Stable isotopes reveal the effects of maternal rank and infant age on weaning dynamics in wild chacma baboons

Maternal strategies reflect the trade-off between offspring needs and maternal ability to invest, a concept described by evolutionary theory of parent–offspring conflict. In mammals this conflict has often been investigated studying weaning, transition from milk consumption dietary independence. An investigation individual variation in weaning can provide information on adaptive significance relation social biological variables. We analysed stable nitrogen isotopes hair samples collected 22 mother–infant dyads wild population chacma baboons, Papio ursinus, conjunction with behavioural data suckling, explore temporal dynamics as well extent determinants these dynamics. The pattern suggested isotope values were congruent. difference infant mother decreased faster age infants low-ranking mothers, which suggests progression towards perhaps due subordinate females experiencing lower resource availability so being less able bear costs lactation over prolonged periods. Additionally, within-infant showed an increase (which was not detectable infants), potentially highlighting nutritional that imposes offspring. Our combination analysis provides insight into evolution strategies. particular, it quantity care is affected her rank, possibly lactate for long benefiting earlier.