Nile crocodile

Nile crocodile
Temporal range: Late MiocenePresent, 11.6–0 Ma[1]
At Le Bonheur Crocodile Farm near Stellenbosch, South Africa
CITES Appendix I (CITES)[3][note 1]
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Clade: Archosauromorpha
Clade: Archosauriformes
Order: Crocodilia
Family: Crocodylidae
Genus: Crocodylus
Species:
C. niloticus
Binomial name
Crocodylus niloticus
Laurenti, 1768
   approximate range sensu lato (true area of occupancy considerably smaller and western African populations now considered to belong to the West African crocodile)[2]
Synonyms
  • Crocodylus vulgaris Cuvier, 1802

The Nile crocodile (Crocodylus niloticus) is a large crocodilian native to freshwater habitats in Africa, where it is present in 26 countries. It is widely distributed in sub-Saharan Africa, occurring mostly in the eastern, southern, and central regions of the continent, and lives in different types of aquatic environments such as lakes, rivers, swamps and marshlands.[4] It occasionally inhabits deltas, brackish lakes and rarely also saltwater. Its range once stretched from the Nile Delta throughout the Nile River. Lake Turkana in Kenya has one of the largest undisturbed Nile crocodile populations.[5]

Generally, the adult male Nile crocodile is between 3.5 and 5 m (11 ft 6 in and 16 ft 5 in) in length and weighs 225 to 750 kg (496 to 1,653 lb).[6][7] However, specimens exceeding 6.1 m (20 ft) in length and 1,000 kg (2,200 lb) in weight have been recorded.[8] It is the largest predator in Africa, and may be considered the second-largest extant reptile in the world, after the saltwater crocodile (Crocodylus porosus).[9][10] Size is sexually dimorphic, with females usually about 30% smaller than males. The crocodile has thick, scaly, heavily armoured skin.

Nile crocodiles are opportunistic apex predators; a very aggressive crocodile, they are capable of taking almost any animal within their range. They are generalists, taking a variety of prey,[10][11] with a diet consisting mostly of different species of fish, reptiles, birds, and mammals. As ambush predators, they can wait for hours, days, and even weeks for the suitable moment to attack. They are agile predators and wait for the opportunity for a prey item to come well within attack range. Even swift prey are not immune to attack. Like other crocodiles, Nile crocodiles have a powerful bite that is unique among all animals, and sharp, conical teeth that sink into flesh, allowing a grip that is almost impossible to loosen. They can apply high force for extended periods of time, a great advantage for holding down large prey underwater to drown.[10]

Nile crocodiles are relatively social.[12] They share basking spots and large food sources, such as schools of fish and big carcasses. Their strict hierarchy is determined by size. Large, old males are at the top of this hierarchy and have first access to food and the best basking spots. Crocodiles tend to respect this order; when it is infringed, the results are often violent and sometimes fatal.[13] Like most other reptiles, Nile crocodiles lay eggs; these are guarded by the females but also males, making the Nile crocodiles one of few reptile species whose males contribute to parental care.[14] The hatchlings are also protected for a period of time, but hunt by themselves and are not fed by the parents.[11][15]

The Nile crocodile is one of the most dangerous species of crocodile and is responsible for hundreds of human deaths every year.[16] It is common and is not endangered, despite some regional declines or extirpations in the Maghreb.

  1. ^ Rio, Jonathan P.; Mannion, Philip D. (6 September 2021). "Phylogenetic analysis of a new morphological dataset elucidates the evolutionary history of Crocodylia and resolves the long-standing gharial problem". PeerJ. 9: e12094. doi:10.7717/peerj.12094. PMC 8428266. PMID 34567843.
  2. ^ a b Isberg, S.; Combrink, X.; Lippai, C. & Balaguera-Reina, S.A. (2019). "Crocodylus niloticus". IUCN Red List of Threatened Species. 2019: e.T45433088A3010181. doi:10.2305/IUCN.UK.2019-1.RLTS.T45433088A3010181.en. Retrieved 22 January 2022.
  3. ^ "Appendices | CITES". cites.org. Retrieved 1 March 2023.
  4. ^ Pooley, A. C. (1982). "The status of African crocodiles in 1980". Crocodiles. Proceedings of the 5th Working Meeting of the IUCN/SSC Crocodile Specialist Group, Gainesville, Florida. Gland, Switzerland: IUCN Crocodile Specialist Group. pp. 174–228.
  5. ^ Modha, M. L. (1967). "The Ecology of the Nile Crocodile (Crocodylus niloticus Laurenti) on Central Island, Lake Rudolf". African Journal of Ecology. 5 (1): 74–95. Bibcode:1967AfJEc...5...74M. doi:10.1111/j.1365-2028.1967.tb00763.x.
  6. ^ Barlas, Robert (2010). Uganda (Second ed.). New York: Marshall Cavendish Benchmark. p. 53. ISBN 9780761448594.
  7. ^ Haywood, K. (2011). Crocodiles and alligators. New York: Marshall Cavendish Benchmark. p. 31. ISBN 9780761440482.
  8. ^ Hart, Adam (2023). The Deadly Balance Predators and People in a Crowded World. London: Bloomsbury Publishing Plc. ISBN 978-1-4729-8532-3.
  9. ^ Wood, G. (1983). The Guinness Book of Animal Facts and Feats. Sterling Pub Co Inc. ISBN 978-0-85112-235-9
  10. ^ a b c Guggisberg, C.A.W. (1972). Crocodiles: Their Natural History, Folklore, and Conservation. David & Charles. p. 195. ISBN 978-0-7153-5272-4.
  11. ^ a b Cott, H.B. (1961). "Scientific results of an inquiry into the ecology and economic status of the Nile crocodile (Crocodilus niloticus) in Uganda and Northern Rhodesia". The Transactions of the Zoological Society of London. 29 (4): 211–356. doi:10.1111/j.1096-3642.1961.tb00220.x.
  12. ^ Huchzermeyer, F. (2003). Crocodiles: Biology, Husbandry, Diseases. CABI International Publishing. UK and Massachusetts.
  13. ^ Garrick, L. D. & Lang, J. W. (1977). "Social signals and behaviors of adult alligators and crocodiles". American Zoologist. 17: 225–239. doi:10.1093/icb/17.1.225.
  14. ^ "Nile Crocodile". Animals. 1 March 2014. Retrieved 30 April 2023.
  15. ^ Kofron, C. P. (1990). "The reproductive cycle of the Nile crocodile (Crocodylus niloticus)". Journal of Zoology. 221 (3): 477–488. doi:10.1111/j.1469-7998.1990.tb04014.x.
  16. ^ Sideleau, B. & Britton, A. R. C. (2012). "A preliminary analysis of worldwide crocodilian attacks". Crocodiles. Proceedings of the 21st Working Meeting of the IUCN-SSC Crocodile Specialist Group. Gland: IUCN Crocodile Specialist Group. pp. 111–114.


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