“Wash my fur, but don’t get me wet.”: A demand that clearly does not reflect the needs of the giant otter. For the largest relative of our native otter, about two metres long and weighing over 30 kilograms, things run more the other way around. Getting wet is something these highly sociable animals, roaming in groups of up to ten in the water of rivers, lakes, and floodplains, do constantly anyway. Yet impressive 70,000 hairs per square centimetre and an air layer enclosed in the fur still prevent the otter from getting wet down to the skin.
The super fur allows it, along with its oar-like tail and webbed feet, to bathe continuously. Unfortunately, however, its advantages have also led to intensive hunting of the species in the past and today in broad parts of its former range that stretched across tropical South America east of the Andes from Venezuela to Argentina the species has been extirpated.
Today the giant otter faces even bigger problems. Mine wastewater poisons its rivers, in which it hunts fish as a top predator, which is why in its homeland it is also nicknamed the “River Wolf”. And like its namesake here, the giant otter has a problem with governments that do not know much about species protection: despite prior protection promises by Brazil, deforestation in the Amazon region under the right-wing populist Bolsonaro government, which was in power until 2023, has surged to new record levels and has further fragmented the remaining habitats of mustelids.
Climate change and the droughts that accompany it do the rest. In particular, the numerous dam projects in the region prove to be dangerous obstacles. Giant otters actually move with the river levels far inland, turning waterways into migratory routes — provided they are not blocked by barriers such as hydroelectric plants. There is then no passage left even for these land- and water-savvy, strong animals.
Placed Under International Protection
Therefore the otters have now been included in the international treaty framework at the UN Conference COP15 in Brazil, which over the weekend addressed the conservation of migratory wild species. Specifically: The signatory states are obliged to protect otters on their own terrain—but also to collaborate internationally to secure their migratory routes across borders.
This is also urgently needed if the fragmented otter populations are to grow again into a healthy, well-connected total population. In Argentina, for example, there had been no giant otters for decades. Last year, however, animals bred in captivity under the leadership of the Schwerin Zoo were successfully reintroduced there for the first time — a historic achievement for conservation. Now they simply need to reproduce properly and re-establish contact with their conspecifics, for instance in the Brazilian Pantanal. The new international protection under the UN’s aegis will hopefully help with that.
The signatory states are now obliged to protect otters on their own terrain—but also to cooperate internationally
The otter is therefore also a beautiful example against the current political trend: progress ultimately comes only with international cooperation — and migration across all borders. May the giant otter row forward!
