The Relationship between Age, Dominance Rank and the Number of Offspring in Taiwanese Macaques (Macaca cyclopis)

• Main Authors: Huei Yu Lu, 路蕙宇
• Other Authors: Guo Jing Weng
• Format: Others
• Language: zh-TW
• Published: 2012
• Online Access: http://ndltd.ncl.edu.tw/handle/57244801252600465799

碩士 === 國立屏東科技大學 === 野生動物保育研究所 === 100 === Social animals live together in order to obtain more resources or space, but individuals in a group compete with each other for genetic contribution to next generation. The age and dominance rank of an individual may have effects on the number of offspring. This research aimed to answer the following questions using genetic information: 1) Younger females have better physical condition to reproduce, but older mothers have more experience in rearing their children. What is the relationship between age and accumulated number of offspring of female Taiwan macaque (Macaca cyclopis)? 2) Individuals of higher dominance rank have higher priority and frequency of mating. Is dominance rank positively correlated with actual number of offspring? 3) Individuals of different dominance rank use different strategy to increase genetic contribution to next generation. Do individuals of a particular dominance rank prefer to mate with individuals of any particular dominance rank? Focal animal sampling was carried out at Fu-shan Experimental Forest in Yilan. Maternity was confirmed by direct observations. Genetic material was collected from fecal samples. Microsatellite DNA was used to identify possible father of offspring. Results show that 1) For females of 5 to 15 years of age, the age of female is significantly positively related to the probability of reproduction, but female has significantly lower probability of reproduction if she produced offspring in the previous year; 2) Dominance rank and number of offspring are not significantly correlated for females; 3) There is no significant correlation in number of offspring among dominance ranks of males and females, indicating that individuals of a particular dominance rank do not mate with individuals of any particular dominance rank. This research shows that age and reproduction experience in the previous year of females are significantly correlated with probability of reproduction of the year. Presumably because old female has more experience in rearing offspring. Dominance rank of female is not significantly correlated with total number of offspring produced by females of that dominance rank. Although dominance rank of female does not correlate with number of offspring, offspring of higher dominance rank female may obtain better resources and higher probability of survival. Individuals do not prefer to product offspring with any specific dominance rank of individuals. These patterns of reproduction produce a genetic composition similar to the result of random mating; thereby maintain the genetic diversity of populations.