Chimpanzees, It Turns Out, Have Accents

Chimpanzees, it now appears, have regional accents. Scientists have reported that young chimpanzees living in different corners of Africa do not sound alike, and that the gap between them widens as the animals grow older.

Chimpanser har, viser det sig nu, regionale accenter. Forskere har rapporteret, at unge chimpanser, der lever i forskellige hjørner af Afrika, ikke lyder ens, og at forskellen mellem dem vokser, efterhånden som dyrene bliver ældre.

The research team worked through more than eleven thousand recorded calls from infants and juveniles at two sites, a rescue centre in Zambia and a national park in Tanzania. They sorted the recordings into grunts, whimpers and laughter, then measured them. The youngest animals sounded broadly alike regardless of location. The older ones did not: each group had drifted toward its own particular manner of grunting.

Forskerholdet arbejdede sig igennem mere end elleve tusind optagede lyde fra unger og halvvoksne dyr på to steder, et opsamlingscenter i Zambia og en nationalpark i Tanzania. De sorterede optagelserne i grynt, klynk og latter og målte dem derefter. De yngste dyr lød stort set ens uanset sted. De ældre gjorde ikke: hver gruppe havde bevæget sig mod sin egen særlige måde at grynte på.

That drift is the arresting part, since chimpanzee calls were long presumed fixed at birth, encoded in the animal rather than absorbed from its neighbours. If a young chimpanzee is instead soaking up the sound of the group around it, much as a child absorbs the vowels of a particular street without being taught them, then accent may be an older habit than anyone had been prepared to admit.

Den bevægelse er det slående ved det, eftersom chimpanselyde længe blev antaget at være fastlagt ved fødslen, indkodet i dyret snarere end opsuget fra dets naboer. Hvis en ung chimpanse i stedet opsuger lyden fra gruppen omkring den, nogenlunde som et barn opsuger vokalerne fra en bestemt gade uden at blive undervist i dem, kan accent være en ældre vane, end nogen havde været parate til at indrømme.