Mighty Dons Of Science News

par­tic­u­larly well-known among ro­dents, rab­bits and their rel­a­tives, and—less often—dogs and apes.

The par­ticipa­t­ion of this last group has caused caused par­tic­u­lar shock among hu­man wit­nesses, not least be­cause apes are sup­posed to be our close ev­o­lu­tion­ary rel­a­tives.

But two new stud­ies may of­fer a meas­ure of com­fort. At least, such as can be found in such a dis­mal situa­t­ion.

The stud­ies sug­gest that chimps and bono­bos—the two spe­cies that are our clos­est ape rel­a­tives—eat po­o­p not for its own sa­ke, but in or­der to re­trieve hard, nu­tri­tious seeds from it.

Cop­roph­a­gy may be an “adap­tive feed­ing strat­e­gy dur­ing pe­ri­ods of food scarcity,” wrote Tet­suya Saka­maki of the Pri­ma­te Re­search In­sti­tute at Kyo­to Un­ivers­ity, Ja­pan, in a study pub­lished in the Oct. 31 ad­vance on­line is­sue of the jour­nal Pri­ma­tes.

Saka­maki re­ported that he spent a total of no less than 1,142 hours (48 days) watch­ing a group of about two doz­en wild bono­bos at the Lu­o Sci­en­tif­ic Re­serve in the Con­go. Among them, “at least five fe­males… prac­ticed cop­roph­a­gy and/or fe­cal in­spec­tion,” he wrote.

Samakaki found most of the episodes hard to see clear­ly, be­cause they oc­curred high in trees, but he came away with the im­pression that the apes were try­ing to get at seeds. In the most clearly vis­i­ble case, a young fe­male “used her lips to ex­tract Di­al­ium seeds from the fe­ces in her hand, ate the seeds, and dis­carded oth­er fi­brous parts in the fe­ces,” he wrote.

Di­alum plants are mem­bers of the leg­ume fam­i­ly.

A study in the April 2004 is­sue of the jour­nal sug­gested si­m­i­lar con­clu­sions re­gard­ing chim­panzees, not­ing that similar seed types were in­volved: “two types of Di­al­ium seeds were com­monly found in the fe­ces.”

The au­thors of this pre­vi­ous study added that stress, bore­dom or food scarcity did­n’t ap­pear to play a role in the cop­roph­a­gy. Saka­maki in the more re­cent study mostly agreed, except he wrote that cop­roph­a­gy did seem more com­mon when food was hard to find.