Nile crocodiles are the largest freshwater predators in Africa, their considered the second largest reptiles in the world, after the saltwater crocodile. Nile crocodiles are widely spread throughout the sub-Saharan Africa; they occur in the central, southern and eastern regions of the continent, they live in different types of aquatic environments such as rivers, lakes and marshlands. However their known of living in saline environments, this type of species is found in saltwater, they occasionally inherit the brackish lakes and deltas the species stretched northwards throughout the Nile as well as far North as the Nile delta.
The Adult male crocodile is between the weight of 225 to 750 kg and the length of 3.5 and 5m.however the specimens exceed 6meters in length; it weighs up to 1,100kg as recorded by researchers.
Sexual dimorphism is very prevalent, with female’s there usually 30% that is smaller than males. They have thick scaly skin that is heavily armored.
Nile crocodile is apex predator very aggressive species of crocodile that is capable of taking animals within its range.
They take a variety of prey, and their diet consists of different species of fish, birds, mammals and reptiles. Nile crocodile is an ambush predator that stays in hide and waits for weeks, days and hours very ready to attack.
They comufoulage in mud and they are agile wait for the opportunity for a prey item to come within range. Like any other crocodiles, crocodiles have an extremely powerful bite very unique among others; they have sharp conical teeth that sink into flesh allowing for a grip which is almost impossible loosen. They hold down large prey underwater to drown, this is by applying high levels for force extended period of time.
Nile crocodiles are very social, sharing a basking spots and large food sources, such as big carcasses and schools.
The strict hierarchy is determined by size. Old males, large are at the top of this hierarchy, they have ordinary access to the best basking spots and food.
Nile crocodiles always respect the infringed, which results in violent and sometimes fatal. The eggs lied by Nile crocodiles are guarded by the female crocodile. After a period of time hatchers are protected for a period of time, parents do not feed the hatchers but hunt by themselves.
Nile crocodiles are very dangerous species of crocodiles that are responsible for hundreds of human deaths every year. They’re not endangered despite regional extinctions and regional declines. Local crocodiles appear more osteoderms in their ventral surface than other known populations which are thus lesser value in leather trading; the segregation of the West African crocodile from Crocodiles is supported by morphological characteristics that are genetic materials and habitat. There are two that are recognized by the IUCN this is their last evaluations of the group that was in 2008 and 2009, the years before supporting the distinction of the West African crocodiles.
The Adult Nile crocodiles have dark bronze coloration above, their appearance has faded blackish spots and stripes variably across the back and a dingy off yellow on the belly, and however the mud in water or along the lake shores can obscure the crocodile’s actual color.
There yellowish-green in color, with dark patches that are arranged in oblique stripes in highly variable patterns. Some variations are relative to environment, specimens from swift-flowing waters they tend to be lighter in colour than those dwelling in lakes, swamps ,they provide camouflage that suites the environment there in this includes clinal variation. Nile crocodiles have green eyes; the colouration is an additional that helps them to camouflage, their grey, multi-colored, brown, with dark cross-bands on the tail and body. Young crocodiles are yellowish in green as they mature, Nile crocodiles becomes darker and cross-bands fade, especially those on the upper-body there tendency has colors that change during maturation and mostly noted in crocodile species. Nile crocodiles are quadruped with short, splayed legs that are four, a long tail, scaly hide with rows of pssified scutes that run down throughout the back and to the tail, they also have powerful elongated jaws.
They react to changes in water pressure, allowing tracking prey movements in water. The skin is poorly understood and it may at times react to changes in water pressure, this allows them to track prey movements in water.
Nile crocodiles have fewer osteoderms on their belly that are much conspicuous on some of the modestly sized crocodilians. This type of species has small oval osteoderms that are located on the sides of the body as well as the throat part. The Nile crocodile shares with crocodiles a nictitating membrane to protect the eyes and glands in order to cleanse its eyes with tears.
Nostrils, ears and eyes are located on top of the head, the rest of the body are concealed underwater bodies. The body has four-chambered heart, this is modified for ectodermic nature due to an elongated cardiac septum this is also similar to the heart of a bird; this is efficient to oxygenate their blood. Nile crocodiles have exceptional high levels of lactic acid in their blood, this allows them to sit motionless in water for a period of 2 hours, the levels of lactic acid is high and crocodiles would kill the vertebrates. However, the exertion by crocodilians always lead to death due to increasing lactic acid to lethal levels, this then turns to lead into failure of animal’s internal organs. This record is rarely in wild crocodiles, they have been observed in very many cases where humans have mishandled crocodiles through extended periods of physical struggle and stress.
