Zoo Biology 29 : 615–625 (2010) HUSBANDRY REPORT Successful Captive Breeding of Mitchell’s Water Monitor, Varanus mitchelli (Mertens 1958), at Perth Zoo Glen Gaikhorst,1 James McLaughlin,2 Brian Larkin,3 and Meagan McPharlin3 1 Native Species Breeding Program, Perth Zoo, South Perth, Western Australia, Australia 2 CSIRO Marine and Atmospheric Research, Centre for Environmental and Life Sciences (CELS), Floreat, Western Australia, Australia 3 Reptiles, Perth Zoo, South Perth, Western Australia, Australia Mitchell’s water monitors (Varanus mitchelli) have been maintained on display at Perth Zoo since 1997. They are generally a timid species but have been maintained and bred in a mixed species water feature exhibit. In this article we describe their captive management and behavior with an insight into their reproductive biology. Between 2002 and 2005, 11 clutches were laid ranging from 13 to 27 (X ¼ 20) eggs from one female. Egg size ranged between 3.00 and 6.08 g (X ¼ 4:77 g) in weight, 22.8 and 31.9 mm (X ¼ 28:3 mm) in length, and 11.1 and 19.3 mm (X ¼ 17:1 mm) in width. Oviposition included double and triple clutches ranging between 41 and 60 days apart (X ¼ 48 days), events n 5 6. Four clutches were incubated at three different temperatures and hatchlings emerged after 157–289 days. The weight of the hatchlings ranged between 2.60 and 4.52 g (X ¼ 4:34 g). Total length ranged between 140.1 and 178.0 mm (X ¼ 165:9 mm) and snout–vent length ranged from 53.8 to 70.0 (X ¼ 64:4 mm). Juvenile growth and development information is presented from hatching through to approximately 3 years of age. Zoo Biol 29:615–625, 2010. r 2009 Wiley-Liss, Inc. Keywords: behavior; captive management; growth and development; reproductive biology Correspondence to: Glen Gaikhorst, Native Species Breeding Program, Perth Zoo, Labouchere Road, South Perth, WA 6951, Australia. E-mail: glen.gaikhorst@perthzoo.wa.gov.au Received 13 August 2008; Accepted 22 December 2008 DOI 10.1002/zoo.20244 Published online 18 May 2009 in Wiley Online Library (wileyonlinelibrary.com). r 2009 Wiley-Liss, Inc. 616 Gaikhorst et al. INTRODUCTION Mitchell’s water monitor (Varanus mitchelli) is a common species whose distribution extends from the Kimberley of Western Australia through the Northern Territory into the extreme northwest of Queensland [Cogger, 2000; Ehmann, 1992; Vincent and Wilson, 1999; Schultz and Doody, 2004]. It inhabits areas with permanent or semi-permanent water bodies. The water is either fresh or brackish with thick riparian vegetation consisting of Pandanus, Melaleuca, freshwater mangroves, and bamboo or rocky habitats on the edge of water ways [Schultz and Doody, 2004]. Generally, the color is quite variable from dark brown to bluish black, blackish gray to olive gray above, covered in a scattering of yellowish or cream flecks, spots, or ocelli, whereas the sides of the neck and throat are bright yellow to orange with black flecks. The underbelly is pale in color [Cogger, 2000; Vincent and Wilson, 1999; Schultz and Doody, 2004; Steel, 1997]. The tail is 1.7–2.1 times longer than the head and body length [Storr, 1980] and is laterally compressed and double keeled [Steel, 1997]. The nostrils are upward and outward facing to assist with living in a semi-aquatic environment. Mitchell’s water monitor is medium-sized with a total length (TL) of 60–96 cm [Vincent and Wilson, 1999]. It is a member of the Odatria subgenus, which comprises 17 species including sister species V. semiremex and V. timorensis [Schultz and Doody, 2004]. Its wild diet consists of arthropods, fish, frogs, small reptiles and their eggs, and small mammals and birds. The diet changes seasonally with the advent of the wet-season flooding [Shine, 1986; Steel, 1997; Schultz and Doody, 2004]. Breeding usually occurs in the dry season with females depositing eggs between April and June [Shine, 1986; James et al., 1992; Vincent and Wilson, 1999]. Clutch sizes in the wild have been recorded at 3–11 [Ehmann, 1992], 7–12 [Shine, 1986], and 12 [Steel, 1997; Schultz and Doody, 2004; James et al., 1992; Vincent and Wilson, 1999], and in captivity there is a report of up to 20 eggs [Schultz and Doody, 2004]. Very little is known about the biology of this species as Mitchell’s water monitor has been kept in captivity only rarely, with one record of successful captive breeding being published [Schultz and Doody, 2004]. Similar species have been maintained and bred