primates

Death without Weeping: Maternal Bonds towards Deceased Offspring among Non-Human Primates

Nonhuman primate mothers do not weep in response to death of their infants. When a non-human primate mother has her offspring, she has already invested considerably time as well as physical and metabolic energy to gestation and birth of the infant. Death of an infant, therefore, is detrimental to the mother who already invested in her offspring, as well as the group’s genetic continuity. Whether or not the death of non-human primate mother’s offspring elicits an emotional or affectionate response is more difficult to identify.

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Primatologists have long acknowledged the importance of death of a primate for calculations of demographic trends and constructing life tables (Altman and Altman, 1970). Studies of behavioral responses to death among rhesus macaques include elevated grooming levels between group members, possibly to counteract the loss of a group member. The living also engaged with the deceased by grooming, inspection, as well as aggression towards the corpse (Buhl et al., 2012). Female hamadryas baboons show increase in stress hormone levels after the death of a conspecific (Engh et al., 2006). Studies of chimpanzees group responses to pre- and post-death care of members of their cohort indicate that behaviors typically include close inspection and tests for signs of life at the moment of death, male aggression towards the corpse, all-night attendance by family members, cleaning of the corpse, and even avoidance of the place where death occurred (see Goodall, 1977, Anderson et al., 2010, and Biro et al., 2010).

Whether or not there exists a general trend of maternal responses to primate death remains poorly understood. The mother-offspring bond is considered to be one of the longest and most essential social bonds among mammals (Cronin et al., 2011). The maternal reposes associated with the permanent, premature disruption of this social bond—the death of the offspring—has rarely been investigated (Cronin et al., 2011). Early primatological studies documented male responses to dead infants among semi-free-ranging Barbary macaques (Merz, 1978). A long-term study of wild geladas from Ethiopia recorded 14 cases of dead infants being carried by females was the first attempt to explore responses to death in non-human primates, focusing on allomaternal-like behavior towards dead infant (Fashing et al., 2010). Primate death and behavioral responses from group members have also been documented from several sites, including the Gombe, Tai Forest, and safari park in Scotland (Teleki, 1973; Boesch and Boesch-Achermann, 2000; Anderson, 2011, respectively).

Primatological studies have documented instances when mothers continue to handle the corpses of their infants. Given this prolonged interaction, I wonder, does maternal attachment continues after the death of her offspring? If so, what triggers this particular behavior?

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Before I examine the behavioral responses to infant death, it is important to briefly describe what is considered “normal” mother-infant behavior among primate. Mothers and their infants represent a central focus of interest for other females in the group among species and groups of social primates (e.g. Hrdy 1976; Seyfarth 1976; Altmann 1980; Nicolson 1987; Maestripieri 1994a). Females visibly show their interest in interacting with newborn infants. When new infants are present in a group, subadult and nulliparous females approach the mothers and attempt to sniff, investigate, and pick up the young infants (Nicolson 1987). Females also have been observed grooming the mother in exchange for handling her new infant (Altmann, 1980, O’Brien & Robinson, 1991, Muroyama, 1994, Di Bitetti, 1997, Silk, 1999).

While female attraction to infants represents a common feature of primate species, maternal response to infant handling shows a certain degree of variability (Nicolson 1987; Maestripieri 1994b). Maternal responses to infant death have been attributed to several ecological and circumstantial explanations as well as several hypotheses in the primatological literature:

  • Unawareness of Death Hypothesis (Hrdy, 1999)
  • The Decomposition Hypothesis (Fashing et al., 2011)
  • Post-Parturient Condition Hypothesis (Kaplan, 1973; Biro et al., 2010)
  • “Learning to Mother” Hypothesis for Learning about Death (Warren and Williamson, 2004

Unawareness of Death Hypothesis

Extended carrying of a dead infant may indicate that the mother is unaware that her infant is no longer alive. According to the hypothesis, primate mothers of recently dead infants continue interacting with her infant exhibiting behaviors typical of new mothers, such as grooming and licking. For example, Kaplan (1972) recorded responses of captive female squirrel monkeys that were presented with the corpses of their dead infants. The infants had been dead for approximately two weeks. The mothers seemed unaware that their infant was no longer living, yet attempted to retrieve the corpse by lifting it or administer vocalizations regardless (Kaplan, 1972). However, these experiments do not simulate a situation that would occur in the squirrel monkeys’ natural environment. The mother’s infant was immediately retrieved after its death, which denied the mothers an opportunity to interact with her infant post-mortem.

Contrary to the hypothesis, there are examples of maternal behavior that shows the mother continues handling her infant while also exhibiting behaviors indicating that she is fully aware that her infant is no longer alive. A white-faced capuchin mother continued to groom and lick the body while trying to repel carnivorous insects from the corpse. She also allowed her dead infant to be fully submerged in water while she drank. Once she finished, she retrieved the corpse, and continued to transport her dead infant for several days (Perry and Manson, 2008). Similarly, chimpanzee mothers from Bossou, Guinea, appear to be aware that the bodies of the infants they carried were inanimate, and adopted carrying techniques not normally used with healthy juveniles (Biro et al., 2010).

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It is possible that uniparious mothers are unable to differentiation between living and non-living offspring due to a lack of experience. Studies have shown, however, that number of living offspring does not necessarily contribute to the duration for which in infant corpse is handled. Two multiparious snub-nosed monkey mothers carried and handled their dead infants for 4 days and one month. The mothers had had infants previously, and therefore could differentiate between normal, responsive infant behavior and abnormal, unresponsive infant behavior (Li et al., 2012). Similarly, multiparious chimpanzees mothers have been documented carrying their infant’s corpses for longer compared to the chimpanzee mothers carrying the corpse of their first and only offspring (Biro et al., 2010). Warren and Williamson (2004) also noted that two multiparious gorilla females also continued to handle their infants long after their death. Whether or not a primate mother is nulliparious or multiparious does not appear to influence how long she continues to interact with the corpse of her infant.

