Testosterone positively associated with both male mating effort and paternal behavior in savanna baboons (Papio cynocephalus)

Abstract

Testosterone (T) is often positively associated with male sexual behavior and negatively associated with paternal care. These associations have primarily been demonstrated in species where investment in paternal care begins well after mating activity is complete, when offspring are hatched or born. Different patterns may emerge in studies of species where investment in mating and paternal care overlap temporally, for instance in non-seasonal breeders in which males mate with multiple females sequentially and may simultaneously have multiple offspring of different ages. In a 9-year data set on levels of T in male baboons, fecal concentrations of T (fT) were positively associated with both mate guarding (“consortship”) – a measure of current reproductive activity – and with the number of immature offspring a male had in his social group – a measure of past reproductive activity and an indicator of likely paternal behavior. To further examine the relationship between T and potential paternal behavior, we next drew on an intensive 8-month study of male behavior, and found that fathers were more likely to be in close proximity to their offspring than expected by chance. Because male baboons are known to provide paternal care, and because time in proximity to offspring would facilitate such care, this suggests that T concentrations in wild male baboons may be associated with both current reproductive activity and with current paternal behavior. These results are consistent with the predicted positive association between T a mating effort but not nd with a negative association between T a paternal care; in male baboons, high levels of nd T occur in males that are differentially associating with their offspring.

Testosterone and reproductive effort in male primates

“…In Amboseli, proximity between males and their offspring was closer than that between males and unrelated infants, though it was not clear which party was responsible for maintaining that relationship. Additionally, males showed a positive correlation between testosterone production and the number of immature offspring they had in the group (Onyango et al 2013). Paternal care in this case thus appears to involve tolerance and aggressive defense, rather than nurturance.…”

“…Yellow baboon ( Papio cynocephalus : Onyango et al 2013) males had higher levels of fecal testosterone in months when they obtained consortships than those in which they did not. Chacma baboon males ( Papio ursinus ) similarly increased testosterone production during consortships (Beehner et al 2006, Kalbitzer et al 2015), but this was not true for Guinea baboons ( Papio papio: Kalbitzer et al 2015).…”

Sources of variance in a female fertility signal: exaggerated estrous swellings in a natural population of baboons

“…Female baboons reach menarche at a median of 4.5 years (Charpentier et al 2008; Onyango et al 2013). During adulthood, they exhibit the highly visible sexual swellings that are the subject of this study, and that correspond to ovarian cycle phase (follicular vs luteal; Wildt et al 1977).…”

Hormonal correlates of natal dispersal and rank attainment in wild male baboons

“…Testosterone regulates the production of gametes, enhances anabolism, and maintains musculoskeletal performance (Adkins-Regan, 2005; Bardin, 1996; Bribiescas, 2001). Testosterone has previously been associated with behaviors such as territoriality, mate guarding/consortship, aggression, and mating display (Beehner et al, 2006; Onyango et al, 2013a; Wickings and Dixson, 1992; Wingfield et al, 1990). The ‘challenge hypothesis,’ designed to explain the link between T and competitive behavior in seasonal breeders, predicts that T levels rise in response to social challenges, particularly those associated with competition for mates, and specifically that T levels can be rapidly elevated when critically needed to promote aggressive competition in a reproductive context (Wingfield et al, 1990).…”