Nile crocodiles are filled with 64 to 68 sharply pointed shaped teeth that is about a dozen of less than alligators.
The Crocodiles teeth can be replicated, on every side of the mouth, there about five teeth in the front of the upper jaws, 13 or 14 are in the upper jaw, and about 14 or 15 there found at the side of the lower jaw the mandible.
The 4th lower tooth fits into the Notch which is found on the upper jaw and its very visible when the Jews are closed, this is similar with all true crocodiles.
There are egg tooth that are hardened piece of skin and found on top of the hatchlings mouths that are quickly lost, more so the egg tooth are used to break through their eggshells at birth. The Nile crocodile possesses a relatively long snout; it’s approximately 1.6 to 2 times as long as broad at the level of the front corners of the eyes.
Saltwater crocodiles, Nile crocodiles are considered with medium-width snout relative to other extant crocodilian species.
The muscles are exceptional weak however their exceptionally weak, this allows a human to easily hold them shut, the larger crocodiles they can always be brought under control by the use of duct-tape that helps to bind the jaws together.
The Nile crocodile is considered to be the second largest crocodile after the saltwater crocodile. The average size is much as 4.5 to 5.5m; however this is an excess size for the actual average size per studies as represented by the upper limit of sizes which is attained by the very largest animals.
The average mature size of a Nile crocodile is between 3.4 and 3.7 m, while aleander and marais state is 2.8to 3.5m.the average length and weight of the Nile crocodile from Uganda and Zambia breeding maturity was 3.16m and 137.5kg.
Nile crocodiles they are sexually dimorphic just like the other crocodiles, with 30% in males though the differences are less compared to saltwater crocodile. Male Nile crocodiles are about 30- 50 cm with an average at sexual maturity and more ,the females become sexually mature ,they expand in bulk exceeding 4m in length. Adult male Nile crocodiles range in length from 3.3 to 5m long; these weigh an average sized male that may weigh from 150 to 700kg.
Males of South Africa in Limpopo are very old, and grow to 5.5 m or more in length from 1900 onwards .the mature female Nile crocodile’s measure 3.8m of which the length of specimen weighs 40 to 250kg.
Bulk and mass individuals Nile crocodiles are variable, with some animals being slender, while are very robust, female are often bulkier than the males of similar length.
Distribution and habitat
Nile crocodiles in Africa can be seen throughout the continent. The crocodiles are saltwater crocodiles that occur over a broader geographic area. These were found as far as north Mediterranean coast in the Nile delta across the Red sea in Israel and Syria. According to research Nile crocodile have been recorded in different areas of extinct. The areas inhabiting the species and recorded include Lake Edward on the border between the Democratic Republic of Congo and Uganda. This species is thought to have become extinct in the areas of Seychelles in the early 19th century. Nile crocodiles are found in Kenya, Uganda, Ethiopia, Somalia, Egypt, Equatorial , Democratic Republic of Congo,Tanzania,Guinea,Burundi,Rwanda,Zimbabwe,Zambia,Angola,Gabon,Malawi,South Arica, Sudan, Botswana and Cameroon. Nile crocodiles distribute in the regions of Lake Nasser in Egypt, Cunene of Angola, Okavavango Delta of Botswana and olifants River in south Africa. They exist in Madagascar and occur in the western and southern parts from sambirano to Tolanaro .They have spotted in Zanzibar and Comoros in modern times although it’s very rare.
A Nile crocodile as thought it was extended into the west and central Africa, they are typically recognized as a distinct species.
They were boundaries that where poorly understood these followed with several studies, that are better known. The West African crocodiles are found throughout the west and central parts of Africa, these range east to south Sudan and Uganda, and the species come into contact with the Nile crocodiles.
Nile crocodiles are becoming absent from the central Africa and west Africa, these range into the regions of eastern and southern Democratic Republican of Congo along the central African coastal Atlantic region. The level of habitat segregation is between the two species although it remains to be confirmed for certain.
Nile crocodiles are able to tolerate an extremely broad range of habitat types; these include small brackish streams, swamps, dams, fast flowing rivers, and tidal lakes.
In the East African regions, they are found in rivers, marshes, dams, lakes, these favors the opening of broad bodies of water.
Nile crocodiles of Madagascar live within the caves.
Nile crocodiles are relatively inert creatures these are large cold blooded creatures.
