Some sharks live in large schools, some live solitary lives and others come together to from groups only to feed or mate... Every species is unique. Scientists thought great white sharks (Carcharodon carcharias) were solitary and actually quite competitive with if they ever did come into contact with each other, but recent research may have turned all of this on its head... Maybe great whites actually work together when they are hunting. So are these sharks truly solitary or are they social? And do they actually hunt in packs?
Flying Solo
When they are first born, white sharks live in "nursery habitats", where the young sharks can grow in an area where there is plenty of food and they are safe from predators. At this age they live in a loose group, but as they get older and move offshore, great whites are solitary and only come into contact with others to feed or mate. For example, you often find aggregations of great whites around seal colonies, where they are all hunting for food, but these groups are not necessarily social (Heupel et al, 2007; Anderson et al, 2021).
In fact, when they are in close proximity to each other great whites can actually be very competitive over food resources. Generally the sharks adhere to a strict hierarchy where the largest shark around the food gets first dibs and smaller sharks get the hell out of their way (Sperone et al, 2009).
Sometimes great whites will even actively compete for the right to the food. They do this be bringing their tail out of the water and slapping it down onto the water surface in the direction of their opponent. The sharks that makes the loudest noise and/or biggest splash wins the prize. This is called a "tail slap". (Sperone et al, 2009).
Jumping for Food
Whilst they close in on food sources over long distances thanks to their great sense of smell, great whites are visual predators, identifying a target over close range by sight. As their prey are also able to see well, the sharks utilise a stealth hunting strategy to catch their target unawares. The shark will dive beneath the water and sneak up on a seal at the surface from below. When in position, they shark accelerates incredibly rapidly, to take the seal at the surface. They get such momentum, that the whole shark will sometimes fly out of the water. This is known as "breaching" (Klimley at al, 2001).
So it always seemed that white sharks are solitary and hunt alone... but recent research is starting to make us question this idea.
White Sharks Have Social Lives
Recently scientists have discovered that great whites are more social than we previously thought! (Schilds et al, 2019; Anderson et al, 2021).
Research performed in California has taught us that white sharks do not avoid other sharks and they do not even group randomly within their aggregations. In fact, the same sharks are often sighted at the same time, with certain sharks spending more time close to other specific individuals. So scientists now think that great whites actively choose to hang out with specific individuals - they have a gang (Schilds et al, 2019; Anderson et al, 2021).
Another study in Australia found similar findings. They also learned that the associations between inidvidual white sharks were so strong that there were actually sub-communities within the larger group (Anderson et al, 2021). So it seems great whites might actually live in quite complex social groups!
Teaming Up
Recent work has taken things even further... showing us that white sharks might even hunt together! A team of scientists studying white sharks at Guadalupe Island in Mexico has discovered that white sharks form strong, short-term associations with other individuals whilst they are patrolling for prey. The sharks came together and remained together for as long as 70 minutes, whilst swimming around looking for seals. They would follow each other to find food and feed off of the same kills. They would even work as a team by taking turns to patrol for food. You can check out the footage the scientists caught on video here (Papastamatiou et al, 2021).
- Papastamatiou et al, 2021
These findings are surprising because it seems white sharks actually sometimes share food resources, rather than fighting over them. Even more than that, the researchers concluded that the sharks may actually get together to gain hunting information from each other (Papastamatiou et al, 2021).
When animals get together they can learn about the locations of resources from others, either by following each other or by communicating in some way. This is known as "social learning". By working as a team whilst hunting, white sharks are using social learning to make their foraging more efficient - maximising the amount of food they can get whilst minimising the amount of effort they have to put in (Papastamatiou et al, 2021).
It seems great whites have much more complex social lives than we previously thought! Who knows what more we might find out about these fascinating animals in the future!
References
Anderson J, Clevenstine IJ, Stirling BS, Burns ES, Meese EN, White CF, Logan RK, O’Sullivan J, Rex PT, May J (III), Lyons K, Winkler C, García-Rodríguez E, Sosa-Nishizaki O & Lowe CG (2021). Non-random co-occurrence of juvenile white sharks (Carcharodon carcharias) at seasonal aggregation sites in southern California. Frontiers in Marine Science, 8:19, 688505. Access online.
Heupel MR, Carlson JK & Simpfendorfer CA (2007). Shark nursery areas: Concepts, definition, characterization and assumptions. Marine Ecology Progress Series, 337, 287–297. Access online.
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.
Papastamatiou YP, Mourier J, TinHan T, Luongo S, Hosoki S, Santana-Morales O & Hoyos-Padilla M (2022). Social dynamics and individual hunting tactics of white sharks revealed by biologging. Biology Letters, 18: 20210599. Access online.
Schilds A, Mourier J, Huveneers C, Nazimi L, Fox A & Leu ST (2019). Evidence for non-random co-occurrences in a white shark aggregation. Behavioural Ecology and Sociobiology, 73. Access online.
Sperone E , Micarelli P, Andreotti S, Spinetti S, Andreani A, Serena F, Brunelli E & Tripepi S (2009). Social interactions among bait-attracted white sharks at Dyer Island (South Africa). Marine Biology Research, 6. Access online.
By Sophie A. Maycock for SharkSpeak
