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Species
Varanus niloticus Linnaeus in Hasselquist, 1762
IUCN
NCBI
EOL Text
Nile monitors are sometimes known as "water monitors", or "water leguaan" in South Africa.
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Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Varanus_niloticus/ |
Continent: Africa
Distribution: Republic of South Africa, Swaziland, Namibia, Botswana, Tanzania, Mozambique, Zimbabwe, Zambia, Angola, Malawi, Tanzania, Gaon, W/N/S Democratic Republic of the Congo (Zaire), Kenya, Uganda, Cameroon, Central African Republic, Ethiopia, Eritrea, Somalia, Dudan, Chad, Egypt, Liberia, Ivory Coast, Ghana, Togo, Benin, Burkina Faso, Niger, Nigeria, Mali, Mauritania, Senegal, Gambia (HÅKANSSON 1981)
Type locality: “Indiis”
Estimates vary, but the expected lifespan in captivity is reported at between 10 and 20 years.
Typical lifespan
Status: captivity: 10 to 20 years.
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Varanus_niloticus/ |
The Nile monitor (Varanus niloticus) is a large member of the monitor lizard family (Varanidae) found throughout much of Africa. Other common names include the African small-grain lizard,[2] water leguaan[3] or river leguaan (leguan, leguaan, and likkewaan mean monitor lizard in South African English, and can be used interchangeably).[4] Until 1997, the Nile monitor included the ornate monitor (V. ornatus) as a subspecies.[5]
Description[edit]
Nile monitors can grow to about 120 to 180 cm (3 ft 11 in to 5 ft 11 in) in length, with the largest specimens attaining 244 cm (8 ft 0 in).[6][7] In an average-sized specimen, the snout-to-vent length will be around 50 cm (1 ft 8 in).[8] In body mass, adults have been reported to vary widely, one study claiming only 0.8 to 1.7 kg (1.8 to 3.7 lb), others state weights ranging from 5.9 to 15 kg (13 to 33 lb) in big monitors. Variations may be due to age or environmental conditions.[9][10][11] Exceptionally large specimens may scale as much as 20 kg (44 lb), but this species weighs somewhat less on average than the bulkier Varanus albigularis, the only other African lizard to rival the Nile monitor in size.[12] They have muscular bodies, strong legs, and powerful jaws. Their teeth are sharp and pointed in juvenile animals and become blunt and peg-like in adults. They also possess sharp claws used for climbing, digging, defense, or tearing at their prey. Like all monitors, they have forked tongues, with highly developed olfactory properties. The Nile monitor has quite striking, but variable, skin patterns, as they are greyish-brown above with greenish-yellow barring on the tail and large, greenish-yellow rosette-like spots on their backs with a blackish tiny spot in the middle. Their throats and undersides are an ochre-yellow to yellow-cream with some faint barring often on their throats.[12]
Their nostrils are placed high on their snouts, indicating these animals are highly aquatic. They are also excellent climbers and quick runners on land. Nile monitors feed on fish, snails, frogs, crocodile eggs and young, snakes, birds, small mammals, large insects, and carrion.
Range[edit]
Nile monitors are native to Africa and the species is distributed throughout the entire central and southern regions of the continent, including Sudan and a portion of central Egypt along the Nile river. [13] They are not found in any of the desert regions of Africa, however, as they thrive around rivers. [14][15]
Invasive species[edit]
In Florida, established breeding populations of Nile monitors have been known to exist in different parts of the state since at least 1990. [16] The vast majority of the established breeding population of the species is in Lee County, Florida, particularly in the Cape Coral and surrounding regions, including the nearby barrier islands (Sanibel, Captiva, and North Captiva), Pine Island, Fort Myers, and Punta Rassa. Established populations also exist in adjacent Charlotte County, especially on Gasparilla Island.[15] Areas with a sizeable number of Nile monitor sightings in Florida include Palm Beach County just southwest of West Palm Beach along State Road 80.[17] In July 2008, a Nile monitor was spotted in Homestead, a small city southwest of Miami.[18] Other sightings have been reported near Hollywood, Naranja, and as far south as Key Largo in the Florida Keys.[17] The potential for the established population of Nile monitors in Lee, Charlotte, and other counties in Florida, to negatively impact indigenous crocodilians (American alligator Alligator mississippiensis and American crocodile Crocodylus acutus) is enormous given that they normally raid crocodile nests, eat eggs, and prey on small crocodiles in Africa. Anecdotal evidence indicates a high rate of disappearance of domestic pets and feral cats in Cape Coral. It also prey on other invasive species such as the Burmese Python egg nest[15]
In captivity[edit]
Nile monitors require experienced care as pets and are not recommended for beginners; nevertheless they are often found in the pet trade. Albino (amelanistic) specimens have been found and propagated in captivity.
