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Behavioral Assessment of Manual Dexterity in Non-Human Primates
Published on: November 11, 2011
Sexual dimorphism in the squirrel monkey, Saimiri sciureus (Linnaeus, 1758) and Saimiri ustus (I. Geoffroy, 1844)
B Goldschmidt1, A Mota-Marinho, C Araújo-Lopes
1Departamento de Primatologia, Centro de Criação de Animais de Laboratório, Fundação Oswaldo Cruz, Rio de Janeiro, RJ, Brazil. bibi@fiocruz.br
Summary
A unique black spot near the ear distinguishes adult female squirrel monkeys (Saimiri sciureus) over five years old. This age-related coat color change aids in identifying females in the wild without capture.
Area of Science:
- Primate Morphology
- Animal Behavior
- Zoology
Background:
- Sexual dimorphism in primates is often studied using morphological traits like body weight and canine length.
- Coat color variations can also signify differences between sexes and age groups in primate species.
Purpose of the Study:
- To describe a novel coat color characteristic observed in adult female squirrel monkeys (Saimiri sciureus).
- To determine the age and sex specificity of this unique coloration.
- To assess the potential of this trait for non-invasive identification of adult female squirrel monkeys in their natural habitat.
Main Methods:
- Observational study focusing on coat color patterns in squirrel monkeys.
- Age and sex determination based on established criteria.
- Documentation of a specific black hair spot anterior to the pinna in adult females.
Main Results:
- A distinct black hair spot, located anteriorly to the external ear, was identified exclusively in adult female squirrel monkeys aged over five years.
- The intensity or size of this spot appears to increase with age in the studied females.
- This characteristic was absent in all males and younger individuals of the species.
Conclusions:
- The described coat color trait serves as a reliable indicator of adult female Saimiri sciureus.
- This finding offers a non-invasive method for distinguishing adult females in wild populations, potentially aiding ecological and behavioral studies.
- Further research could explore the hormonal or developmental basis for this sexually dimorphic trait.
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