Dawn breaks on Cocha Otorongo

It is 5:15 am and the otters are stirring in their den. A series of soft cooing sounds, followed by the characteristic “Let’s go” hum, indicates that they are ready to start their day. A moment later, out comes Isla, the breeding female. As she sniffs the latrine area in front of the den, she is joined by Hueco, her partner. Together they urinate and defecate on the latrine, their broad, flattened tails held high, before thoroughly spreading and mixing their scat with those that have accumulated over¬night. The circling movements of their forepaws and the simul¬taneous shuffling of their hind legs combine to resemble a comical scent marking dance.

A third otter appears at the entrance of the den. It is Arpon, named after the arrow head outlined on his throat. Unlike his parents, he pauses only briefly to defecate, not lin¬gering to mix the scat, and is followed in rapid succession by four other otters, all of whom eagerly rush into the water after a quick, obligatory stop on the latrine. Hueco does the work for them, waddling once more over the latrine while simulta¬neously dribbling urine. Isla enters the water sedately and begins to groom herself on a submerged log while she waits for Hueco; he is the last to leave the den site. Isla hums once and the group sets off along the shoreline just as a gossamer mist is beginning to lift from the surface of the water.

The giant otter is a highly social species living in close- knit family groups each consisting of a reproductive pair plus their offspring of various years. Families usually inhabit

the same home range for several consecutive addition to resident groups, a typical giant otter population also includes dispersers, individuals who have left their natal groups, normally after attaining sexual maturitv. often solitary, dispersers may form temporary asociations, referred to as transient groups, which do  n : estanot have an established territory.

During our research in Madre de Dios, only seven per cent of sightings were of lone otters: the bulk of the population at any one time is made up of groups. Average resident group size in Manu floodplain lakes was 5.9. while the average size of transient groups was 2.6. The largest group, in Cocha Salvador, comprised 13 individuals. In the palma Real River, another key study area, average resident group size was 3.6, and the average size of transient groups was two. The largest group was six otters. Group size is naturally limited by the balance between birth of cubs and dispersal of young adults.

Tambopata Sandoval Lake Lodge

Giant otters are active only during the day, between and dusk. Nights are spent together inside a shallow den excavated in the river or lake bank, frequently under root systems or fallen trees. Giant otters have not been observed to ‘adopt’ dens of other animals. The den consists of one or more tunnels leading to a chamber several square in size. Only once did we discover a den with a submerged entrance, in the Patuyacu River: we could hear the of water as the otters left it, followed seconds later by by the  appearance of their heads above the surface of the water. A giant otter den is easily recognised by a cleared slide or concave path that leads from the entrance to the water´s edge, and by the presence of a nearby latrine. Fresh tracks, of leaf litter, trampled vegetation, the presence of insects, and a strong, fishy smell, all indicate that a den is in use.

The otter family emerges from the den at dawn and spends the next ten minutes or so on the latrine in front of the enamma before embarking on the day’s activities.