Common marmoset

Common marmoset[1][2]
Conservation status
Least Concern (IUCN 3.1)[3]
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Primates
Family:	Callitrichidae
Genus:	Callithrix
Species:	C. jacchus
Binomial name
Callithrix jacchus (Linnaeus, 1758)
Geographic range
Synonyms
albicollis Spix, 1823 communis South, 1845 hapale Gray, 1870 leucotis Lesson, 1840 moschatus Kerr, 1792 rufus Fischer, 1829 vulgaris Humboldt, 1812

The common marmoset (Callithrix jacchus) is a New World monkey. It originally lived on the Northeastern coast of Brazil, in the states of Piaui, Paraiba, Ceará, Rio Grande do Norte, Pernambuco, Alagoas and Bahia.^[4] Through release (both intentional and unintentional) of captive individuals, it has expanded its range since the 1920s to Southeast Brazil (its first sighting in the wild for Rio de Janeiro was in 1929) and became there an invasive species, raising concerns about genetic pollution of similar species such as the buffy-tufted marmoset (Callithrix aurita) and predation upon bird nestlings and eggs.^[5]

Physical description and morphology

Drawing of a marmoset

Common marmosets are very small monkeys. Males and females are of similar size with males being slightly larger. Males have an average height of 188 mm (7.40 in) and females have an average height of 185 mm (7.28 in). Males weigh 256 g (9.03 oz) on average and females weigh 236 g (8.32 oz) on average.^[6] The pelage of the marmoset is colored a blotchy brown, grey, and yellow. It also has white ear tufts and its tail is long and banded. Their faces have pale skin and have a white blaze on the forehead.^[7] At birth, infants have brown and yellow coats and develop the ear tufts as they age.

As with other members of the genus Callithrix, the common marmosets have claw-like nails known as tegulaes on most of their fingers. Only their halluxes (big toes) have the flat nails or ungulaes that most other primates have.^[8] Marmosets have an arboreal locomotion similar to squirrels. They cling to tree vertically, run across branches quadrupedally and leap between trees.^[6][9] Tegulaes are an adaptation of this type of locomotion. Callitrichines also are unique in having enlarged, chisel-shaped incisors and specialized cecums for their diet.^[6]

Range and ecology

Common marmosets are native to Brazil. They live in the northeastern and central forests ranging from the Atlantic coast and inland into Rio Grande. They have been introduced into other areas and live within the cities of Rio de Janeiro and Buenos Aires, Argentina.^[10] Marmosets can found in a number of forest habitats. They live in Atlantic coastal forests as well as semi-deciduous forests farther inland. They can also inhabit savanna forests and riverine forests.^[11] Marmosets excel in dry secondary forests and edge habitats although they show great variety in the habitats in which they can live.^[9]

Common marmoset at Salvador, Bahia, Brazil.

Diet

The common marmoset’s claw-like nails, incisor shape, and gut specialization reflect their unique diet which is primarily made of plant exudates and insects. Common marmosets feed on gum, sap, latex, and resin the most out of the callitrichines.^{[clarification needed][9][11]} They use their nails to cling to the side of a tree and, with lower incisors as big as their canines, gnaw off the bark stimulate the flow of edible exudates.^[12] The marmoset will inflict a wound on the tree and lick or swoop the exudates with its teeth.^[13] 20-70% of the marmot’s foraging activities is made of eating exudates.^[12][6]

Exudates provide marmosets with a reliable food source in the marmoset’s seasonal habitat. Exudate foraging is especially high for January to April when fruit is scare.^[11] A marmoset may keep visiting a previously made tree wound or even use those made by other animals. In addition to exudates, insects also prove an important food source for marmosets, making 24-30% of their foraging time. The small size of the marmoset allow then to subsist on insects. They are skilled in stalking and pouncing on large, mobile insects in the understory and middle layers of the forest.^[11] Marmosets will also eat fruits, seeds, flowers, fungi, nectar, snails, lizards, tree frogs, bird eggs, nestlings, and infant mammals. ^[13] It is possible that marmosets compete for fruit with birds, such as parrots and toucans, and woolly opossums.^[13]

