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Reproduction in the vervet monkey (Cercopithecus aethiops): II. Annual menstrual patterns and seasonality
American Journal of Primatology
|January 26, 2020
Summary
Female vervet monkeys exhibit varied menstrual cycles, with prolonged cycles potentially linked to breeding seasonality. This study monitored menstrual patterns and progesterone to understand reproductive cycles in captive primates.
Area of Science:
- Primate reproductive endocrinology
- Comparative reproductive biology
Background:
- Understanding menstrual cycle variations is crucial for primate reproductive health.
- Previous research indicates normal menstrual cycle lengths in vervet monkeys.
Purpose of the Study:
- To characterize menstrual cycle patterns and progesterone profiles in female vervet monkeys.
- To investigate the incidence and potential causes of prolonged menstrual cycles.
Main Methods:
- Longitudinal monitoring of menstrual patterns and weekly progesterone levels over 5 years.
- Categorization of menstrual cycles into short, normal, and prolonged types based on cycle length.
- Analysis of cycle data in relation to the natural breeding period.
Main Results:
- Normal cycle length averaged 32.5 days and menses duration 4.8 days.
- Prolonged cycles (>50 days) constituted 20% of all cycles, with reduced occurrence during the peak breeding season.
- Progesterone data suggested prolonged cycles were often associated with extended luteal phases or anovulation.
Conclusions:
- Vervet monkeys display diverse menstrual cycle lengths, with prolonged cycles being relatively common.
- The incidence of prolonged cycles suggests a potential, albeit weak, seasonal influence on vervet monkey reproduction in indoor colonies.
- Extended luteal phases or anovulation are likely contributors to prolonged menstrual cycles in this species.
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