Updated: Jul 13
With their huge size and impressive teeth, great white sharks are undeniably one of the most iconic and magnificent species of sharks on the planet. But it is not only the way they look that makes these sharks so alluring, it is also their behaviour that is completely fascinating. White sharks are amongst only a handful fo species that will actually jump out of the water - launching their incredible bulk several metres out of the surface and crashing back down amongst an enormous splash. It's great to witness, but why do white sharks "breach" like this? What is it for? And do we even know why sharks jump?
Meet the Great White
Great white sharks, also known as white sharks or white pointers, are the third largest sharks alive today. Unlike their larger, filter-feeding cousins - the basking sharks (Cetorhinus maximus) and whale sharks (Rhincodon typus) - great white are incredibly active, agile predators (Klimley et al, 2001, Martin et al, 2005, Sperone et al, 2012, Semmens et al, 2019).
White sharks are "generalists", feeding on many different prey items, including boney fishes, squids, octopi and other sharks. When they reach a critical size of 3 metres long, they also expand their diet to include marine mammals, like seals and dolphins. This is known as an "ontogenetic diet shift" (Klimley et al, 2001, Martin et al, 2005, Semmens et al, 2019).
A Sneak Attack
Great whites don't just rely on brute strength when they are hunting. They actually use very clever tactics to be able to sneak up on their prey... They will descend into the water and sneak underneath a seal at the surface.
Their coloration allows them perfect camouflage for this, because their dark back makes them difficult to see from above, whilst it is very easy for the shark to see a seal at the surface, silhouetted against the sky (Klimley et al, 2001, Martin et al, 2005, Sperone, et al, 2012, Semmens et al, 2019).
When right beneath their target, great whites will accelerate incredibly quickly and take their prey at the surface. They can reach speeds of 25 miles per hour on their approach! They rely on their speed, weight and incredible jaw strength to immoblise their prey with one extremely powerful bite (Klimley et al, 2001, Martin et al, 2005, Semmens et al, 2019).
It is this great speed that causes white sharks to fly out of the surface of the water when they are hunting. Giving us one of THE most spectacular sights in our natural world. White sharks can launch their entire body out of the water - more than half a tonne of muscle - for several seconds, before diving back down.
Recently though, scientists have been wondering if breaching is only important for hunting or if this behaviour might have some other function...
Researchers working with these sharks have noticed that how many breaches they see can vary depending on what is going on in the environment. For example, white sharks are more likely to breach when the weather is partly cloudy. They also breach more often at certain times of the year and are especially spritely during periods of warm weather (Pyle et al, 1996).
How often a shark breaches also depends on the individual - male sharks breach more often than females (Klimley et al, 1996, Sperone et al, 2012).
This has made scientists wonder if breaches might also be used for communication.
Just because they cannot speak, this does not mean that animals do not communicate. Sharks send signals to other sharks in many different ways. Different sharks might hunch their backs, change the angle of their fins or gape their mouths to show off their impressive teeth. These "agonistic behaviours" are all silent threat displays - without words, they are telling other individuals that they need to back off (Klimley et al, 1996, Sperone et al, 2012).
White sharks also use splashes and sound as visual and auditory signals. When two sharks fight over the same piece of food, great whites will use "tail slaps" as a threat display. They lift their tail up and slap it down on the surface of the water to make a splash. The shark that creates the biggest splash and loudest sound will win the duel (Sperone et al, 2012).
Researchers wonder if breaches might also be used in the same way. Breaches make enormous splashes and loud sounds under water, which other sharks are able to see and hear. So scientists are now investigating whether white sharks also jump to show off their large size and impressive speed when they are competing for resources (Klimley et al, 1996, Sperone et al, 2012).
We have so much more to learn about these magnificent animals we may never know all the ins and outs of exactly why they jump... But I for one am more than happy to keep watching them do it!
Klimley AP, Pyle P & Anderson SD (1996). Tail slap and breach: agonistic displays among white sharks?. In: Klimley, AP & Ainley DG (Eds). Great White Sharks The Biology of Carcharodon carcharias. Academic Press, San Diego, p.241-255.
Klimley AP, Le Boeuf BJ, Cantara KM, Richert JE, Davis SF, Van Sommeran S & Kelly JT (2001). The hunting strategy of white sharks (Carcharodon carcharias) near a seal colony. Marine Biology, 138, 617-636. Access online.
Martin RA, Hammerschlag N, Collier RS & Fallows C (2005). Predatory behaviour of white sharks (Carcharodon carcharias) at Seal Island, South Africa. Journal of the Marine Biological Association UK, 85, 1121-1135. Access online.
Pyle P, Anderson SD, Klimley AP & Henderson RP (1996). Environmental factors affecting the occurrence and behavior of white sharks at the Farallon Islands, California. In: Klimley, A.P. & Ainley, D.G. (Eds.). Great White Sharks The Biology of Carcharodon carcharias. Academic Press, San Diego, p. 281-291.
Semmens JM, Kock AA, Watanabe YY, Shepard CM, Berkenpas E, Stehfest KM, Barnett A & Payne NL (2019). Preparing to launch: biologging reveals the dynamics of white shark breaching behaviour. Marine Biology, 166:95. Access online.
Sperone E, Micarelli P, Andreotti S, Brandmayr P, Bernab I, Brunelli E. & Tripepi S (2012). Surface behaviour of bait-attracted white sharks at Dyer Island (South Africa). Marine Biology Research, 8:10.