What does the giraffe say ? Until now , they were only known to make a few grunt , snigger , and bleats . Most of their sounds seem to fare from sudden bursts of zephyr out their nostrils . But after listen to nearly 1,000 hour of audio , researchers find out that giraffes make low - frequency humming noises at night . The findings were published inBMC Research Notesthis week .
Giraffe herds are organized into the same sort of societal organization as talkative fauna like spotted hyenas and chimpanzee who use vocal communication to alleviate group dynamics . However , there has been no evidence that giraffes use vocalizations to intercommunicate . While they do have a well - develop voice box ( or voice box ) and laryngeal nerves , their long neck were think to impede melodic phrase - stream with sufficient velocity to get ego - keep , outspoken fold vibrations .
To investigate , theUniversity of Vienna ’s Angela Stoeger and colleagues amass 947 hour of audio recording during the Clarence Day and night from captive Giraffa camelopardalis live in three European zoos : Berlin Tierpark , Copenhagen Zoo , and Vienna Zoo . When they analyzed various components of the acoustic signal hold in in the recording , the team discover harmonic , sustained , and frequence - modulated “ humming ” vocalisation . A sum of 65 humming vocalizations were recorded during night seance , with an average frequency of 92.01 Hz . ( you may heed to giraffes humminghere . )
“ I was mesmerised , because these signal have a very interesting sound and have a complex acoustic structure , ” Stoeger toldNew Scientist . However , because they were n’t able to identify the caller or verify the behavioural context of the calls , the researchers do n’t know what sort of info would be contain in those hums . Vocalizations in other brute with a similar social social system are known to communicate information about age , sex , intimate rousing , dominance , or procreative position .
So why only at night ? It ’s potential that Giraffa camelopardalis pass on visually during the day ; after all , they do have excellent vision with potentially long - image sharpness , the authors write .
Furthermore , none of the nocturnal utterance they recorded were within the infrasonic range , below the normal hearing range of humans . Anecdotal grounds have antecedently suggested that camelopard commune using the same variety of scummy - frequency , infrasonic “ rumbles ” of elephants .