Overall, it appears that the unawareness of death hypothesis does not adequately explain the mechanism of maternal behaviors towards dead offspring. Continued handling of her infant does not necessarily suggest that she is unaware that her infant is not longer living; rather, the mother may be prolonging the separate from her infant for another reason.

The Decomposition Hypothesis

According to the decomposition hypothesis, any long-term carrying of the infant by the mother does not represent a sense of loss or attachment to the infant. Rather, mothers are unaware of the infant’s death and continue to carry the corpse until clear signals of decomposition (e.g. particular odor cues) indicate death (Fashing et al., 2010). Extreme climate conditions (such as cold or hot arid weather) slow the natural rate of decomposition of deceased bodies (Haglund and Sorg, 1997). Prolonged carrying (defined as longer than 10 days) of an infant corpse appears to be more likely in extreme climatic conditions, particularly in cold or hot arid weather, that naturally slows decomposition of infant body (Fashing et al., 2010).

Several studies of primates living in extreme climate conditions have supported the decomposition hypothesis. Gelada monkeys (Theropithecus gelada) of Guassa, Ethiopia, live in an extreme climatic condition that favors a slower rate of decomposition of dead individuals. Over a 3.75 year-long study period, 14 mothers carried and handled their mummified infants for 10 or more days. Extended carrying of dead infants has been documented among mountain gorillas that inhabit unusually cold environments (Fashing et al., 2010b, Nakagawa et al., 2010, Vedder, 1984) and chimpanzees living in extremely arid regions with a long dry season of Bossou, Guinea (Biro et al., 2010, Matsuzawa 1997).

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The decomposition hypothesis is based on another assumption that New World primates in tropical environments appear only to carry or care for dead infants rarely or for only a short period of time. For example, a tufted capuchin mother was reported to carry her dead infant for less than 24 hours after an infanticide attack (Izar et al., 2007). This behavior, however, may be due to the social dynamics of infanticide, rather than the maternal indifference towards her dead infant.

Despite the climatic circumstances that delay decomposition, primates have been documented to carry infants for a long enough period that the body does eventually decay. In this case, signs of decomposition, such as putrefaction and change in the infant’s appearance (e.g. loss of fur and limbs) do not repel mother and, in some cases, other kin and non-kin. For example, Bossou chimpanzee mothers as well as related and unrelated individuals from all age groups of both sexes attempted to handle, lift and drop limbs, and sniff the bodies of three dead infants. Juvenile and infants were even allowed to carry the bodies of infants some distance from the mother in bouts of play. Biro and colleagues (2010) state that they never observed a response that could be interpreted as aversion, despite the bodies’ intense smell of decay and usual appearance of mummified skin and missing fur.

Similarly, four female mountain gorilla continued to carry their dead offspring even when the corpses lost their hair and heads, and despite the pervasive smell of decaying flesh (Warren and Williamson, 2004). Observations made by Rumbaugh (1965) of captive squirrel monkeys in San Diego, California, noted that a mother continued to handle her infant for six weeks as the corpse began to putrefy. Over a 24-year study period of Japanese macaques, a total of 157 mothers continued to carry their dead infants between 1 to 17 days despite the quick progression of the decomposition, and the putrid smell and swarm of flies surrounding the dead infant and the mother (Sugiyama et al., 2009). In this case, however, non-kin avoided the mother and her dead infant, seemingly due to the smell, and she received less social grooming that before their infants had died (Sugiyame et al., 2009). Sugiyama and colleagues (2009) state that they cannot determine why mothers continue to carry the corpses given its bad state of decomposition. It is apparent, however, that mothers do not necessarily abandon their offspring due to aversion.

It is possible that “caretaking” behaviors rather than the environmental setting facilitates mummification. In the study conducted by Biro and colleagues (2010) in Bossou, Guinea, three chimpanzee mothers continued to carry the mummified corpses of their infants for 19, 27, and 68 days following their death, exhibiting extensive care of the body by grooming it regularly, sharing her day and night nests with it, and showing distress whenever they became separated. The mothers also chased away flies that circled the corpses, twice with the aid of a tool (Biro et al., 2010).

In sum, the decomposition hypothesis has several flaws. Infant handling is not limited to primates living in unusually arid, cold regions. In fact, mothers continue to handle their dead infants even though the corpses admit olfactory and visual signs of putrefaction and decomposition. Overall, it seems that the foul odor of decomposing flesh does not appear to deter mothers from transporting and manipulating corpses. Oftentimes, this “care-taking” behavior seems to (unintentionally?) preserve the offspring. Yet, this treatment towards dead infants will be explored in the post-parturient condition hypothesis.

Post-Parturient Condition Hypothesis

Post-parturient condition hypothesis proposes that postpartum hormones influence maternal behaviors toward dead infants. Physical characteristics and particular hormones are essential for the onset and maintenance of infant-carrying behavior and the development of the mother–infant bond towards living infants (Kaplan 1973; Biro et al. 2010). Neuroendocrine mechanisms and physical characteristics of the infant (such as natal attractiveness) stimulate and regulate motherly behavior to care for and protect her offspring (see Maestripieri, 2001, 1991). At birth, an infant’s attractiveness includes size at birth, vocalizations made by the infant (e.g. “purring” noises), infantile facial expressions, distinguishing morphological features such as bug ears or tail tufts, and distinctive coat color (Hrdy, 1976).

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Human, non-human primate, and non-primate mammal studies demonstrate that there are endocrine influences on mother-infant interactions and the formation of bond post-partum (Maestripieri, 1999). In non-primate mammals, pregnancy and lactation hormones enhance maternal responsiveness and behavior although they are not strictly necessary for their onset or maintenance (Stern, 1989). In New World monkeys such as red-bellied tamarins (Saguinus labiatus) and common marmosets (Callithrix jacchus), there is evidence that hormones influence both responsiveness to young during pregnancy and quality of maternal care during lactation (Pryce et al., 1993). Studies of group-living pigtail macaque females show that the females increased their rate of interaction with infants during the final weeks of pregnancy that corresponded with an increase in plasma levels of estradiol and progesterone (Maestripieri and Wallen, 1995; Maestripieri and Zehr, 1998). Fleming and colleagues (1997) showed that human mothers who maintained high levels of estradiol over the parturitional period also had higher feelings of attachment to their own infant in the early postpartum days than mothers whose estradiol levels dropped. Thus, these studies indicate that primate and human parenting is partially influenced by physiological variables.

