Female reproductive conflict and prenatal investment

Abstract

With limiting resources and large demands for resources to breed, this can result in reproductive conflict between individuals of the same sex. Female reproductive competition to produce as many offspring as possible, can come in many forms but the intensity is often underestimated as their methods of competing can be quite subtle. In cooperative species, with high local competition and reproductive skew between females, competition can be more obvious with aggression that can lead to eviction of a female from the group or infanticide. However, females may be able to try to outcompete each other by investing more in their offspring prenatally, giving their offspring a head start. In this thesis, I investigate what influences female prenatal investment and its consequences in a wild population of banded mongooses (Mungos mungo). This work was conducted as part of a long-term project studying a wild cooperative mammal; with valuable data on individuals’ prenatal investment available. Firstly, (Chapter 1) I discover that female investment in fetus size is influenced by female reproductive competition and the level of resources available, which alters the intensity of the conflict experienced. However, I found no advantages or disadvantages to this increase in investment on the short-term survival or weight of their pups. In Chapter 2, I found that when conditions are bad or being a younger and more subordinate female increases the probability of reproductive failure (abortion). Further research is needed to find out if this is an adaptive strategy to conserve energy when experiencing high levels of competition. Overall, this work helps to contribute to our understanding of how wild mammals might be subtly able to alter their prenatal investment, with regards to their competitive environment, and how this might affect their life history stratergies.