Ce qui est déjà plutôt honorable ! [3][74] Although they can remain practically motionless for hours on end, whether basking or sitting in shallows, Nile crocodiles are said to be constantly aware of their surroundings and aware of the presence of other animals. [18], Herodotus claimed that Nile crocodiles have a symbiotic relationship with certain birds, such as the Egyptian plover (Pluvianus aegyptius), which enter the crocodile's mouth and pick leeches feeding on the crocodile's blood, but no evidence of this interaction actually occurring in any crocodile species has been found, and it is most likely mythical or allegorical fiction. : You are free: to share – to copy, distribute and transmit the work; to remix – to adapt the work; Under the following conditions: attribution – You must give appropriate credit, provide a link to the license, and indicate if changes were made. A smaller population from Mali, the Sahara Desert, and elsewhere in West Africa reaches only 2 to 3 m (6 ft 7 in to 9 ft 10 in) in length,[53] but it is now largely recognized as a separate species, the West African crocodile. Nile crocodiles with skulls this size are likely to measure in the range of 5.4 to 5.6 m (17 ft 9 in to 18 ft 4 in), which is also the length of the animals according to the museum where they were found. In fact, probably much of the food from crocodile stomachs may come from scavenging carrion, and the crocodiles could be viewed as performing a similar function at times as do vultures or hyenas on land. [81] Prey taken is often much smaller than the crocodile itself, and such prey can be overpowered and swallowed with ease. Thorbjarnarson, J. Graham (1968) noted that throughout East Africa, crocodile diets are driven by the regional availability of prey. [11] It is a rather common species of crocodile and is not endangered despite some regional declines or extinctions. [7], Frogs are regionally significant prey for small, young crocodiles in many regions, mainly those in the 0.5 to 1.5 m (1 ft 8 in to 4 ft 11 in) size range. [196], Regional reportage from numerous areas with large crocodile populations nearby indicate, per district or large village, that crocodiles often annually claim about a dozen or more lives per year. South Africa or Tanzania) is in August through December. Smaller specimens can gallop, and even larger individuals are capable on occasion of surprising bursts of speed, briefly reaching up to 14 km/h (8.7 mph). In comparison, perenties (Varanus giganteus) (the Australian ecological equivalent of the Nile monitor) succeeds in depredating about 90% of freshwater crocodile (Crocodylus johnsoni) eggs and about 25% of saltwater crocodile nests. [38] The broadest snouted modern crocodilians are alligators and larger caimans. [42] The Nile crocodile has a reputation as a voracious and destructive feeder on freshwater fish, many of which are essential to the livelihoods of local fisherman and the industry of sport fishing. It is the largest freshwater predator in Africa, and may be considered the second-largest extant reptile in the world, after the saltwater crocodile (Crocodylus porosus). Crocodylus niloticus. [7][153] After this stage, crocodiles may loosely associate with similarly sized crocodiles and many assuredly enter feeding congregations of crocodiles once they attain 2 m (6 ft 7 in), at which size predators and cannibal crocodiles become much less of a concern. Examples translated by humans: nijlbaars, nijltilapia, nijlkrokodil, westnijlvirus, victoriabaars. [7][112][113][114] Larger land birds, such as bustards, guineafowl, ground hornbills (Bucorvus spp.) [39] However, despite their robust skulls, alligators and caimans appear to be proportionately equal in biting force to true crocodiles, as the muscular tendons used to shut the jaws are similar in proportional size. [14][100] The Nile crocodile is a strong example of an apex predator. Cite error: The named reference "Aust" was defined multiple times with different content (see the. [18][182] Retraction of wetlands due both to direct habitat destruction by humans and environmental factor possibly related to global warming is perhaps linked to the extinction of Nile crocodiles in the last few centuries in Syria, Israel and Tunisia. Le crocodile marin est un prédateur opportuniste, capable d’attraper des animaux de la taille d’un buffle mâle adulte, aussi bien dans l’eau que sur la terre ferme. Natural predation on quelea. In such a trance, some mother Nile crocodiles may show no discernable reaction even if pelted with stones. [7][144] An additional case of predation on an adult black rhino was reportedly observed in northern Zambia. [49] The most significant prerequisites to a nesting site are soil with the depth to permit the female to dig out the nest mound, shading to which mother can retire during the heat of the day and access to water. Ressemblances et différences : reconnais les animaux en un clin d’œil ! Notable amongst scientific work is the monograph Cott (1961), the theses produced on the crocodile at Lake Turkana, part Contextual translation of "crocodile du nil (l" into English. largely insufficient to produce sustainable populations of young crocodiles, on par with times prior to the peak of leather trading. The range of this species once stretched northward throughout the Nile, as far north as the Nile delta. Un féroce prédateur capable de s'attaquer à l'éléphant ou à la girafe. D'après des tests génétiques récents, il semblerait que ce crocodile du désert soit assez proche de ses congénères habitant au Sénégal ou en Côte d'Ivoire. In Kruger National Park, over the course of 22 years of discontinuous observation, 60% of the large-game kills observed as perpetrated by crocodiles consisted of impala, while more than 15% of observed kills were made up of waterbuck (Kobus ellipsiprymnus), the largest of the genus Kobus at more than 200 kg (440 lb) in weight. [3][42][50][51] This gives the Nile crocodile somewhat of a size advantage over the next largest non-marine predator on the African continent, the lion (Panthera leo), which averages 188 kg (414 lb) in males and 124 kg (273 lb) in females, and attains a maximum known weight of 313 kg (690 lb), far less than that of large male crocodiles. [49][157] Cott noted little detectable discrepancy in the mating habits of Nile crocodiles and American alligators. Selous, F. C. (1908). Fish become especially significant around this age and size. Gustave est le nom donné à un célèbre crocodile du Nil ayant vécu au Burundi et qui a tué de très nombreuses personnes à partir des années 1990. Les jeunes s’en tiennent à des proies plus petites, comme des insectes, des amphibiens, des crustacés, de petits reptiles et des poissons. [156][157] Once a female has been attracted, the pair warble and rub the undersides of their jaws together. [3][10] The Nile crocodile is one of the most dangerous species of crocodile and is responsible for hundreds of human deaths every year. With the Nile crocodile and the saltwater crocodile, the mean size of crocodiles involved in non-fatal attacks was about 3 m (9 ft 10 in) as opposed to a reported range of 2.5–5 m (8 ft 2 in–16 ft 5 in) or larger for crocodiles responsible for fatal attacks. [13], Subadult and smaller adult Nile crocodiles use their bodies and tails to herd groups of fish toward a bank, and eat them with quick sideways jerks of their heads. [3][85] Even the largest frog in the world, the goliath frog (Conraua goliath), has reportedly been preyed on by young Nile crocodiles. This size range consists of subadult males and a mixture of subadult and adult females. [125][126] Other nonungulate prey known to be attacked by Nile crocodiles includes aardvarks (Orycteropus afer)[127] and African manatees (Trichechus senegalensis). [73], Generally, Nile crocodiles are relatively inert creatures, as are most crocodilians and other large, cold-blooded creatures. [77], Nile crocodiles have been widely known to have gastroliths in their stomachs, which are stones swallowed by animals for various purposes. [7][101][102] While adults have a sufficient bite force to crush turtle shells, younger crocodiles sometimes are overly ambitious, and will choke to death attempting to swallow whole large river turtles. Young crocodiles are rather shy and evasive due to the formidable gaunlet of predators that they must face in sub-Saharan Africa, spending little time sunning and moving about nocturnally whenever possible. [4][6][9] According to Cott (1961), the average length and weight of Nile crocodiles from Uganda and Zambia in breeding maturity was 3.16 m (10 ft 4 in) and 137.5 kg (303 lb). Bon mouvement sur la terre, peut développer une vitesse décente jusq… More or less, the size of the tendons used to impart bite force increases with body size and the larger the crocodilian gets, the stronger its bite is likely to be. Only the largest individuals engaging in aestivation leave the burrow to sun on warmest days, otherwise these crocodiles rarely left their burrows. [3] In Maasai Mara, Tanzania, large crocodiles congregate at river crossings used by migrating herds of Burchell's zebras and blue wildebeests (Connochaetes taurinus), picking off hundreds of these large ungulates annually. [19], The Nile crocodile is presently the most common crocodilian in Africa, and is distributed throughout much of the continent. [153] Earlier studies support that breeding is often inconsistent in females less than 3 m (9 ft 10 in) and clutch size is smaller, a female at 2.75 m (9 ft 0 in) reportedly never lays more than 35 eggs, while a female measuring 3.64 m (11 ft 11 in) can expect a clutch of up to 95 eggs. While, like all crocodilians, the Nile crocodile digs out a hole for a nest site, unlike most other modern crocodilians, female Nile