Within the order Primates, lemurs have traditionally been considered to be unique in that females can be dominant to males (referred to as female dominance). Recently the universality of female dominance among lemurs has been questioned although there have been no systematic studies of this behavior to date on wild populations. Therefore, the purpose of this study is to answer the following questions: 1) how do male and female reproductive strategies influence the expression of female dominance and female feeding priority?, 2) can female feeding priority exist in the absence of female dominance?; 3) are there alternative behavioral strategies that individuals can use to influence their foraging efficiency in the absence of or in conjunction with female dominance and feeding priority?, 4) can these behaviors be considered types of feeding priority, and 5) how do environmental constraints (specifically ecological stress) and male deference work together to influence the expression of female dominance, feeding priority, and/or alternative ways to increase foraging efficiency. These questions will be answered by examining the feeding ecology and behavior of three endangered species of primate (Varecia variegata, Propithecus diadema edwardsi and Eulemur fulvus rufus) in the Ranomafana National Park over a three and a half year period.
This research has several important implications. The main objectives are: a) to test specific predictions regarding the relationship of female dominance and feeding priority in lemurs; and b) develop methods that can document the subtle ways female primates influence their feeding ecology through non-aggressive means in response to reproductive demands and seasonal changes in food. This research has the potential to contribute in a broader way to primatology by challenging existing paradigms that rely on a narrow definition of a dominance hierarchy to identify individuals who have social and ecological influence within social groups. In fact in recent anthropological studies on humans, researchers emphasize that the concepts of status and prestige can be considered distinct entities from dominance. In human societies that are male dominant, females can still have power and prestige in public or private domains. Although the cultural concepts of power and prestige are not appropriate to non-human primates, the concept that females can behave in subtle ways that influence social dynamics and foraging efficiency should be examined more carefully in non-human primates, particularly if these behaviors significantly impact survivability and reproductive success.
It is assumed in this project that male and female mating strategies in addition to the ecological stress experienced by females when reproductive, work together to influence the expression of female dominance, feeding priority, and/or alternative strategies to improve foraging efficiency. These alternative strategies include intersexual differences in food selection and coordination of group movements. To test this hypothesis, behavioral and ecological data will be collected on at least two study groups of each lemur species during different reproductive phases and food availability periods.