References[edit]
Wikimedia Commons has media related to Varanus niloticus. |
Wikispecies has information related to: Varanus niloticus |
- ^ IUCN Red List and search for Varanus niloticus
- ^ a b "Synonyms of Nile Monitor (Veranus nioloticus)". Encyclopedia of Life. Retrieved 15 December 2013.
- ^ Varanus niloticus, The Reptile Database
- ^ Oxford Dictionaries. Oxford University Press http://www.oxforddictionaries.com/us/definition/english/leguan. Retrieved 17 December 2013. Missing or empty
|title=
(help) - ^ Böhme, W., & Ziegler, T. (1997). A taxonomic review of the Varanus (Polydaedalus) niloticus (Linnaeus, 1766) species complex. The Herpetological Journal 7: 155-162.
- ^ Nile Monitor Care Sheet
- ^ Enge, K. M., Krysko, K. L., Hankins, K. R., Campbell, T. S., & King, F. W. (2004). Status of the Nile monitor (Varanus niloticus) in southwestern Florida. Southeastern Naturalist, 3(4), 571-582.
- ^ "Varanus niloticus". Monitor Lizards – Captive Husbandry. Monitor-Lizards.net. Retrieved 15 December 2013.
- ^ Condon, K. (1987). A kinematic analysis of mesokinesis in the Nile monitor (Varanus niloticus). Experimental biology, 47(2), 73.
- ^ Hirth & Latif 1979
- ^ "ANIMALS - Varanus niloticus". Dr. Giuseppe Mazza's Photomazza. Retrieved 2013-06-06.
- ^ a b "Nile Monitors". L. Campbell's Herp Page. Retrieved 2013-06-06.
- ^ (Schleich et al., 1996; Spawls et al., 2002).
- ^ Reptile Specialists (Nile monitor)
- ^ a b c "NAS - Invasive Species FactSheet: Varanus niloticus (Nile monitor)". Nonindenous Aquatic Species. Gainesville, FL: United States Geological Survey. Unknown parameter
|DUPLICATE_work=
ignored (help)[dead link] - ^ (Campbell, 2003; Enge et al. 2004).
- ^ a b Everglades CISMA
- ^ Hofmeyer, Erik (10 June 2008). "Homestead ARB home to diverse array of wildlife". Homestead Air Reserve Base News (Homestead Air Reserve Base). Retrieved 15 December 2013.
License | http://creativecommons.org/licenses/by-sa/3.0/ |
Rights holder/Author | Wikipedia |
Source | http://en.wikipedia.org/w/index.php?title=Nile_monitor&oldid=654038889 |
The distribution of the Nile monitor extends through much of sub-Saharan Africa, from Senegal across to Somalia and down to northeast South Africa (2) (5) (6). It also occurs along the Nile up into southern Egypt (2).
