These Bolivian dolphins holding an anaconda in their beaks baffle scientists

While studying a pod of river dolphins in Bolivia, researchers were surprised to find that two of the cetaceans were holding an anaconda in their beaks, manipulating the snake like a toy.

A first

The anacondas of Bolivia (Eunectes beniensis) are apex predators, sitting at the top of the food chain and theoretically not being preyed upon by any other animal within their ecosystem. With the exception of a single case of cannibalism, no one had ever seen these reptiles being killed or eaten by another wild creature.

Representing one of four freshwater species found in South AmericaBolivian river dolphins (Inia geoffrensis boliviensis) can be up to 2.8 meters long and have a beak with many teeth that they use to devour fish and crabs. However, snakes are not part of their staple diet.

Play is an essential aspect of the lives of these cetaceans, providing opportunities for juveniles to practice and hone their skills (including those related to nature foraging and mating), and depending on Omar Entiauspe-Neto and his colleagues, the strange scene observed last August and described in the journal Ecology could constitute a hitherto unprecedented form.

It seems that the snake had a lot less fun than the dolphins. Semi-aquatic creatures, Bolivian anacondas can stay fully submerged for quite long periods of time, but it turns out that some of the six dolphins on the scene who were tricked into holding the reptile in their beaks held it underwater for a duration of at least seven minutes, which would have been enough to kill the animal.

Lustful dolphins

While juvenile dolphins also witnessed the scene, introducing the possibility that this unlikely manipulation had an educational purpose, the photos taken by the researchers revealed that several of the cetaceans playing with the anaconda were erect, suggesting that the experience could have been sexually stimulating for them.

Since dolphins are known for their extreme lechery (males have previously been observed wrapping a live, wriggling eel around their sex or attempting to penetrate the blowhole of a pilot whale in an aquarium), the study authors believe it is likely that some of the Bolivian specimens involved also attempted to abuse the snake.

Our knowledge of river dolphins, which live in troubled waters, is much more limited than for their counterparts inhabiting the seas and oceans, but these new discoveries show that these creatures absolutely deserve more sustained attention from the part of scientists.