Last updated 9 April 2012: updated sections on V. salvator and V. baritji and Bibliography.

A look at the

Family VARANIDAE: The Monitor Lizards

Species and care

There are about sixty species of monitor lizard, ranging from the giant and unobtainable to the modest and fairly available. Unfortunately, not all of those that are easily available make good captives, while others are very expensive, difficult to obtain or have a hard requirement to satisfy, eg a large enclosure of water. It is also probably true that some people may be attracted to buying them because of their reputation, in a similar way that the pythons or venomous snakes are seen as "sexy". While monitors are not as life-threatening as a giant constrictor or a venomous snake, they are still potentially dangerous by virtue of their sharp claws, heavy tails and sharp teeth. Please think carefully about this before you acquire one, as reptile sanctuaries are starting to see a steady trickle of monitors who turned out to be too much of a handful for the people that bought them. If your primary desire is for a pet lizard that likes to be handled, I would encourage you to try plated lizards, blue-tongued skinks or bearded dragons.

Notes on feeding

A few things need to be borne in mind relating to the diet of monitor lizards. Firstly, monitors in general are hearty eaters, especially when acclimatised, and will often eagerly go for food. Do not take this as a sign that they are always hungry: the lizards of this genus are among those creatures of the world which find it hard to resist food (and that includes some of the human race!). Seriously, obesity or overfeeding is one of the biggest health problems of monitors in captivity, especially the savannah monitor V. exanthematicus. The problem is often compounded by the fact that tame monitors often spend hours doing little other than laying in their cage and generally doing nothing. While this is to be preferred to non-tame monitors thrashing about, it means that tame captives get a minimal amount of exercise, and diet should be kept to a fairly austere level accordingly.

Secondly, while monitors are good feeders, most in the wild do eat other things than rodents, and some have marked preferences toward such prey items as crustaceans, fish or birds. Dietary considerations are obviously dependent upon species, but keepers should be prepared to experiment somewhat. Tinned cat or dog food is an acceptable treat on an occasional level but should not be offered as a regular meal as it is too rich. Dead chicks will often be taken by larger monitors.

Dwarf monitors, and savannah monitors, need special attention inasmuch as keepers may be tempted to feed the normal captive monitor diet of rodents. This again may constitute a small part of a healthy diet, but in fact most dwarfs feed predominately on invertebrates or smaller, less fatty vertebrates such as geckos. Therefore dwarf monitors should be probably be offered a mainly insectivorous diet, which is indeed what most lizards consume. Those desiring to keep a monitor lizard are encouraged to find out as much about this aspect of their desired species before purchasing one. Although many books in the past 10-15 years accepted that a rodent diet was healthy for V. exanthematicus, this has not been borne out by my own experience, and Daniel Bennett makes the same point in his excellent book on Savannahs.

Finally, the use of tongs or similar instruments to offer food is highly recommended. Not only will this usually prevent accidents (such as a nasty bite caused by over-excitement), it will also allow you to "hand feed" your monitor if so desired. The placing or hiding of food items in different parts of the terrarium may also be beneficial, especially with tame monitors, as a way of encouraging more natural behaviour and exercise.

2007 update

These pages were originally put up some years ago and in contrast with the species pages put up more recently lack a systematic approach, such as scalation and coloration details. I am trying to work through the entries and add such data, but it will necessarily be a somewhat lengthy affair.

A few things have also changed since the creation of these pages. Firstly, several new species of monitor have been described, most if not all from Indonesia. As Daniel Bennett points out, the distribution data for these new species may be questionable: nevertheless these monitors do appear to be valid species. It is unfortunate that they may be discovered in part because of the forest fires and civil unrest (see Bennett).

Secondly, we are learning more about the captive requirements of monitors, although due to the limited captive potential for some of these giants, this was always going to be a slow process. One sad lesson we have learnt is that contrary to some older literature, not all monitors are suited to a diet of rodents and little else. On the positive side there has been success in the UK at least (and doubtlessly also Germany, Netherlands and the US) with the captive breeding of Australian dwarf monitors. I do not condone smuggling, but I do hope that a pool of captive-bred lizards will remove the temptation from people to do this.

Thirdly, coupled with the above, it seems that in the UK at least people are becoming more aware of the restrictive nature of large monitors, much as they have done with green iguanas which are similarly rather demanding in their legitimate needs. Although I do not share Chris Mattison's pessimistic view of monitor keeping, I do agree with him that they are not suitable choices for many households in Britain, especially at a time of high property prices and families having to make do with their existing space. For responsible keepers in other countries less subject to the restrictive conditions in the UK, however, there is no reason why monitors should not be kept if their requirements, and the ramifications of keeping a large reptile in captivity, are taken into consideration.

NAVIGATION: As this is a large page we have placed a couple of navigation links in each species/subspecies box. Click on "B" to go to the Bibliography, or "I" to go back up to the index (Quick Links).

V. acanthurus, Australian Ridge-Tailed/
Thorny-Tailed Monitor

V. albigularis, White-Throated Monitor

V. auffenbergi, Auffenberg's Monitor

V. baritji

V. beccari, Black Tree Monitor

V. bengalensis, Bengal Monitor

V. bogerti

V. brevicauda, Short-Tailed Pygmy Monitor

V. caerulivirens, Turquoise Monitor

V. caudolineatus, Stripe-Tailed Monitor

V. cerambonensis, Ceram Monitor

V. doreanus, Blue-Tailed Monitor

V. dumerili, Dumeril's Monitor

V. eremius, Desert Pygmy Monitor

V. exanthematicus, Savannah Monitor/
Bosc Monitor

V. flavescens, Yellow Monitor

V. flavirufus, Sand Monitor

V. giganteus, Perentie/ Gigantic Lace Lizard

V. gilleni, Pygmy Mulga Monitor/ Gillen's Pygmy Monitor

V. glauerti, Glauert's Monitor

V. glebopalma, Shiny-Footed Goanna

V. gouldi, Gould's Monitor/Sand Goanna

V. griseus, Desert Monitor

V. indicus, Mangrove Monitor

V. jobiensis, Peach-Throated Monitor

V. kingorum, Long-Tailed Rock Monitor

V. komodensis, Komodo Dragon

V. mertens, Mertens' Water Monitor

V. mitchelli, Mitchell's Monitor

V. niloticus, Nile Monitor

V. olivaceous, Gray's Monitor/Butaan

V. panoptes, Argus Monitor

V.pilbarensis, Pilbara Rock Monitor

V. prasinus, Emerald Tree Monitor

V. primordius, Northern Blunt-Spined Monitor

V. rudicollis, Rough-Necked Monitor

V. salvadori, Crocodile Monitor

V. salvator, Water Monitor

V. semiremex, Rusty Monitor

V. spenceri, Plains Goanna

V. storri, Storr's Monitor

V. timorensis, Timor Monitor

V. tristis, Mournful Goanna

V. varius, Lace Monitor

V. yemenensis, Yemen Monitor

V. yuwonoi



Scientific Name

Common Name




V. acanthurus

Australian Ridge-Tailed/
Thorny-Tailed Monitor

Australia (Northern Territory, Queensland, W. Australia)

2'/60-70cm; SVL

In the wild, found in arid and seasonally dry areas among rocky outcrops or similar rocky areas where it lives beneath boulders or in deep crevices. One of the better monitor pet lizards in terms of size, V. acanthurus was for some time very difficult to obtain owing to Australia's ban on wildlife export but is now being bred in captivity in some numbers, although prices are likely to remain high for the foreseeable future. Unlike their larger congenerics, these monitors should be offered a higher proportion of insects and less mice as food. Despite their smaller size they are extremely active and therefore need a large terrarium: 4ft by 2ft would probably be the minimum area necessary. Rogner recommends a substrate of sand and loam mixed at a ratio of 1:10 which the monitors will apparently dig in as is their habit in the wild. Rocks and hollow bark are good cage furniture as V.acanthurus is saxicolous in the wild.. Bartlett notes that if kept outside they are somewhat more cold-tolerant than other monitor species, but if kept indoors they should still be kept warm. He also notes that in a large enough indoor terrarium with enough hiding places, more than one male (unusually) may be kept with females. This may in fact encourage reproductive behaviour. Scalation details: 70-115 rows at midbody. Coloration: dorsal brown reticulated pattern enclosing dull to bright yellow spots, lines or cream ocelli; head brown with yellow or cream sots that may become longitudinal stripes on neck; ventrally white or yellow. [SOURCES: Cogger, Rogner, Steel] B I

V. a. acanthurus

Australia (NW Australia)


Scalation details: ventral scales in 65-75 transverse rows [SOURCE: Steel].