The continued interaction and gradual separation between the mother and infants’ bodies appears to also be a by-product of hormonal condition of pregnancy and the formation of the mother-infant bond in post-parturient female primates. Behavioral studies note that mothers do not simply abandon the corpse of her dead infant. Rather, the mother continues to interact with the corpse, gradually separate herself physically from the body of her dead offspring.

There are several physiological characteristics that may be observed in female primates that indicate that hormone levels are fluctuating and therefore influencing her behavior. Postpartum amenorrhea in chimpanzees lasts around four years, but is shortened with the death of an infant (Wallis, 1997). The infant could no longer breastfeed and lactation ceased, triggering the mothers’ reproductive cycle to return.

To date, there are no studies that directly link changes in hormones during the mother’s transition from handling her infant until the moment she abandons its. Therefore, the post-parturient condition hypothesis relies on behavioral studies. Several behavioral studies report that mothers gradually separate herself from the corpse of her infant. For example, gelada monkey mothers also experience a graduate separation that includes a transition from only the mother handling the infant corpse, and then allowing other group members to handle to deceased juvenile (Fashing et al., 2010).

The post-parturient condition is best illustrated by observations conducted at Chimfunshi Wildlife Orphanage Trust, a chimpanzee sanctuary in Northwest Zambia (Cronin et al., 2010). Shortly after the death of her infant, the mother transitioned from maintaining close, constant proximity to the dead body to creating physical distance from the deceased infant (Cronin et al., 2010). She maintained visual contact with the body when not in immediate proximity to it. As time passes, mothers transition to lessening her contact with the body and allowing others to inspect the body (Biro et al., 2010; Hosaka et al., 2000). Other studies have also reported that chimpanzee mothers gradually transition from extreme attachment to the body of their dead infants immediately following death to weakened attachment to the body as time passes (Hosaka et al., 2000, Biro et al., 2010).

Ring-talked lemur (Lemu catta) mothers have been reported to continue to return to their dead infants several times for several hours after the infant’s death. Every time each female returned to the body, she would sniff, lick, and touch the infant (Nakamichi et al., 1996). Despite the increasing distance between the troop and the deceased infant, the mothers continued to return to her dead infant, even when the troop have moved 400 meters away from the corpse (Nakamichi et al., 1996). Six of the seven mothers attempted to lift the corpses, and one mother clumsily carried the corpse 15 meters and attempted to jump into a tree. Mothers were unable to maintain proximity between both the troop and the corpse concurrently because she was not able to carry her dead offspring (Nakamichi et al., 1996).

The post-parturient hypothesis appears to most adequately examine the mechanism of maternal handling and carrying of deceased infant remains. Carrying and handling a corpse after death expresses a strong attachment, and the gradual separation of mother from her dead infant are behavioral responses to hormonal changes. Whether or not death of an infant elicits a psychological or emotion response is difficult, possibly impossible to identify. To compliment the hormonal-centric tenants of the post-parturient hypothesis, I will explore literature that contemplates whether or not the prolonged carrying and handling of corpses is part of process in which primates “learn” about death.

“Learning to Mother” Hypothesis for Learning about Death

Studies of maternal responses to death among apes provide additional information investigating whether or not the extended interaction with infant corpses is a period during which primates engage in a learning process. The “learning to mother” hypothesis was first proposed by Hrdy (1976) to explain why female young and non-mothers interact so frequently with offspring. Warren and Williamson (2004) adapt this hypothesis to a population of mountain gorillas to illustrate that the prolonged handling of dead infants is a type of social learning for mothers, young, and non-mothers to acquaint themselves with cues typical of death.

Ateles geoffroyi vellerosus Spider Monkey Central America mother and baby

Primatologists have investigated the long-term benefits of young and non-mothers carrying living infants. The handling of live infants by non- mothers has been referred to as aunting, baby-sitting, kidnapping, play-mothering, allomaternal behavior, or allomothering (Hrdy, 1976; Maestripieri, 1994a, 1994b). According to the ‘‘learning to mother’’ hypothesis, young or nulliparous females who handle infants gain maternal experience, and recalling these skills later in life, making them more capable of raising their own offspring (Hrdy, 1976).

The benefits of “learning to mother,” could be gained with a corpse, since the motor skills required to carry an infant while traveling and foraging could still be acquired (Warren and Williamson, 2004). Furthermore, the extending carrying behavior by the mothers, as well as related and unrelated individuals, may be an example of observational learning that promotes prolonged transport of deceased young (Biro et al., 2010). These interactions with a corpse could be part of a process in which the primate learns to recognize death.

Observations of mountain gorillas at Karisoke Research Center, Rwanda, noted that two nullparious mothers in their final months of pregnancy, and two mothers who had recently lost offspring all handled and transported the mothers’ two dead infants (Warren and Williamson, 2004). As previously discussed, the hormonal disposition of the mother may contribute to the continued handle of her infant after death. The hormonal state of pregnant females similarly predisposes her to interact more frequently with infants, even ones that are recently dead. It seems it may be both an innate change in her physiology as well as an opportunity to practice handling infants.

Similarly, Cronin and colleagues (2010) suggest that chimpanzees handle and examine the body of deceased infants in order to recognize cues of a corpse and therefore “learn” about death. Studies conducted at Chimfunshi Wildlife Orphanage Trust, a chimpanzee sanctuary in Northwest Zambia, recorded that one chimpanzee mother touched the body and face of her dead infant, presumably an action that would have provided olfactory and gustatory information about the infant’s condition (Cronin et al., 2010). Every time she returned to the infant’s corpse, she would closely inspected its face and neck. Cronin and colleagues (2010) suggest that close inspection of the face could serve as the best location to assess the condition of the infant. No changes in eye gaze, breathing, or facial musculature could inform the mother that the infant’s condition had irreversible changed (Cronin et al., 2010). The mother was actively gathering novel sensory information about the dead infant, possibly remembering this information for the next time she encountered the same set of cues. In other words, the mother may have been “learning about death.” (Cronin et al., 2010: 420).

