Olive and Benicio, of Kilbirnie, asks :-
When we go to the zoo we never hear the giraffes making any sounds. Do they?
Angela Stöger-Horwath, a cognitive biologist at Vienna University and who is researching Giraffe sounds, responded.
Giraffes are, compared to other animals like elephants, or cows and horses, very silent. Indeed there have been suggestions that the giraffe’s long neck makes vocalisation physically impossible, due to the difficulty of sustaining the required air flow from lungs to mouth over such a distance. Moreover, recent research has found that, contrary to the traditional view of giraffe herds as loose collections of non-bonded individuals, giraffes have a very structured social system based upon strong social bonds. Other species with this kind of social system (such as elephants and buffalo) are strong vocal communicators, which is thought to be crucial in maintaining group cohesion.
Giraffes have excellent vision and signal at lot to each other using visual cues; for example the position of their ears, tail, neck,..., tells a lot about their mood and intention.
Sometimes they do produce sounds; giraffes produce grunts, snorts and bursts (sounds like a strong honking out of the nose). But you need to be very patient (and a bit lucky) in order to observe a vocalization. But now we found that giraffes sometimes talk to each other when it is dark, these vocalizations are termed "humming". We still need to do much more research in order to understand what the giraffes are saying, but it seems that they talk more, once vision is limited. Also, humming was only recorded when the giraffes had been separated into individual stalls for the night. This tentatively suggests that the calls allow group members to keep in touch when they are no longer able to see each other. This could explain why the giraffes remain silent during the day, when they can visually locate other group members.