Behavior

Social organization

Common marmosets live in stable extended families with a few breeding individuals and a flexible mating system.^[14][15] A marmoset group can contain as many as 15 members, but a more typical number is nine.^[13] A marmoset family usually contains a 1-2 breeding females, a breeding male, their offspring and their adult relatives, be it their parents or siblings.^[15] The females in a group tend to be closely related and males less so. Males do not mate with breeding females that they are related to. Marmosets may leave their natal groups when they become adults, in contrast to other primate species who leave at adolescence. Not much is known of the reasons marmosets leave their natal groups. ^[15] Family groups will break apart and separate into new groups when a breeding male dies.^[16] Within the family groups, the breeding individuals tend to be more dominant. The breeding male and female tend to be co-dominant. However if there is more than one breeding female, one will be dominant over the other. In addition, the subordinate female is usually the daughter of the dominant one. For the non-breeding members, social rank is based on age.^[14] Dominance is maintained though various behaviors, postures and vocalizations and subordinates will groom their superiors.^[14]

Two marmosets

Reproduction and parenting

Common marmosets have a complex mating system. It was thought that they were monogamous, however polygamy (of both types) has also been observed.^[14] Nevertheless, most matings are monogamous. Even in groups with two breeding females, the subordinate female often mates with males from other groups. The pregnancies of subordinate females usually do not result in viable offspring.^[17] Nevertheless, this pattern of mating with extra-group males may be a strategy to identify potential future mates. Females that mate successfully but lose their young move to other groups and may gain dominant breeding positions.^[17]

The breeding individuals in a group need the other members to help raise their young. Thus there is behavioral and physiological reproductive suppression of the other members of the group by the breeding pair.^[18][19] Since the suppressed individuals are likely related to the breeding pair, they have an incentive to care for the young as they share genes with them.^[19] In addition, the presence of a related male affects female ovulation. Laboratory studies have shown that females do not ovulate or display sexual behavior in the presence of their fathers, but do so when the father is replaced with another male. They will also display aggressive behavior towards their mothers,^[19] possibly to displace them.

When conditions are right for them to breed, adult females breed consistently for the rest of their lives. Females direct tongue-flicking displays at males to solicit mating. The gestation period lasts for five months, and females are ready to breed again around ten days after giving birth. Their inter-birth intervals last five months and they give birth twice a year. ^[13] Marmosets commonly give birth to two non-identical twins. Because of this, female have high demands during pregnancy and lactation, and need help from the other members of the family. ^[13][9] Infant marmosets have very strong cling reflexes and will not voluntarily leave their carrier’s back for the first two weeks. After that, they become very active and explore their surroundings. ^[13] The breeding male (likely the father) will begin handling the twins, and all members of the family offer caregiving.^[20] In the following weeks, the young spend more time off their carrier’s back and develop locomotory behaviors, play behaviors and coordination. ^[13] Infants are weaned at three months. At five months they enter their juvenile stage. At this time, they have more interactions with family members other than their parents, and play becomes rougher as their future status is being worked out. Another set of infants may be born and the previous young will carry and play with them.^[20] Marmosets become sub-adults between nine and 14 months, have full a repertoire of adult behaviors and go through puberty. At 15 months, they reach adult size and are sexually mature but can’t reproduce until social conditions are adequate.^[20]