Whether or not prolonged handling of infants is indicative of a “cultural” behavior towards death that is passed on throughout the group and through generations may be impossible to prove. Yet, some researchers suggest that the transmission of knowledge for handling of dead infants that occurs throughout multiple generations and occurs among multiple members of a group may indicate that this learning and knowledge may be transferred (see Cronin et al., 2010; Warren and Williamson, 2004; and Biro et al., 2010). For example, three chimpanzee mothers at Bossou, Guinea, all had infants that died during the study period and all exhibited a similar manner of prolonged handling of dead infants. Biro and colleagues (2010) suggest that the similarities in treatments and behaviors may not be a rare occurrence in this particular community. In fact, the prolonged handling may part of the culture of that particular group. In sum, the learning to mother hypothesis provides an intriguing framework in which primatologists may explore prolonged infant handling among the great apes.

Mother-Infant Bonds and Learning to Grieve?

Overall, it appears there is continued attraction and care towards dead infants occurs to some extent in all major taxaonomic groups (Anderson, 2011). Both the decomposition and unawareness of death hypotheses seem insufficient to explain why primate mothers continue to handle the corpses of offspring after death. Contrary to the unawareness of death hypothesis, primate mothers appear to handle their infants in ways that suggest they are aware that their offspring is no longer living. Similarly, primate mothers continue to handle their dead infants regardless of the environmental setting (arid verses humid) and despite putrefaction and decomposition of the corpse.

The post-parturient condition hypothesis, on the other hand, considers both the behavioral and hormonal responses of primate mothers across primate taxa. The formation of the strong mother-infant bond at birth does not simply disappear once the infant dies; rather, it seems that the mother transitions from physiological conditions typical of motherhood (e.g. cessation of lactation amenorrhea) is concurrent with the mother’s gradual separation from and abandonment of her deceased infant.

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It is particularly interesting that mothers slowly allow conspecifics to handle the corpse, and that recognition of particular cues that signal death may illustrate that young and non-mothers are “learning” to recognize death. Whether or not the handling of dead infants should be considered cultural learning is difficult and potentially impossible to identify. Given that multiple mothers of a particular group of chimpanzees and gorillas all exhibited similar behaviors in response to the death of their infant indicates that the behavior may be contributed to both physiological and social influences.

Studies of primate death are greatly biased towards chimpanzees, but long-term and behavioral studies of gorillas, baboons, and new world monkeys are also becoming more common. Overall, primate behavioral and hormonal studies indicate that continued handling and interaction with infant corpses signifies a connection between the mother and her offspring, even if the offspring has died.

Bibliography

Altmann, J. 1980. Baboon Mothers and Infants. Cambridge, MA: Harvard University Press.

 

Altmann SA, Altmann J. 1970. Baboon ecology: African field research. Chicago: University of Chicago Press.

 

Anderson, JR. 2011. A Primatological Perspective on Death. American Journal of Primatology Commentary 73: 410-414.

 

Biro D, Humle T, Koops K, Sousa C, Hayashi M, Matsuzawa T. 2010. Chimpanzee mothers at Bossou, Guinea carry the mummified remains of their dead infants. Current Biology 20:R351–R352.

 

Boesch C, Boesch-Achermann H. 2000. The chimpanzees of the Ta ̈ı Forest: behavioural ecology and evolution. Oxford: Oxford University Press.

 

Buhl, JS, Aure, B, Ruiz-Lambides, A, Gonzales-Martinez, J, Platt, ML, Brent, LJN. 2012. Reponses of Rhesus Macaques (Macaca mulatta) to the Body of a Group Member That Died from a Fatal Attack. International Journal of Primatology 22: 860-871.

 

Cronin, KA, Van Leeuwen, EJC, Mulgenga, IC, Bodamer, MD. 2010. Behavioral Responses of a Chimpanzee Mother Toward her Death Infant. American Journal of Primatology 73: 415-421.

 

Di Bitetti, MS. 1997. Evidence for an important social role of allogrooming in a playtrrhine primate. Animal Behaviour 54: 199-211.

 

Engh, AL, Beehner, JC, Bergman, TJ, Whitten, PL, Hoffmeier, RR, Seyfarth, RM. 2006. Behavioral and hormonal responses to predation in female chacma baboons (Papio hamadryas ursinus). Proceedings of the Royal Society of London B: Biological Sciences 272: 707-712.

 

Fashing P, Nguyen N, Barry T, Goodale C, Burke R, Jones S, Kerby J, Lee L, Nurmi N, Venkataraman V. 2010a. Death among geladas (Theropithecus gelada): a broader perspective on mummified infants and primate thanatology. American Journal of Primatology 71:1–5.
Fashing P, Nguyen, N, Fashing NJ. 2010b. Behavior of geladas and other endemic wildlife during a desert locust outbreak at Guassa, Ethiopia: ecological and conservation implications. Primates 51: 193-197.

 

Fleming, AS, Ruble, D, Krieger, H, Wong, PY. 1997. Hormonal and experiential correlates of maternal responsiveness during pregnancy and the puerperium in human mothers. Hormones and Behavior 31: 145-158.

 

Goodall, 1977. 1977. Killings and Cannibalism in Free-Living Chimpanzees. Folia Primatologica 28: 259-282.

 

Haglund, WD, Sorg MH, editors. 1997. Forensic taphonomy: the postmortem fate of human remains. Boca Raton: CRC Press.

 

Hamai, M, Nishida, T., Takasaki, H, Turner, LA. 1992. New Records of Within-group Infanticide and Cannibalism in Wild Chimpanzees. Primates 33(2) 151-162.

Hosaka, K, Matsumoto-Oda, A, Huffman, MA, Kawanaka, K. 2000. Reactions to dead bodies of conspecifics by wild chimpanzees in the Mahale Mountains, Tanzania. Primate Research 16: 1-15.

