Tuesday, January 31, 2012

crocodile


Never Smile at a Crocodile - The Increasing Number of Crocodile Attacks

Crocodiles - An Ancient Line of Predators
Today there are something like twenty-two species of reptile that make up the Order Crocodylia. Of these species; only thirteen are actually true crocodiles, the remainder are Alligators, Caiman and the extremely rare and endangered, long-snouted gavials, sometimes referred to as gharials. We often get asked how to tell the difference between a crocodile and an alligator. There are a number of anatomical differences between crocodiles and alligators, when observing these reptiles look for a large, fourth tooth in the lower jaw. When the mouth is closed this tooth fits into a notch in the upper jaw and the tooth remains visible even when the mouth is closed. If you can see this tooth, then you are looking at a crocodile.


There are only two species of Alligator left in the world. Firstly, as most people know, there is the American alligator (alligator mississipiensis), which can be found widely distributed across the south-eastern United States, most typically in the Florida Everglades. There is also a second extant species of alligator, although this one is much rarer and confined to the upper Yangtse River valley in China. Scientists had thought that the less aggressive alligator had been "weeded out" of its range by crocodiles, leaving the only representatives of the Alligatoridae family in these isolated pockets. The more efficient crocodiles grew faster and may have been better at consuming food but this is generally regarded as speculation - as in the case of the American alligator, this species competes with the native American crocodile (C. acutus). The American alligator can withstand cold spells far better than the American crocodile, and as a result, has a much more extensive range in the United States.
Crocodylia in the "New World"
The idea of a "less aggressive" member of the Order Crocodylia is also a contradiction in terms. In the USA, once an Alligator reaches a length in excess of 4 feet it is regarded as dangerous to people. Alligator incidents are frequent, beginning in the spring when the warmer weather makes these cold-blooded reptiles more active and they begin to roam more widely. Fortunately, attacks on humans are relatively rare, although they do occur especially where people have been foolish enough to encourage alligators by feeding them. In some parts of the southern United States, special warden teams have been formed who work on a twenty-four call out service capturing and removing alligators that have wandered into areas of human habitation and got into contact with people. Specimens over 3 metres long are exceptionally rare in the wild but these reptiles, with their powerful jaws are still extremely dangerous and should be treated with caution. There is even a countryside code which has been developed by park rangers - a sort of "dos and don'ts" when in American alligator territory.
Crocodylia in the "Old World"
The majority of fatal attacks occur in Asia and northern Australia. Whilst we at Everything Dinosaur, would contend that all species of crocodilian are dangerous and that even a baby crocodile emerging from its egg is quite capable of giving you a nasty bite on the end of your finger - perhaps two of the most dangerous species of crocodile in the world can be found in Asia and Australia.
The "Mugger"
Let us deal with the Mugger crocodile, otherwise known as the Swamp crocodile (Crocodylus palustris). The term "Mugger" does not describe this reptile's habit of attacking humans, the word is a corruption of the Urdu dialect meaning "water monster" and what a beast this creature is. Large specimens can measure up to fourteen feet long and it is a proven man-eater. Although endangered, this crocodile can be found throughout freshwater river systems and marshes on the Indian sub-continent. It is aggressive and large crocodiles specialise in ambushing prey as they come to the water's edge to drink. Unfortunately, people are also attacked by this crocodile, notably children who might be fishing or given the job of fetching water. A number of fatal incidents are reported each year. The Mugger crocodile superficially resembles the Nile crocodile of Africa (Crocodylus niloticus) but it can be distinguished by its shorter, broader snout and the arrangement of prominent scutes (armoured plates) that can be found along the back of this particular crocodile.
The Estuarine Crocodile
The majority of fatal crocodile attacks are put down as being attacks from the Estuarine or "Saltwater" crocodile (Crocodylus porosus). This crocodile can be found across almost the entire Pacific, from Sri Lanka to the Fiji islands, including the northern territories of Australia. This is the largest surviving species of reptile in the world today, with large males growing to more than twenty-two feet in length and weighing more than one tonne. Although, not as big as a dinosaur such as Tyrannosaurus rex, this crocodile is still an extremely formidable predator and it is responsible for a number of fatal attacks each year. Unfortunately, the number of attacks are increasing. This is due to a number of reasons:
1). Increasing crocodile numbers - poaching in the 20th Century led almost to the extinction of this crocodile species in some parts of its range. Once controls on poaching were put in place and hunting restrictions imposed Estuarine crocodile numbers rapidly increased. More crocodiles in rivers and estuaries has led to an increase in crocodile attacks.
2). Decline in natural game - hunting and habitat clearance, as well as over fishing has led to a decline in the natural prey of these large crocodiles. This is particularly noticeable in countries such as Indonesia. As a result, this has led to a number of crocodiles attacking people close to riverbanks and other bodies of water.
3). Increasing human populations - expanding populations in south-east Asia, the expansion of towns and estates in northern Australia has brought more and more people into contact with large saltwater crocodiles. As a consequence, incidents involving crocodiles have grown dramatically.
4). More tourists exploring known crocodile "hot spots" - the growth in the tourism industry in south-east Asia and northern Australia has led to more people visiting and camping in areas where crocodile attacks are known to have occurred.
Recently, a fourteen-year-old, Indonesian boy was dragged from a boat and fatally mauled by a large Estuarine crocodile. Attacks on unwary Australian tourists are on the increase. A dentist, fishing off the coast of the northern Territory was lucky to escape with his life after a crocodile attacked. We read about and indeed we at Everything Dinosaur, report on a number of such incidents each year.
It is difficult to accurately document the number of fatal crocodile incidents each year, we have highlighted the problems with just two species and in writing this article we have not discussed the many crocodile attacks carried out in Africa by the Nile crocodile. Calculating the number of incidents is difficult, most attacks take place in remote areas, most of them impoverished so accurate records are often not kept. It is important that visitors to these areas should heed the warnings of locals and also to consider their own safety when getting close to water. It is worth remembering that a five metre long crocodile can hide in less than 30 centimetres of muddy water!
Remember the old saying "never smile at a crocodile".
Everything Dinosaur is a company run by parents, teachers and real dinosaur experts. It specialises in developing educational dinosaur toys, models, clothing and games and strives to help young people learn more about science through their fascination with prehistoric animals. Many of the items featured on the Everything Dinosaur website http://everythingdinosaur.com/ have been designed and tested by the teachers and real dinosaur experts in the company.
To learn more about the products and services we offer at Everything Dinosaur click on our website links.
Our aim is to help young people learn more about Earth sciences through their fascination with dinosaurs and other prehistoric animals. Team members are happy to provide advice and support supplying free quizzes, drawing materials, puzzles, games even recipes for dinosaur themed biscuits and birthday cakes. With something like 600 products on line including dinosaur party supplies, Everything Dinosaur http://everythingdinosaur.com/ has built up a strong reputation assisting parents, guardians and fellow teachers, helping young people to learn more about science through creative play.

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