Social and Hormonal Correlates of Life History Characteristics and Mating Patterns in Female Colobus vellerosus
Abstract
This dissertation uses behavioural and hormonal data to describe female life history characteristics in Colobus vellerosus. It explores female behaviour patterns that may influence female reproductive success, and focuses on the effect of male group membership on female mating behaviour and investment in offspring. My team and I collected behavioural and faecal data between May 2012 and May 2013 at Boabeng-Fiema Monkey Sanctuary, in central Ghana. From June 2013 to September 2013 I extracted female reproductive hormones (progesterone and oestradiol) from the faecal samples at the Wisconsin National Primate Research Center and mapped the hormone values onto female hormone profiles. I documented ovarian cycle length (24 days), gestation length (mean=168.5 days, range=159-178 days, n = 2), age at first birth (5.87 years, range=4.66-7.08, n=8), and inter-birth interval for females whose infants survived to nutritional independence (mean=16.5 months, range=8.3-24.0 months, n=11) and for females whose infants did not survive to nutritional independence (mean=11.4 months, range=8.0-17.1 months, n=9). I investigated whether or not post-conceptive mating in female C. vellerosus is a by-product of fluctuating and/or elevated oestradiol and progesterone levels during pregnancy, or if it is a result of females' access to multiple males. I found that female progesterone and oestradiol levels increased throughout pregnancy and female mating patterns were associated with elevated progesterone levels. Females directed solicitations significantly differently among group types, and females directed solicitations significantly more in unstable multi-male groups than in stable multi-male groups. Females in stable and unstable multi-male groups copulated more with dominant than non-dominant males. I also investigated if female C. vellerosus stack investment in their offspring by conceiving a new offspring while a previous infant is still in nipple contact. I found that eight out of 16 females stacked investment. Females in stable multi-male groups stacked investment significantly more than those in unstable multi-male groups. Females that stacked investment spent a higher proportion of time with an infant in nipple contact than did those that did not stack investment. The combination of behavioural and endocrine data used in this study contributes to a growing body of work describing primate life history variables and mating systems.
Description
Keywords
Anthropology, Anthropology--Physical, Animal Physiology, Zoology
Citation
Vayro, J. (2017). Social and Hormonal Correlates of Life History Characteristics and Mating Patterns in Female Colobus vellerosus (Doctoral thesis, University of Calgary, Calgary, Canada). Retrieved from https://prism.ucalgary.ca. doi:10.11575/PRISM/27809