 

Hrdy, SB. 1999. Mother nature: a history of mothers, infants, and natural selection. Pantheon Books, New York.

 

Hrdy, SB. 1976. Care and exploitation of nonhuman primate infants by conspecifics other than the mother. In: Advances in the study of behavior vol 6. (Ed. by Rosenblatt JS, Hinde RA, E S, Bier C) New York: Academic Press. 101–158

 

Izar, P. Ramos da Silva, ED, De Resende, BD. Ottoni, EB. 2007. A case of infanticide in tufted capuchin monkeys (Cebus nigritus). Mastozoologîa neotropical 14(1) 73-76.

 

Kaplan, J. 1973. Responses of mother squirrel monkeys to death infants. Primates 14: 89-91.

 

Li, T, Ren, B, Li, D, Shang, Y, Li, M. 2012. Maternal responses to dead infants in Yunnan snub-nosed monkey (Rhinopithecus bieti) in the Baimaxueschan Nature Reserve, Yunnan, China. Primates 52: 127-132.

 

Maestripieri, D. 2001. Is There Mother-Infant Bonding in Primates? Developmental Review 21: 93-120.

 

Maestripieri, D. 1999. The biological of human parenting: insights from nonhuman primates. Neruoscience and Biobehavioral Review 23: 411-422.

 

Maestripieri, D. 1994a. Mother-infant relationships in three species of macaques (Macaca mulatta, M. nemestrina, M. arctodies). I. Development of the mother-infant relationship in the first three months. Behaviour 131: 75-96.

 

Maestripieri, D. 1994b. Social structure, infant handling, and mothering styles in group-living Old World monkeys. International Journal of Primatology 15: 531-553.

 

Maestripieri, D, Wallen, K. 1995. Interest in infants varies with reproductive condition in group-living female pigtail macaques (Macaca nemestrina). Physiological Behavior 57: 353-358.

 

Maestripieri, D, Zehr, JL. 1998. Maternal responsiveness increases during pregnancy and after estrogen treatment in macaques. Hormones and Behavior 34(3): 223-230.

 

Matsuzawa, T. 1997. The death of an infant chimpanzee at Bossou, Guinea. Pan African News 4:1.

 

Merz, E. 1978. Male-male interactions with dead infants in Macaca sylvanus. Primates 19: 749-754.

 

Muroyama, Y. 1994. Exchange of grooming for allomothering in female patas monkeys. Behaviour 128: 103-119.

 

Nakagawa N, Nakamichi M, Sugiura, H, editors. 2010. The Japanese macaques. New York: Springer.

 

Nakamichi M, Koyama N, Jolly A. 1996. Maternal responses to dead and dying infants in wild troops of ring-tailed lemurs at the Berenty Reserve, Madagascar. International Journal of Primatology 17:505–523.

 

Nicolson, NA. 1987. Infants, mothers, and other females. In: Primate Societies (Ed. by B. Smuts, D. Cheney, R. Seyfarth, R. Wrangham & T. Struhsaker) 330-342. Chicago: Chicago University Press.

 

O’Brien, TG and Robinson, JC. 1991. Allomaternal care by female wedge-capped capuchin monkeys: effects of age, rank and relatedness. Behaviour 119: 30-50.

 

Perry S, Manson JH. 2008. Manipulative monkeys: the capuchins of Lomas Barbudal. Cambridge, MA: Harvard University Press.

 

Pryce, CR, Dobeli, M, Martin, RD, 1993. Effects of sex steroids on maternal motivation in the common marmoset (Callithrix jacchus), development and application of an operant system with maternal reinforcement. Journal of Comparative Psychology 107: 99-115.

 

Rosenson, LM. 1977. The response of some prosimian primate mothers to their own anesthetized infants. Primates 18: 579-588

 

Rumbaugh DM. 1965. Maternal care in relation to infant behavior in the squirrel monkey. Psychological Reports 16: 171–176.

 

Scheper-Hughes, N. 1992. Death Without Weeping: The Violence of Everyday Life in Brazil. Berkeley, CA: University of California Press.

 

Scheper-Hughes, N. 1984. Infant mortality and infant care: Cultural and economic constraints on nurturing in Northeast Brazil. Social Science & Medicine 19(5): 535-546.

 

Seyfarth, RM. 1976. Social relationships among adult female baboons. Animal Behavior 24: 917–938

 

Silk, JB. 1999. Why are infants so attractive to others? The form and function of infant handling in bonnet macaques. Animal Behaviour 57: 1021-1032.

 

Stern, J. 1989. Maternal Behavior: Sensory, Hormonal, and Neural Determinants. In: Psychoendocrinology (Ed. by FR Brush, S Levine) 105-225 San Diego, CA: Academic Press.

 

Sugiyama, Y, Kurita, H, Matsui, T, Kimoto, S, Shimomura, T. 2009. Carrying of dead infants by Japanese macaques (Macaca fuscata) mothers. Anthropological Science 117: 113-119.

 

Teleki G. 1973. Group responses to the accidental death of a chimpanzee in Gombe National Park, Tanzania. Folia Primatologica 20:81–94.

 

Vedder, A. 1984. Movements patterns of a group of free-ranging mountain gorillas (Gorilla gorilla beringei) and their relation to food availability. American Journal of Primatology 7: 73-88.

 

Wallis, J. 1997. A survey of reproductive parameters in the free-ranging chimpanzees of Gombe National Park. J. Reprod. Fertil. 109: 297–307.

 

Warren Y, Williamson EA. 2004. Transport of dead infant mountain gorillas by mothers and unrelated females. Zoo Biology 23:375–378.

 

 

Anatomy and Behavioral Strategies of Human and Nonhuman Primate Parturition

In March of 2000, Sofia Pedro’s village in Mozambique was ravaged by floods. People were forced to higher grounds to avoid the floodwaters, and many people, including the heavily-pregnant Sofia Pedro, were climbed to shelter in the treetops. She was trapped in the tree for four days. On the third day, she gave birth to her daughter, Rositha.

