Desert or Grey Monitor, Transcaspian Desert Monitor, Indo-Pak Desert Monitor Varanus griseus, Varanus griseus caspius, Varanus griseus koniecznyi FACT FILE: Local Name: Goa (Urdu) Family: VARIANIDAE Genus: Varanus Status: Common to Rare Warning: This lizard inflicts a powerful bite with its long, strong and sharp teeth, that can cause dizziness, muscular aches, pains, accelerated heartbeat and difficulty breathing through the mouth   Photo Credit: Daniel Bennett (www.mampam.com)     Species and sub species: This Monitor is represented in Pakistan by the following species and sub species: Desert or Grey Monitor (Varanus griseus) Subspecies: Transcaspian Desert Monitor (Varanus griseus caspius) Indo-Pak Desert Monitor (Varanus griseus konuecznyi) Description and Biology: General characteristics:  The Desert or Grey Monitor has a snout-vent length 560-579 mm, tail 865-870 mm.   In the Desert Monitor the Dorsum is  gray to yellowish brown; body and  tail  with brownish crossbars; 2-3 streaks on neck; ventrum yellowish. In adult vivacity of dorsal pattern is lost.   In the Transcaspian Desert Monitor sub specie the body has 5-6, while tail has 16-19 transverse bands. Males tend to be longer than females (largest male recorded from Turkmenistan by Shammakov (1981) was 58.5cm SVL, largest female was 46cm) but not much heavier (heaviest male was 2,850g heaviest female 2,700g). It is the largest race of the desert monitor. The Transcaspian Desert Monitor is distinguished from other races of V.griseus largely by the shape of its tail, which is laterally compressed in contrast to the tails of other races, which tend to be more or less rounded in cross section.   The Indo-Pak sub specie has 4 transverse bands, while the tail has 10-15 transverse bands. Indo-Pak Desert Monitor is the smallest subspecies of V.griseus. Males reach a maximum length of 84cm TL (37cm SVL) and a weight of 580g. Females grow to 75cm TL (34cm SVL) and weigh up to 520g. Sexual maturity, for females at least, is attained at about 24cm SVL.   Biology: It is very secretive monitor and is more active during the early hours of the day, spending most of its time in its burrow. It feeds on rodents, lizards,  snakes, birds, eggs, frogs, and  toads. Since it is a varanid of warm areas, it is not known to hibernate.   When encountered, it stiffens its legs to raise its body which is arched outward,  and snarls and hisses vigorously by squeezing and inflating its body. The neck is puffed, and the tongue is extended largely, while the tail is vigorously lashed  from  side  to side.          Breeding season extends from late March to late May; 10-25 eggs are laid in burrows or pits excavated  for  the  purpose, which are then covered with vegetation and debris.   Transaspian Desert Monitors are strong diggers. In clay desert where the substrate is too hard to excavate they shelter in mammal burrows and in river valleys they often utilise the burrows of ground dwelling birds. In sandy desert burrows are often more than 500cm long and typically 50-120cm deep. Burrows used during the spring and summer tend to be in more open areas than those used for hibernation, which are dug under bushes Yadgarov 1968; Makayev 1982; Bennett 1992b). Mating occurs during April and May. Up to 34 eggs are laid in a burrow 70-114cm deep usually situated on a slope during June and July. Sometimes the burrows of rodents are used as nesting sites. Females spend up to a week digging test holes and preparing nests, guard the eggs for several weeks after egg laying and have been reported to return to the vicinity of their eggs around hatching time. The eggs hatch in September or October but the youngsters remain together in the nest and do not commence activity until the following spring. Eggs laid in captivity weigh 32-35g (Yadgarov 1968; Shammakov 1981; Tsellarius & Menshikov 1995; Dujsebayeva 1995; Makayev, pers.comm; Kudryatsev pers. comm.). Sexual maturity is attained within three years (Shammakov 1981). Tsellarius and Cherlin (1991) note that many Caspian monitors have scars on the back, which they attribute to attempted predation by birds, but are interpreted in other species as wounds received during ritual combat. Bipedal combat occurs in the typical fashion of large monitor lizards (Tsellarius 1994).   