Nile crocodiles may easily die from overheating, and their jaws are bound together in extreme midday heat. They remain motionless for hours on end whether basking in shallows, Nile crocodiles are constantly aware of their surroundings and the presence of other animals. Although mouth-gaping may serve as a threat display to other crocodiles, the specimens have been observed mouth-gaping at night when there is no overheating.
Lake Turkana was found basking through the day unlike crocodiles from most other areas; they are usually sitting motionless exposing the surface in shallows with no apparent ill effect from basking of land.
South Africa, Nile crocodiles are easily observed in winter because of the extensive amount of time they spend basking at this time of year. They spend most of their time in water, in rainy or misty days. The southern reaches of their range ,this is as a response to dry, cool since they cannot survive externally, Nile crocodiles may dig and take refuge in tunnels.
Nile crocodiles dive for only a few minutes at a time they are known for swimming underwater for up to 30 minutes if threatened, in case they remain inactive they hold their breath for two hours and this caused due to their high level of acid in their blood.
Nile crocodiles are known for their rich vocal range,and good hearing system,they normally crawl on their bellies as well as high walking with their trunks raise above.
The specimens gallop,and larger individuals that are capable on occasion of surprising bursts of speed,they briefly reach up to 12 to 14 km/hr.they swim faster by moving their bodies and tails,this form of movement lasts longer than on land, this is more than three times than any human a maximum speed of 30 to 35km/hr.
Nile crocodiles have gastrulates in their stomachs, these are stones that are swallowed by animals, for very many various purposes. Large specimens have large number of gastrulates these weigh about 240kg of stones inside the stomach.
Herodotus also claim that Nile crocodiles have a symbiotic relationship with a certain type of birds these include the Egyptian plover, they enter the crocodiles mouth and pick leeches feeding on the crocodiles blood, although there is no evidence of this interaction ,this occurs in crocodile species its is most likely mythical or allegorical fiction. Some birds are usually seen picking scraps of meat from the teeth of basking crocodiles ,they prey from soil which is very near basking crocodiles, is is felt impossible that a bold, hungry bird may occasionally enter a crocodiles mouth.
HUNTING AND DEIT
Nile crocodiles are apex predators throughout their range of living in water; this type of species is agile and rapid hunter relying on both movement and pressure sensors to catch any prey unfortunate enough to present itself inside or near the waterfront. Out of water, Nile crocodiles rely on their limbs, especially when they gallops on solid grounds, in order to chase prey, no matter where they attack the prey other crocodiles will practically take all their food by ambushing and grab the prey in seconds leading to their success. Nile crocodiles have a ectodermic metabolism in order to survive for long periods between meal, although when they eat, they can easily eat up to half of their body weight at a time. However their stomachs are relatively small, not bigger than basketballs an average sized adult, they are voracious eaters.
Young Nile crocodiles feed more actively than their elders according to studies in Uganda and Zambia. Generally Nile crocodiles hunt within confines of waterways, either terrestrial or by attacking aquatic prey when they come to the water to drink or to cross.
Nile crocodiles hunt land animals by fully submerging its body underwater.
Nile crocodiles surface quietly on water the eyes and nostrils are visible, then swims quietly and stealthy towards its mark. The Nile crocodile attacks sudden and unpredictable.
It lungs its body out of water in a blink of an eye and grasps its prey. On occasion, the upper body is visible, the terrestrials prey animal on higher ground, this direction of prey item as the top of an embankment on a tree branch. Crocodiles teeth are used for tearing up flash, they deep their teeth into the prey item. They use force to bite in large adults; this is to ensure the prey item can’t escape through a grip. Some preys can be overpowered by crocodiles making it easy for them to be swallowed. Incase it’s a large prey; it depends on the crocodiles body weight and power to pull the prey item back in water. It will be drowned or killed by tearing it into pieces and sudden thrashes of the head, this done with the help of other crocodiles.
Nile crocodiles small or sub-adult use their tails to herd groups of fish towards a bank, with quick sideway jerk of their heads; at times they prey on specimen where it easily drowned. They also cooperate, by blocking migrating fish a cross the river by forming a semicircle. In a circle the dormant crocodiles eat first. They lay their bodies underwater, with their speed over short distances, by making them opportunistic of larger prey. A prey is grabbed in their powerful jaws; it will drag the prey there after hold it underneath until it will drown. Nile crocodiles are seen stealing preys from other predators, these include leopards and lions. Nile crocodiles travel hundreds of meters from waterway to feast on a carcass.
