Nile crocodile predator vs prey behavior4/16/2024 There are an estimated 250,000 to 500,000 individuals in the wild. ![]() Crocodile 'protection programs' are artificial environments where crocodiles exist safely and without the threat of extermination from hunters. National laws, and international trade regulations have resulted in a resurgence in many areas, and the species as a whole is no longer threatened with extinction. The population was severely depleted, and the species faced extinction. It was previously thought to extend into West Africa, but these populations are now recognized as a distinct species, the Desert Crocodile.įrom the 1940s to the 1960s, the Nile crocodile was hunted, primarily for high-quality leather, though also for meat and purported curative properties. In Madagascar, they have adapted to living in caves. They have been known to enter the sea in some areas, with one specimen having been seen 11 kilometres off St Lucia Bay in 1917. In East Africa, they are found mostly in rivers, lakes, marshes, and dams. Until recently, many permanent waters in the Sahara still housed relict populations. They have occasionally been spotted in Zanzibar and the Comoros. In Madagascar, crocodiles occur in the western and southern parts from Sembirano to Port Dauphin. The Nile crocodile's current range of distribution extends from the Senegal River, Lake Chad, Wadai and the Sudan to the Cunene and the Okavango Delta. It is known from fossil remains that they once inhabited Lake Edward. They are thought to have become extinct in the Seychelles in the early 19th century. ![]() In antiquity, Nile crocodiles occurred in the Nile delta and the Zarqa River, and they are recorded by Herodotus to have inhabited Lake Moeris. Occasionally, both will hunt and prey on each other, depending on size, if regular food becomes scarce. Outside water, crocodiles can meet competition from other dominant Savanna predators, notably felines such as lions and leopards. Hatchlings quickly lose a hardened piece of skin on the top of their mouth called the ''egg tooth'', which they use to break through their egg's shell at birth. On each side of the mouth, there are 5 teeth in the front of the upper jaw, 13 or 14 in the rest of the upper jaw, and 14 or 15 on either side of the lower jaw. Their mouths are filled with a total of 64 to 68 cone-shaped teeth. However, the muscles responsible for opening the mouth are exceptionally weak, allowing a man to easily hold them shut with a small amount of force. The bite force exerted by an adult Nile crocodile has been shown by Dr. Their skin has a number of poorly understood integumentary sense organs, that may react to changes in water pressure. They have a rich vocal range, and good hearing. They have an ectothermic metabolism, so they can survive a long time between meals - though when they do eat, they can eat up to half their body weight at a time. They normally dive for only a couple of minutes, but will stay underwater for up to 30 minutes if threatened, and if they remain inactive they can hold their breath for up to 2 hours. They have a four-chambered heart, although modified for their ectothermic nature due to an elongated cardiac septum, which is physiologically similar to the heart of a bird, which is especially efficient at oxygenating their blood. They can swim much faster by moving their body and tail in a sinuous fashion, and they can sustain this form of movement much longer at about 30 to 35 km/h. Smaller specimens can gallop, and even larger crocodiles are capable of surprising bursts of speeds, briefly reaching up to 12 to 14 km/h. They normally crawl along on their bellies, but they can also "high walk" with their trunks raised above the ground. The underbelly is yellowish, and makes high-quality leather. As they mature they become darker and the cross-bands fade, especially those on the body. ![]() Their coloration also helps them hide: Juveniles are grey, multicoloured, or brown with darker cross-bands on their tail and body. Nostrils, eyes, and ears are situated on the tops of their head, so the rest of the body can remain concealed underwater. They have nictitating membranes to protect their eyes and have lachrymal glands, and can cleanse their eyes with tears. ![]() Like all crocodiles, they are quadrupeds with four short, splayed legs long, powerful tails a scaly hide with rows of ossified scutes running down their back and tail and powerful jaws. There is some variation relative to environment specimens from swift flowing waters tend to be lighter in colour than those dwelling in lakes or swamps. The flanks, which are yellowish green in colour, have dark patches arranged in oblique stripes. Nile crocodiles have a dark bronze colouration above, with black spots on the back and a dirty purple on the belly.
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