Mundo Azul

Scientific name: Pteronura brasiliensis (Gmelin, 1788).

Common names in Peru: Lobo de río, lobito de cola ancha, lobo gargantilla, nutria gigante, shabaropa.

Distribution: Amazonian lowland rivers and oxbow lakes from Venezuela to northern Argentina.

Threats:

In Peru, giant river otters have been extensively hunted between 1940 and 1970 for the international fur trade. From 1946 to 1971 a total of 23,162 skins have been exported.

1. Export of skins from giant river otters (Pteronura brasiliensis) (according to the Ministry of Agriculture)
2. Not included are skins that have been exported via Leticia (Columbia), which have not been officially registered.
Remaining skins of already hunted animals, being exported after prohibition of hunting in 1970.

According to former hunters, the giant river otter was shot when leaving his den. The animal was shot in the head in order to avoid fur damage. Usually, several animals of the same group were killed this way but juvenile otters were abandoned and regularly starved to death.

If taking into account that not always the hunters managed a clear shot resulting in fur damage, adding to the death of juvenile otters, the number of killed animals must be much higher than the numbers indicated by official statistics.

As the statistics show, there is a clear reduction of skins being exported from 1955, indicating a depletion of the populations. In 1973, the species therefore was included in Annex I of the Convention on International trade in Endangered Species (CITES), prohibiting any trade with parts of the species. On the national level, the species was protected in 1970 by Minister Resolution N° 5056-70-AG. Nevertheless, even today cases of illegal hunting of the species are registered, caused by the lack of control and enforcement in the rainforest in inaccessible areas and may also be by a lack of knowledge on the conservation status of the species.

The Giant river otter is a species in danger of extinction and is protected within the National Parks Manu, Yanachaga Chemillén and Bahuaja Sonene; in the National Reserves Pacaya-Samiria and Tambopata; as well as in the reserved Zone of Güeppi.

Description:

The giant river otter is the biggest otter species of Peru, reaching a length of two meters and a weight of 22 - 32 kg. The fur is dark brown on the back with a big creamy patch on the throat and chest. This patch is used by researchers to identify individual animals like a fingerprint. The tail is 50 to 70 cms long. Vertical movements of the tail are used to give propulsion to the animal while swimming. The otter's feet are short and wide, the fingers are connected to each other with skin. The nose is covered with hair.

Habitat:

In Peru, the Giant river otter mainly lives in oxbow lakes in the lowland rainforest. In the Manu National Park, 242 times animals have been observed in rivers and only 21 times have been sighted in rivers. In the oxbow lakes, the water is clearer than in the lowland rivers and therefore offers better hunting conditions. Additionally, the changes in water levels are not as strong in the lakes as in the rivers; therefore there is a lower risk of flooded dens.

Diet:

Giant river otters almost exclusively feed on fish. Studies in the area of Madre de Dios did find, as main prey, the fish species Bujurki (Stanoperca jurupari) 43,25 % and Boquichico (Prochilodus caudifasciatus) with 28,23%. Other species hunted were Steichdachnerina sp. (7%), Hoplias malabaricus (6%), Potamorhina altamazonica (4%), Curimata sp. (3%), Triportheus angulatus (3%) and Crenicichla semicinta (2%). Additionally, it was found that the otters do select their prey instead of hunting the most abundant species. Adult otters may eat up to 4 kg of fish per day, which represents approximately 15% of their body weight.

Behavior:

The giant river otter lives in family groups and individuals communicate with each other by using a wide range of different sounds. The group is usually formed by a pair of reproductive adults plus their sub adult sons and daughters, as well as the pubs. The younger adults stay with the group for a while and help raise the next generation, before abandoning the group. Each family group marks their territory with excrements and urine. The vegetation near the den is usually destroyed by the otters and mostly one observes a big area of mud covered with fish scales. The otters spend the night in their dens, which they excavated in the shoreline.