crocodiles bury their eggs in sand or soil rather than incubate them in rotting vegetation. Some variation occurs relative to environment; specimens from swift-flowing waters tend to be lighter in colour than those dwelling in murkier lakes or swamps, which provides camouflage that suits their environment, an example of clinal variation. [3][6][49] In attempts to parse the mean male and female lengths across the species, the mean adult length was estimated to be reportedly 4 m (13 ft 1 in) in males, at which males would average about 280 kg (620 lb) in weight, while that of the female is 3.05 m (10 ft 0 in), at which females would average about 116 kg (256 lb). Communal nesting areas also reported from Lake Victoria (up until the 1930s) and also in the 20th century at Rahad River, Lake Turkana and Malawi. [13] The flanks, which are yellowish-green in colour, have dark patches arranged in oblique stripes in highly variable patterns. Translation for 'crocodile du Nil' in the free French-English dictionary and many other English translations. [169][170][171][172] It may take a few years before predation is no longer a major cause of mortality for young crocodiles. [128], Among the mammals, the bulk of the prey for adults is antelopes. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): Since this proposal relates specifically to Madagascar’s Nile crocodile (Crocodylus nioticus) population, no information on other countries is included. In the northern extremes of the distribution (i.e. [3][7] Their diet consists mostly of different species of fish, reptiles, birds, and mammals. Si ce dernier peut atteindre une taille de 5 m, le crocodile d'Afrique de l'ouest ne dépasse que rarement les 2,50 m de long. [3][7] As an example of the body mass increase undergone by mature crocodiles, one of the larger crocodiles handled firsthand by Cott (1961) was 4.4 m (14 ft 5 in) and weighed 414.5 kg (914 lb), while the largest specimen measured by Graham and Beard (1973) was 4.8 m (15 ft 9 in) and weighed more than 680 kg (1,500 lb). In addition, as an animal that feeds rarely, sometimes only a few times in a year, even the individual stomach content examinations sometimes prove to be unsuccessful. In Florida", "Introduction of Nile Crocodiles in southern Florida", "Nile crocodiles captured in South Florida still have scientists seeking answers", "An experimental and morphometric test of the relationship between vertebral morphology and joint stiffness in Nile crocodiles (, "Croc Blog: Crocodile myths #1 – the curious trochilus", "Nile Crocodile: Photos, Video, E-card, Map – National Geographic Kids". The mother will sometimes carry her young on her back to avoid the natural predators of the small crocodiles, which can be surprisingly bold even with the mother around. Crocodile du Nil taille Crocodile du Nil — Wikipédi . [7] Crocodile teeth are not used for tearing up flesh, but to sink deep into it and hold on to the prey item. Webb, and S.C. Manolis. 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[96][97], When capturing large fish, they often drag the fish onto shore and swing their heads around to smash the fish onto the ground until it is dead or incapacitated. [27] Pooley found in Royal Natal National Park that during aestivation, young crocodiles of 60 to 90 cm (24 to 35 in) total length would dig tunnels around 1.2 to 1.8 m (3 ft 11 in to 5 ft 11 in) in depth for most, some tunnels measuring more than 2.7 m (8 ft 10 in), the longest there being 3.65 m (12 ft 0 in). (1993). Un crocodile très âgé possède une dentition plus abîmée. [7], The Nile crocodile mostly hunts within the confines of waterways, attacking aquatic prey or terrestrial animals when they come to the water to drink or to cross. Slow-swimming pelicans are also frequently vulnerable to crocodiles. Zisadza-Gandiwa, P., Gandiwa, E., Jakarasi, J., van der Westhuizen, H., & Muvengwi, J. [7] After burying the eggs, the female then guards them for the three-month incubation period. [20] The separation of the two is not recognized by the IUCN as their last evaluations of the group was in 2008 and 2009,[1][21] years before the primary publications supporting the distinction of the West African crocodiles. Among the larger males of a population, territorial clashes can lead to physical fighting between males especially if they are near the same size. Ce reptile est l'un des plus grands représentants du genre Crocodylus avec le crocodile marin. Nile crocodiles are absent from most of West and Central Africa, but range into the latter region in eastern and southern Democratic Republic of Congo, and along the Central African coastal Atlantic region (as far north to Cameroon). Nile crocodiles of under two years are much more rarely observed than larger specimens, and more seldom seen than the same age young in several other types of crocodilian.
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