font settings and languages

Font Size: Large | Normal | Small
Font Face: Verdana | Geneva | Georgia
Languages:

Varanus exanthematicus

(Bosc's Monitor)

Overview

[ Back to top ]

Interesting Facts

[ Back to top ]
 

Common Names

[ Back to top ]

Click on the language to view common names.

Common Names in English:

Bosc's Monitor, Savannah Monitor Lizard, Savannah Monitor

Common Names in German:

Steppenwaran

Description

[ Back to top ]

Physical Description

Species Varanus exanthematicus

The Savannah Monitor in the wild can weigh five to five and a half kilograms , yet in captivity it is often found weighing over six kilograms. In the wild, the average length of this Monitor is of approximately 1 to 1.5 meters. Varanus exanthematicus has small scales in the cranial region, larger abdominal scales, and keeled scales on the caudal area. This stout creature’s tail tapers and has a double toothed crest . The body is gray to brown, with alternating yellow and brown rings on the tail, and some yellow on the abdominal area, as well as inside the limbs. The front legs have extremely sharp claws which are used for digging, while the longer rear legs are more fitted for running . This lizard has a blue snake-like tongue and a head that can turn in all directions . Monitors, just like snakes , can significantly expand their mouths to accommodate the swallowing of larger prey . Males are slightly larger and have shorter tails than females, yet females tend to be more heavily bodied.

Habitat

The Savannah Monitor has been able to flourish throughout this region due to the coloration of its skin , which provides a camouflage among the similarly colored Savannah’s grasses. Although no consensus exists upon the exact distribution of the Savannah Monitor, Senegal, Eritrea, Northern Zaire, Ghana, and Togo have all been mentioned as places where it can be found in the wild. The distribution of this Monitor demonstrates some of its capabilities of adaptation, however, it has not yet successfully adapted to either rainforests or deserts. The adults usually live on the ground . The juveniles usually seek shelter in trees or burrows of other animals, to avoid predation .

Ecology: This species is restricted to grasslands and agricultural areas within the savannah belt (D. Bennett pers. comm. ). Within and around low-intensity agricultural areas, population densities can be quite high (Bennett and Thakoordyal 2003).[1].

List of Habitats :

Biology

[ Back to top ]

Diet

Adults in the wild will eat birds, snakes , snails, small mammals, and even carrion . Due to their undeveloped sharp teeth, yet keeping with their carnivorous diet , juveniles will eat an assortment of insects.

Reproduction

Fertilization occurs within the female where the sperm can be stored in the oviducts for long periods of time, therefore making it difficult to determine accurate paternity. When the female is ready to lay her eggs , she will dig a hole or find a termite mound into which to deposit her eggs. Twenty to fifty soft leathery eggs can be laid at one time. Unless they are eaten by a predator , all eggs will hatch . Hatching occurs during the months of March and April. Hatchlings weigh about 10 grams and measure approximately 12 centimeters. During the first couple of months these lizards exhibit very rapid growth.

Behavior

The Savannah Monitor is diurnal and is most active in warm sunshine. During periods of drought or cool weather, it becomes dormant . For this reason, its feeding pattern is that of feast and famine. During the typical eight month wet season of the Savannah, when food is most plentiful, the Monitor will consume an enormous amount of food which will create the fat reserves necessary to sustain life during the dry season. It is estimated that in a typical wet season day, Varanus exanthematicus can consume one tenth of its body weight . The males tend to be highly territorial . Before striking at other males, they display their aggression by making a loud hissing sound and trashing their tail. However, the Savannah Monitor is a shy animal and will avoid areas populated by humans. Occasionally, when this Monitor encounters a human it will play dead in an attempt to avoid capture .