Nile crocodiles feed on dead hippos as a group such as four or three, tolerating each other. Much of the food from crocodile’s stomachs comes from crocodiles and scavenging carrion, this could be viewed performing similar function as hyenas and vultures that stay on land. As soon as the prey is dead, they will rip off and swallow chunks of flesh. When the group shares a kill, they will use each other for leverage, twisting and biting down hard to tear off large pieces of meat in a death roll.
Nile crocodiles have unique predation behavior this is characterized by ability of preying within the natural habitat and out of the habitat; this may result into unpredicted attacks on any animal up to a couple of its size. Most hunting skills crocodiles use are done at night when their lying on the roadsides or near forest trails this is up to 50m.their speed on land is outmatched by terrestrial animals, they use obscure vegetation in order to have a chance of succeeding land based hunts.
In case an adult crocodile is charged from water to bank shores of the bank to kill a bushbuck it will drag it into water as observed to kill instead of dragging it into water, or into the cover of the bush.
The crocodile can jump up and grab a donkey by neck it will then drag a prey off.
The size of prey depends on the crocodile, the diet of the young crocodile is made up of large of insects and other invertebrates this is the only prey which animals can take in.
Nile crocodiles more or less much the same small prey as smaller crocodiles such as arachnids and insects they take many small to medium-sized vertebrates and their quickly capable taking down prey of their own weight. Lake Turkana, Kenya, Lake Turkana arid land is relatively barren with numerous preys other than fish .Lake kyoga and lake kwana of Uganda with 73.1% of the crocodiles with no empty stomachs.
Nile crocodiles line up in dozens a cross narrow straits of the estuary in order to effectively force the mullet into easy striking distance with no observation in fighting .Larger fish including freshwater bass and cat fish are preferred by adults of more than 3m in length.
There small fish that are eaten in case of an encounter, in shallow dry season ponds where much effort is needed to catch the agile prey that are small. Mostly their observed in fishing by crocodiles that take place in water and lesser than 1.5m deep and fish which is often caught when they swim with the Nile crocodiles head, literally right into reptiles mouth. Nile crocodiles are is destructive feeder on freshwater fish, which are essential livelihoods of local fisherman and industry of sport fishing.
The cold blooded creatures (Nile crocodile) eat less compared to equivalent weighted warm –blooded animal. There various important types of fish such as Tilapia, these cause a lot of conflicts between crocodiles and humans however crocodiles need relatively little fish without other influences. Crocodiles take dead or dying fish whenever their given an opportunity this incidentally improves the health of fish species populations.
Frogs always prey for small, young crocodile’s .the main amphibian prey species from Uganda and Zambia is the African common toad.
Nile crocodiles prey on big cats, especially lions. Sometimes large male cats are helpless if caught off-guard and hit with a crippling powerful crocodile bites. Most attacks by crocodiles on leopards and lions has so far occurred within Kruger National Park ,where some studies have taken a number of research works on crocodiles ,there was a scene of a male lion who took control with his brother and was preyed by a crocodile.
Nile crocodiles have 13 species of crocodiles, there varieties of fruits that have been found in stomach content. It has also been found in history crocodiles act as seed dispersers.
INTERSPECIFIC PREDATORY RELATIONSHIPS.
Nile crocodiles come into contact with multiple large predators.
Nile crocodiles become sexually mature from 12 to 16 years. The onset of sexual maturity that occurs when they are about 4m and the mass of 155kg.
Female sexual maturity occurs when they reach 3m in length .During the mating season; males will attract females by slapping their snouts in water, bellowing, blowing water out of their noses, and much verity of noises. Among the population of males, territorial clashes leads to physical fighting between the males of the same size. Clashes are brutal affairs that can end in mortality but typically with victor and loser still alive. a female has attacked by the male, a pair warble and rub the undersides of jaws together this is a tender behavior or sign of the females being accepted by the male. Males can mate with a number of females, however if a female enters, his claimed territory, although annual monogamy appears in this species.
Females lay their eggs about one to two months after mating. Nesting season fall in every month of the year. Crocodiles between these distributions, egg lying occurs in intermediate months, this occurs between April and July.
The benefits are presumable that nest flooding is considerably reduced at this time when the hatchlings begin their lives out of the egg shell which is roughly at the beginning of the rainy season, this is when the water levels are still very low and insect preys are in recovery.
Crocodiles usually nest in sandy shores, dry stream beds, or riverbanks. Females dig holes a few meters from the bank and end up to 1 m deeper, they lay eggs between a total number 25 and 80 egg. The total number of eggs depends on the size of the female. The nests are built in soils with access for the female to dig out the nest mound, while the mother retires during the heat of the day back to the waters.