Communication

Common Marmoset in Zoo Hannover, Germany

Common marmosets employ a number of vocal and visual communications. To signal alarm, aggression, and submission, marmosets use the "partial open mouth stare," "frown," and "slit-stare", respectively. To display fear or submission, marmosets flatten their ear-tufts close to their heads. ^[13] Marmosets have two alarm calls: a series of short ascending calls called "staccatos", and brief descending calls given either alone or in a series. These are called "tsiks". Marmoset alarm calls tend to be brief and high-pitched.^[16] Marmosets monitor and locate group members with generic calls called "trills". They have a lower pitch and cyclic frequency fluctuations that give them a distinctive vibrato sound. ^[21] Marmosets also employ "phees" which are generic calls made of a series of one to five notes that last about two seconds each and play a role in long-range communication, mate attraction, group cohesion, territorial defense, and finding of lost group members.^[21] Marmosets will mark objects with secretions from specialized scent glands on their chests and around their anus and genitals. These are meant to convey social status, and advertise reproductive status. ^[13]

Status

The common marmoset remains an abundant species and is not currently threatened in any part of its range. Nevertheless its habitat had been degraded at a large rate, with least 67% of the cerrado region converted to human use in the 1990s and around 80% cleared for agriculture more recently.^[22]In addition, marmosets are caught and sold in pet trades. Though attractive as pets, they become destructive as they age and are thus abandoned or killed.^[23] Common marmosets have also been used for medical experiments. They are used as such in Europe more so than in the United States, as they are the most frequently used non-human primate in research laboratories there.^[24] They are used as model organisms in areas of research such as teratology, periodontal disease, reproduction, immunology, endocrinology, obesity, and aging.^[25][24]