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | Copyright Wildscreen 2003-2008 |
Source | http://www.arkive.org/nile-monitor/varanus-niloticus/ |
Maximum longevity: 14.6 years (captivity)
License | http://creativecommons.org/licenses/by/3.0/ |
Rights holder/Author | Copyright © 2002 - 2009 by Joao Pedro de Magalhaes |
Source | http://genomics.senescence.info/species/entry.php?species=Varanus_niloticus |
Nile monitors may be Africa's largest lizards, though a former subspecies, now recognized as the species Varanus ornata, may be as big or bigger. Hatchlings are about 30 cm long and weigh about 26 g, but adults may grow to lengths of 2.4 m and have an impressively powerful physique. Sharp claws and strong muscular legs make it easy for them to climb trees. A deep, stoutly constructed skull, blunt crushing posterior teeth, and a bowed lower jaw make it easy for Nile monitors to eat hard-shelled prey such as mollusks. The tough skin is covered by bead-like scales. They have rounded nostrils which are located slightly nearer to the eye than to the snout. The toes are strong and moderately long. The tail of Nile monitors is compressed laterally with a dorsal keel and a very low double-toothed crest.
Adult Nile monitors are brownish or greenish-gray, with darker reticulation and yellowish spots or stripes on the back and limbs and yellowish-green spots on the head. Ventral surfaces are yellowish with blackish cross-bands. Juveniles are black, with the head bearing yellow cross-lines with black and yellow vertical bars on the lips. The neck features yellow lines and the back has a transverse series of yellow spots. The tail of juveniles has alternating black and yellow bars. This species exhibits no sexual dimorphism.
Range length: 2.4 (high) m.
Other Physical Features: heterothermic
Sexual Dimorphism: sexes alike
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Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Varanus_niloticus/ |
Nile monitors are a polygynandrous species and will mate promiscuously. Males may reportedly fight each other in violent "wrestling matches," presumably due to competition for mating opportunities.
Mating System: polygynandrous (promiscuous)
Varanus niloticus breeds once annually, with the season starting in June and ending in October range-wide. Mating and egg laying usually follows the rainy season, which varies regionally. This season correlates with the development of the gonads. The testicles of males are enlarged from June until September while the females are being sought. Regression of the gonads subsequently occurs until January and then the cycle recommences.
After spring rains (August through September), the female excavates a hole in the ground or in an active termite nest and lays 20 to 60 eggs. This may take 2-3 days to complete. If she lays her eggs in a termite nest, the termites will repair the hole in their nest, and the monitor eggs develop inside. Eggs may take up to 1 year to hatch. The small young weigh an average 26 g upon hatching. After hatching, the young may need to wait for rain to soften the hard nest, or reportedly the mother monitor may return at the right time and open the nest to free the hatchlings. Once they have emerged, however, the baby Nile monitors are on their own.
Breeding interval: Varanus niloticus breeds once a year.
Breeding season: Varanus niloticus breeds from June until October.
Range number of offspring: 20 to 60.
Average number of offspring: 35.
Range age at sexual or reproductive maturity (female): 3 to 4 years.
Range age at sexual or reproductive maturity (male): 3 to 4 years.
Key Reproductive Features: iteroparous ; seasonal breeding ; sexual ; fertilization ; oviparous
Parental investment for Nile monitors does not extend far past initial egg fertilization and laying. The female will excavate a secure place to lay her clutch, either in the ground or in an active termite nest. The mother monitor may return to the clutch sometime after the young hatch and open the buried nest to free her hatchlings. Once the young have emerged, however, they are on their own.
Parental Investment: no parental involvement; female parental care ; pre-fertilization (Provisioning, Protecting: Female)
License | http://creativecommons.org/licenses/by-nc-sa/3.0/ |
Rights holder/Author | ©1995-2013, The Regents of the University of Michigan and its licensors |
Source | http://animaldiversity.ummz.umich.edu/accounts/Varanus_niloticus/ |
120 to 160 centimeters
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Rights holder/Author | tubbymcentire, tubbymcentire |
Source | http://en.wikipedia.org/wiki/Nile_monitor |
The following is a representative barcode sequence, the centroid of all available sequences for this species.
There are 2 barcode sequences available from BOLD and GenBank.
Below is a sequence of the barcode region Cytochrome oxidase subunit 1 (COI or COX1) from a member of the species.
See the BOLD taxonomy browser for more complete information about this specimen and other sequences.
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