V. a. brachyurus

Australia (mainland range except NW Australia)


Scalation details: ventral scales in 56-71 transverse rows [SOURCE: Steel].

V. a. insulanicus

Australia (Groote Eylandt, the largest island in the Gulf of Carpentaria, off Northern Territory, and Marchinbar Island)


Recently doubt has been raised on the status of this subspecies and whether it represents part of V. acanthurus, part of V. baritji or a distinct species (see Wikipedia entry for details) . Scalation details: ventral scales in 65-75 transverse rows. Coloration: melanistic [SOURCE: Steel].

V. albigularis

White-Throated Monitor

Most of sub-Saharan Africa: Namibia, Botswana, South Africa, Zimbabwe, Mozambique, Zambia, Angola, Tanzania, S.Ethiopia, S.Somalia, Kenya, Uganda


Formerly considered a subspecies of V. exanthematicus (see below) but recently raised to species level: correctly in my opinion since V. albigularus is considerably bigger than the Savannah Monitor subspecies and also has a meaner temperament. You should be aware of both these facts before you consider getting one of these lizards. They require a considerable amount of space and some patience on the part of the keeper. There are four possible subspecies, whose validity is often questioned, apart from the nominate subspecies: V. a. angolensis, V. a. ionidesi, V. a. microstictus and V. yemensis. Apart from the greater size and temperamental problems of the White-Throated Monitor, care is fairly much the same as for the Savannah Monitor (see below). See also Bennett. B I

V. a. albigularis



Scalation: 137-167 scale rows around body. Coloration: overall tan with yellowish markings; light throat [SOURCES: Bennett, Sprackland].

V. a. angolensis

Angola, Democratic Republic of Congo


Scalation: 110-141 scale rows around body. Coloration: predominantly grey; indistinct dorsal ocelli; dark throat [SOURCES: Bennett, Sprackland].

V. a. ionidesi



Mostly no longer regarded as a valid subspecies. Coloration: distinct dark temporal streaks that meet on nape [SOURCES: Bennett, Sprackland].

V. a. microstictus

E Africa (S Sudan and Ethiopia south to Zimbabwe and Mozambique)


Scalation: 122-152 scale rows around body. Coloration: indistinct dark temporal streaks [SOURCES: Bennett, Sprackland].

V. auffenbergi

Auffenberg's Monitor



One of the later monitors to be described (by R G Sprackland, 1999), and named after Professor Walter Auffenberg. Apart from this I have so far come across little else. Click here for the EMBL database entry. B I

V. baritji

Black Spotted Ridgetailed Monitor

Australia (Arnhem Land in Northern Territory)

50cm/20"; max 60cm

A little-known dwarf species with a small range in Northern Australia. It was only described in 1987 and apparently little is still known about its natural history, but Cogger states it is found in stony hills and dissected ranges and scarps, and Wilson and Swann, that it is also found in old termite mounds. Steel describes it as a rather more elongated version of V. storri. Non-Australians are unlikely to see this monitor for many years. Click here for Daniel Bennett's page on V. baritji. and here for a picture. Scalation details: 80-112 rows at midbody; 57 transverse ventral rows. Other: dorsolateral nostril, roughly equidistant between eye and tip of snout; tail with double crest and spinose dorsal and lateral scales; 12 enlarged ventral caudal spines behind cloaca. Coloration: dorsally reddish-brown, with numerous small dark spots which tend to align in transverse rows on the sides; dark streak from nostril to eye; another dark streak may be present from angle of jaws through ear to neck; limbs and tail dorsally brown, with dark brown and offwhite patterning; tail is banded; ventrally whitish to fawn, gular region yellow. Reproduction: no details available [SOURCES: Cogger, Steel, Wilson and Swan] B I

V. beccarii

Black Tree Monitor

Aru Islands, Indonesia


Formerly considered a subspecies of the Emerald Tree Monitor (V. prasinus), V. beccarii was raised to species level in 1991 as a result of R G Sprackland's research. It does indeed bear a resemblance in body shape to V. prasinus, but the colours of the two are strikingly different. Most of the care requirements of the Emerald Tree Monitor apply equally to the Black Tree Monitor, but less is known about the latter, particularly its reproductive life. V. beccarii are also reclusive (Bartlett & Bartlett) and thus require a densely planted vertical cage with hideboxes if possible. Bartlett & Bartlett also note that both Emerald- and Black Tree Monitors are often very dehydrated and stressed when they are imported, and recommend plenty of soaking and misting for both species when they arrive, and also checking for parasites. They also recommend a warm, well-sprayed cage with temperatures in the gradient of 84-92 deg F (29-33 deg C) and a basking spot of up to 98 deg F (37 deg C), with the temperature gradient dropping only slightly at night. Finally, the authors warn that these monitors are reluctant to be held and can put up quite a fight! B I

V. bengalensis

Bengal Monitor

Southern central Asia, including SE Iran and Afghanistan, through the Indian subcontinent into SE Asia as far as Java, Vietnam and Malaya


The import of the Bengal monitor has been restricted in recent years, which from a keeper's point of view is something of a pity as it is one of the more malleable monitors. However, apart from the pressure it faces in its habitat, it cannot be denied that again such a large lizard is really beyond the reach of most hobbyists and private keepers, at least in the UK. Their natural habitat tends to be forest, where they dig burrows but will also climb up into the trees, especially if threatened. They are also somewhat aquatic: they are good swimmers, and freshwater fish forms part of their diet. Rathnayake cites Auffenberg that in Sri Lanka Bengal monitors prefer the more humid areas of arid regions and the drier areas of humid regions. In that country it is widely distributed in the lowlands and is sympatric with V. salvator. In captivity a receptacle of water large enough to soak in should therefore be available. Rogner recommends a temperature of gradient of 35-22 deg C by day, falling to about 20 deg C at night, and humidity levels of 75% by day and 85% at night. V. bengalensis can live for 16-17 years. There are three subspecies apart from the nominate subspecies: V. b. irrawadicus, V. b. nebulosus and the recently (1996) nominated V. b. vietnamensis (first considered a full species, V. vietnamensis, in 1994). B I

V. b. bengalensis

Scalation: supraocular scales in irregular rows of nearly equal-sized scales. Coloration: dorsally overall grey to tan, with pattern of round cream or yellowish spots [Sprackland].

V. b. irrawadicus

Irrawaddy Monitor?


V. b. nebulosus

Clouded Monitor

Scalation: supraocular scales differently-sized (cf V. b. bengalensis). Coloration: dorsal pattern indistinct [Sprackland].

