ANIMALS – Sometimes fascinating and inspiring, nature is also sometimes very strange. Researchers were able to observe a completely new behavior, informed in a study published on April 12 in the scientific journal Ecology.
Taken in August 2021 near the Tijamuchi River in Bolivia, we discover various shots of boto, or pink dolphins of the Amazon (Inia geoffrensis boliviensis). “Just seeing them with their heads above the river was extraordinary,” said for the New York Times Steffen Reichle, biologist at the Noel Kempff Mercado Natural History Museum in Bolivia.
But the most surprising is not there. If the researchers had noted that the dolphins had remained unusually long with their heads above water, they did not know why. The answer came after viewing the photos taken at the time. Like a kind of toy, they waved an anaconda (Eunectes beniensis) while they swam.
“I don’t think the snake had a very good time”
The researchers were able, through the different photos taken, to see that the dolphins interacted with the snake in different ways. They were thus able to estimate that it was probably not a predation activity, but rather a leisure activity: “It became clear that they were playing with the snake rather than trying to eat it” relate the scientists .
A snap shows two of the mammals swimming in sync with the snake held in their mouths. The researchers also found youngsters among the dolphins. “There were also juveniles at the scene, and it appeared that the adults were showing them the snake,” the researchers surmise.
Another hypothesis for this unprecedented behavior is that it was an activity with a sexual connotation. The researchers explain that “subsequently, we were able to observe in the photographs that the adult males were sexually aroused by engaging in object games with the anaconda”.
However, the principal concerned did not seem to benefit from this activity as well. “I don’t think the snake had a very good time”, declared to New York Times one of the team members, biologist Steffen Reichle. Indeed, although the anaconda is a semi-aquatic species that can hold their breath for a while, the latter remained submerged for a long time and did not move during this macabre game. He therefore most likely perished.
A species very difficult to observe
These river dolphins are relatively rare creatures, as they are critically endangered. Observing them is difficult, especially since they usually swim below the surface. Observations therefore generally only report a fin or a tail.
But here, six animals were observed with their heads out of the murky water, as the researchers claim. The latter relativize all the same, explaining that “it was difficult to estimate the size of their group”. It is therefore an unusual spectacle, not to mention the episode of juggling with the anaconda.
This behavior is not unique to this species, however. Dolphins, but also cetaceans, are indeed known for their playful activities, during which other animals are sometimes involved (voluntarily or not).
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