Sperm Whale’s Forehead is Intended to be Used in Battles
A recent study shed some light in the ramming hypothesis of sperm whales.
According to the study published in the journal PeerJ, researchers discovered that their findings are consistent with the hypothesis that the structure of a sperm whale's forehead evolved to be used as a massive battering ram during male-to-male competition.
The ramming hypothesis, according to the authors of the study, was proposed by whaler Owen Chase after a large male sperm whale rammed and sank a ship in the Pacific.
In a press release, lead author Dr. Olga Panagiotopoulou from the University of Queensland said the ramming hypothesis remains controversial because of the two large oil-filled sacs located in the forehead of sperm whales.
These two large sacs, known as the "spermaceti organ" and "junk," play a vital role in echolocation and buoyancy.
According to a report from Business Insider Australia, experts in different fields from Japan, U.K., U.S. and Australia joined Dr. Panagiotopoulou in the study.
For the study, researchers used structural engineering principles combined with probabilistic simulation in order to determine if the unique structure of the junk significantly reduces stress in the skull during the ramming impact.
Researchers found frequent significant scarring in the junk, indicating that sperm whales uses it and avoids using the spermaceti organ as the point of impact.
The study showed that connective tissue partitions in the junk can reduce von Mises stresses across the skull.
On the other hand, impact on the spermaceti organ generated lesser stresses in the skull compared to the junk.
However, an impact to the spermaceti organ can cause high compressive stresses on the anterior aspect of the organ and the connective tissue case, which can make these structures prone to failure, study shows.
"Increased skull stresses at a ramming event can be detrimental for the animal since they can cause fatal fractures," said Dr. Panagiotopoulou in a statement.