Food Sharing across Borders

Abstract

Evolutionary models consider hunting and food sharing to be milestones that paved the way from primate to human societies. Because fossil evidence is scarce, hominoid primates serve as referential models to assess our common ancestors’ capacity in terms of communal use of resources, food sharing, and other forms of cooperation. Whereas chimpanzees form male-male bonds exhibiting resource-defense polygyny with intolerance and aggression toward nonresidents, bonobos form male-female and female-female bonds resulting in relaxed relations with neighboring groups. Here we report the first known case of meat sharing between members of two bonobo communities, revealing a new dimension of social tolerance in this species. This observation testifies to the behavioral plasticity that exists in the two Pan species and contributes to scenarios concerning the traits of the last common ancestor of Pan and Homo. It also contributes to the discussion of physiological triggers of in-group/out-group behavior and allows reconsideration of the emergence of social norms in prehuman societies.

Inter‐group aggressive interaction patterns indicate male mate defense and female cooperation across bonobo groups at Wamba, Democratic Republic of the Congo

“…Cooperation across groups is often considered as a uniquely human characteristic (Hill et al, ), but bonobos are known to share food with out‐group individuals (Tan & Hare, ; Fruth & Hohmann, ; Yamamoto, Tokuyama, & Ryu, unpublished data). Here, we provide further evidence of cooperation across groups in this species, in the form of coalitions.…”

“…Groups of bonobos encounter each other frequently and may mingle and range together for anywhere from a few hours to a few days, especially when fruit is abundant (Hohmann & Fruth, ; Idani, ; Kano, ; Sakamaki, Ryu, Toda, Tokuyama, & Furuichi, ). During these inter‐group associations, bonobos interact with out‐group individuals both aggressively and affiliatively (such as grooming, playing, copulating, and food sharing), and have never been observed to kill out‐group individuals, including infants (Fruth & Hohmann, ; Furuichi, ; Hohmann & Fruth, ; Idani, ; Wilson et al, ). Such inter‐group relationships in bonobos differ from those in chimpanzees ( Pan troglodytes ), despite these two Pan species being closely related and having similar basic social organizations (Boesch, Hohmann, & Marchant, ; Wrangham, ).…”

Evaluating the self‐domestication hypothesis of human evolution

“…71,72 In addition, bonobos, unlike chimpanzees, readily share food with strangers 73 and also, unlike chimpanzees, show contagious yawning in response to strangers. 74 Wild bonobos have recently also been seen to share meat with members of other communities, 75 something unimaginable among chimpanzees.…”

Intergroup food transfers in wild golden lion tamarins (Leontopithecus rosalia)

“…The six observations clearly show that sharing food with strangers is not a uniquely human or great ape characteristic. As with bonobos, it is possible that this sharing between members of different groups show a new level of tolerance in golden lion tamarins (Fruth & Hohmann, 2018). However, unlike bonobos, the food resources that were transferred between the golden lion tamarins were easily monopolisable by just one individual, and unlike Fruth & Hohmann (2018), I do not think that our data helps explain the emergence of social norms in human societies.…”

“…As with bonobos, it is possible that this sharing between members of different groups show a new level of tolerance in golden lion tamarins (Fruth & Hohmann, 2018). However, unlike bonobos, the food resources that were transferred between the golden lion tamarins were easily monopolisable by just one individual, and unlike Fruth & Hohmann (2018), I do not think that our data helps explain the emergence of social norms in human societies. Although sharing between groups might have played an important role in human evolution, I suggest, like Westergaard & Suomi (1997), that such sharing between groups evolved independently in different primate linages.…”