in captivity including V. semiremex [Jackson, 2005], V. mertensi [Eidenmüller and Wicker, 1995; Vincent and Wilson, 1999], and V. timorensis [Debitter, 1981; Eidenmüller, 1986; Bennett, 1998]. Reproduction of V. mitchelli at Perth Zoo began in 2001 with one small clutch of eggs laid on the enclosure’s surface. All the eggs were dehydrated except one, which was artificially incubated and hatched. This breeding event and data were reported by Schultz and Doody [2004]. This article reports on the subsequent successful breeding of V. mitchelli from 2002 to 2005 at Perth Zoo (Figs. 1 and 2). METHODS Study Animals The male was a wild-caught adult of unknown age, collected on 26/04/1997 from Kununurra, Western Australia. The female was originally a wild-collected specimen from northwest Western Australia; however, the collection date and the location are unknown. She was donated under permit to Perth Zoo by the University of Western Australia on 03/02/2000. Zoo Biology Captive Breeding of Mitchell’s Water Monitor 617 32 9 8 28 7 26 24 6 22 5 Change in mass (g) Change in size (mm) 30 20 Egg length Egg diameter Egg mass 18 16 4 3 27 Oct 02 31 May 02 Date Fig. 1. Mean (7s.e.m.) changes in egg length, diameter, and mass between laying and 8 days prior to first eggs hatching from clutch 2 during incubation. 450 SVL 60 400 TL WT 50 300 40 250 30 200 150 Weight (g) Length (mm) 350 20 100 10 50 0 0 20 40 60 80 100 120 140 0 160 Time (weeks) Fig. 2. Mean of 11 individuals’ (7s.e.m.) growth in weight (WT), snout–vent length (SVL), and total length (TL) over time. Housing The V. mitchelli were housed together (see Fig. 3) in a display enclosure measuring 370 cm  300 cm  120 cm. The enclosure is mock rocked along the back with the viewing area and sides made of glass panels with a swinging door for keeper access. The substrate was a mock rock floor with a small area of pea gravel and sand, tapering down into a pond at the bottom. The pond also housed six pink-eared turtles (Emydura victoriae), a primitive archerfish (Toxotes lorentzi), and blue catfish (Arius graeffei). The enclosure habitat provided a permanent source of water for the monitors and was continuously pumped through a sand filter. The pond was heated via four 300 W aquarium heaters and maintained a water temperature range of 24–261C in summer and 22–241C in winter. Zoo Biology 618 Gaikhorst et al. Fig. 3. Pair of Mitchell’s water monitors (Varanus mitchelli) basking in the public exhibit at Perth Zoo. Male left, female right. Fig. 4. (a) Front of nest box located in V. mitchelli exhibit in which clutches of eggs were deposited. (b) Nest box in V. mitchelli exhibit with lid removed. Branches were provided for climbing, allowing the lizard’s vantage spots for basking under the ultraviolet (UV)/heat lamps, bark hides, and a mock rock heat pad (set at 30–351C). A concrete nest box was provided, which was triangular in shape (400 mm  400 mm  400 mm triangle 300 mm deep) with an entry hole close to the top lip (see Fig. 4a, b). The box was mock rocked to visually blend with the furnishings of the exhibit and was filled with a layer of moist sand and peat mix (50/50) to a depth of approximately 250 mm to aid in oviposition. Artificial lighting was provided over the exhibit with halogen bulbs (Sylvania Aqua-arc HSI-TD 150 W, MA) and there were several basking spots heated by five heat and UV lamps (two infra-red 375 W globes (MA) and three Osram ultra-vitalux (MA) or Radium ultra-vitalux 300 W globes, MA). These provided adequate heat and UV rays for the animals. Basking sites were maintained around 351C. Seasonal photoperiod was Zoo Biology Captive Breeding of Mitchell’s Water Monitor 619 maintained through the lighting system, which was on a timer system providing variation in day length with a longer exposure in summer than winter. The animals were maintained together all year round and only disturbed if weighing or physical examinations were required. Juveniles were housed separately in opaque/clear plastic tubs within a steel rack system. The dimensions of the tubs were 300 mm  600 mm  280 mm. Three racks were used in total holding 12 tubs in each. Each tub had a 100 W spotlight that supplied a hot basking area on pieces of Hardiflexs sheet (James Hardie, Welshpool, WA, Australia) to a heat of 35–401C (approximately 30 cm away). Each tub also had exposure to a 40 W Repti-sun fluorescent bulb (CA) and a 40 W Repti-glo fluorescent bulb (CA) at 