V. boehmei

Yellow Speckled Tree Monitor, Golden Speckled Tree Monitor

Papua New Guinea (Raja Ampat island group)


Slender tree monitor related to V. prasinus: see B I

V. bogerti


Limited range in Papua New Guinea (d'Entrecasteaux archipelago)


Formerly considered a melanistic subspecies of V. prasinus but raised to species level by Sprackland in 1991. In view of its former subspecies status it would seem logical to keep this lizard in much the same way as the Emerald Tree Monitor. B I

V. brevicauda

Short-Tailed Pygmy Monitor

NW Australia


This, the smallest monitor species, is a very desirable monitor in terms of captivity due to its size, although it is fairly robust. Scalation details: dorsal and lateral scales strongly keeled; 75-80 transverse rows of ventral scales; tail covered in spiny scales. Coloration: ground colour is a shade of brown that is usually either yellowish- or reddish brown, with a sprinkling of white and dark spots on the back and a ventral surface that is any shade between greyish white and yellow (Rogner, Steel). In addition there is usually a dark line running from the snout across and behind the eye, whose iris is a striking orange or red. The short tail is less than the snout-vent length of the lizard (unusually for a monitor) and becomes round as it progresses towards the tip: it is used to store fat. In the wild V. brevicauda preys largely on insects, eggs and small lizards: it itself is preyed upon by larger Australian monitors, amongst others. Its preferred habitat is the spinifex-covered sand dunes, where it lives in burrows. Rogner recommends a terrarium of 50 x 30 x 35 cm (20" x 12" x 14") with a sand substrate of about 5" that should be kept slightly moist at the lower layers, plus a few flat rocks and small hollow branch for hiding places. Most importantly he notes that while in the Australian summer (Dec-Feb) these monitors often experience temperatures of 40 deg C upwards, in the winter (Jun-Aug) they can experience ground frost and temperatures that vary as much as 20 deg C in the course of the day. He recommends 10-25 deg C for winter temperature gradients and 20-35 deg C for the summer. Food should be the standard variety of invertebrates: as the only vertebrates eaten by V. brevicauda are small skinks or geckos, it is debatable whether they should be offered mammalian fare such as rodents, even if they were to accept it. Steel notes that the breeding season is probably around August due to the males' increased testes size, and that egg clutches normally comprise six or fewer eggs. B I

V. caerulivirens

Turquoise Monitor

Indonesia (Halmahera, Moluccas)


Species only discovered in 1999: very little data yet available, but presumably this is a fairly rare species. Click here and here for a picture. B I

V. caudolineatus

Stripe-Tailed Monitor

W Australia


This species was reconfirmed in 1983 after mistaken reclassification in 1901. It is a mainly arboreal dweller of arid mulga land and scrublands that are characterised by hard stony soil (Steel). V. caudolineatus is rather slender, being of a yellow grey colour dorsally with a dark brown streak behind the eye and four longitudinal dark brown stripes down the tail. Ventral surfaces are pale yellow with light brown flecks: the throat is speckled brown. In nature it lives off geckos, predominantly the arboreal Gehyra variegata, as well as the normal invertebrate fare. Breeding takes place in July-August, females laying 4-5 eggs in November-December. B I

V. cerambonensis

Ceram Monitor

Indonesia (Seram and Ambon islands in Moluccas)


This was identified as a 'sibling species' of V. indicus in 1999 by the same team that discovered V. bogerti. Care would probably be fairly similar to that as for the Mangrove Monitor. B I

V. doreanus

Blue-Tailed Monitor

Halmahera Island (Moluccas), Waigeo Island (west of New Guinea), Sorong, Vogelkop, Jayapura, and Merauke areas of Irian Jaya, Indonesia; Madan, Papua New Guinea, Bismarck Archipelago


Formerly designated as V. indicus kalibecki or V. kalibeck, this monitor was elevated to full species level again in 1994. It is similar in appearance to V. indicus but with a blue- and black banded tail instead of the normal cream and white of the Mangrove Monitor. This is a much sought-after monitor, but unfortunately little breeding has yet taken place, a situation that must change in the near future. Care is otherwise similar to that of the Mangrove Monitor. B I

V. dumerili

Dumeril's Monitor

S. Thailand, Burma, W. Malaysia, Indonesia (Sumatra, Borneo, Bangka, Kalimantan, Riou, Biliton), Sarawak


Although still on the large side, Dumeril's Monitors have much to recommend them in that they are colourful when young and are fairly docile relative to other monitors when older. They inhabit mangrove swamps, river estuaries and the like, and prefer the safety of the water to that of the trees. Rogner claims that crabs form a large part of their diet [Rogner], together with molluscs, some fish and small mammals and of course insects. In captivity a roomy vivarium is also required, with a reasonably large receptacle of water being very desireable if not essential. The bright orange and blacks of the juveniles fade fairly soon to the brown bands (still quite attractive) of the adults. The tail is semi-prehensile. B I

V. eremius

Desert Pygmy Monitor

W & C Australia


A reddish- or greyish-brown (occasionally yellowish-brown) monitor with dorsal surfaces flecked with dark and pale brown spots, and a rather complex series of lines and streaks. V. eremius can be distinguished from dwarf monitors of similar size such as V. caudolineatus and V. gilleni by its keeled head scales and dark streaks on the throat (Steel). Its habitat is almost entirely open territory, eg the spinifex grass on the dunes, where it preys mainly on small lizards (Pianka notes that 76% of the stomach contents of captured V. eremius was made up of lizards). This prey item may indicate that the Desert Pygmy Monitor is really only suited for advanced keepers or zoos, if at all, as the typical rodent fare might be detrimental to it. Interestingly it is active all year round in its native habitat, even venturing out on relatively cold days in winter. B I

V. exanthematicus

Savannah Monitor / Bosc's Monitor

Most of sub-Saharan Africa: Senegal, Gambia, Guinea Bissau, Guinea, Sierra Leone, Liberia, Mali, Ivory Coast, Burkina Faso, Ghana, Togo, Benin, Niger, Nigeria, Chad, Cameroon, Central African Republic, Sudan, Ethiopia, Eritrea, Kenya, Uganda


The reputation of the Savannah Monitor has been somewhat improved following the removal of the White-Throated Monitor, V. albigularus, as a species from its number. Savannahs are still potentially very snappy and hissy but are easier to tame with age. Like some other large lizards they are feisty when young and somewhat moody in the juvenile stage, but age and captivity, especially regular feeding, seem to mellow them somewhat. Both mine became quite tame. If anything you need to watch out that they don't become too lethargic, and above all DO NOT overfeed them. I reiterate the warning that a diet of rodents is not healthy: insects, supplemented perhaps by other invertebrates, are more natural. See also Savannah Monitors. B I

V. flavescens

Yellow Monitor

India, Pakistan, Burma, Malaya, Thailand and Indo-China


The Yellow Monitor was once fairly common across India, but human activity (including hunting for skins) have reduced its population somewhat. However, there are signs that it is adapting by colonising areas such as fish farm parks and irrigated paddy fields (Steel). Its natural habitat is marshland in low-lying adjacent areas adjoining rivers or lakes: these areas are usually subject to annual flooding. In coloration these monitors are usually a brownish-yellow or sometimes olive brown, with darker bands that run into stripes. During the rainy season broad red bands also appear. Due to its medium size the Yellow Monitor might be thought a good choice for a captive species, but its threatened status would suggest otherwise, as might its diet: apparently 40% of its food intake consists of frogs, in addition to the normal quantities of insects, earthworms, other amphibians, birds, small mammals and eggs (Steel). However, Rogner notes that the diet of captive V. flavescens at Rotterdam Zoo did not contain any frog and these individuals do not seem to have suffered, although none of their eggs produced any young that survived. Any form of captive habitat for this species would have to be semi-aquatic on the lines of those used for V. salvator, the Water Monitor, which would be beyond the resources of most keepers, certainly in the UK. B I

