Self-suckling in Barbary Macaque (Macaca sylvanus) mothers before and after the death of their infant

Abstract

We report here self-suckling in four wild female Barbary macaques (Macaca sylvanus), living in two troops (i.e. ‘‘Flat face’’ and ‘‘Large’’ troop) in the middle-Atlas Mountains, Morocco. The four females lost their infants due to predation or for unknown causes. Self-suckling was observed before and after the infants died in the four females living in the ‘‘Flat face’’ troop. When the infants were still alive, self-suckling was of short duration and it was probably a method to improve milk flow when the infant switched from one nipple to the other. After the infants died, self-suckling lasted significantly longer and the females were apparently drinking their own milk. Self-suckling was never observed among the four lactating females in the ‘‘Large’’ troop (including one monkey who lost her infant) and it could thus represent a cultural difference. Moreover, self-suckling after the death of an infant may be explained by the energetic and immunological benefits that a monkey may gain from drinking their own milk. Finally, selfsuckling may have a stress-releasing effect on the mothers who have lost their infants