References

1. ^ Groves, C. (2005). Wilson, D. E., & Reeder, D. M, eds. ed. Mammal Species of the World (3rd ed.). Baltimore: Johns Hopkins University Press. pp. 131. OCLC 62265494. ISBN 0-801-88221-4. http://www.bucknell.edu/msw3/browse.asp?id=12100197. 
2. ^ Rylands AB and Mittermeier RA (2009). "The Diversity of the New World Primates (Platyrrhini)". In Garber PA, Estrada A, Bicca-Marques JC, Heymann EW, Strier KB. South American Primates: Comparative Perspectives in the Study of Bahavior, Ecology, and Conservation. Springer. pp. 23–54. ISBN 978-0-387-78704-6. 
3. ^ Rylands, A. B., Mittermeier, R. A., Oliveira, M. M. & Keirulff, M. C. M. (2008). Callithrix jacchus. In: IUCN 2008. IUCN Red List of Threatened Species. Downloaded on 2 January 2009.
4. ^ Macdonald, David (Editor) (1985). Primates. All the World's Animals. Torstar Books. p. 50. ISBN 0-920269-74-5. 
5. ^ Brandão, Tulio Afflalo (December 2006). "BRA-88: Micos-estrelas dominam selva urbana carioca" (in Portuguese). Rio de Janeiro. http://biodiversityreporting.org/article.sub?docId=23835&c=Brazil&cRef=Brazil&year=2007&date=December%202006. Retrieved 10 April 2009. 
6. ^ ^{a b c d} Rowe N. (1996) The pictorial guide to the living primates. East Hampton (NY): Pogonias Pr.
7. ^ Groves C. (2001) Primate taxonomy. Washington DC: Smithsonian Inst Pr.
8. ^ Garber PA, Rosenberger AL, Norconk MA. (1996) "Marmoset misconceptions". In: Norconk MA, Rosenberger AL, Garber PA, editors. Adaptive radiations of neotropical primates. New York: Plenum Pr. p 87-95.
9. ^ ^{a b c d} Kinzey WG. 1997. "Synopsis of New World primates (16 genera) ". In: Kinzey WG, editor. New world primates: ecology, evolution, and behavior. New York: Aldine de Gruyter. p 169-324.
10. ^ Rylands AB, Coimbra-Filho AF, Mittermeier RA. 1993. "Systematics, geographic distribution, and some notes on the conservation status of the Callitrichidae". In: Rylands AB, editor. Marmosets and tamarins: systematics, behaviour, and ecology. Oxford (England): Oxford Univ Pr. p 11-77.
11. ^ ^{a b c d} Rylands AB, de Faria DS. (1993) "Habitats, feeding ecology, and home range size in the genus Callithrix". In: 'Rylands AB, editor. Marmosets and tamarins: systematics, behaviour, and ecology. Oxford (England): Oxford Univ Pr. p 262-72.
12. ^ ^{a b} Ferrari SF, Lopes Ferrari MA. (1989) "A re-evaluation of the social organization of the Callitrichidae, with reference to the ecological differences between genera". Folia Primatol 52: 132-47.
13. ^ ^{a b c d e f g h i j} Stevenson MF, Rylands AB. (1988) "The marmosets, genus Callithrix". In: Mittermeier RA, Rylands AB, Coimbra-Filho AF, da Fonseca GAB, editors. Ecology and behavior of neotropical primates, Volume 2. Washington DC: World Wildlife Fund. p 131-222.
14. ^ ^{a b c d} Digby LJ. (1995) "Social organization in a wild population of Callithrix jacchus: II, Intragroup social behavior". Primates 36(3): 361-75.
15. ^ ^{a b c} Ferrari SF, Digby LJ. (1996) "Wild Callithrix group: stable extended families? " Am J Primatol 38: 19-27.
16. ^ ^{a b} Lazaro-Perea C. (2001) "Intergroup interactions in wild common marmosets, Callithrix jacchus: territorial defense and assessment of neighbours". Anim Behav 62: 11-21.
17. ^ ^{a b} Arruda MF, Araujo A, Sousa MBC, Albuquerque FS, Albuquerque ACSR, Yamamoto ME. 2005. "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): 10-20.
18. ^ Baker JV, Abbott DH, Saltzman W. (1999) "Social determinants of reproductive failure in male common marmosets housed with their natal family". Anim Behav 58(3): 501-13.
19. ^ ^{a b c} Saltzman W, Severin JM, Schultz-Darken NJ, Abbott DH. (1997) "Behavioral and social correlates of escape from suppression of ovulation in female common marmosets with the natal family". Am J Primatol 41:1-21.
20. ^ ^{a b c} Yamamoto ME. (1993) From dependence to sexual maturity: the behavioural ontogeny of Callitrichidae". In: Rylands AB, editor. Marmosets and tamarins: systematics, behaviour, and ecology. Oxford (England): Oxford Univ Pr. p 235-54.
21. ^ ^{a b} Jones CB. (1997) "Quantitative analysis of marmoset vocal communication". In: Pryce C, Scott L, Schnell C, editors. Marmosets and tamarins in biological and biomedical research: proceedings of a workshop. Salisbury (UK): DSSD Imagery. p 145-51.
22. ^ Cavalcanti RB, Joly CA. (2002) "Biodiversity and conservation priorities in the cerrado region". In: Oliveira PS, Marquis RJ, editors. The cerrados of Brazil: ecology and natural history of a neotropical savanna. New York: Columbia Univ Pr. p 351-67.
23. ^ Duarte-Quiroga A, Estrada A. (2003) "Primates as pets in Mexico City: an assessment of the species involved, source of origin, and general aspects of treatment". Am J Primatol 61: 53-60.
24. ^ ^{a b} Abbott DH, Barnett DK, Colman RJ, Yamamoto ME, Schultz-Darken NJ. (2003) "Aspects of common marmoset basic biology and life history important for biomedical research". Compar Med 53(4): 339-50.
25. ^ Rylands AB. (1997) "The callitrichidae: a biological overview". In: Pryce C, Scott L, Schnell C, editors. Marmosets and tamarins in biological and biomedical research: proceedings of a workshop. Salisbury (UK): DSSD Imagery. p 1-22.

External links

• Lang, Kristina Cawthon (2005-05-18). "Common marmoset: Callithrix jacchus". Primate Factsheets. Primate Info Net. http://pin.primate.wisc.edu/factsheets/entry/common_marmoset. Retrieved 10 April 2009.