V. flavirufus

Sand Monitor

Central Australia


This species was formerly a member of the V. gouldii species complex, but was elevated to full species status by Böhme in 1991 (see EMBL entry for more details). This is the most colourful and according to the Bartletts the most coveted of the former Gould's monitor subspecies, being marked with reds, russets and yellows (Bartletts) that blend in with the typical reddish sand environment of the interior of the continent. Click here for a good page with photographs. B I

V. giganteus

Perentie, Gigantic Lace Lizard

C & W Australia


The largest Australian lizard is a long, rather elongated creature with a narrowish head. The overall colour varies between brown and black, and the back and tops of the limbs are covered with a regular arrangement of large ocelli ("eyes"). It is an inhabitant of arid areas, where it often digs long burrows to hide during the hottest part of the day: failing that it will shelter beneath stones. Their favoured microhabitat seems to be rocky outcrops. Befittingly for such a giant, prey taken includes young kangaroos and even seagulls in addition to the usual fare of lizards, snakes, smaller mammals, carrion and eggs, and smaller specimens of its own kind. Each lizard will also cover a very large territory in its search for food. Despite being terrestrial, the perentie is quite capable of climbing trees, and is also noted for its habit of treating humans or horses as such if panicked (Steel, Sprackland). Hibernation takes place May-August: I have no data on mating seasons, but incubation for the eggs is quite long, about 230 days. Apart from the creature's jaws and claws, the tail is particularly potent as a weapon and one blow is reportedly able to break the legs of a dog (Steel). This lizard likes to maintain a body temperature of about 100 deg. F, so any captive would have fairly heavy heating requirements, especially outside its native land: this, plus its appetite and particularly its size, make it unsuitable for keeping by any but zoos and the most advanced, and wealthy, private keepers. Eric Pianka has some interesting observations on the large ranges and unapproachability of the Perentie. B I

V. gilleni

Pygmy Mulga Monitor/
Gillen's Pygmy Monitor

W & CAustralia


Similar in habit to V. caudolineatus (Steel), but the ranges of the two lizards do not overlap. The Pygmy Mulga Monitor also prefers mulga woodlands, shrublands and desert oaks (Steel). V. gilleni can be distinguished from V. caudolineatus by the streaked markings on its head and the bands, as opposed to spots, across its body. The dorsal overall coloration is a light shade of rust of varying degrees of redness, with the slender dorsal bands being a distincter red across the back and thinner but darker on the tail. The head streaks form a somewhat intricate pattern of similarly slightly darker red-brown than the background. Diet consists of the usual run of arthropods, arachnids and eggs, but the major constituent seems to be geckos, especially Gehyra variegata. An interesting aspect of this monitor is the ritualised combat that takes place between males, with both locking in an embrace and arching in a struggle supported only by snouts and tails: this lasts until the "arch" collapses, the uppermost male presumably being the victor (Steel). Breeding takes place in the spring (September-October): about seven eggs are laid in a clutch, which hatch out in December. For captive specimens Rogner recommends a vivarium with a 3-4" layer of sand kept constantly but lightly moist in certain areas, and temperatures of at least 27-30 deg C, higher under a spotlamp. Small numbers are now being bred in the US. B I

V. glauerti

Glauert's Monitor

NW Australia, Arnhem Land


One of the rarer Australian monitors, V. glauerti is a retiring creature that lives principally in rocky gorges and escarpments. It is a slender, somewhat dorsally depressed monitor, with a dorsal coloration of black or dark grey but with distinctive ocelli in bands across the back and tail, with the head, neck and upper surfaces of the limbs being somewhat lighter, the head in particular usually being overall grey. Little is known about these monitors, or at least little has appeared in print, nor have I heard of any in captivity. Diet would probably be similar to that of other dwarf monitors and temperature ranges similar to those for monitors living in the same area. Apparently V. glauerti has been bred to F3 and F4 generations in the States. B I

V. glebopalma

Shiny-Footed Goanna

N Australia


V. glebopalma is very similar in appearance to V. glauerti, but can be distinguished by its tail, whose end half is whitish or yellow, contrasted with that of V. glauerti which is banded in black. The name of this monitor is derived from the black pads on the soles of its feet, notably around the toes. Overall colour varies from red-brown to some shade of grey, with a network of narrow black lines over most dorsal surfaces as far back as the base of the tail. The limbs are black with yellow or white spotting, and the ventral surfaces are "brownish white" (Steel), again with a darker pattern superimposd on it. It is to be noted that the tail in juvenile specimens is almost entirely black, whitening progressively from the tip with age. The preferred habitat of these monitors is crevices in rock formations, from which they are difficult to extract if aware of a human presence. Diet consists mainly of smaller lizards, frogs and toads, and various invertebrates including spiders, beetles and centipedes (Steel). In very hot weather they are known to hunt at twilight. Interestingly, Rogner mentions that the captive specimens kept by Horn & Schurer did not apparently like crickets. For captive care he recommends a terrarium of at least 150 x 50 x 50cm (roughly 5' x 1½' x 1½) with a receptacle of water which is large enough to allow the monitors to bathe in. This species was first described in 1948 and is still not well known today. B I

V. gouldi

Gould's Monitor/
Sand Goanna

Australia except extreme SE & northern Arnhem Land


According to the Bartletts this is the Australian monitor most commonly seen by TV viewers around the world, and it is also one most eagerly sought by collectors. It is also one of the most widely distributed and adaptable, being very catholic in its habitat. It can live in wooded areas, forest, heathland, and offshore islands or even seashore, although its preferred environment is arid and sandy. Although heavy-bodied, it can climb trees in an emergency. Like many large monitors it is also not fussy about what it consumes, its diet including eggs (including those of crocodiles) and roadkills in addition to the usual small vertebrates and invertebrates. B I

V. g. flavirufus

Gould's Monitor/
Sand Goanna

Australian interior


V. g. rosenbergi

Rosenberg's Monitor

Southern Australia except extreme SE



V. griseus

Desert Monitor

N Africa to C Asia


One of the most widely distributed monitors, the Desert Monitor is nevertheless not as well known as other varanids, possibly because of its inhospitable habitat. It is elongated rather than stocky, with a long narrow head and nostrils set back closer to the eyes than the snout. The overall coloration is yellow and grey, with a few very thin dark grey dorsoventral bars from the front leg posteriorly that form rings around the tail. Behavioural patterns of this lizard vary according to subspecies and geography, but as a rule V. griseus is active during the morning and afternoon but has to take refuge from the heat during the middle of the day: accordingly it often digs its own burrow. It can also swim and climb if necessary. Interestingly, the species is not particularly territorial, with some ranges overlapping. However, they will make an aggressive display if cornered, and are supposedly capable of leaping up to 3' and of biting larger four-legged mammals (such as those ridden by humans!) in the belly. The bite is also supposedly somewhat toxic, probably in a similar if milder manner to the Komodo Dragon. Steel notes that the diet of Israeli specimens studied included gerbils and other rodents, bird eggs and chicks, smaller lizards, tortoises, snakes (including venomous), leverets, shrews and toads, in addition to the usual wide range of arthropods and their eggs. Desert Monitors are hunted themselves by local people for their skin and fat. B I

V. g. griseus

Trans-Caspian Desert Monitor

N Africa eastwards into the Middle East and Arabia

V. g. caspius

Trans-Caspian Desert Monitor

S Kazakhstan, Iran, Afghanistan to N Baluchistan

This subspecies dwells in the Trans-Caspian desert area. It intergrades with the nominate subspecies on the western side of its range (Steel). Coloration: overall light with black crossbands that extend behind the ears to meet on the nape [Sprackland]. B I

V. g. koniecznyi

Indian Desert Monitor

Sind and Punjab across C India.


