Did you know?
- Saltwater (Estuarine) crocodiles can live for more than 70 years, and freshwater crocodiles are thought to live for at least 50 years.
- Although ungainly, crocodiles can walk on land at a speed of about 1-2 km/h. Short bursts of speed on land rarely exceed 10 km/h, and tire the animal quickly. Freshwater crocodiles can reach speeds of up to 18 km/h.
- Large crocodiles can stay underwater for at least an hour by dropping their heart rate to 2-3 beats per minute to conserve energy.
- Although commonly referred to as 'cold-blooded', crocodiles need heat to function and prefer a body temperature of 30-33°C. Unlike mammals which generate their own heat, crocodiles rely on the sun to warm them.
- As much as 50%, even 70% of the food which a crocodile eats is converted to flesh and energy. In humans it is about 3-4% because so much (80%) is used to produce heat. This means that crocodiles can survive for months without eating.
- A female saltwater crocodile lays her eggs in a nest of vegetation. The sex of her offspring is determined by the temperature at which the eggs are incubated. If the nest is below 30°C exclusively females are produced, at 31°C a mix results, and 32-33°C produces mostly males.
- The skin on crocodiles is composed of a network of interconnected scales or scutes of various types and sizes. On the belly surfaces, these scales tend to be square and flat; it is the skin of this region that is most commonly used in the leather industry. The scales on the flanks and the neck tend to be round with a raised centre, while along the back and upper surfaces of the tail, the scales are raised in a very pronounced way. These raised scales (osteoderms) are provided with a rich blood supply that transports heat back into the body when crocodiles bask.
- A crocodile can float with only eyes and nostrils exposed, enabling it to approach prey without being detected.
- When underwater, a special transparent eyelid protects the crocodiles eye. Their eyes function best in low light. The pupils of the eye which are reduced to a slit in daylight, open wide and a special layer of light reflecting crystals behind the retina, common in nocturnal animals, enhances night vision. These crystals cause the eyes to shine red when caught in torch or spotlight.
- 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.
- Crocodiles have excellent hearing, which helps them to locate prey.
- While crocodiles may regularly lose teeth, they have a second tooth sitting underneath the external tooth, which can replace the lost tooth.
- Some crocodiles swallow hard items such as stones to assist in digestion and possibly also to help balance the animal in the water.
- When opening its mouth, a crocodile can seal the back of its throat to avoid gulping water.
- Opening its mouth while basking in the sun prevents a crocodile's brain overheating while its body continues to absorb heat.
- The jaws are extremely powerful and a large crocodile can crush the head of a pig with a single bite.
- Crocodiles have no vocal chords. Growls are made by snorting air through the back of the throat or nostrils.