Studying Hormonal Stimuli in Mountain Gorillas Yields Many Clues
This is the second in a series of posts about Sosthene Habumuremyi’s dissertation research on the hormonal correlations of socio-sexual behaviors in female mountain gorillas. Please see part one here.
By Sosthene Habumuremyi
My study has gathered data on mating behavior, solicitations, and any displays/aggression from adult males towards the females. Sexual swellings, which are extremely small in gorillas, are also noted.
The plan is to monitor at least 6 nulliparous (never having given birth to offspring) females and 10 cycling parous (given birth to offspring at least once) females for 2 cycles each (2-4 months per female) as well as obtain weekly measures from pregnant females. To ensure that the time of ovulation is measured hormonally, urine and or fecal samples must be collected regularly, on a nearly daily basis without gaps of more than 2-3 days.
My research on nulliparous mountain gorillas may answer these questions:
- Are cycles ovulatory?
- How do hormonal profiles relate to sexual swelling patterns and mating activities?
- How do hormonal profiles change with increasing age?
- How do hormonal patterns differ in comparison to parous females?
My research on cycling (parous) mountain gorillas may answer these questions:
- How does mating behavior relate to ovulation in parous females?
- How does mating behavior differ between one-male and multimale groups?
- How does mating behavior differ depending on whether the male is dominant or subordinate?
- How do patterns of mating solicitations (by the male or female) and potentially coercive behavior (aggression and displays by the males) vary according to reproductive status of the females?
- How do female hormone profiles vary in relation to the age of their dependent offspring, age of the female and proximity to conception?
