Shark behaviour

snowstreams

Is there really such thing as a rogue shark?

Or is it more likely that something would have attracted a number of sharks into an area frequented by swimmers, and hence there was an attack.

Here are two recent articles of examples of shark attacks that happened in quick succession together in areas that do not normally get shark attacks.

http://www.independent.ie/world-news/europe/honeymoon-shark-attack-victim-had-no-chance-ndash-police-2850110.html

http://www.telegraph.co.uk/news/worldnews/africaandindianocean/egypt/8182482/Egypt-shark-attack-kills-tourist.html

Also it is the general scientific opinion that sharks only attack humans by mistake and will leave the human after they have realised that they are not their normal prey.
However in many or all of the above attacks, the swimmers acquired multiple bites.
So maybe these particular sharks had acquired a taste for human flesh?

steddyeddy

snowstreams wrote: »

Is there really such thing as a rogue shark?

Or is it more likely that something would have attracted a number of sharks into an area frequented by swimmers, and hence there was an attack.

Here are two recent articles of examples of shark attacks that happened in quick succession together in areas that do not normally get shark attacks.

http://www.independent.ie/world-news/europe/honeymoon-shark-attack-victim-had-no-chance-ndash-police-2850110.html

http://www.telegraph.co.uk/news/worldnews/africaandindianocean/egypt/8182482/Egypt-shark-attack-kills-tourist.html

Also it is the general scientific opinion that sharks only attack humans by mistake and will leave the human after they have realised that they are not their normal prey.
However in many or all of the above attacks, the swimmers acquired multiple bites.
So maybe these particular sharks had acquired a taste for human flesh?

You hit the nail on the head about the "rouge shark" description. What they describe as a rouge shark is simply a shark that found a new food source. The authorities in the seychelles are probraly stating that theres a rouge shark out there that needs to be killed as some form of damage control.

The general scientific opinion is that a large amount of animals will only attack out of fright, mistake or hunger. The latter is less common with sharks. The thing about animal behaviour is it isnt text book, what you find in ethology papers ten years ago isnt always going to be true today. Animals change behaviour quite radically depending on the cost and/or advantage to them. For example polar bears are carnivorous were as their ancestors* were largely omnivores, that in part was due to a change in available food sources. So the change in behaviour at least sometimes comes after the change in diet. Some animals are opportunistic which could be said of some types of sharks.

The authorities of the sychelles say it could possibly be a tiger shark or bull shark both of which are known to be aggressive anyway. The taste for blood thing is trotted out a lot but theres no evidence that a particular species aquires a "taste" as we see it for another species, its more to do with cost versus effort regarding aquiring the meal.





*Polar bear ancestors were recently found to be Irish brown bears!

snowstreams

They have looked at his bites in the seychelles and say that they are bites from a bull shark.
They would be the only species of shark i would genuinely be afraid of on holidays in a tropical in shallow water.
But the odds of coming across one is so small.
The attacks in Egypt however seemed to be from at least 2 different species all in the space of a week.
A few bites were from oceanic white tip sharks and one was even a mako shark.
Both are deep water sharks.
Interestingly you can apparently get mako sharks in deep irish waters during summer.

Adam Khor

snowstreams wrote: »

Also it is the general scientific opinion that sharks only attack humans by mistake and will leave the human after they have realised that they are not their normal prey.
However in many or all of the above attacks, the swimmers acquired multiple bites.
So maybe these particular sharks had acquired a taste for human flesh?

The "general scientific opinion" is bull****. It is true that great white sharks often bite a human, then leave. It is not because they mistook the human for a seal or another "normal prey item". Sharks are smart enough to tell a man apart from a seal, besides their senses of smell and taste are much better developed than ours. The way in which a seal swims, besides, is different than the way a human swims and gives out different vibrations in the water, which the shark can sense and recognize.
Truth is, if sharks were stupid and sensorially impaired enough to mistake humans for seals and other animals, attacks on humans would be much more frequent.
When a shark bites a human, its usually because it KNOWS its not its usual prey, and it wants to know what it tastes like, if it is good to eat. Sharks react like this to any new object of prey they encounter- first they touch it with their skin, usually by bumping their head against the new object, then they take a bite out of it. If it's not to their liking, they spit it out. If they like it, they may bite a second time. It's their way of learning more about a new thing- its not a dumb mistake.
Great white sharks usually don´t like eating humans because we are low fat- they prefer high fat meat like seal and sea lion because more calories help them keep warm and active in cold waters. That's why great whites seldom eat humans even after the exploratory bite.

On the other hand, other shark species, like the tiger and bull sharks, are less picky about what they eat and they will often eat their victim. To these sharks, once they taste our flesh and know we are edible, they will keep eating us because at the end of the day, we are just meat.

It bugs me how journalists and even scientists wonder after an animal attack, "why did this happen?", "what made this animal attack a human?", as if it was so difficult to understand.
Predators kill and eat flesh, that's what they do. If you're going into the water, be aware that you MAY be attacked by a shark. There's no reason for them to respect us more than they respect their usual prey. :cool: