Quick Links
Home Page
Site Map
Monitors
Search Mampam.com
       You are here: Home > Species List > Varanus griseus
Butaan Project camera trap archive
Main Menu
Home
About Mampam
Viper Press
Advertise
Contact Us
Book Reviews
Varanus Species A-Z
Monitors
Monitor Lizard News
Little Book
Captive Care
Species List
Butaan Project
Magazine Articles
Monitors
Caspian Monitor
Wall of Shame
Wall of Praise
Library
Varanus A-Z
Projects
Butaan Project
Savannah Monitors
Bui Hippo Project
Frogs of Coorg
Polillo Project
Madagascar Bats
Western Visayas
Turkmenistan
Library
Monitor Lizards
Glossop

 

Varanus griseus Print E-mail

Desert monitor, Grey monitor

Extract from A Little Book of Monitor Lizards © D. Bennett 1995. Viper Press, UK

Varanus griseus griseus   Daudin 1803   Grey monitor
Varanus griseus caspius  Eichwald 1831 Caspian monitor
Varanus griseus koniecznyi Mertens 1942  Indian desert monitor

Varanus griseus is one of the most widespread monitor lizards. It has an enormous range, occurring from the Sahara Desert through the Arabian Peninsula and the deserts of central Asia as far east as northern India. Within this massive area three subspecies are currently recognised, which will be discussed separately.

Mertens (1954) distinguished between the subspecies of V.griseus largely on the basis of pattern;

V.griseus griseus has 5-8 narrow grey bands on the back and 19-28 bands on the tail which extend almost to the tip. The tail is round in cross section, 131-146% of SVL.

V.griseus caspius has 5-8 bands on the back and 13-19 bands on the tail with a plain tail tip. The tail shows significant lateral compression and is 118-127% of SVL. There are about 143 rows of scales at midbody,

V.griseus koniecznyi has 3-5 bands on the back and 8-15 bands on the tail with a plain tail tip. Tail may show some lateral compression, but not to the extent seen in V.griseus caspius. It is 118-127% of SVL. In addition its head is broader and flatter than that of V.griseus griseus. There are 108-139 rows of scales at midbody.

His descriptions were based on a very small number of specimens and it is likely that this taxonomy will be revised at some time in the future, hopefully using biochemical features rather than external ones.

The desert monitor is an magnificent animal. It is my favourite monitor lizard for several reasons. It inhabits some of the most hostile regions of Earth, experiencing blistering heat in the summer and extreme cold in the winter. Grey monitors are lizards with attitudes. They are very spirited creatures which cannot be tamed and they appear to hate humanity with a vengeance. In turn, people generally hate the grey monitor and it is persecuted almost everywhere it is found. The energy and spirit of its threat display are doubtless responsible for the many sinister characters that are attributed to it by humanity. They are believed by many to be as venomous as any snake, and are also supposed to be capable of inflicting a variety of deforming, debilitating and terminal illnesses on any unfortunate person they encounter. In fact the grey monitor is probably a benefit to humanity where it is allowed to survive unmolested. They eat large numbers of crop-destroying beetles and larger specimens consume adult cobras and vipers with great relish. Its defensive posture is largely bluff and is only assumed if the animal is cornered and unable to escape. In captivity the desert monitor is not particularly co-operative. They have been kept in captivity for over a century (Von Rathgen 1894), but only a single captive breeding has been reliably reported. Our failure with the captive maintenance of this species is largely attributable to a lack of understanding about its way of life in the wild and in particular about its seasonal behaviour.