Somewhat smaller subspecies: sympatric with the Bengal Monitor throughout much of its range. Coloration: darker than V. g. caspius: post-temporal streaks do not meet on the nape. B I

V. indicus

Mangrove Monitor

New Guinea, N. Australia, Celebes, Timor, Moluccan-, Solomon- and Bismarck Islands as well as individual S. Pacific islands


A species much coveted by varanophiles, the Mangrove Monitor is a slimmish, rather attractive lizard with a longish snout, black background colour and spots of white or yellow scattered over its body. Although it is a good climber and the young of the species are very arboreal, it seems to be at least semi-aquatic in its habits, as it is a good swimmer (and diver) and captives spend much of their time coiled up in water receptacles (Bartlett & Bartlett). In the wild they are normally found in the vicinity of water, and like iguanas and water dragons will spend time resting on branches directly overhanging it (Rogner). In keeping with their habitat they feed quite heavily on crabs, worms, fish and insects, as well as smaller reptiles and birds. R G Sprackland also reports that these lizards do not seem to fare so well on mammalian food, ie the usual rodents, and suggests that mice rather than rats should be offered (Bartlett & Bartlett). While frisky and prone to the normal monitor defences of tail whipping, scratching and voiding the cloaca (Bartlett & Bartlett), Mangrove Monitors do apparently tame down with handling. Temperatures should be 85-92 deg F (25-32 deg C per Rogner) with a hotspot of 35-40 deg C (Rogner). The biggest problem with keeping Mangrove Monitors is their requirement for a considerable amount of space, much of which should be dedicated to a receptacle of water with, if possible, overhanging branches (Rogner). Most are still imported from the wild, which necessitates treatment for endoparasites. For further information see Bennett. B I

V. i. indicus




Scalation: neck scales of subequal size and a nearly smooth texture. Coloration: tongue is dark.

V. i. rouxi




No details currently available.

V. i. spinulosus




Scalation: neck scales are small and keeled. Coloration: tongue is light.

V. jobiensis

Peach-Throated Monitor

N. New Guinea, Papua New Guinea


Another lizard once considered a subspecies of V. indicus, V. jobiensis was formerly designated as V. indicus jobiensis, was then elevated to full species level as V. karlschmidti (by which it is called in Rogner), and finally became V. jobiensis in 1991. Individuals vary in colouring according to locality (Rogner) but usually have a peach- or orange-coloured throat, a large number of small cream dots running over the body that sometimes seem to form bands, and possibly a hint of blue on the end portion of the tail (Bartlett). Rogner also notes that the tongue is bright red with a white tip, that the top of the head is grey-blue and that as a variation on the normal background colouring some specimens are black or grey-black with a yellow-green stippling effect, with a black instead of white tip on the tongue. In the wild the preferred habitat of the Peach-Throated Monitor is aquatic areas in rainforest zones, but like the Mangrove Monitor it is also a good climber. Care requirements are similar to that of the Mangrove Monitor, except that recommended temperatures are slightly higher: 28-32 deg C by day, dropping to 22-24 deg C ar night. Again, a hot spot should provide substantially higher temperatures in one part of the tank. Rogner recommends moist terraria sprayed heavily at least once per day and quotes the example of a keeper who used a 6" deep substrate of a mixture of earth and turf. This keeper also fed his captives quite heavily on frogs: this may prove, as in the case of the Mangrove Monitor, that mammalian prey items are less acceptable to these lizards than normally would be the case. Other food items can include chicks and arthropods, plus mice if rodents are to be offered. The Bartletts note that little is yet known of the natural history of V. jobiensis. B I

V. keithhornei

Nesbit River Monitor

Australia (Queensland)


No other information available. B I

V. kingorum

Long-Tailed Rock Monitor

E. Kimberley and Northern Territory, Australia


A little-known monitor with a restrictive range. Unusually for a monitor, two-thirds of its length consists of the tail, a proportion more usually seen in other lizard families such as the lacertids. It is also wary, living among rocks. Colouring is dull grey to rich red brown (Steel). I have not come across any mentioned outside of their native country, but I am informed that Frank Retes of the Goanna Ranch is currently breeding small numbers. B I

V. komodoensis

Komodo Dragon

Flores and Komodo and nearby islands (Indonesia)


The famous Komodo Dragon probably needs no introduction: along with geckos and the Green Iguana it is probably the most famous lizard in the world, ironically so given that only about 5,000 of them are left on three islands in the Indonesian archipelago. Fortunately these majestic reptiles are now completely protected by the authorities, and furthermore some captive breeding has been successfully carried out in zoos around the world. Although their reputation as eaters of humans has been somewhat exaggerated in the past, they have killed villagers and tourists on occasion, partly because their bite is extremely toxic due to four strains of dangerous bacteria resident in their mouths. Needless to say they are completely unavailable to private owners, which is just as well as they consume pigs, deer and other expensive or hard-to-obtain food.. There are a number of books and monographs on the Komodo Dragon, and several TV documentaries have been made. B I

V. kordensis




Regarded by some authorities as a synonym of V. prasinus.

V. mabitang

Mabitang, Panay Monitor



Diet at least partly vegetarian. B I

V. macraei




See Bennett: no other information available. B I

V. melinus

Quince Monitor

Indonesia (Moluccas)


Closely related to V. indicus, but distinguished from that species by its yellow coloration. Click here for a comprehensive description of appearance and captive breeding report. B I

V. mertensi

Merten's Water Monitor

Australia (northern areas inc. Cape York, Kimberley district and Northern Territory)


 Another highly aquatic monitor, Merten's Water Monitor is usually found near water, often along the banks of lakes and rivers or streams. It seems to avoid however the coastal mangrove swamps favoured by V. indicus (Steel). The tail is laterally compressed with a double keeled crest, while the nostrils have a valve that closes when the lizard is under water. This species is also a good climber of trees, often found laying on branches over water in a manner possibly reminiscent of Water Dragons (Physiognathus coccinus) or Green Iguanas (Iguana iguana). In keeping with its habitat, much of its diet consists of aquatic fare (fish, frogs and crabs as well as other water-dwelling invertebrates) in addition to the more "normal" monitor items. V. mertensi is usually a dorsal olive-brown or grey or even black (Bartlett) with very small white spots on the head and yellowish spots over the rest of the body. The snout is slender and depressed at the tip. This is one of the few species where sexual dimorphism is present, the males being considerably larger than the females and developing a blue tinge to the sides of the face, as opposed to the pale orange of the female. Bartlett (1996) records that breeding success with Merten's Water Monitor has so fare been poor and that further research is needed. Steel notes that some of these monitors become semi-tame in the locality of humans, especially around camp sites where they learn to scrounge food. (See also his account of interesting threat display behaviour by captives). Given however the low rate of breeding and the highly aquatic nature of the beast, it is a probably a poor choice for any keeper who cannot afford to offer the considerable facilities such a captive specimen would need. B I

V. mitchelli

Mitchell's Monitor

Australia (extreme north).


Similar to the larger V. mertensi in build, distribution and habitat, although V. mitchelli also inhabits swamps, favouring especially Pandanus vegetation (Steel). It is also a dietary generalist, taking both aquatic and terrestrial prey. Overall dorsal colour varies between dark- , black- or olive-grey, with whitish ventral surfaces with narrow grey crossbands (Steel). Patterning varies according to the location: Kimberley specimens have small black and white spots, while those from the Northern Territory have ocelli, black bands and white spots. Breeding takes place in the dry season, the female laying up to 12 eggs. B I

V. niloticus

Nile Monitor



This is one of the most attractive and impressive-looking monitors, but unfortunately also one of the meanest. In fact R D Bartlett reckons there is no harder lizard to tame than the Nile Monitor. It is unfortunate also that so many are still being imported and sold, often under different and potentially misleading names such as the Burundi Monitor. Niles are notoriously aggressive, possibly because of their shared habitat with Nile Crocodiles whose eggs they often prey upon. In captivity, apart from the usual heating and UV lighting, Niles need a large enclosure and a body of water to bathe and defecate in. The chances of taming one are seriously reduced (apparently to practically zero) unless you begin with a very young hatchling and handle it two or three times a day regularly. Please avoid purchasing one unless you have the facilities, the experience and the patience to deal with such a large and potentially injurious lizard. B I

V. olivaceous

Gray's Monitor/

Philippines (Bicol area of SE Luzon and adjacent Cantanduanes)


The only monitor known to eat much plant matter in the wild, with molluscs making up most of the rest of the diet. Its preferred habitat is "dipterocarp" forest growing at altitudes of up to 3,300': however, Steel notes that where this has been cleared and replaced by secondary growth, the butaan (fortunately) has adapted by using the shelter of rocky fissures instead. Nevertheless by preference they sleep high up in the trees or plant cover. The butaan shows some interesting physiological adaptations for its way of life: the bones of the palate are unusually robust to facilitate the swallowing of hard fruits, the small intestine is lined with large absorptive villi and the caecum is larger than that found in other monitor species. It may void gastric pellets orally after meals. V. olivaceous is not a particularly active creature in comparison with its congenerics, and is also rather shy, preferring flight to fight - according to Steel it may leap from trees up to 100' high to avoid capture. However, if cornered it is capable of a very painful and sustained bite. Mating begins in April, when males start to indulge in ritual combat: the testes begin to increase in weight from March and reach their maximum in May-July. Females lay a single annual clutch of 4-11 eggs in July-August, usually in a hollow tree or branch, although some larger specimens may lay a second clutch in October or November. An interesting aspect of butaan reproduction is that incubation may vary between 6 and 12 months, the young always emerging at the beginning of the wet season in June, when a plentiful supply of food is ensured. Because of ecological pressure on V. olivaceous (adaptability notwithstanding) and its restricted range, captive specimens are usually restricted to zoological faculties. In any event, it might be hard for many keepers to provide the fruit matter which this lizard commonly eats. B I

V. panoptes

Argus Monitor

W Australia, N Australia (Kimberley, Northern Territory, N Queensland), New Guinea


At times considered a subspecies of V. gouldi. The common name arises from the pattern of spots, or "eyes", on the lizard's back. The overall dorsal colour is a dark shade varying between blackish brown and dull reddish brown (Steel), with alternating transverse rows of large and small spots across the back. This pattern of alternate large and small spots is repeated on the ventral surface and sides. The tail is double-crested. The Argus Monitor seems to prefer riverside habitats, and consequently it consumes aquatic fare such as crabs, fish and frogs (Steel) in addition to the more expected diet of various invertebrates (including scorpions), smaller lizards and other reptiles, birds, rodents and other mammals including the echidna. Breeding takes place in the wet season, courtship taking place in July (Steel). Females lay about 12 eggs per clutch. B I

V. p. panoptes

N Australia

Nominate subspecies. Patterning may become obscure in old specimens. This subspecies can be distinguished by two streaks on the side of the head, a pale-edged one extending through the eye along the neck and the other a thinner one extending from the lip (Steel). The end of the tail varies in colour between yellow and light brown and is banded with dark brown: unlike the rest of the body patterning, this banding does not fade with age. B I

V. p. rubidus

W Australia

Differs from V. p. panoptes in its reddish overall colour, end of tail becomes completely yellow with age as in V. gouldi (Steel). B I

V. p. horni

New Guinea

Very similar in appearance to the nominate subspecies (Bartlett). B I

V. pilbarensis

Pilbara Rock Monitor

Pilbara region of NW Western Australia


The Pilbara Rock Monitor is rarely mentioned in articles on monitors or even Australian reptiles, probably because its range is so small. It is a reddish-coloured varanid that is saxicolous in its habits, ie preferring rock faces, crevices and boulders and the like. Unlike some Australian dwarf monitors, this one is very rarely seen outside of its native land, although Goanna Ranch in the US are apparently breeding some. B I

V. prasinus

Emerald Tree Monitor

Australia and New Guinea


A very desirable monitor, in terms of both beauty and size, but by no means an easy captive. Despite its small-medium size (about the same length as the Savannah Monitor) and slimmer build the Emerald Tree Monitor is not shy of biting, nor of voiding its cloaca (Bartlett) at a perceived threat (like a keeper). Also the caging for this species demands not only more vertical space, as it is arboreal, but a fairly thick planting of sturdy branches and a relatively high humidity. Furthermore imports (and there are hardly any captive-bred available) usually need treatment for a heavy parasite load. They are more insectivorous than other monitors and should not be fed too many mice, which is largely an unnatural food to them. Slugs and snails, on the other hand, are quite acceptable (Bartlett). The prehensile tail of V. prasinus is often curled up watchspring-style like that of a chameleon. B I

V. primordius

Northern Blunt-Spined Monitor

NW Northern Territory, Australia


This species is actually known only from one specimen (Steel) described in 1942. This, and the fact that it is very similar indeed to V. storri, whose range it partially overlaps, has led many people to doubt its validity, regarding it as more probably a subspecies of V. storri. (Bartletts note that the number of scales encircling the mid-body of V. primordius, is 69, that of V. storri, 71). None seem to appear outside Australia. Click here for a page with a photograph. B I

V. rudicollis

Rough-Necked Monitor

S. Burma, Malaysia and across the Rhio archipelago as far as Sumatra, Bangka and Borneo


This is another arboreal monitor, built for life among the trees with its slender build and long (up to two-thirds of its body length) semi-prehensile tail. While occasionally observed in small coastal mangrove swamps (Rogner), they are mostly creatures of the forest canopy. Although often confused with Dumeril's Monitor (Bartlett), the Rough-Necked Monitor is different in appearance and especially in behaviour. V. rudicollis has a more pointed, "bird-like" snout, as opposed to the broader snout of V. dumerili. Also V. rudicollis is persistently arboreal, whereas V. dumerili is terrestrial in adulthood if not through its whole life. They are also considerably shyer and more nervous than the Dumeril's Monitor, and when freshly imported can be difficult to persuade to feed (Bartlett). For this reason, the Bartletts consider them "delicate and problematic" captives. A vertical cage thickly planted with branches and if possible elevated hide boxes seems to be essential. Cage temperatures should probably be the same as for other lizards from the jungles and forests of SE Asia, with a bowl provided for soaking, which they do occasionally. Diet consists of the usual insects when young, graduating to larger arthropods, small live fish (Rogner) and rodents and chicks. I am uncertain as to whether spraying is necessary. B I

V. salvadori

Crocodile Monitor

SE Asia

Up to 9'

While the Latin species names of V. salvadori, the Crocodile Monitor, and V. salvator, the Water Monitor, could be easily confused (and sometimes are), the two are not very similar in appearance. The Crocodile Monitor has a rather bulbous snout, is somewhat slender in appearance despite its huge length, and has eyes that appear proportionately larger to those of the Water Monitor. The common name Crocodile Monitor is itself something of a misnomer, for far from being terrestrial these are arboreal lizards. Because of their huge size and climbing requirements, some authorities recommend keeping them in greenhouses thickly planted with branches firm enough to bear their weight. These enormous lizards are not as bad-tempered as the Nile Monitor, but their greater size and strength, not to mention their claws, jaws and powerful tail, make them dangerous if angered. This, and their habitat requirements and comparatively high price, make them really suitable only for experts, zoological gardens or breeders with large facilities. B I

