Myth Busted: Circling is NOT an Aggressive Behaviour

From monster movies, like The Meg and Deep Blue Sea, and thrillers like The Shallows and endless same-same-but-different James Bond movies, you might think that sharks circling in the water are primed and ready to attack. They seem to be looping around, ready to rush in on their prey. However, this could not be further from the truth. In reality, "circling" is actually not an aggressive behaviour at all. So why do sharks circle? And if it's not threatening, why do they do it? And what do genuinely aggressive sharks look like?

Circling is not an aggressive behaviour, in fact, it only happens when a shark is reluctant to approach more closely (Image Credit: Diego Delso / WikimediaCommons)

Grey reef sharks perform a distinctive agonistic display [B] of hunching, gaping, fin dipping and swimming in a more exaggerated manner compared to normal [A] when they feel threatened (Myrberg, 1987)

Hunching is an agonistic display that a shark uses to communicate that it will attack if you don't back off (Martin, 2007)

Many sharks dip their pectoral fins as a threat displaye.g. 1. tiger shark, 2. silvertip shark, 3. Galapagos shark (Martin, 2007)

References

Martin RA (2007). A review of shark agonistic displays: comparison of display features and implications for shark–human interactions. Marine and Freshwater Behaviour and Physiology, 40. Access online.

Myrberg Jr AA (1987). Understanding shark behavior. In: Cook S (Ed.). Sharks: an inquiry into biology, behavior,¢ fisheries, and use. Proceedings of the Conference

Portland, Oregon USA.

Ritter E (2006). Understanding Sharks: The Fascinating Behavior of a Threatened Hunter. Krieger Publishing Company.

By Sophie A Maycock for SharkSpeak