Taxonomy

[ Back to top ]

Synonyms

Lacerta exanthematicus • Lacerta exanthematicus Bosc 1792: 25 • Varanus exanthematicus — Boulenger 1885: 308 • Varanus exanthematicus — De Lisle 1996: 123 • Varanus exanthematicus — Schmidt 1919: 480 • Varanus ocellatus • Varanus ocellatus Duméril and Bibron 1836: 496 • Varanus ocellatus HEYDEN in RÜPPELL 1830: 21< /i> (Fide Mertens 1963: 7) • Varanus ocellatus — Boulenger 1885: 308 • Varanus ocellatus — DumÉril & Bibron 1836: 496 • Varanus ocellatus — Loveridge 1936: 59 • Varanus< /i> (Polydaedalus) Exanthematicus — BÖhme 2002

Notes

Name Status: Accepted Name .

Comment: Hunted as food by local people in Mali (Joger & Lambert 1996). For a detailed distrubtion map and locality data see BAYLESS (2002).

Similar Species

[ Back to top ]

Members of the genus Varanus

ZipcodeZoo has pages for 55 species and subspecies in this genus:

V. acanthurus (Spiny-Tailed Monitor) · V. albigularis (White-Throated Monitor) · V. albigularis albigularis (White-Throated Monitor Lizard) · V. baritji (Black-Spotted Ridge-Tailed Momitor) · V. beccarii (Black Tree Monitor) · V. bengalensis (Bengal Monitor Lizard) · V. bogerti (Bogert's Monitor) · V. brevicauda (Short-Tailed Pygmy Monitor) · V. caerulivirens (Turquoise Monitor) · V. caudolineatus (Line-Tailed Pygmy Monitor) · V. doreanus (Bluetail Monitor) · V. dumerilii (Dumeril Monitor) · V. eremius (Rusty Desert Monitor) · V. exanthematicus (Savannah Monitor Lizard) · V. finschi (Finsch's Monitor) · V. flavescens (Calcutta Oval-Grain Lizard) · V. giganteus (Perentie) · V. gilleni (Pigmy Mulga Monitor) · V. glauerti (Glauert's Monitor) · V. glebopalma (Black-Palmed Rock Monitor) · V. gouldii (Sand Goanna) · V. griseus (Desert Monitor) · V. griseus griseus (Desert Monitor) · V. indicus (Indian Monitor Lizard) · V. indicus rouxi (Indian Monitor Lizard) · V. jobiensis (Peach-Throated Monitor) · V. keithhornei (Nesbit River Monitor) · V. kingorum (Pygmy Rock Monitor) · V. komodoensis (Komodo Dragon) · V. mabitang (Panay Monitor Lizard) · V. mertensi (Mertens's Water Monitor) · V. nebulosus (Clouded Monitor) · V. niloticus (Nile Monitor) · V. olivaceus (Gray's Monitor) · V. panoptes (Argus Monitor) · V. panoptes panoptes (Yellow-Spotted Monitor) · V. pilbarensis (Pilbara Rock Monitor) · V. prasinus (Green Tree Monitor) · V. primordius (Northern Blunt-Spined Monitor) · V. rosenbergi (Heath Monitor) · V. rudicollis (Roughneck Monitor) · V. salvadori (Crocodile Monitor Lizard) · V. salvadorii (Crocodile Monitor) · V. salvator (Common Water Monitor) · V. salvator salvator (Common Water Monitor) · V. salvator togianus (Common Water Monitor) · V. scalaris (Banded Tree Monitor) · V. salvator subsp. salvator (Common Water Monitor) · V. spenceri (Spencer's Monitor) · V. spinulosus (Solomon Island Spiny Monitor) · V. storri (Storr's Monitor) · V. timorensis (Spotted Tree Monitor) · V. tristis (Black-Headed Monitor) · V. varius (Lace Monitor) · V. yemenensis (Yemen Monitor)

More Info

[ Back to top ]

Further Reading

[ Back to top ]

Notes

[ Back to top ]

Contributors

Data Sources

Accessed through GBIF Data Portal February 27, 2008:

Identifiers

Footnotes

  1. Bennett, D. & Sweet, S.S. 2010. Varanus exanthematicus. In: IUCN 2011. IUCN Red List of Threatened Species. Version 2011.2. <www.iucnredlist.org>. Downloaded on 05 February 2012. [back]
Last Revised: 2012-07-18