An investigation into the hormonal and behavioural mechanisms of parental care in the common marmoset

The first half of this thesis concentrates on investigating the hormonal mechanisms of paternal care in the common marmoset (Callithrix jacchus). Chapter 3 examines the way in which a number of hormones correlate with the expression of paternal care. In Chapters 4 and 5, I discuss the affect of transiently manipulating the circulating level/effectiveness of prolactin and endogenous opioid peptides while fathers were caring for infants, to evaluate whether either of these hormones is involved in stimulating the behaviour. In the second half of the thesis, I look in detail at paternal food sharing behaviour and the energetic cost of infant care. Chapter 6 examines how food novelty, food accessibility and infant age determine the willingness with which fathers and mothers share food with infants. Chapter 7 concentrates on the benefit infants may get from sharing food, and looks at whether sharing food or watching parents eat are important in the development of long term infant feeding preferences. Both infant carrying and food sharing are energetically costly to both parents. Chapter 8 uses weekly body weight measurements to assess whether body size and infant carrying affects the body weight of fathers and mothers during the first 3 months after the infants are born. Finally, in Chapter 9 I discuss the results of my experiments within the context of current hypotheses and published data.EThOS - Electronic Theses Online ServiceGBUnited Kingdo