Female sociality during the daytime birth of a wild bonobo at Luikotale, Democratic Republic of the Congo

Abstract

Parturition is one of the most important yet least observed events in studies of primate life history and reproduction. Here, I report the first documented observation of a bonobo (Pan paniscus) birth event in the wild, at the Luikotale Bonobo Project field site, Democratic Republic of the Congo. The nulliparous mother's behaviour before, during and after parturition is described, along with reactions of other community members to the birth and the neonate. Data were collected through focal-animal observations, and the events postpartum were photo-documented. The behaviour and spatial distribution of party members were recorded using scan samples. Parturition occurred during the late morning in a social context, with parous females in close proximity to the parturient mother. Placentophagia occurred immediately after delivery, and the parturient shared the placenta with two of the attending females. I compare this observation with reports of parturition in captive bonobos, and highlight the observed female sociality and social support during the birth event. Plausible adaptive advantages of parturition occurring in a social context are discussed, and accrued observations of birth events in wild and free-ranging primates suggest that females may give birth within proximity of others more frequently than previously thought. This account contributes rare empirical data for examining the interface between female sociality and parturition, and the evolution of parturitional behaviours in primates.

Factors of influence and social correlates of parturition in captive Campbell's monkeys: Case study and breeding data

“…We found that births in our captive conditions occurred systematically at night, like most observed births in most diurnal primates (Alford, Nash, Fritz, & Bowen, ; Jolly, ; Nekaris, ; van Schaik, )—although not systematically as deliveries sometimes occur in the morning (Douglas, ; Duboscq et al, ; Graham‐Jones & Hill, ; Ratnayeke & Dittus, ; Yang, Zhang, Huang, Garber, & Li, ) but very rarely in the afternoon (Condit & Smith, ; DeLuycker, ; Dias, ; Stewart, ; Turner et al, ). The common explanation is that this protects females from various dangers, mainly predators and aggressive conspecifics (van Schaik, ).…”

“…This is due to the unpredictability and typically nocturnal occurrence of delivery in most primate species (Brandt & Mitchell, ; Jolly, ). Consequently, photographically illustrated descriptions of labor and parturition are also scarce (Douglas, ; Duboscq, Neumann, Perwitasari‐Farajallah, & Engelhardt, ; Turner et al, ). However, information concerning primate behavior before, during, and after birth is important as identification of intra‐ and inter‐specific behavioral variations would contribute to a better understanding of the evolution of primate reproductive strategies (Brandt & Mitchell, ).…”

“…Indeed, subordinate females had more sons when they were young, while dominant females had more sons when they were old (Packer, Collins, & Everly, ). Interspecific variation in individual and social behaviors during the perinatal period has also been observed, in particular those associated with labor contractions and parturition (e.g., Brandt & Mitchell, ; Douglas, ; Jolly, ; Turner et al, ). Key factors of flexibility seem to be the level of environmental disturbance, notably predation, and the degree of social tolerance of the species (Douglas, ; van Schaik, ).…”

Comparative primate obstetrics: Observations of 15 diurnal births in wild gelada monkeys (Theropithecus gelada) and their implications for understanding human and nonhuman primate birth evolution

“…In almost all human cultures, childbirth is a social event at which midwives, relatives or friends provide assistance or support to the expectant mother (Rosenberg & Trevathan, ; Trevathan, ). Although direct assistance with birth has rarely been reported in nonhuman primates (Trevathan, ), the presence of conspecifics nearby (<5 m) at birth have recently been reported in several species (DeLuycker, ; Douglas, ; Turner et al, ). These and earlier reports of female primates giving birth within sight of other group members (e.g., Gorzitze, ; Moreno, Salas, & Glander, ; Peker, Kowalewski, Pave, & Zunino, ; Stewart, ) suggests that complete isolation from conspecifics during birth may not always be possible—or desirable—for female primates.…”

“…Even in the rare instances when births have been observed in the wild, poor visibility in the arboreal environments where most primates live often prevents researchers from observing one or more phases of the birth process (e.g., the moment of delivery: Brogan & Cords, ; Douglas, ; Martins, Chaves, Neves, & Bicca‐Marques, ). Thus, the behaviors common to primates during the entire birth process have been difficult to identify (Rosenberg & Trevathan, ).…”