V. salvator

(Asian) Water Monitor

India (Orissa, Bengal and Andaman and Nicobar Islands), Bangladesh, Sri Lanka, and SE Asia

Up to 7'

The Asian Water Monitor is a semi-aquatic species found in a variety of habitat, including fresh and brackish water, gallery forests, marshlands, agricultural fields and even garbage dumps, roadsides and home gardens (Rathnayke). Their highest population densities are reached within swampy mangrove areas (ibid). In Sri Lanka it is widely distributed in the lowlands and is sympatric with V. bengalensis. A very large and demanding lizard in terms of space and habitat requirements, chief and most difficult of which is a large body of water to bathe in (and often defecate in as well). Having said that, the Water Monitor is quite intelligent and if its requirements can be met (unlikely, sadly, for most of us) then it can become a good pet. Robert Sprackland vouches that he knew of captive Water Monitors which were housetrained enough to use a litter tray and to come looking for their owner at mealtimes. (Then again, he had the advantage of living in Australia). For most of us, however, these are lizards to be admired from afar rather than kept. An interesting aside is that water monitors formed part of a cult in the southeast Asian islands whereby dead villagers were placed in special baskets and hung from trees. These baskets were so modified that only water monitors could get into them, the purpose being to entice the water monitors to eat the person's body and, in native belief, free their soul (possibly into the body of a monitor). Rathnayake describes the Water Monitor as highly adaptable to man-made surroundings and therefore presumably less endangered by the destruction of natural habitat than many other tropical organisms. On the other hand, the species is used by humans for both flesh and its skin, thousands of skins being exported annually. An invaluable web resource on this species is Daniel Bennett's extract from his Little Book of Monitor Lizards. B I . Scalation details: scales on dorsum of head bigger than temporal scales; 4-10 supraorbital scales; dorsal scales small, oval and keeled; 74-102 transverse ventral rows of keeled scales. Other: neck long; snout elongate, with depressed tip; valvular nostrils, located close to end of nose; tail compressed with serrated double-toothed dorsal crest. Coloration: variable, see subspecies entries. Reproduction: nominate subspecies lays clutches of up to 35 eggs.

V. s. salvator


India, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia


Most widespread of the subspecies. Scalation: 80-95 transverse ventral rows. Coloration: pale spots and banded tail [SOURCE: Sprackland].

V. s. andamanensis


Andaman Islands


Melanistic form [SOURCE: Bennett].

V. s. bivittatus


Indonesia (Java)


Now recognised as a valid subspecies by some authorities.

V. s. cumingi




This subspecies is recognised as a full species by some authorities: see the Reptile Database. Scalation: large dorsal neck scales; fewer occipital scales than nominate species; 77-85 transverse ventral rows. Coloration: bright yellow to orange head and nape, conspicuous small dorsal spots [SOURCES: Sprackland, Steel].

V. s. komaini




Melanistic (all black) subspecies, formally considered part of the nominate subspecies.

V. s. macromaculatus

Bangladesh, Myanmar, Thailand, Cambodia, Laos, Vietnam, Malaysia, Indonesia (Borneo, Sumatra)

Although this subspecies was described by Deraniyagala in 1944, it does not seem to have cropped in much herpetological literature. No other information currently available.

V. s. marmoratus

Marbled Water Monitor



This subspecies is recognised as a full species by some authorities: see the Reptile Database. Scalation: 84-102 transverse rows of ventral scales. Coloration: dark head; orange to pink lips; small dorsal spots; large nuchal scales; ventrally a marble colour [SOURCES: Sprackland, Steel].

V. s. nuchalis




This subspecies is recognised as a full species by some authorities: see the Reptile Database. Similar to V. s. marmoratus, but nuchals larger than both dorsal scales and occipitals; 85-89 transverse ventral rows [SOURCES: Sprackland, Steel].

V. s. togianus


Indonesia (Sulawesi and adjacent islands)


Darker form with larger scales [SOURCES: Bennett, Steel]. This subspecies is recognised as a full species by some authorities: see the Reptile Database.

V. s. ziegleri

C Indonesia (Obi Island)

Described in 2010.

V. semiremex

Rusty Monitor

Coastal strip of SE Queensland (Australia)


This small aquatic monitor dwells principally in the mangrove swamps of its range, being both a good climber and good swimmer, aided by its relatively short but laterally compressed tail. The nostrils are slightly closer to the tip of the snout than the eyes and as befits an aquatic lizard are somewhat high up. The classification of this monitor has been contended, with some suggesting that it is in fact a subspecies of V. timorensis. Thus no subspecies are recognised, but there are two "forms", the "eastern" (grey-brown in ground colour with black flecks across the body, blackish limbs with cream spots, dark grey-brown tail, white or pale yellow ventral surfaces with irregular brown bands and head dorsally dark but laterally paler, with lips barred with dark brown) and the "northern" (differing from the above in being darker overall with a more discernible pattern and white ocelli in rows across the neck and body)(Steel). B I

V. spenceri

Plains Goanna

NE Australia (interior)


Steel describes this monitor as "notably amiable", although it does not seem to be a common captive subject. It lives in the arid regions of the north-eastern interior of Australia, where it shelters beneath rocks or in deep cracks, occasionally digging or taking over burrows. Hot, still days seem to be the preferred weather for foraging (Steel). The most striking aspect of the Plains Goanna is its long neck and rather unusually shaped head (Steel). Overall colour is a shade of either grey- or red-brown, with pale bands and dark markings that are chevron-shaped on the neck but subsequently straight as far as the end of the tail. The ventral surfaces are light grey flecked with dark grey or brown. Females lay a clutch of 10-30 eggs in spring. The hatchlings are quite brightly coloured, having 8-9 yellow bands across the back, 2-3 chevron-shaped markings on the neck and a white belly, but this pattern fades with adulthood. B I

V. storri

Pygmy Ridge-Tailed Monitor/ Dwarf Monitor


Up to 1'

Highly sought but still expensive dwarf monitor, despite captive breeding in small numbers and an apparently abundant presence within its range. V. storri occurs in two separate locations, each representing a separate subspecies (see below). According to Steel this monitor is very similar to V. acanthurus except for its smaller size. The tail is very spiny along top and sides and is used to block the lizard's burrow when it is inside. Overall coloration is reddish brown, with dark brown-black flecks on the head, and there is a brown-black net pattern across the upper surfaces of body and limbs that sometimes encloses pale spots. Other black-brown spots cover the body and may form vertical bars on the lips and temples (Steel). There is also a dark streak (sometimes pale-edged) running from the eye to the ear. Diet is apparently mostly invertebrates of various kinds but may also include geckos. Females lay 5-7 eggs. Steel gives interesting notes on a Queensland colony of about 50 individuals that was observed over a period of time, while Bartlett also has interesting notes on a small group that he and his wife maintained outdoors. B I

V. s. storri

Australia (Northern Territory and Northern Queensland)

V. s. ocreatus

Australia (Kimberley district, W Australia, and adjacent Northern Territory)

This subspecies is distinguished from the nominate form by enlarged scales beneath the distal part of the hind leg and fewer mid-body scale rows and transverse ventral scales. It also has proportionately longer limbs and tail (Steel). B I

V. telenestes




Named by Sprackland, 1991: no other information currently available.

