An American radio host recently went viral by posting a video on Twitter showing an impressive gathering of crocodiles in Brésil. While the video alarmed many, it reveals no cause for concern. Here's what you need to know about the presence of these reptiles in the Pantanal and their way of life…

Caimans making waves…

A few days ago, a video of a caiman invasion in Brésil went viral worldwide. The footage quickly captured global attention because it shows a spectacular number of caimans gathered on a narrow stretch of sand. 

The buzz originated from a post by American radio host Ken Rutkowski. He shared the video on Twitter with the caption: "In Brésil, an invasion of crocodiles flooded one of the beaches with several hundred, even thousands of individuals, and the local population is in panic". The video was filmed near the city of Corumbá in the Pantanal, at the border between Brésil and Bolivia.

Based on the footage, one might think such gatherings are spectacular or unusual. But while the images are authentic, they're hardly alarming…

A closer look at Brésil's jacarés

Contrary to what the American radio host claims, these animals don't belong to the crocodilian family but to the alligatoridae family. Zilca Campos, a Brazilian researcher specializing in these reptiles, identified them as "Pantanal jacarés" (Caiman yacare). 

For reference, the term "jacaré" translates from Portuguese as "caiman" or "alligator". The word comes from the ancient indigenous Tupi language, in which "jaeça-karé" means "the one with eyes on the side". 

In any case, this species differs from crocodiles in several physical traits. The jacaré has a wider, more stocky U-shaped jaw and is smaller than crocodiles. There are 6 species of jacaré in South America. In Brésil, they're particularly found in the Pantanal, a bioregion often nicknamed "the little Amazon". 

A common occurrence during dry seasons

While this gathering of caimans in the Pantanal appears impressive, it's actually a normal phenomenon. This species is known to migrate and has a habit of congregating in large numbers to hunt together and reproduce. 

According to researcher Zilca Campos, "Such animal gatherings are common, especially during dry seasons. Particularly since the Pantanal has suffered from a severe lack of water since 2019". "Generally, these gatherings occur between September and November. During this dry period, water levels drop and jacarés congregate around the remaining water-filled river channels in search of food. It's the period when they're weak due to food scarcity," she explained. 

Threats facing the Pantanal jacarés

Contrary to what one might think, and despite their resemblance to crocodiles, jacarés are not considered dangerous to humans. Despite a population estimated at 3 million individuals in the Pantanal, caiman attacks on humans are extremely rare.

Rather, it's the jacarés that face human threats and must survive environmental hazards. "Deforestation, the construction of hydroelectric dams, fires… these have reduced populations in certain areas to alarming levels," warns the researcher.