Social tolerance in bonobos (Pan paniscus): what underlies individual and group variation?

Melissa Vanderheyden
Persbericht

Social tolerance in bonobos (Pan paniscus): what underlies individual and group variation?

Bonobo Black Friday

Wat gebeurt er als je een groep mensapen gelijktijdig laat grabbelen in een hoop pinda’s? Een recente studie neemt onder de loep hoe verdraagzaam bonobo’s zijn als er lekker eten in de buurt is. Daaruit blijkt dat de ene bonobo de andere niet is.Stel je voor: na een lange lezing ben je eindelijk op de receptie aanbeland. Iedereen heeft honger, maar tot in de verste hoeken van de zaal valt geen eten te bespeuren. Plots is hij daar. De reddende engel in zwart-wit, een zilveren plateau vol lekkers hoog boven het hoofd geheven. De kelner baant zich een weg door de massa en arriveert in jouw groep. Eindelijk oog in oog met die heerlijk geurende gefrituurde scampi’s. Iedereen kijkt. Je hoort je buurman krampachtig zijn overmatige speekselproductie onder controle houden. Wie slaat eerst toe?In dit soort situaties weten de meeste mensen doorgaans hun fatsoen te behouden. Bij apen ligt dat echter anders, zij kennen geen sociale regels. Toch?Een recente studie onderzoekt de verdraagzaamheid van bonobo’s in de nabijheid van voedsel. Op die manier wordt aan het licht gebracht of bepaalde apen elkaar beter tolereren, en wie liefst het verst uit elkaars buurt blijft. Door te kijken naar de koppels waarbij de tolerantie het hoogst is kan je afleiden welke relaties het belangrijkst zijn in de bonobomaatschappij.

Grabbelfestijn

Black Friday, de vrijdag na Thanksgiving waarop verkopers in de VS met mooie koopjes de klanten tot waanzin drijven. Wie kent de beelden niet? Ongeduldige wachtrijen voor winkeldeuren ’s ochtends. Mensen die trekken en duwen voor dat laatste, felbegeerde exemplaar. Voor het meten van de tolerantie bij bonobo’s wordt iets gelijkaardigs georganiseerd: een pindaversie van Black Friday. De geliefde pinda’s – ze heten niet voor niets apennootjes – worden verspreid over een afgebakend stukje grond. De bonobo’s worden losgelaten en … het grabbelen kan beginnen. De verdraagzaamheid per koppel wordt getest door de tijd die ze doorbrengen in elkaars buurt af te klokken.

Grumpy old bonobo

Wat blijkt? Niet alle apenkoppels zijn even (on)verdraagzaam. Bevriende koppels, bonobo’s die elkaar vaak vlooien, vertonen meer verdraagzaamheid. Hetzelfde geldt voor apen die dicht bij elkaar staan in de dominantierangorde.Ook blijkt dat oudere apen minder verdraagzaam zijn. Dat roept meteen associaties op met ongeduldige senioren in de supermarkt. Het grumpy old man syndroom, in Engelse bewoording. Er zou wel eens een grond van waarheid in kunnen zitten. Een andere bevinding was immers dat bonobovrouwtjes toleranter zijn dan mannetjes. Dat laatste komt mogelijk doordat deze soort ‘meiden aan de macht’ in het vaandel draagt, en de bondgenotes maar beter op goede voet staan met elkaar. Het is natuurlijk ook mogelijk dat die mannetjes net knorrig worden van het leven onder de knoet van de vrouwen, al is dat voorlopig een wilde hypothese.

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Universiteit of Hogeschool
Biologie, afstudeerrichting 'Evolutie & gedrag'
Publicatiejaar
2015
Kernwoorden
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