Goeldi's marmoset, or Goeldi's monkey (Callimico goeldii), is a small New World monkey found on the South American continent, mainly in the upper Amazon basin of Bolivia, Brazil, Colombia, and Perú. It is the only species classified in the monotypic genus Callimico, thus these monkeys are sometimes referred to as "callimicos". The species takes its name from its discoverer, Swiss-Brazilian naturalist Emil August Goeldi.

Likely an evolutionary adaptation for camouflage and the evasion of predators, Goeldi's marmosets are a dark-furred species, usually a blackish-gray or darker brown in color. Superficially, the short hair on their head gives them a vague resemblance to the larger woolly monkey (Lagothrix); however, the back of their necks, their backside, and tails often display light, horizontal striping or highlights.

Taxonomy and evolution

Goeldi's marmoset was first described in 1904, making Callimico one of the more recent monkey genera to be described. and sometimes, along with the marmosets and tamarins, in the subfamily Callitrichinae in the family Cebidae. Similarities in delayed embryonic development and secondary limb-bone ossification between C. goeldii and marmosets are evidence of their close evolutionary relationship.

Reproduction

Females reach sexual maturity at 8.5 months, males at 16.5 months. The gestation period lasts from 144 to 159 days. Callimicos studied in captivity in North America and Europe for near 40 years have shown to produce on average 3.5 offspring during their lifetime. However, 30% of the females and 45% of the males observed in these settings never reproduced.

Unlike other New World monkeys, they have the capacity to give birth twice a year. However, mothers in the wild have been observed giving their babies to other members of the troop as early as 10 days after parturition, which is late for other marmosets. The life expectancy in captivity is about 10 years.

Development

From birth to about 18 months old, callimicos grow faster than other marmosets in part because the energy they would otherwise invest on thermal regulation and activity costs if they were not carried by their mothers is instead directed to growth. Likewise, a longer lactation period is also responsible for a faster development. Growth rate and weight gain is similar in both male and female infants and juveniles. The distribution of the species is patchy, and its density seems to be dependent on polyspecific associations with tamarins.

Sightings of Goeldi's marmosets have been made at the base of the Cordillera Oriental of the Andes in Colombia, in the Department of Putumayo, along the Putumayo and Caquetá Rivers. This is perhaps because Goeldi's marmosets are not known to have the X-linked polymorphism which enables some individuals of other New World monkey species to see in full tri-chromatic vision.

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File:Goeldis monkey - butterfly lunch - big.jpg|Marmoset eating a butterfly

File:Goeldi's Marmoset.jpg|At The Living Rain Forest in Berkshire, UK.

File:Callimico goeldii in Venezuela.jpg|Marmoset in Venezuela

File:Callimico goeldii, Universeum.ogv|Callimico goeldii at Universeum, Gothenburg, Sweden

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References

  • ARKive - images and movies of the Goeldi's monkey (Callimico goeldii)
  • Press release on recent research on Goeldi's monkey by scientists at the University of Washington
  • Primate Info Net Callimico goeldii Factsheet
  • Pictures of Goeldi's Monkey