Path breaking research on savanna chimpanzees at Fongoli, Senegal

Now, here comes a big surprise, a fact that is turning topsy-turvy our understanding of animal behaviour.

Sharing food has always been thought of as a defining characteristic of human beings.  Chimpanzees (Pan troglodytes) are one exception, as they commonly transfer meat among non relatives. Latest Research by Jill Pruetz and Stacy Lindshield from Iowa State University has conclusively proved that chimpanzees from her Fongoli research site in Senegal frequently share food and hunting tools with other chimps. This is the first study to document non-meat sharing behavior.

The researchers examined four hypotheses that have been applied to food transfer in apes:

(1) Testing for male-coercive tendency (van Noordwijk and van Schaik, Behav Ecol Sociobiol 63:883-890, 2009),

(2) Costly signaling (Hockings et al. PLoS ONE 2:e886, 2007),

(3) Food-for-sex (Gomes and Boesch, PLoS ONE 4:5116, 2009), and

 (4) sharing-under-pressure (Gilby, Anim Behav 71:953-963, 2006).

The researchers also consider hypotheses posed to explain transfer among callitrichids, where such behavior is more common (Ruiz-Miranda et al. Am J Primatol 48:305-320, 1999)

Finally, they examined variables such as patch and food size and food transport. They discuss their findings relative to general patterns of non-meat transfer in Pan and examine them in the context of chimpanzee sociality in particular. They then contrast chimpanzee species and subspecies in terms of non-meat food and tool transfer and address the possibility that a savanna environment contributes to the unusual pattern observed at Fongoli.

Journal reference

Jill D. Pruetz, Stacy Lindshield. Plant-food and tool transfer among savanna chimpanzees at Fongoli, Senegal. Primates, 2011; DOI: 10.1007/s10329-011-0287-x