V. timorensis

Timor Monitor, Spotted Tree Monitor

Australia, New Guinea


Now more commonly available in captivity, but its high desirability usually means a still expensive price tag. These dwarf monitors apparently make good captives. Click here for a picture. B I

V. t. timorensis

Timor and associated islands, New Guinea


This is the subspecies usually seen in captivity. Overall coloration is blackish with variable but mostly gold-coloured ocelli (Bartletts). B I

V. t. similis

NE Australia, S New Guinea


Some authorities consider this a separate species, V. similis. Overall coloration is more variable than in V. t. timorensis but usually blackish with white and grey spots and ocelli (Bartletts). B I

V. t. scalaris

Australian Spotted Tree Monitor

NW Australia


Also sometimes considered a separate species, V. scalaris. So far only found in captivity in Australian collections (Bartletts). Overall coloration is a shade of almost black with small yellow spots (Bartlett). Click here for pictures. B I

V. tristis

Mournful Goanna, Racehorse Monitor

Australia except far east and south


 An adaptable monitor primarily found in woodlands (but probably not rainforests, see Bennett) but also capable of living terrestrially among rocks where tree cover is absent. The common name is derived from its dark overall colour (black in the nominate subspecies), although in practice writers seem to refer instead to the Black-Headed Monitor or Freckled Monitor, both being the two recognised subspecies. Pianka has some interesting notes on V. tristis, including its highly seasonal activity (building up fat reserves for the drought) and its habit of visiting any tree on its path for food. Lizards make up a considerable part of its diet, as do bird eggs and fledglings, but V. tristis also takes invertebrates. At one setting it is able to gorge about one quarter of its body weight and can swallow even the inedible-looking Moloch. Other noteworthy achievements of this species are its ability to bear tremendously high temperatures (47.3 deg C recorded in one instance, see Bennett) and its high speed when running. In captivity Bennett notes also that this monitor may be kept in reasonably modest (but not cramped!) conditions and that a diet of rodents and invertebrates is sufficient. Rogner recommends a terrarium of 150 x 70 x 100cm with a sand substrate and suitable cage furnishings including an artifical cave. A clutch of 5-17 eggs is laid in late spring, with hatching taking 116-140 days (Steel). They have apparently reproduced in captivity several times, but rarely appear for sale to private keepers outside Australia. Click here for a picture. Matthew Bonnett also has a nice summary and pictures. B I

V. t. tristis

Black-Headed Monitor

W & C Australia

 Distinguished from V. t. orientalis by its darker overall colour (melanistic black in some western specimens) and spinier scales on the tail (see Bennett). Steel notes that the ocelli are also smaller and form a fine reticulum. As a rule, coloration darkens in both subspecies with age. B I

V. t. centralis


C Australia

A proposed subspecies which has not yet found full support among authorities (Steel). Bennett notes that this is also an obsolete designation for V. t. orientalis. B I

V. t. orientalis

Freckled Monitor

C, N & E Australia

Sprackland considers this a full species. However, both subspecies are found in some areas, which has led some (eg Rogner) to question the validity of the subspecies and whether or not they are simply forms. B I

V. varius

Lace Lizard



The second largest Australian lizard, although much of its length is tail. Most specimens are a bluish-black colour with large rosettes (Sprackland), but a New South Wales variant has been recorded which has a basic overall colour of yellow with irregular dark transverse bands (Steel). Its habitat is the coastal forests and lowlands, where they tend to make their homes in holes in trees (Steel) in what is often a range of several kilometres. By nature this species is a terrestrial forager, being a notorious egg robber of both nests and henhouses, but all manner of other prey is also taken, including frogs, snakes, rabbits, insects, fox cubs and especially carrion. Mating takes place during the summer, with several males gathering around a receptive female and indulging in ritualised combat which may last for 20-30 minutes. Females lay their eggs (6-12) by choice in termite mounds: research indicates that they return nine months later to break open a hole for the hatched young to escape. The hatchlings, about 12" long at birth, are brightly coloured and predominantly arboreal: their colours darken after about 2 years. Steel notes that the lungs of V. varius are highly complex, incorporating a high number of diverticula, and that this may indicate a descent from larger species of the Pleistocene era. B I

V. yemensis

Yemen Monitor



 This species was discovered almost by accident, its existence being confirmed only in the 1980s. Even then for some time it was uncertain as to whether it was a subspecies of V. exanthematicus, since the morphological differences were restricted to the hemipenes. Daniel Bennett notes however that differences in blood proteins and the structure of the hemipenes and lungs were sufficient to prove species validity. The Yemen Monitor's range is among the foothills of Yemen's mountains at altitudes of 1,000-4,500 ft, where it is relatively common (Steel). This area is characterised by basaltic rocks with both wild vegetation (buses, acacia trees and Euphorbia) and cultivated fields. Steel notes that this monitor is mainly diurnal. It is drawn to watercourses to forage for insects, especially beetles, and snails, but will also take young hares. Although this seems a predominantly invertebrate diet, Steel notes that captives will eat a more varied menu including the more usual vertebrate items. I am not aware whether Yemen Monitors are being kept in captivity by private keepers. Click here for a picture. B I

V. yuwonoi


Halmahera Island (Indonesia)


A recently described species: see EMBL database entry for details. B I

V. zugorum




Named by Böhme and Ziegler, 2005: no other information available.


The following books all offered very useful information and data on the various species:

Monitors, Tegus and Related Lizards, R D & P Bartlett, Barrons. The Bartletts are always informative and have had a good deal of experience with most cold-blooded terrestrial vertebrates. We particularly recommend this book if you wish to purchase one of the less commonly available monitors or a tegu.

The General Care and Maintenance of Popular Monitors and Tegus, Michael Balsai, Advanced Herpetocultural Library. This is an updated version of Balsai's previous book in the same series, The General Care and Maintenance of Savannah Monitors. Apart from an enlargement of the care notes, mainly to include observations from other sources (mainly keepers!), the book includes an increased number of species, including a few of the desirable Australian monitors and the popular tegu. It goes a bit more in depth into the care of the Savannah Monitor than the Bartletts' book, but both are excellent. The only proviso I would make is that Balsai recommends a staple diet of rodents, which in my experience is dangerous for smaller monitors such as the Savannah (and this is also Daniel Bennett's view).

Giant Lizards, Robert Sprackland, TFH 1996. A useful book on many of the monitor species, plus of course the tegus, the large iguanas and a few other species that qualify for Sprackland's admittedly arbitrary 3-foot minimum to be classified as a "giant lizard". Of particular use are the scale pattern descriptions and the graphic representation of patterns on the different subspecies. Owing to the date of publication, "newer" monitor lizards are not included.

Echsen [Lizards] Vol 2, Manfred Rogner, Ullmer 1994. Rogner's volumes, although now some years old, are normally a reliable and comprehensive source of data. Some of the taxonomic data may have changed since publication.

"An account of monitor lizards in Sri Lanka: status and distribution", Nimal D Rathnayake, Occasional Papers of the Amphibia and Reptile Research Organisation of Sri Lanka, December 2001. Covers not just the status and distribution of the two species (V. bengalensis and V. s. salvator) but also cultural beliefs and practices regarding the lizards, and has a good bibliography (about a page and a half).

See also the Index of Herpetological Magazine Articles: Varanids.

Links also do a very fine monitor page, with classification (up to 1998) and photos, although as far as I am aware there are no care sheets.

Very highly recommended is Daniel Bennett's monitor pages. Daniel is a professional researcher whose interests cover monitors in the field.

The Wikipedia entry for Varanus bengalensis has a useful section on identifying the different varanids of South Asia. is, as the URL suggests, dedicated to tree monitors (V. prasinus and relatives).

Eric Pianka has a good section on Varanus of the Great Victoria Desert.

Back to Varanids | Back to Lizards | Back to Reptiles | Back to Homepage