Crocodile - the largest living reptile |
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Unique Features
Crocodiles are carnivorous (flesh eating) and the largest living reptiles on earth. Crocodiles first appeared about 200 million years ago. Crocodiles are amphibious, living on both land and in water. The crocodile's hide is extremely tough, with boney plates forming a kind of armor.They have 30-40 teeth in each jaw which interlock when the jawbones are closed. Their jaws are powerful enough to crush the bones of small animals, but so weak when opening that they can be held together by a human hand. The internal anatomy of the crocodile resembles that of birds. Description The average lifespan of a crocodile is 45 years in the wild, and up to 80 years in captivity. The average size of a fully grown crocodile is some 5 meters (about 16ft) and their weight may easily exceed 225 kgs (about 500lb). Crocodiles live in rivers, freshwater marshes, estuaries and mangrove swamps. On land, crocodiles move fastest in a kind of slithering belly crawl, but they are also able to walk on all four legs in a slow kind of swagger. They are social animals that work in groups to dig tunnels to cool off, and they care for their young. Crocodiles are vocal reptiles and able to make sounds from soft hisses to roars and bellows. In extreme heat, they spend the majority of their days basking on riverbanks with mouths wide open. Mouth gaping is similar to the panting of a dog; it helps a hot crocodile cool off. Predators Crocodiles are lethal predators and have few natural enemies. They use their powerful tails as deadly clubs when capturing prey. Unable to bite, the crocodiles corkscrews the bodies of their prey in the water to rip off chunks of flesh and lift their heads clear of the water when swallowing. The crocodile floats almost completely submerged, only its eyes, nostrils and part of its back are visible when stalking prey. Their prey include zebra, hippo, porcupine, pangolin and wildebeest. Crocodiles also eat fish and can eat their prey underwater as well as on land. The have vertical pupils that open wide in low light that make them formidable nocturnal hunters. Reproduction Crocodiles are egg-laying reptiles and reach productive maturity at around the age of ten years old. Females nest on sandy shores, dry stream beds or riverbanks, and lay between 20-90 eggs, about the size of a goose egg. The female buries its eggs in the sand or mud where they are left to hatch, incubated by the heat of the sun. The female remains in the area to protect the nest until the eggs are hatched 3-4 months later. As far as reptiles are concerned, crocodiles are the best at parenting. These reptiles provide the most parental care for their offspring. The female lays her eggs in a carefully dug hole in the sand or mud on lake or river shores. For the next three to four months she closely guards the nest, viciously attacking any intruder. When the young are ready to hatch they make a chirping sound from the buried eggs. The female then gently digs up and breaks open the eggs with her mouth, releasing the 30 cm (12 in. ) long babies. The female crocodile scoops them up in her mouth and carries them to the river. She will guard her babies for over a year after they've hatched. Even though a female crocodile is a force to be reckoned with, many smaller crocodiles fall prey to animals such as marabou storks, heron, ibis, turtles, and catfish. Less than two percent of crocodile eggs hatch and grow to maturity. |