Giving birth in the treetops is unusual for humans, but not for many primate species.

Stories like Sofia’s are particularly interesting because they pose the question: are humans unique in that they alone experience difficulties during birth? Do both human and nonhuman primates therefore adopt methods and strategies to minimize the risk and maximize survival of themselves and their offspring?

In other words, is there a gap in human and nonhuman primate parturition behavior?

To investigate the similarities and differences between human and nonhuman primate parturition strategies, one must examine 1.) the Anatomical characteristics to examine the physical difficulties humans and primates face when giving birth and 2.) Parturition strategies, in other words, how human and nonhuman primates manage birth and improve probability of survival of both the mother and infant.

Anatomical Characteristics 

The human and nonhuman birth canal divided into three transverse planes: the inlet, midplane, and outlet (fig. 1). Each plane is described as being either longest at either the anterior-posterior diameter or widest at the transverse diameter. Each plane may be aligned, meaning all three planes parallel to one another, or misaligned, the planes are perpendicular to one another, with the greatest diameter varying among the three planes

Figure 1. Pelvic inlet, midplane, and outlet

In the genus Pan birth canal, for example, the anterior-posterior diameter exceeds the transverse diameter. In Australopithecine (specifically A. aferensis) the pelvis inlet transverse diameter exceeds the anterior-posterior diameter, resulting in a platypelloid shape (i.e. a flat, oval shape). Among humans the three transverse are all misaligned; the inlet is widest transversely, and the outlet widest anterior-posteriorly; thus creating two perpendicular planes.

Figure 2. Comparison for the mechanism of birth in Pan, A.L. 288-1 (Australopithecus aferensis) and Homo (Tague and Lovejoy, 1986: 247)

The Australopithecine birth canal is an example of how useful it is to reconstruct and understand changes in birth and parturition among human and nonhuman primate ancestors.

Australopithecus serve as one of the earliest sources of fossil material for examining early human bipedalism, and for the purpose of this post, mechanisms of birth.  The cranial capacity of Australopithecus similar to that of modern chimpanzees. Pelvic and limb morphology indicate Australopithecines was bipedal, not but obligatory like our hominid ancestors. Australopithecines also had an increase in shoulder breadth co-occurs with bipedalism, helping with balance.

Australopithecine birth canal would have restricted fetal head rotations at all levels within the canal. Yet, the birth canal was adequate to allow passage of a neonate’s cranium only if the infant’s head entered with its occipital bone oriented transversely with ansynclitism, meaning the neonatal head tilted towards its left or right shoulder, and exited without rotating. The shoulders which followed probably would not have been able to pass through without changing orientation.

It is more difficult, if not impossible, to determine whether or not Australopithecines gave birth in solitude, among conspecifics, or sought attendants to assist with birth. Trevathan (1987) suggests that the presence of attendants at childbirth has been part of the genus heritage for at least one million to two million years, originating with encephalization in our linage. Hominid ancestors would have been able to give birth without assistance, but having that assistance and support would have made the difference between life and death for mothers and their infants. A slight reduction in mortality would lead to selection for the behavioral characteristic of seeking companionship during parturition, resulting in its widely universal distribution in the modern human species.

Anatomical Features of Human and Nonhuman Primate Birth

Sherwood Washburn referred to the human birth as the “obstetric dilemma,” resulting from the shrunken dimensions of the human birth canal mandated by the mechanical requirements of upright bipedal locomotion and the evolution of progressively larger human brains (Washburn, 1960). Among humans, the fetal head must be flexed as it passes underneath the subpubic arch/pubic symphysis, with the occiput against the pubic bones, the frontal bone passing along the concave anterior surface of the sacrum.  The infant’s head then emerges from the canal occiput anterior: meaning that the infant generally emerges from the birth canal facing the opposite direction from the mother.

Primate mechanism of parturition is slightly more difficult to investigate because observations and accounts of primate births in the wild are scarce. Primatologists who have observed primate births note the difficulties in differentiation between pregnant and non-pregnant females until the pregnant female is actually in labor. Also, some primates give birth nocturnally, thus lower the changes that they will be observed, and some even seclude themselves in the foliage of trees during parturition. Among greater apes, the spacious birth canal and large body size allow for the neonate to easily navigate the birth canal. Small-bodies primates and lesser apes (Ateles), proboscis monkeys (Nasalis), macaques (Macaca), and lesser apes or gibbions (Hylobates), have a smaller head-to-body proportions, thus potentially complicated the birthing process. In her PhD dissertation, Stoller (1995) examined radiographs of laboratory animals during parturition showed that squirrel monkey and baboon neonates entered the birth canal in various positions, but then rotate to exit face first, facing the maternal pubic bones with their heads in an extended position.

Human Primate Birthing Strategies 

Humans have adopted many strategies to combat the risks and difficulties in childbirth, one of which is seeking assistance from medical professionals or family members during the birth. Humans do have the ability to give birth without assistance, yet today many women giving birth prefer not to do it alone. Before the advent of modern obstetric care, pregnancy and childbirth were risky and dangerous, and the complex anatomical features involved in parturition predisposed humans to certain conditions, such as obstructed labor, which could result in a myriad of injuries to both the mother and infant (Roberts and Mancester, 2007; Arrowsmith et. al., 1996; Wall et. al., 2005). Thus, many women in developed societies view childbirth as an event to be managed with the presences of a trained professional using technological intervention (Liamputtong. 2007) to ensure that their pregnant bodies and fetuses are completely controlled, and therefore, safe (Liamputtong, 2007). To be sure there are benefits in having a trained medical professional present at the birth.

Obstructed births are a common complication humans face, one type in particular is shoulder dystocia, which occurs when the shoulders are unable to pass through the pelvis after delivery of the head when the neonate is too large and the pelvis too small. The typical medical intervention is a surgical incision to remove obstruction, which may be dangerous as it sometimes results in tearing or hemorrhaging, either of which might cause permanent damage or be fatal to the mother, infant, or both. Midwifes, on the other hand, adopt different strategies to combat shoulder dystocia: typically the maneuvers the parturent mother into different positions to widen the birth canal.