30 cm to provide UV to the young monitors. Within the tubs, white sand was used as substrate to a depth of 30 mm. Hardy fencing material was cut into 200 or 150 mm squares and siliconed together with glass marbles in between. These were used to supply hide spots between the hardy fence layers as well as provide a basking site. Pieces of bark were also used around the tub as refuges. A water bowl was placed at the far end of the heated area. Because of the intense heat created by the lighting, a large reverse cycle airconditioning unit was used to maintain the ambient air temperature at around 251C. All eggs were incubated in a Repti-life (Reptile Incubator, Lyons Electronic Company, Chula Vista, CA) reptile egg incubator. Husbandry All enclosures were serviced daily. This included cleaning and changing of water bowls, removing fecal matter, and checking animal well-being. In the display enclosure, cleaning included removing old food items, picking up slough, and removing/scrubbing urate stains off the mock rock. A large bacterial filtration system (approximately 120 l), for the display pond and waterfall, aided in maintaining water quality. This was serviced daily and reverse cycle cleaned once a week. The entire filter was stripped and cleaned approximately every 4 months. The juvenile monitors required a more humid environment (60% or greater); therefore, the immediate area around the water bowl was moistened daily and enclosures misted with hand units as required. Lighting and heating equipment was changed as required. Diet Mitchell’s water monitor is an active forager and feeds on a variety of animals in the wild [Vincent and Wilson, 1999]. At Perth Zoo, the monitors were fed three times a week. Their primary diet consisted of large crickets, wood cockroaches, small mice (or chopped mice), fish (whitebait, pilchards, or bluebait), and prawns, which were dusted with calcium carbonate powder (Wednesdays and Fridays) and a 1:1 Herptevite (Rep-Cal Research Labs, Los Gatos, CA)/calcium carbonate mix on Mondays. Each feed consisted of approximately 30–50 g of food per animal, which was adjusted according to the condition of the animals. For example, during the breeding season or when the female was seen to be gravid, small extra feeds were given as required to assist with egg development. Juveniles were fed daily initially on a diet of small invertebrates consisting of crickets and small wood cockroaches dusted with calcium carbonate powder (Wednesdays and Fridays) and a 1:1 Herptevite/calcium carbonate mix on Mondays. Zoo Biology 620 Gaikhorst et al. Once feeding reliably, they were introduced to chopped fish, diced mice, or dead pinkie mice. Sizes of the food items offered increased with age. Adults and juveniles could be fed via tongs or by scatter feeding. Water was supplied to all animals via large water bowls and cleaned on a daily basis. The water bowls were large enough to allow the animals to submerge. Measurements and Observations Growth measurement data were recorded from 11 juvenile monitors from clutch 5 over a 3-year period. Weight measurements were taken on precision electronic scales. For more accurate data, scales to the second decimal gram were used particularly while the animals were small. To prevent the animals from escaping, small zip-lock bags (Glad zip-lock bags (CA), sandwich size, Australia) were used to temporarily hold the animals while their weight was recorded. Two length measurements were recorded—snout–vent length (SVL) and TL. Snout–vent measurement is from the tip of the snout to the cloaca and TL was measured from the tip of the snout to the tip of the tail. Length measurements were taken with a clear ruler, to the nearest millimeter. All measurements were recorded every 2 weeks for 12 months and then opportunistically for a further 2 years. All measurements were taken from the actual time of birth so that data could be plotted on the same scale. Changes in egg size were recorded from clutch 2 (n 5 20) at the time of oviposition and 8 days prior to hatching. Eggs were measured by weight, length, and width. Weight was recorded on precision electronic scales and length and width measurements were taken using calipers and recorded to 0.1 mm. Observations on specific events (such as behavior or reproductive activities) were made opportunistically during feeding events or routine monitoring of the animals. Analysis Size parameters were expressed as