Image
Varanus griseus hatching

The grey monitor V.griseus griseus occurs in the deserts of north Africa (from Morocco and Mauritania east to Egypt and Sudan), the Arabian Peninsula (although it appears to be absent from the island of Bahrain). south-eastern Turkey, Syria, Israel, Palestine, Lebanon, Jordan and Iraq (e.g. Haas 1951; Hass & Battersby 1959; Anderson 1969; Schmidt & Marx 1956, 1957; Schmidt 1919; Aktan 1971, Arnold 1984; Bishai 1960, Martens & Kock 1992). It reaches a maximum size of about 120cm TL in Iraq (Khalaf 1959) and 100cm TL in Israel, but in Algeria specimens of 80cm TL are rare (Mammeir. pers. comm.). Total size attained seems to depend on the climate of the area, with largest specimens coming from areas which yield more food or allow longer activity seasons. Mosauer (1934) noted that specimens from Tozeur and Nefta in Tunisia were smaller than those from Gafsa. The largest male found during a comprehensive study in the coastal plains of Israel was 46cm SVL and 1,261g, the largest female 38cm SVL and 702g (Stammer & Mendlessohn 1987). In captivity however they can attain weights in excess of 3,000g.  The tail varies between 120-150% of SVL. Details of scalation and morphology can be found in Mertens (1954). The pattern and colouration of this lizard shows great variability. In dry areas with little vegetation (e.g. the sand dunes of Mauritania) grey monitors may have no pattern at all, in wetter areas with more luxuriant plant growth the animals can have very bright patterns. Juveniles are always brighter than their parents.

In Israel grey monitors tend to avoid beaches and keep to more inland areas. They inhabit sand dunes and are not adverse to areas of human activity including rubbish dumps and building sites (Stammer & Mendlessohn 1983, 1987). Anderson (1963) records them from as high as 1,200m above sea level and Arnold (1984) records them from a variety of substrates including gravel in Arabia. In the Sahara desert they inhabit all regions but are much more common in the more humid zones (about 6 per km2)  than in more arid areas (about 2 per km2) (Vernet 1982). In the coastal plains of Israel Stanner & Mendlessohn found about 4 specimens per km2. Perry & Dmi'el (1995) note that the grey monitor has disappeared from many disturbed dune areas.

Not surpisingly the diet of the grey monitor varies enormously depending on its habitat. Where other vertebrates are plentiful they tend to form the bulk of their prey. In Israel other lizards and snakes are their most common prey, along with ground-nesting birds, tortoise and the eggs of all these animals. They also prey on toads and mammals (including gerbils and young hares) and will take carrion including dead hedgehogs and cats (Stanner & Mendlessohn 1986). Invertebrate prey are less important than in many other desert-dwelling monitor lizards, but include beetles, orthopterans, heteropteran bugs, ants, snails, centipedes and scorpions. This wide variety of prey suggest that, like many monitor lizards, the grey monitor devours any animal of a suitable size that it encounters. Diet in Algeria appears to be very similar (Vernet & Grenot 1973). Seven stomachs of animals from a variety of locations examined by Losos & Greene (1988) also contained lizards and snakes. Aktan (1971) found two large lizards and pieces of eggshell in a specimen from Turkey. Lizards, snakes and mammals have also been recorded from the stomachs of animals in Arabia (Arnold 1984, Tilbury 1988), Egypt (Schmidt & Marx 1957, 1958) and Tunisia (Mosauer 1934). Andres (1904) records that adults will eat small puppies.


 
 

 

About Mampam
Savannah Monitor Book

 

Our pet-owners' guide to savannah monitor lizard is the first ever written by people who have studied the animals in the wild and bred them in captivity. There are at least seven books in print about the savannah monitor, but we think this is the only one worth reading! Last few available 

bokcoverall-200.jpg

 

 

 

 

 

 

  

 

Worldwide orders available

 

 
Help Mampam

Please help us in our conservation efforts by making a small donation to us through PayPal... every little bit helps!

 

 
The Butaan Project
The Butaan Project - Foraging behaviour

butaan7.jpgWe use feces to investigate diet and activity areas of butaan. In total we have examined more than 1500 samples, possibly the largest ever collected for a single population of reptiles.  Butaan and their relatives are huge specialised frugivores, much bigger than any other specialised frugivorous animal in  the Philippines. They need a constant supply of fruit but lack the wings that allow other frugivores to forage in different forest fragments. Large and immobile, the butaan depends on a very narrow range of foods.

Read more...
 

 

© 2014 Mampam Conservation