Call/Sound: adult calls
Giant otter groups have high cohesion among each other, performing most of their daily activities together. When an individual loses the group, they vocalize high screams or adult calls, calling the group.
When something new appears in their territory, giant otters show curiosity and might approach the observer, exposing their necks showing the spots they have on their throat and chest. This behavior is calling periscoping. If there is an intruder, they will investigate it, emitting noisy and exclusive sounds, called snorts. These vocalization may get more intense and loud. The explosive snort may represent an alert for the other individuals to leave the area.
Scent-marking/ Sound: purr and coos
Giant otters are territorial, defending large stretches of the river where they live. Groups patrol their territories daily and choose some specific points along the banks to leave their scent and signalize their ownership to other giant otters. During the territory scent-marking all members of the groups defecate and urinate on latrines (bathrooms located on the banks), they use to purr while scent-marking this sites. The purr may get intense and be interspersed by a high pitched sound like coos and high coos.
Agonistic encounters/ Sound: snorts, calls and screams
When an intruding individual or group is detecting by a resident group usually a fight will occur. This is what biologists call “agonistic encounters”, and may cause a long chase and even violent physical confronts. During these encounters the groups vocalize a noisy and loud chorus with loud calls, screams and snorts. Giant otters can be seriously injured in these fights and some may even die from injuries.
Defense for food/ Sound: growl
Although the group will do almost all daily activities together, giant otters do not share their food. When one giant otter gets close to another while eating, they will vocalize an intimidating growl, which may get more intense when the other individual approaches.
Cubs caring/ Sounds: pur, hum and coos
Within a giant otter group, just the dominant male and female reproduces, but all the other members help to care the cubs. After the third week, adults begin to carry the cubs outside the den, for the cubs first swimming lessons. Some adults can be more clumsy, but these lessons are very important for the success of the cubs. During these activities it is common to hear purs and coos, interspaced by higher coo’s vocalized by the adults. The cubs will scream and vocalize high pitch calls during the bathing. During the fishing lessons the adults have more work, mainly when the litter is hungry. The adults with catch small fish that are sill alive near the shore to give to the cubs for them to learn how to catch and kill them. Yet, sometimes the capture is not successful and the cubs vocalize high screams and begging calls asking for more fish.