Crocodile facts

Crocodile facts

1. Crocodiles are large, carnivorous reptiles of the order Crocodilia, found in tropical and subtropical regions. Crocodiles live in swamps or on river banks and catch their prey in the water. They have flattened bodies and tails, short legs, and powerful jaws. The eyes, ears, and nostrils are located near the top of the head and are exposed when the crocodile floats on the surface of the water. The ears and nostrils have valves that close when the animal is submerged.

2. Most crocodiles are more aggressive than the related alligators. The two forms are distinguished by the long lower fourth tooth: in crocodiles, but not in alligators, this tooth protrudes on the side of the head when the mouth is closed. Also, the snouts of most crocodiles are narrower than those of alligators.

3. The larger species of crocodiles can be very dangerous to humans. The Saltwater and Nile Crocodiles are the most dangerous, killing hundreds of people each year in parts of South East Asia and Africa. American Alligators, and possibly the endangered Black Caiman, can also be dangerous to humans.

3. Crocodiles tend to congregate in slow moving rivers and lakes, and feed on a wide variety of living and dead mammals and fish. Some species, notably the Saltwater Crocodile of Australia and the Pacific islands, have been known to venture far out to sea. They are an ancient lineage, and are believed to have changed little since the time of the dinosaurs.

4. Small crocodiles feed on fish and small aquatic animals; larger crocodiles also catch land mammals and birds that approach the water. Members of some large species sometimes attack and eat humans.

5. Crocodiles are very fast over short distances, even out of water. They have extremely powerful jaws and sharp teeth for tearing flesh. All large crocodiles also have sharp welters and powerful claws. They have limited lateral movement in their neck, so on land one can find protection by getting even a small tree between the crocodile's jaws and oneself.

6. Crocodiles are ambush hunters, waiting for fish or land animals to come close, then rushing out to attack. As cold blooded predators, they can survive long periods without food, and rarely need to actively go hunting.

7. The crocodile's bite strength is up to 3000 pounds per square inch, comparing to just 100 psi for a large dog. Despite their slow appearance, crocodiles are the top predators in their environment, and various species have been observed attacking and killing lions, large ungulates and even sharks.

8. A famous exception is the Egyptian Plover which is said to enjoy a symbiotic relationship with the crocodile. According to unauthenticated reports, the plover feeds on parasites that infest the crocodile's mouth and the reptile will open its jaws and allow the bird to enter to clean out the mouth.

9. Wild crocodiles are protected in many parts of the world, but they also are inhumanely farmed commercially. Their hide is tanned and used to make leather goods such as shoes and handbags, while crocodile meat is also considered a delicacy in many parts of the world. The most commonly farmed species are the Saltwater and Nile crocodiles, while a hybrid of the Saltwater and the rare Siamese Crocodile is also bred in Asian farms.

10. With the exception of the two African dwarf crocodiles (Osteolaemus) and the so-called false gavial (Tomistoma) of Asia, crocodiles are classified in the genus Crocodylus, with about a dozen species.

11. The saltwater crocodile is the largest living reptile species. It can grow up to six metres and is a serious threat to humans. Saltwater crocodiles have evolved special characteristics that make them excellent predators.

12. Large saltwater crocodiles can stay underwater for at least one hour because they can reduce their heart rate to 2-3 beats per minute. This means that crocodiles can wait underwater until they see prey, or if people are using the same spot regularly, the crocodile can wait underwater until someone approaches the water’s edge.

13. A crocodile can float with only eyes and nostrils exposed, enabling it to approach prey without being detected.

14. When under water, a special transparent eyelid protects the crocodile’s eye. This means that crocodiles can still see when they are completely submerged.

15. The tail of a crocodile is solid muscle and a major source of power, making it a strong swimmer and able to make sudden lunges out of the water to capture prey. These strong muscles also mean that for shorts bursts of time crocodiles can move faster than humans can on land.

16. Crocodiles have a thin layer of guanine crystals behind their retina. This intensifies images, allowing crocodiles to see better at low light levels.

17. Crocodiles have a ‘minimum exposure’ posture in the water, which means that only their sensory organs of eyes, cranial platform, ears and nostrils remain out of the water. This means that they often go unseen by prey, but if they are observed, the prey is often not able to tell how big the crocodile is.

18. Crocodile eyes are located very closely together and they are oriented forward. This enables them to judge distance very accurately so they can determine the exact location of their prey prior to attack.

19. Crocodiles have excellent hearing, which helps them to locate prey particularly in poor light or low visibility conditions.

20. While crocodiles may regularly lose teeth, they have a second tooth sitting in reserve underneath the external tooth, which can replace the lost tooth.

21. The jaws of crocodiles are designed to generate enormous power when the jaws are closing. This enables them to quickly crush prey.

22. The marsh crocodile, or mugger (C. palustris), is a freshwater species of India and Sir Lanka, regarded as sacred in some regions.

23. The American crocodile (C. acutus) is found in fresh and saltwater in South Florida, the West Indies, Central America, and North West South America. It does not attack humans without provocation.

24. The Orinoco crocodile (C. intermedius) is a freshwater species of the Orinoco basin of Colombia and Venezuela. Two smaller species are found in limited areas of Central America and Cuba.

25. Crocodiles spend most of their time in saltwater.

26. To weep crocodile tears is to put on an insincere show of sorrow. The first crocodiles appeared 240 million years ago, at the same time with the dinosaurs.

27. Crocodiles are much more closely related to birds and dinosaurs than the other reptiles.

28. Crocs can live up to eighty years!

29. Crocodiles sweat through their mouth, so when they lie on the riverbanks with their mouths wide open, that’s not an aggressive posture, but a way to cool off.

30. Crocodiles have very sharp teeth. However, they cannot open their mouth if it is held closed, even with the help of an adhesive tape.

31. Each crocodile jaw has 24 sharp teeth, used for grasping and crushing, but not chewing. The teeth of a crocodile get replaced continuously, throughout its life.

32. The eggs of a crocodile are almost the same size as that of a goose.

33. The crocodiles have a four-chambered heart, which behaves like a three-chambered reptilian one, when underwater.

34. The eyes of a crocodile reflect light, making them appear red, and make night vision possible.

35. Crocodiles do not shed their skin, rather they grow into it.