mean7s.e.m. and comparisons made using paired t-test. Differences were considered significant if Po0.05. RESULTS Behavior and Breeding Information Adult We found Mitchell’s water monitor to be a nervous species that did become more relaxed in time and with keeper interaction. The pair could be maintained together for long term and only required separation to stop breeding or after an aggressive confrontation where short-term medical intervention was required. The animals were often observed lying on each other under basking lights but the female displayed more basking behavior than the male. The male preferred to lie under a piece of wood on the heat pad. During courtship, the male became very interested in the female, displaying rapid head movements and nuzzling her sides and head. Head movements consisted of bobbing and sideways jerking. The male was often observed lying parallel to the female with one forelimb on her back. No open mouth aggression was recorded at this time. Copulation occurred on and off the ground and composed of the pair lying parallel to each other with his cloaca pushed under/alongside hers and tails coiled. It Zoo Biology Captive Breeding of Mitchell’s Water Monitor 621 was difficult to determine for how long the pair mated each time but we estimate it to be 15–45 min. The period from copulation to oviposition ranged between 18 and 36 days (X ¼ 28 days, n 5 7). The female when gravid became distended in the abdomen and lost physical condition of her tail exposing the vertebrae above the cloaca. Feeding would increase at this time. She received extra feeding to assist in egg development and in an attempt to keep her in good physical condition. She would stop feeding 1–8 days prior to oviposition. During this time she would spend long periods under the UV/heat lighting basking or pacing the enclosure, digging test holes 1–2 days prior to oviposition. When oviposition was imminent, the female became very restless often pacing and exploring the enclosure. This was often observed in the afternoon period. Once satisfied with the nest site (often in the nest box), she entered, dug a burrow, and resided in it for several hours laying the clutch before backfilling the hole and returning to her enclosure to bask. Prior to oviposition, the female’s body weight ranged from 318 to 393 g and postoviposition dropped to 206–260 g. The female began feeding again 24–48 hr after oviposition was completed. Clutches laid in the nest box were used in the incubation and hatchling data. Aggression toward the male was recorded on one occasion 2 days after oviposition with blood drawn from the male after he presented to her for an attempted breeding event. He was bitten on the snout and neck. This also occurred during feeding sessions in which both individuals inflicted head injuries on one another. No aggression was seen toward the E. victoriae or the fish species in the pond. Juveniles Juveniles were very timid, often only observed retreating to hides when a keeper was present, but their timid nature decreased with age. Enclosures housing multiple individuals were tried initially with juveniles, but dominance interactions and competition occurred between individuals, and therefore subsequently only single individuals were kept in enclosures. Careful inspection of the enclosure was required to prevent escapes as juveniles were capable of squeezing out of the smallest gaps. Clutches Eleven clutches were recorded between 16/4/2002 and 27/9/2005 with clutches laid in almost all months, though they varied greatly between different years. The breeding period was between April and May in 2002, between June and July in 2002, and between January and March in 2004. The year 2005 had two periods of November 2004 and January 2005, then again from June to September. Double clutching occurred five times and a triple clutch occurred once. Multiple clutch intervals ranged between 41 and 60 days (X ¼ 48 days), events n 5 6. Clutch size varied between 13 and 27 eggs with an average number of 20 eggs produced (excluding clutch 8 from this analysis). Egg size ranged between 3.00 and 6.08 g (X ¼ 4:77 g) in weight, 22.8 and 31.9 mm (X ¼ 28:3 mm) in length, and 11.1 and 19.3 mm (X ¼ 17:1 mm) in width as seen in Table 1. Artificial Incubation Four clutches (43 eggs in total) were artificially incubated. The eggs were prepared for incubation in 1:1 water to vermiculite by weight mixture. A depth of approximately 40 