Birth positions in particular vary cross-culturally. Even though the semi-upright positions of kneeling and sitting are the best positions for parturition, the supine position is the most common in developed countries where birth typically occurs in a hospital. It is possible that many women do not have the stamina to remain in kneeling or sitting position for the length of time usually required to deliver a child. The supine position allows the medical professional to have optimal access to the birth canal as well. Interestingly, Friedman (1978) found that in general, the upright position is optimal for increasing intra-abdominal pressure and the diameter of the pelvis. Women who were upright in a seated or semi-reclined position during labor had a shorter labor length compared to women in a supine position (Friedman 1978).

Many women assign certain meanings to the birthing process; they feel a sense of achievement and pride in their ability to cope with intense pain. Mayan women living in Guatemala stated that they accept pain as an obligation of a woman’s life, and consider it a point of pride to confront the birth with stoic dignity and courage. In fact, the indigenous word for birth (patan) literally translates into “burden.”

Expressing and vocalizing any pain was, to some women, considered shameful because they believe such actions like screaming diverted energy needed to give birth. This is particularly true for Chinese women, who are also expected to use soft voices and demonstrate quiet demeanor during parturition.

Parturition Behaviors Among Nonhuman Primates 

Anatomically, it appears that the mechanism of parturition varies between primate species, specifically between large bodied and small-bodied apes. When scholars opine that primates have little to no problems during parturition, they do not consider the extrinsic challenges primates encounter when giving birth in their natural habitat. Observations of baboons reveals that females give birth among conspecific group members. Squirrel monkeys give birth within their group as well as a form of cooperation against predators, anti-predator vigilance, and defense of neonates. Among Chimpanzees, Goodall (1971) noted that pregnant females become more solitary as parturition approaches. Among some primates, females seek seclusion and take advantage of the tree foliage that provides a natural protection from terrestrial predators (Rosenberg and Trevathan 2002). In a study published in Primates in July 2014, primatologists observed a bonobo birth for the first time, and found that the parturent female was accompanied by two other females who, according the researchers, were “offering companionship and support.” After the birth, the mother as well as the so-called birth attendants all consumed the placenta.

Primate births may be diurnal verses nocturnal; in fact, primates give birth at times of day that offer the lowest predation risk. Among squirrel monkeys labor may being at dawn, and if the infant has not been birthed by daytime, labor will spontaneously stop and start again during the appropriate time, most likely during dusk.

Primates also maneuver into positions to widen pelvis, particularly among smaller-bodied primates with a very close caphalopelvic fit (e.g. macaca mullata). Primates also express pain when giving birth. Patas, Rhesus macaques, and bonobos have been observed having pained looks on faces and express said pain with vocalizations. Breeched births might occur among primates with a close cephalopelvic dimension, such as macaca mullata, rhesus macaques, spider monkeys.

So How Wide is the Parturition Gap?

The mechanism of birth appears to be more complex for humans, small-bodied primates, and lesser apes than compared to larger-bodied, greater apes. Humans opt to seek assistance during birth and while primates sometimes opt to give birth among group members, it is unclear whether or not primates actively seek birth attendants. Primates maneuver in positions optimal for birth while humans in medicalized cultures give birth in a less optimal, supine position; maybe humans should consider a primate model for birthing positions! Both human and nonhuman primates experience pain when giving birth, yet humans are unique in that they assign cultural meaning to their pain.

In sum, both face similar challenges when giving birth, yet the adaptive methods to overcome those challenges varies between species worldwide. It seems to be that the parturition gap between human and nonhuman primates is not a wide gap after all.

             

Sources:

Abitbol, M. (1996). Birth and Human Evlution; Anatomical and Obstertical Mechanics in Primates. Westpoint: Bergin & Garvey.

Abitbol, M. (1987). Obstetrics and psoture in pelvic anatomy. Journal of Human Evolution, 16, 243-256.

Arrowsmith, S., Hamlin, E., and Wall, L. (1996). “Obstructed labor injury complex”: obsteteric fistual formation and the mulitfaceted morbidity of maternal birth trauma in the developing world. Ostetrical and Gynecological Survey, 51, 568-574.

Berge, C. (1984). Obstetrical interpretation of the australopithecine pelvic cavity. Journal of Human Evolution, 13, 573-587.

Berge, C., and Ponge, J. (1983). Les caracteristiques de bassin des australopitheques (A. robustus, A. africanus, A. afarensis) sont elles licees a une bipedie de type humain?

Bulletins et Mémoires de la Société d’Anthropologie de Paris, 10, 335-354.

Berge, C., and R. Orban-Segebarth, P. S. (1984). Obstetrical Interpretation of the Australopithecine Pelvic Cavity. Journal of Human Evolution, 7, 573-587.

Boinski, S. (1987). Birth synchrony in squirrel monkeys (Saimiri oetstedi). Behavioral Ecology and Sociobiology, 21, 393-400.

Brandt, E., and Mitchell, G. (1971). Parturition in primates: behavior related to birth. In Primate Behavior: Developments in Field and Laboratory Research L. Rosenblum (Ed.), (Vol. 2, pp. 177-223). New York: Academic Press.

Chism, J., Olson, D., and Rowell, T. (1983). Diurnal Births and Perinatal Behavior Among Wild Patas Monkeys: Evidence of an Adaptive Pattern. International Journal of Primatology, 4(2), 167-184.

Clark, L., Khalaf, I., Semenic, S., Kartchner, R., and K.Vehvilainen-Julkunen. (2003). The Pain of Childbirth: Perceptions of Cultually Diverse Women. Pain Management Nursing, 4(4), 145-154.

DeSilva, J., and Lesnik, J. (2008). Brain size at birth throughout human evolution: A new method for estimating neonatal brain size in hominins. Journal of Human Evolution, 55, 1064-1074.

Dunbar, R.I.M. and Dunbar, P. (1974). Behavior related to birth in wild gelada baboons (Theropithecus gelada). Behavior, 185-191.

