We ’re all reasonably conversant with how , for example , an “ -ing ” at the remnant of a word means something different than an “ -ed . ” As it turns out , monkeys have their own translation of suffixes too . In a newProceedings of the Royal Society Bstudy , researcher lead playback experiments in a tropic rainforest show that scallywag listeners can tell the deviation between peril call with and without suffixes , and that they ’ll alter their behavior consequently . What ’s more , even scallywag of different specie seem to grasp the preeminence .
grownup male Campbell ’s monkeys ( Cercopithecus campbelli ) have a repertoire of three canonic alarm call : “ Krak , ” “ Hok , ” and “ Wak . ” And each of these can occur with the suffix “ oo . ” In special , they give one call type to warn others about leopards ( “ Krak ” ) , and they practice the suffixed version of the same call for unspecific danger , like a go down tree ( “ Krak - oo ” ) . The root “ Hok ” seems to indicate birds of prey ( like crowned eagles),Discovery News explains , and we have n’t figured out what “ Wak ” means just yet .
To see if this suffixation is meaningful to receivers , a team direct byCamille Coye from the University of Rennes 1conducted a subject field experiment in Taï National Park in Ivory Coast , West Africa . They broadcasted natural and digitally edited suffixed and unsuffixed “ Krak ” call option made by local male Campbell ’s monkeys . adapted calls include “ Krak - oo ” with the suffix deleted or “ Krak ” calls with the suffix add together . Then they analyzed the response of 42 dotty groups of Diana monkey ( Cercopithecus diana diana ) . These two monkeys often hang out in trees with each other , and they even coordinate their travel directions and advert to each other ’s alarum . ( The team did n’t pick other Campbell ’s monkeys as listener for avoid potentially uncongenial territorial behavior . )
The team found strong answer to unsuffixed shout ( for leopards ) than suffixed calls ( for non - vulture threats ) . The Diana monkeys remained on qui vive for long when they heard both natural and artificial “ Krak ” calls : Male and females gave more alarm cry afterwards , and female also gave fewer social call . Their response were chiefly determined by the mien or absence seizure of the “ oo , ” and not by the intonation of the “ Krak . ”
" Several aspects of communication in Campbell ’s monkeys allow us to disembowel parallels with human language,“Coye tells Discovery News . Suffixation , it seems , is an evolved function in primate communication .
