Pregnancy outcome in free-ranging vervet monkeys (Cercopithecus aethiops)

Area of Science:

• Primate reproductive biology
• Wildlife conservation
• Behavioral ecology

Background:

• Understanding reproductive success in wild vervet monkeys (Cercopithecus aethiops) is crucial for population management.
• Individual differences in conception and fetal wastage can significantly impact population dynamics.
• Previous studies on captive animals suggest age and social rank influence pregnancy outcomes.

Purpose of the Study:

• To preliminarily assess individual female differences in conception rates and fetal wastage in a wild vervet monkey population.
• To determine the feasibility of using electrophoretic analysis of blood samples for pregnancy diagnosis.
• To explore the relationship between biological data and observed behavioral patterns in reproductive success.

Main Methods:

• A population of wild vervet monkeys was trapped for biological sampling.
• Blood samples were analyzed using electrophoretic methods to identify a specific serum aminopeptidase phenotype for pregnancy confirmation.
• Pregnancy status and birth outcomes were monitored for a subset of females.
• Data from three troops over three years were compared.

Main Results:

• A distinctive serum aminopeptidase phenotype accurately identified pregnant females.
• Out of seven diagnosed pregnant females, only three gave birth.
• Fetal loss was observed in nulliparous and very old females, suggesting age-related factors.
• Yearly birth success fluctuated among individual females, with a high overall miscarriage rate.

Conclusions:

• Individual variation in reproductive success, including conception and fetal wastage, is significant in wild vervet monkeys.
• Electrophoretic analysis provides a reliable method for pregnancy diagnosis in this species.
• Integrating behavioral and biological data is advantageous for a comprehensive understanding of primate reproduction and conservation efforts.