London:�German researchers have found that gorillas, well known for their booming and chest-beating roars, also �sing� and �hum� frequently while eating food.
This behaviour is more prevalent among adult males than their female or younger counterparts, the findings showed. �Singing� and �humming� was observed more frequently in association with food, especially while eating aquatic vegetation, flowers, and seeds.
The researchers believe that the calling linked with food could be a means of expressing well-being. It could also aid social cohesion. For the study, published in the journal PLOS ONE , the researchers tracked two wild western lowland gorilla populations in the Republic of Congo, assessing 20 gorillas in both the groups. Females and juveniles were quieter, perhaps to reduce risk of predation.
�Similar to the function of food calls in chimpanzees, gorillas may call to let their group mates know when it is time to finish eating,� said researcher Eva Maria Luef from Max Planck Institute for Ornithology in Germany.
�Silverback males may have to call more frequently since they are often the ones initiating changes in group activity,� she added.