The bull shark (Carcharhinus leucas) is regarded as one of the most dangerous sharks to human beings. It is named the bull shark because of its stout appearance and aggressive behaviour. The behaviour of the bull shark is also characterised as unpredictable. It is instructive to study the bull shark's behaviour, since it is this that is responsible for it being one of the three species of sharks that are likely to attack human beings. The most noteworthy aspects of bull sharks are their freshwater tolerance, hunting strategy and aggression.
Unlike most other marine species, bull sharks can exist in both fresh and salt water. The species seems to prefer salt water, but it can tolerate fresh water for long periods. This is why bull sharks, thought not migratory in most cases, can be found in lakes and rivers. The bull shark can travel far up rivers, making a bull shark sighting inland likely. Freshwater tolerance may also be the reason for the frequent attacks on human beings. Many bull shark attacks have been recorded in rivers and freshwater lakes. As an aside, bull sharks seem to prefer shallow waters as well. This enables them to exist in various habitats, along with their freshwater tolerance.
Hunting strategy and diet
As an apex predator, the bull shark's diet is varied. It has been known to eat human flesh in some cases. Its diet extends to other sharks, ray, turtles, birds, dolphins and so forth. Bull sharks are not known to be cannibalistic. Just as the white shark, bull sharks are typically solitary hunters. Known for sudden bursts of speed, the bull shark utilises the bump and bite technique in attack. This technique is a manifestation of a bull shark's aggression and territoriality. It enables the shark to disorient prey before administering potentially lethal bites. Bumping is also a violent non-verbal action used to deal with intruders.
The bull shark's aggression is perhaps a direct result of the high territoriality they display. Bull sharks are apt to attack any animal- including humans- that enters their territory. Bull sharks are remarkably unpredictable as well. On some occasions researchers have been in the water with the bull sharks without incident. At a moment's notice, or due to some external stimuli, the bull sharks may suddenly become very aggressive and violent.
It is largely because of the habitat flexibility of the bull shark that it is more likely to attack humans. Coupled with its trademark aggression and consumption of human flesh, the bull shark is sometimes regarded as the most dangerous to human beings. Even the notorious white shark is not as dangerous. Most white shark attacks on humans occur due to mistaken identity or provocation. If a white shark bites a human being once and decides not to engage, the person could still bleed to death or drown. The behaviour of the bull shark is not attributed to either mistaken identity or provocation necessarily. That is what makes it so unpredictable and dangerous.
Crist, R. 2002. "Carcharhinus leucas" (On-line), Animal Diversity Web. Accessed August 08, 2008 at http://animaldiversity.ummz.umich.edu/site/accounts/information/Carcharhinus_leucas.html.