The diet of the Caspian monitor is similar to that of the nominate race. In many areas they feed on hatchling tortoises which emerge in the spring and excavate and consume tortoise eggs which are laid in May. They also eat small mammals, including the giant gerbil and young hares. Transcaspian monitors will also prey on smaller members of their own species (Makarov 1985). The lizards ability to prey on snakes that are extremely dangerous to man  is particularly interesting. Experiments to determine the Caspian monitors' ability to tolerate viper and cobra venom by injecting them with venom sufficient to kill up to 4,000 adults humans seem to indicate that the lizards have considerable resistance to both haemotoxic and neurotoxic venoms (Rjumin 1968).   The Indo-Pak Desert Monitor are inactive between December and March, or at least they stop feeding. Corkill (1928) records that they do not hibernate and are seen throughout the day during the winter, and only in early morning and late afternoon during the summer.   Koniecznyi's or Indo-Pak Monitor feeds largely on invertebrates (especially beetles) lizards, reptile eggs, toads and small mammals. It finds most of its food below the ground or under debris.  Mating occurs in July or August, during the monsoon and 2-15 eggs are laid in September and October (Auffenberg et al 1989). According to Auffenberg (1986) bipedal combat is characteristic of all Indian monitors and occurs in Koniecznyi's monitor between May and early July. Male Koniecznyi's monitors may become more intense in colour during the breeding season. Auffenberg et al (1989) suggest an incubation period of up to ten months. They also record a biased sex ratio of 2.23:1 in favour of males.   Habitat, Distribution and Status: This is a varanid of sandy fields with uneven surfaces and tracts of hard soil with sparse vegetation. It excavates burrows in the roots of trees and bushes.   Varanus griseus is one of the most widespread monitor lizards. The varanid has a wide range in the arid desert areas of India , Pakistan , and the Middle East . It ranges  from Rajasthan to the Caspian Sea and  North Africa . The Pakistani population of this varanid is distinguished in the following two races:     Varanus griseus caspius Distribution: The Caspian monitor is found in both sandy and clay deserts. They avoid areas of dense vegetation but are found in sparse woodland. Those from clayey areas are often a distinctive reddish colour (Bennett 1992a).  They are sometimes found on the edges of agricultural land, but, because they are often killed when encountered, Caspian monitors tend to be very uncommon in areas of human habitation. In abandoned settlements they often inhabit cracks in wattle and daub houses. Caspian monitor lizards reach their highest densities where colonies of mammals are abundant. The Caspian monitor (V.griseus caspius) is the largest race of the desert monitor. It is considered to be in danger of extinction and is one of the few monitor lizards whose commercial trade is completely outlawed. Despite this they are regularly offered for sale at pet markets. The Caspian monitor extends from the Transcaspian Desert to southern Khazakistan and Afghanistan , extending into northern and western Balochistan.   Varanus griseus koniecznyi Distribution: Koniecznyi's monitor, or the Indo-Pak desert monitor is found in central and western Pakistan and India, from central India , to Cholistan, Sindh, and the Kharan Desert in Pakistan . Auffenberg et al (1989) provide extensive distribution data. They considered that the subspecies occurs only in the past and present Indus valley and is largely restricted to sandy desert, being uncommon in clay deserts. Auffenberg (in Luxmoore & Groombridge 1990) suggests a density of 9 lizards per km2 in the desert scrub of Pakistan.       Credits: Dr. Muhammad Sharif Khan, Herpetological Lab Rabwah, Pakistan Daniel Bennett (www.mampam.com) Nausherwan Ahmed ©1997-2002 Wildlife of Pakistan-All Rights Reserved.