Friedman, E. (1978). Labor: Clinical Evaluation and Management. New York: Appleton-Century-Crofts.

Goodall, J. (1971). In the Shadow of Man. New York: Dell.

Gorzitze, A. (1996). Birth-related Behaviors in Wild Proboscis. Primates , 37 (1), 75-78.

Hausler, M., and Schmid, P. (1995). Comparisons of the pelves of Sts 14 and Al 288-1: implications for birth and sexual dimorphism in australopithecines. Journal of Human Evolution, 29, 363-383.

Hopf, S. (1967). Notes on pregnancy, delivery and infant survival in captive squirrel monkeys. Primates, 8, 323-332.

Kadam, K., and Swayamprabha, M. (1980). Parturition in the slender loris (Loris tardigradus lydekkerianus). Primates, 21, 567-571.

Kibii, J., Churchill, S., Schmid, P., Carlson, K., Reed, N., de Ruiter, D., et al. (2011). A Partial Pelvis of Australopithecus sediba. Science, 333, 1407-1411.

Kummer, H. (1968). Social Organization of Hamadryas Baboons. Basel: Karger.

Leaky, M., Feibel, C., McDougall, I., & Walker, A. (1995). New four-million-year-old hominidspecies from Kanapoi and Allia Bay, Kenya. Nature , 376, 565-571.

Lefebvre, L., and Carli, G. (1985). Parturition in Non-Human Primates: Pain and Auditory Concealment. Pain , 21, 315-327.

Likens, E. (2013). Resolving Shoulder Dystocia: Is Episiotomy Best Practice? Midwifery Today, 44-45.

Lipscomb, K. (1994). Shoulder dystocia. In D. M. Brenner (Ed.), Management of Common Problems in Obstertrics and Gynecology (pp. 227-232). London: Blackwell Scientific.

McKenna, J. (1974). Perinatal behavior and parturition of a Colobinae Presbytis entellus entullus (hanuman langur). Lab. Primate Newsletter, 13, 13-15.

Mir, S., & Ahmad, A. (2010). Shoulder Dystocia. Journal of Medical Education and Research, 12 (4), 165-167.

Oppenheimer, J. (1976). Presbytis entellus: Birth in free-ranging primate troop. Primates, 17, 541-542.

Rawal, J., Shah, A., Stirk, F., & Mehtar, S. (1994). Water birth and infection in babies. British Medical Journal , 309, 511.

Roberts, C., & Mancester, K. (2007). The Archaeology of Disease. Ithaca: Cornell University Press.

Rosenberg, K. (1992). The evolution of modern human childbirth. Yearbook of Physical Anthropology, 35, 89-124.

Rosenberg, K. and Trevathan, W. (2001). The Evolution of Human Birth. Scientific American, 285(5), 72-71

Rosenberg, K., and Trevathan, W. (2002). Birth, obstetrics and human evolution. International Journal of Obsterics and Gynaecology, 109, 1199-1206.

Ruff, C. (1995). Biomechanics of the hip and birth in early Homo. American Journal of Physical Anthropology, 98, 527-574.

Schultz, A. (1949). Sex differences in the pelves of primates. American Journal of Physical Anthropology, 7, 401-423.

Sekulic, R. (1982). Birth in free-ranging howler monkeys Alouatta seniculus. Primates, 23, 580-582.

Smeltzer, A. (1986). Prevention and management of shoulder dystocia. Clinical Obstetrics and Gynecology, 29, 299-308.

Stoller, M. (1995). The obstetric pelvis and mechanism of labor in nonhuman primates. [PhD dissertation]. University of Chicago.

Strum, S., and Fedigan, L. (2000). Changing Views of Primate Society. In Primate Encounters (pp. 3-49). S. Strum, & L. Fedigan (Eds.), Chicago and London: University of Chicago Press.

Suzuki, M., T. Ono, M. K., and Cho, F. (1990). Hour of Delivery in Cynomolgus Monkeys Under Indoor Individually-caged Conditions. Primates, 31 (2), 215-255.

Tague, R., and Lovejoy, C. (1998). A. L. 288-1—Lucy or Lucifer: gender confusion in the Pliocene. Journal of Human Evolution, 35(1), 75-94.

Tague, R., and Lovejoy, C. (1986). The Obstetric Pelvis of A.L. 288-1 (Lucy). Journal of Human Evolution, 15, 237-255.

Takeshita, H. (1961-1962). On the delivery behavior of squirrel monkeys (Saimiri sciurea) and a mona monkey (Ceropithecus mona). Primates, 3(1), 59-72.

Tinklepaugh, O., and Hartman, C. (1930). Behavioral aspects of parturition in the monkey (Macascas rhesus). Comparative Psychology 11, 63-98.

Trevathan, W. (1988). Fetal emergence patterns in evolutionary perspective. American Anthropology, 90, 674-681.

Trevathan, W. (1987). Human Birth: An Evolutionary Perspective . New York: Aldine de Gruyter.

Trevathan, W. (2003). The evolution of bipedalism and assisted birth. Medical Anthropology Quarterly, 10, 287-298.

Trevathan, W., and Rosenberg, K. (2000). The shoulders follow the head: postcranial constraints on human childbirth. Journal of Human Evolution , 39, 583-586.

Wall, L., Arrowsmith, S., and Briggs, N. (2005). The obstetric vesicovaginal fistula in the developing world. Obstetrical Gynecological Survey, 60, S1-S55.

Ward, C. (2002). Interpreting the posture and locomotion of Australopithecus afarensis: where do we stand?. Yearbook of Physical Anthropology, 45, 185-215.

Washbum, S. (1960). Tools and human evolution. Scientific American, 203, 3-15.

White, T. (2000). Human Osteology. San Diego: Academic Press.

Wittman, A., & Wall, L. (2007). The Evolutionary Origins of Obstructed Labor: Bipedalism, Encephalization, and the Human Obstetric Dilemma. Obstetrical and Gynecological Survey, 62 (11), 739-748.

Wolpoff, M. (1999). Paleoanthropology. Boston: McGraw-Hill.

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