Comparative postcranial body shape and locomotion in Chlorocebus aethiops and Cercopithecus mitis

Area of Science:

• Primatology
• Comparative Anatomy
• Locomotor Biomechanics

Background:

• Guenon species exhibit diverse locomotor preferences, influencing their morphology.
• Understanding these adaptations is key to primate evolutionary studies.

Purpose of the Study:

• To compare body weight, length, and limb segment lengths between two guenon species.
• To correlate morphological differences with distinct locomotor behaviors.

Main Methods:

• Measurement of body weight, length, chest girth, and seven postcranial limb segments in adult wild-caught guenons.
• Statistical comparison of morphological data between Chlorocebus aethiops and Cercopithecus mitis.
• Interpretation of results in the context of locomotion and social organization.

Main Results:

• Cercopithecus mitis showed significantly greater body weight and trunk length than Chlorocebus aethiops.
• Proximal limb segments were longer in C. mitis (arboreal adaptation), while distal limb segments were longer in C. aethiops (terrestrial adaptation).
• Contrary to expectations, vervets (C. aethiops) had longer relative tail lengths, potentially aiding arboreal balance.

Conclusions:

• Interspecific morphological differences in guenons are largely explained by adaptations to different locomotor modalities.
• Some findings challenge conventional ideas linking morphology solely to locomotion, suggesting other factors like sexual selection may play a role.
• Greater sexual dimorphism in the more arboreal blue monkeys may relate to seasonal mating competition.