Sexual conflict over parental care: the role of negotiation between parents in determining their relative share of care

Since both parents are related to their shared offspring but are unrelated to each other, both benefit from their partner taking on most of the care for their shared offspring, resulting in sexual conflict over parental care. This conflict can lead to different patterns of care, with each parent having to decide whether to provide care, and if so, how much. There is a huge amount of variation in parental care provisioning. So can sexual conflict over parental care explain these different patterns of care? Two factors that have been assumed to play a role in this for a few decades already are discussed first – remating opportunities (1) and paternity (2) - after which I focus on a more recent development in this field, which is the study of interactions between parents on a behavioural time-scale (3). Including the behavioural interactions between parents is necessary to understand the decisions parents make within a single breeding event, as opposed to the pattern of care that develops over evolutionary time. Negotiation models have provided us with predictions of how a parent should respond to a change in parental effort by its partner. However, there is a lack of match between these predictions and empirical data, especially in the case of biparental care. Possible explanations for this are discussed, including models that have extended on negotiation models in an attempt to explain the variety of responses that are found.