mm of vermiculite was put in clear rectangular plastic containers Zoo Biology 622 Gaikhorst et al. TABLE 1. The mass, length, and width (mean and range) of eggs from 11 clutches laid by one female Clutch number Date of oviposition Clutch size Mass (g) Mean (range) Length (mm) Mean (range) Width (mm) Mean (range) 1 2 3 4 5 6 7 8 9 10 11 16/04/2002 31/05/2002 07/06/2003 18/07/2003 18/01/2004 02/03/2004 06/11/2004 10/01/2005 19/06/2005 07/08/2005 27/09/2005 16 20 23 20 23 19 22 6a 13 14 27 5.55 (4.72–6.08) 4.77 (4.38–5.10) 4.19 (3.81–4.55) 4.55 (4.35–4.88) 4.85 (3.85–5.51) 5.27 (4.71–5.79) 4.17 (3.44–4.83) 5.56 (5.10–5.80) 4.00 (3.00–5.00) Not recorded Not recorded 30.3 (28.5–31.4) 28.6 (27.0–31.0) 27.9 (26.1–30.7) 27.7 (26.8–30.6) 28.7 (26.0–30.5) 29.3 (23.0–31.9) 28.0 (25.1–29.7) 28.0 (23.0–31.1) 26.5 (22.8–30.7) Not recorded Not recorded 18.5 (17.6–19.3) 17.3 (17.0–18.0) 16.4 (16.1–17.2) 17.3 (16.6–17.9) 17.6 (16.8–18.2) 17.6 (15.5–18.5) 15.7 (11.1–17.0) 17.9 (17.3–18.3) 15.9 (14.1–17.9) Not recorded Not recorded a Suspected more eggs laid in the water and destroyed by turtles. Fig. 5. (a) Hatchling Mitchell’s water monitor (V. mitchelli) with head protruded from a slit in egg. (b) Juvenile Mitchell’s water monitor (V. mitchelli) 2 hr after hatching. with 8–10 eggs half buried in each container. Lids were placed over the eggs and they were aired daily for appropriate gas exchange. Two clutches were maintained at 30–311C and hatched after 157–185 days. The third clutch was maintained at 28–291C and hatched after 226–229 days and the fourth clutch was incubated at 26–271C and hatched after 255–287 days. Clutch hatching success was not measured because only the numbers required for Perth Zoo’s animal collection were incubated, whereas the remaining eggs were discarded. Eggs from clutch 2 were measured and numbered upon starting incubation and approximately 8 days prior to hatching we found that the eggs’ width and weight had increased (Po0.005), but the length was maintained (Fig. 1). Hatchlings Hatching was recorded in the months of September to January with peak hatchings occurring in September and November. Pipping was observed at all hours of the day but was primarily seen first thing in the morning during the first inspection Zoo Biology Captive Breeding of Mitchell’s Water Monitor 623 (see Fig. 5a). This meant that pipping probably commenced sometime during the night. Once pipping had started, juveniles emerged from the egg between 24 and 48 hr later (see Fig. 5b). Juvenile’s measurements (weight, TL, and SVL) were recorded and can be seen in Table 2. Weight of the hatchlings ranged between 2.60 and 4.52 g, averaging 4.34 g (n 5 49). TL ranged between 140.1 and 178.0 mm, averaging 165.9 mm (n 5 33), and SVL ranged between 53.8 and 70.0, averaging 64.4 mm (n 5 33). The weight of the hatchling reduced when incubation was extended under lower temperatures. Eggs incubated at 30–311C had average juvenile hatchling weights of 3.69 g, whereas those incubated at 26–291C had average hatchling weights of 3.47 g (Po0.04). Hatchlings sloughed their skin for the first time 4–10 days posthatching and also began feeding within this time. DISCUSSION During the captive maintenance of Mitchell’s water monitors at Perth Zoo, they were easily bred and kept in captivity. Although timid initially, adults settled down and became good display animals within a multispecies exhibit. Minimal health issues arose and injuries that did occur were often minor and required little attention. Aggression observed was not considered to be any different from that seen in normal monitor interactions. Observations of feeding and oviposition site selection were similar to those described by Irwin [1996], although prior to the female being provided with a nest box, eggs were deposited randomly around the enclosure suggesting that no sites were preferred. Captive reproduction was easily achieved in this species; indeed, the pair had to be separated in order to stop producing clutches. Breeding behavior such as head bobbing, nuzzling, and reproductive engagement was similar to that found in other varanid species [Horn and Visser, 1997]. Double clutching was achieved on five occasions. This is well documented in other species [Horn and Visser, 1989; Irwin, 1996]. A triple clutch was produced once. One clutch contained 27 eggs. This is more than the maximum number previously reported for other members of the Odatria group—21 