Giraffes hum at night, FYI

Giraffes the Tallest Residents of a Zoo Hum to Each Other at Night

"Notwithstanding, giraffes are, in principle, capable of producing sounds". But research published this month in the journal BioMed Central, suggests the opposite.

Previously it was believed that giraffes probably make sounds that are impossible for humans to hear, alike elephants, but the latest study has suggested otherwise.

Scientists can not say what type of communication this may be.

A new study from the University of Vienna has found that giraffes, long believed to be silent animals, hum to one another throughout the night. Although researchers could not find any evidence of infrasonic communication among giraffes, they were able to notice a humming sound coming from enclosures of giraffe at night in all three zoos. Giraffes produce infrasonic vocalizations that are below the level of human perception. They think it might be way among these animals to reassure each other about their location.

The researchers of the new study wanted to come up with a comprehensive investigation regarding the vocal interaction among giraffes using information from captive species during the day and night.

Giraffes have been known to make some small noises, which the study describes as "bleating", quiet "mooing", or even "coughing". This was achieved by establishing a set of acoustic parameters, and visually examining "spectral and temporal components" of each sound produced by the animals. But scientists are still not sure what these sounds are used for.

In the past, park rangers and scientists thought that the long necks of giraffes hindered them to have adequate airflow in its trachea that measures about four meters long.

However, the research team identified 65 "harmonic, sustained and frequency-modulated "humming" vocalizations during night recordings".

They use their voice to communicate with each other and convey information about the physical and motivational attributes of the caller. Because of this, the giraffes were hypothesized to lack the ability to vibrate their vocal folds and generate sounds. This new discovery helps us see giraffes in a totally different light, making them a lot more romantic or sensitive than we ever thought them to be.