to predation by raptors, hawks, cats, and snakes.
In the wild, after selecting a sleeping spot,. The group then gathers together in a tight ball, where they remain until the morning. In captivity, marmosets require sleeping boxes and will select the most secure, covered box. When an ideal box is not available they will select one that offers the most cover or is in the highest position. This exemplifies the highly adaptable nature of marmoset behavior, contradicting the outdated assumption that marmosets are primitive, cognitively simple, or fragile Warren One common thread among all of these behaviors is the critical nature of social interaction; guarding against potential threats, sleeping, raising young, and gathering food are all done in groups.
In the context of research, the effect of this is that keeping marmosets in isolation can substantially alter the resulting model. In general, there is a dearth of evidence regarding optimal cage sizes. Several researchers noted that overall cage size may not be as important as the density of marmosets within an area. Higher densities can lead to territorial behaviors and aggression, and also increase the risk of infectious and respiratory diseases, and other health problems, though there is mixed evidence on whether density also affects wasting syndrome.
Stress and other problems tend to increase when marmosets are housed very close to animals outside of their family group. Female marmosets have the specialized endocrinology typical of New World primates i.
David Abbott , a professor of obstetrics and gynecology at the WPNRC, discussed his research aimed at understanding and controlling the marmoset reproductive cycle. Although puberty in marmosets begins at 8—10 months of age, the reproductive cycle is irregular until 2—6 years of age.
As they age, marmosets. Ovarian cycles of adult female marmosets are typical for an anthropoid primate, ranging from 28—30 days. The cycle includes several phases. The first is the follicular phase, an approximately 7-day period when progesterone levels are low in the corpus luteum. Unlike humans who only exhibit one follicle stimulating hormone peak during the follicular phase, marmosets have two Gilchrist et al.
Following pregnancy, the marmoset cycle returns to normal, leaving no post-partum control on immediate pregnancy Abbott Social cues and conditioning can play an important role in reproductive behaviors and controlling reproductive cycles in marmosets.
Socially subordinate female marmosets show suppressed ovulation cycles and sexual behavior when around a dominant female.
Moreover, babies born to socially subordinate females are often killed and eaten by the dominant female. In groups with related marmosets, inbreeding avoidance further inhibits sexual behavior Abbott et al. Abbott and other researchers have developed methods to control the timing of marmoset ovarian cycle onset to increase its predictability. While social cues can be powerful, pharmacological interventions can predictably control reproductive cycles and end the post-ovulatory phase or early pregnancies.
To control the timing of ovarian cycles, pharmacological mechanisms induce luteolysis, the degradation of the corpus luteum. Prostaglandin F2alpha analogues and gonadotropin-releasing hormone antagonists are established methods and 90 percent effective at controlling the cycle Alper and Fauser ; Fraser et al. Managing breeding colonies of marmosets requires careful attention to selecting mates, choosing and administering contraception as needed, monitoring pregnancies, handling difficult births, and caring for infants.
With a range of standardized and acceptable options available, in many cases colony managers are able to choose the best approaches for their unique colony. Although aggression between pairs of males and females is rare, the introduction of partners to create new pairs of marmosets should be done gradually. At MIT, this entails using two cages with a modifiable window to regulate interaction, while limiting visual access to the previous family group. If the two animals initially seem compatible, the likelihood that the relationship will turn aggressive is low.
This gradual introduction method,. It is important to use genetic information to drive pair selection for captive marmosets. Computer programs with pedigree trackers help facilitate this. Of the available injections, one needs to be administered 3 weeks postpartum and then monthly Cloprostenol and another must be injected within 10 days postpartum or it will not be effective Medroxyprogesterone.
Other more permanent options include subcutaneous implants Etonogestrel and Melengestrol acetate or surgical remedies, such as vasectomy or tubal ligation. If no contraceptive methods are being utilized, a female marmoset typically becomes pregnant within a few months of being matched with a mate. If not, the colony manager will need to identify the root cause, for example performing a thorough physical exam to look for abnormalities in external genitalia, measurement of male and female hormone levels, and the use of ultrasound to look for internal maladies.
Diagnosing pregnancy can be done by an expert trained in uterine palpitation or ultrasonography to obtain uterine and fetal measurements. Measurement of the length from crown to rump gives an indication of when the fetus will be born. Generally, marmosets experience a to day inter-birth interval and litter size ranges from one to five with twins as the default litter size. Early pregnancy loss is common in marmosets and often goes unnoticed, except when examining inter-birth intervals.
The majority of marmoset births occur in the evening after the lights have been turned off. In some locations, lights will be manipulated to encourage births during hours when staff are present. Most births are uncomplicated but dystocia can occur and may require surgical intervention. Other reproductive issues that can require surgery are uterine prolapse, uterine rupture, and several congenital anomalies. Researchers have not established the threshold of gestational length beyond which caesarian is recommended, though one facility reported using a threshold of 4 days past the expected due date in pregnancies when the date of embryo implantation is known.
If a pregnancy seems to be extending well beyond the expected delivery date but there may be some uncertainty about the timing of implantation, the first step would be an ultrasound to confirm normal fetal heart rates although more work is needed to determine what is a normal fetal heart rate and what variation can be considered within the normal range.
If fetal heart rates appear. Some participants suggested a consortium of researchers could examine available records on gestation and birth to elucidate possible differences in outcomes and offer practice guidance on this issue. Infant viability can be assessed by a checklist of reflexes and measurements, including tail curl, position on parent, grip strength, temperature, weight, and others. Triplet litters present one of the most significant areas of concern for breeding marmosets.
In these instances, which currently account for more than one-third of marmoset births in captivity, the mother does not increase resources and care to accommodate the additional infant, thus spreading the same amount of resources more thinly among three instead of two infants.
In this scenario, colony managers can take any or some combination of these actions: 1 no intervention, 2 remove one infant, 3 foster, 4 supplemental feeding and assisted rearing, or 5 full nursery rearing.
At MIT, Burns implements a protocol that supplements natural feeding on a rotational schedule. Different practices for handling triplet litters likely have some impact on immunological response, microbiome, and other factors. The selection of milk replacement is also likely important, and varies from facility to facility.
These differences and their impacts are worthy of further investigation. The choice of milk replacement may also have implications for obesity, because marmoset milk, human breastmilk, and various artificial formulas all have different densities of protein and calories. Along with variation in husbandry practices and diets, each marmoset colony has unique genetic and infectious disease profiles. Also, the big toe and the thumb are not opposable.
Marmosets, as well as their close cousins, tamarins, are considered to be the most primitive monkeys because of these anatomical characteristics, according to Dennis O'Neil, a professor of behavioral science at Palomar College in San Marcos, California.
The pygmy marmoset is smallest marmoset — and the smallest monkey. Its length is 4. Its tail length is 6. Goeldii's marmoset is one of the larger species, with a length of 8 to 9 inches 21 to 23 cm , and a tail length of 10 to They weigh These small monkeys spend their time in the trees of South America.
Many species live in the rainforest surrounding the Amazon River, or in the tropical forests along the Atlantic coastline. Marmosets are active during the day and spend their time foraging. They are social animals that live in small groups, called troops, made up of four to 15 relatives and are often territorial. A territory for a common marmoset troop, for example, can range from 5, to 65, square meters 1.
Marmosets are omnivores, which means they eat a variety of foods. Their diet includes insects, fruit, tree sap and other small animals.
Pygmy marmosets love the sap of trees. They saw holes into the bark to get at the sap with their teeth and can make thousands of holes in a small selection of trees.
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