How common is the infamous “death roll” of the crocodiles and alligators? It was previously observed in just a few crocodile species, but a new study shows that it may be a universal maneuver among crocodiles.
Crocodile ‘Death Roll’
The so-called death roll has been documented in several movies and nature documentaries. In the infamous maneuver, crocodiles would bite their prey and do a full-body twisting motion to disable, kill, and dismember their prey into small pieces. This is because contrary to what many believe, crocodiles can't actually chew.
In the past, only several of the living crocodile species were observed to do the maneuver, but researchers of a new study find that it might be a universal maneuver for crocodilians.
Universal Trait
It was previously believed that crocodilian species such as the Indian gharial likely do not engage in the death roll because their diet consists of smaller prey such as fish. However, for a new study, researchers observed all living crocodilian species and found that 24 out of 25 do the death roll, and not just when they are feeding.
In their observations, researchers noted that the creatures also do the maneuver when they are being aggressive, for instance when they are establishing dominance over another crocodile, or when they are fighting over a female.
Of all the species they observed, it was only Cuvier’s dwarf caiman that did not do the maneuver, although researchers note that it might be possible that the creature was just being uncooperative at the time of testing.
Ancient Crocodiles
“Crocodile relatives have played the role of semi-aquatic ambush predator since the Age of Dinosaurs,” said lead author Stephanie Drumheller-Horton of the University of Tennessee, Knoxville.
Since crocodiles have similar bodies and lifestyles as their ancestors did, it is possible that ancient crocodilians used the maneuver as well.
The study is published in Ethology, Ecology & Evolution.