eggs in V. semiremex [Jackson, 2005] and 18 eggs in V. accanthurus [Horn and Visser, 1997]. Information from field studies suggests that clutch size ranges from 7 to 12 [Schultz and Doody, 2004], which is considerably smaller than those found in this study. Temperature is important for hatching success. High or fluctuating temperatures have been previously shown to result in poor hatching in V. primordius and V. baritji [Husband, 2001]. In the absence of any previous reports of hatching in captivity for V. mitchelli, eggs in this study were kept at three different temperatures of 26–27, 28–29, and 30–311C. Fortunately, healthy hatchlings were achieved at all temperatures used, although longer incubation times occurred at lower temperatures, which is consistent with observations on other varanid species [Horn and Visser, 1997] and reptiles in general [Köhler, 2005]. Longer incubation times resulted in smaller juveniles in weight with no ill effects. Lower weight is a result of additional stored resources in the egg being metabolized by the neonate prior to hatching [Köhler, 2005]. The increase in egg weight prior to hatching in this study was the result of an increase in width rather than length of the egg, increasing the overall volume of the eggs. This is considered to be normal egg growth development [Köhler, 2005]. The rate of growth of hatchlings varies considerably between species. This study showed Zoo Biology 624 Gaikhorst et al. Zoo Biology TABLE 2. The incubation information and mass, snout–vent length, and total length (mean and range) of hatchlings from four clutches Clutch number Oviposition 1 16/04/2002 2 31/05/2002 3 07/06/2003 5a 18/01/2004 a Incubation time (days) and Dates of hatching temp. (1C) 27/09/2002–21/ 10/2002 03/11/2002–27/ 11/2002 19/1/2004–22/1/ 2004 30/9/2004–1/11/ 2004 161–185 days 30–311C 157–181 days 30–311C 226–229 days 28–291C 255–287 days 26–271C Number hatched Snout–vent length (mm) Mean (range) Total length (mm) Mean (range) Mass (g) Mean (range) at N 5 16 Not recorded Not recorded 3.74 (3.17–3.96) at N 5 18 64.7 (55.0–70.0) 166.3 (150.0–178.0) 3.65 (3.10–4.52) at N54 64.0 (62.0–66.0) 167.3 (161.0–170.0) 3.42 (3.28–3.55) at N 5 11 64.5 (53.8–70.0) 164.2 (140.1–173.5) 3.53 (2.60–3.85) Growth measurement data in juvenile monitors were recorded from clutch 5. Captive Breeding of Mitchell’s Water Monitor 625 an increase in daily weight for V. mitchelli of approximately 0.3 g per day (see Fig. 2). This compares with weight increases of approximately 0.6 g per day for V. varius [Boylan, 1995] and 6 g per day for V. komodoensis [Lemm et al., 2004]. Boylan [1995] fed a range of food types in a similar method to this study suggesting a similarity in the growth pattern. The difference in weight would be owing to the relative size of the different species. Lemm et al. [2004] conducted their research on growth rates of Komodo dragons using turkey mince as the base diet. This could have influenced the growth rate of their study animals and explain the high rate of growth. The sizes of the animals may also be a factor. V. mitchelli is very small compared with V. komodoensis; therefore, the rate of growth in weight may be dramatically reduced. In summary, this study has shown that V. mitchelli can be bred successfully in captivity and provides data on breeding behavior, oviposition, egg incubation and hatching, and the growth and development of hatchlings. ACKNOWLEDGMENTS We thank Ric Dunlop, Perth Zoo’s Supervisor of Reptiles, Helen Robertson and John Lemon Curators (at the time) of Australian fauna, as well as Perth Zoo’s Research and Ethics Committee for their assistance with the project. We also thank Phil Matson for the supervision, assistance, and comments on the manuscript. REFERENCES Bennett D. 1998. Monitor lizards: natural history, biology and husbandry. Frankfurt am Main: Chimaira. Boylan T. 1995. Field observations, captive breeding and growth rates of the lace monitor, Varanus varius. Herpetofauna 25:10–14. Cogger HG. 2000. Reptiles and amphibians of Australia, 6th ed. Sydney: Reed Books. 775 p. Debitter PM. 1981. Varanus timorensis timorensis. Lacerta 40:48–49. Ehmann H. 1992. Encyclopedia of Australian animals. Reptiles. Sydney: Collins Angus & Robertson. Eidenmüller B. 1986. Observations on the care and recent breeding of Varanus (Odatria) timorensis timorensis Gray 1831. Salamandra 22:181–197. 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