The female will find a soft spot to allow her to dig a slanted burrow. She will then deposit her eggs in a terminal chamber and packs the sand over the nest pit.
Nile crocodiles dig holes for a nest site; female Nile crocodiles will bury their eggs in sand or soil rather to incubate them in rotting vegetation. Females will keep the soils moist this prevents soil from hardening .after burying the eggs; females guard them for about three-month incubation period. Nests are recorded in concealed positions such as in grasses and buses, they open in spots on the bank. Nile crocodiles cannot nest under heavy forest covers two of the three other African crocodiles because of they do not utilize rotting leaves thus they require sunlight on soil and sand the surface of the egg chamber which provides warmth for embryo development. The Nile crocodile have been free from disturbance in the past; nests are gregariously lying close together after hatching the rims of craters which are contiguous. Female Nile crocodiles are considered to be unpredictable and driven by region extent of human disturbance and persecution in natural variability in other areas ,the mother only leaves the nest in case of any need to cool off by taking quick dip or seeking a patch of shade.
Females cannot leave their nest site even though the rocks are thrown at them, Nile crocodiles show no discernable reaction even if their pleted with stones. Females attack anything that approaches their eggs, their joined by crocodiles which may be young. The nests are usually raided by monitor lizards and humans or animals while the female is temporarily absent.
Nile crocodiles have temperature-dependent sex determination, this means the sex of their hatching is determined by genetics this is the same case in mammals and birds, incubation period is about 90 days that is if the temperature inside the nest is above 34.50c, the young one will be a female. Males are born with a temperature of narrow range, as the hatchlings will start to make a high-pitched noise before hatching, as the mother will rip open the nest. Mother crocodile picks up the eggs in her mouth, she will them roll them between their tongues thus to help them crack the shell to release her offspring’s. As soon as the eggs hatch, female crocodile may lead the hatchlings to water, or even to carry them in her mouth.
Nile crocodiles are between 280 and 300 mm long and they weigh around 70 g. Hatchlings grow each year for the first several years. New mother will protect her off spring for two years, there multiple nests.
The mothers pick up their offspring in their mouths or throat pouch, in order to keep his babies safe.
She will sometimes carry her offspring’s on the back in order to avoid natural predators that can be bold even when the mother is around. Nile crocodiles of two years are observed than larger specimens, their seen in same age in many other crocodilians. Nile crocodiles are very shy due to a number of predators that they face in sub-Saharan Africa.
The hatchlings is about 1.2 m long, they will naturally depart the nest area in order to avoid territories larger and older crocodiles. Crocodiles associate with sized crocodiles they enter the feeding congregations of the large crocodiles once they attain 2m,of which predators and cannibal ,this becomes much less concern. Nile crocodiles have larger species, the Nile crocodile lives longer and have a potential average life span of 70 to 100 years, and no lifespan that exceeds 50 to 60 years in captivity.
Natural mortality of young Nile crocodiles
About 10% of eggs will survive in order to catch 1% will eventually successes in order to reach adulthood. The range for mortality of young Nile crocodiles is not understood, the very young and small Nile crocodile are observed. African fish eagles are known of taking crocodile hatchlings upto few months of age and honey badgers which preys on yearnings. As soon as they reach juvenile stage, the large African rock pythons and big cats, remain as the only predatory threat to young crocodiles. Perhaps no predators are more deadly to Nile crocodiles than larger crocodiles of their own species.
The species are very dangerous to their own kind which considers aggressive disposition to bear.
Mother crocodile reacts aggressively towards predators which beed recorded catching and killing interlopers into her range.
Conservation has determined the main threats to Nile crocodile this turns a loss of habitat, hunting, habitat, pollution and human activities as accidental entanglement of nets. Nile crocodiles have been hunted.
Nile crocodiles behave aggressively to humans or regard humans as they prey than saltwater crocodiles. The man eating crocodiles species these include saltwater crocodiles, they move through their range thus becoming frequent in contact. Crocodiles are capable of overpowering and they prey on small apes including smaller adult humans and children although the majority exceeds 3m in length.
It is claimed that the largest size of the Nile crocodile is attained approximately 5m,this is claimed as the top size which is expected in species.
In lake Kyoga of Uganda a specimen was killed by captain Riddick, who stated the measurement of the Nile crocodile with approximately 9.93m in total length.
Nile Crocodiles can be spotted in lakes and different lakes in uganda including Lake Kyoga,Lake Katwe