Marine Biology

Behavior of the Bull Shark

Jonte Rhodes's image for:
"Behavior of the Bull Shark"
Image by: 

The bull shark is relatively common and can be found along many tropical and sub tropical coastlines. Unlike most sharks it also enters rivers and lakes, and is therefore also known as the Lake Nicaragua shark and the Zambezi shark. It is also thought to be responsible for the greatest number of attacks on humans among the shark species, making it one of the most dangerous you can encounter in the water. Despite this most people know very little about bull sharks, and even less about what kind of behaviours that they commonly exhibit.

The bull shark has a quite distinctive appearance, being only 3.5 m long and very thickly built. It has a blunt, rounded snout and small eyes, as well as a sharply pointed first dorsal fin. Despite this however it is often confused with other sharks of the same family, such as the Grey Reef shark (Carcharhinus Amblyrhynchos). Because of its size and shape it is a very powerful shark, and doesn't tend to exert a lot of energy when it hunts for prey.

The Bull shark generally moves sluggishly around in the shallower water, and will eat anything that it can catch and bite. It will readily eat other sharks, rays, turtles, dolphins, crustaceans, molluscs, birds and even animals that fall into the water. In some inland rivers it has also been known to attack crossing herds of cattle and similar animals when the depth of the water permitted. In short, the bull shark will eat just about anything else in the water with it, including people.

The only species that competes with the bull shark is thought to be the crocodiles and alligators that it sometimes encounters when it ventures inland into rivers and lakes. Although both are generally top predators in their own right, they occasionally come into contact with each other and may compete for prey. Confrontations between shark and reptile are rare however, and they will generally try to avoid each other rather than risk being killed, as either species could conceivably kill the other.

Other than these occasional meetings however the bull shark rarely meets other species that can compete with it in shallow water. There are some species of shark that are longer than the bull shark, and that are also active predators, however the bull sharks powerful build and aggressive nature tend to keep them away. The other sharks that live around the Bull shark also tend to be faster moving and more suited to chasing and attacking smaller prey, so avoid the sluggish bull shark fairly easily.

Unlike most sharks, Bull sharks are also very territorial, and spends their time hunting alone in its own area. Any intrusion into its territory by other sharks or very often other animals of any sort results in the bull shark attacking. Along with their appearance, it is this nature that earned them their name, with their tendancy to charge at intruders like a bull would.

Because the Bull shark lives close to the shore in some areas it is vulnerable to fisheries and is regularly caught. This has meant that the numbers of bull shark in local areas is often much reduced from natural levels. In less heavily fished areas it is one of the most common sharks to be found in shallow water. This is often because it has no natural predators and is highly successful due to the fact it has a very varied diet. Its aggressiveness and willingness to eat almost anything tends to keep other sharks out pf the same areas as bull sharks as well.

Because the bull shark is often found in relatively shallow water, and is also found in fresh water, it is thought to be responsible for numerous attacks on people. Also because many of the areas that it occupies are poor, attacks aren't given as much publicity as those committed by other sharks in more affluent areas. So from this we can easily see that the bull shark is fairly aggressive and not that picky about what it eats. After all most sharks will tend to have preferred prey species rather than eating anything they see.

More about this author: Jonte Rhodes

From Around the Web