Colored monitor
| Colored monitor | ||||||||||||
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Colored Monitor ( Varanus varius ), Myall Lakes National Park, New South Wales |
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| Varanus varius | ||||||||||||
| ( Shaw in White , 1790) |
The colored monitor lizard ( Varanus varius ) is a species of monitor lizard ( Varanus ) native to Australia . It inhabits forested areas in eastern Australia and is both soil and arboreal. Like all monitor lizards, the colored monitor is a diurnal loner and, like most monitor species, a carnivore.
features
The colored monitor grows up to around 2 m long and weighs up to 14 kg. Females are smaller than males and reach a maximum length of 1.5 m. The largest recorded head-torso length for the spotted monitor is 76.5 cm, but the species usually remains smaller. The nostrils are on the side and closer to the tip of the snout than to the eye. About 200 rows of scales are laid out around the middle of the trunk. The long tail is quite slender. Its cross-section is round at the base, but becomes more triangular and laterally compressed towards the tip of the tail. There are two scale keels on the top of the tail.
The colored monitor, which is dark gray to cloudy blue on the upper side of the body, is marked with numerous cream-colored dots, which form dotted or partly continuous bands. There are striking black stripes on the chin. The tail has narrow, light bands at the base on a dark base color, which become wider towards the end of the tail. Large colored monitors are often dirty and therefore often look uniformly dark brown to gray from a distance. Young animals are much lighter and more clearly drawn than old animals.
There is a morph , which is drawn with very wide yellow and black bands, it is called "Bells Waran" ( bells monitor ). The Bells Monitor Lizard inhabits W- New South Wales and N- Victoria west of the Great Dividing Range as well as dry areas of New South Wales and Queensland . It appears sympatric with the normal color form.
distribution and habitat
The distribution area of the spotted monitor includes a stretch of coast from the Cape York Peninsula to the south of Victoria. In the southern distribution area, the colored monitor penetrates deeper inland: in New South Wales to Broken Hill , and even further south the species expands its distribution westward to South Australia . These monitor lizards predominantly live in wooded areas in the lowlands, but in places they reach 800 m above sea level. In the northern part of the range, spotted monitors inhabit dense, tropical forests in addition to lighter forests, while in the rest of the range, more open tree savannahs ( woodlands ) are preferred. In the drier inland, color monitor populations are concentrated on the forested banks of rivers, for example around the Murray River and Darling River . Further to the south, temperate forests offer the monitor lizard a habitat.
Way of life
activity
Like all monitor lizards, the colored monitor is a diurnal loner. On the one hand, colored monitors often stay on the ground, but they are also very good climbers and are often referred to as tree-dwelling. Colored monitor lizards can swim, but rarely use this ability. Colored monitor lizards spend the night in burrows or tree holes; the lizards leave their burrows around two hours after sunrise. The activity peaks in summer are in the morning and afternoon, because the high temperatures mean that the monitor lizards are less active over midday. During about 8.5% of the sunny time of the day, spotted monitors show movement activity. In most of its distribution area, the colored monitor is active all year round on sunny days, even if they do not come out of their burrows until later in winter and the activity is concentrated around noon. On many winter days, colored monitors do not leave their burrow at all, during this time of the year the animals feed on fat reserves.
The colored monitor is capable of effective thermoregulation through sun etc. and usually has body temperatures of 32.8–36.4 ° C outdoors. Lower temperatures limit the activity of the colored monitor in winter; Although they can reach 38 ° C body temperature even at 16 ° C air temperature through the sun, this drops too quickly when the colored monitor leaves the sun place to forage.
Action spaces and social behavior
Spaces of action and movements of colored monitor lizards were investigated by radio telemetry in a population near Lake Burrendong (New South Wales). If you only calculate the distances between the whereabouts communicated by the transmitter signals, then in the summer, colored monitors cover an average of 335 m per day. In autumn this value is 114 m, in winter 57 m and in spring 187 m. In the early summer, during the mating season, males cover long distances of often more than 1 km per day in search of females. The activity areas in summer are 107.5–387 hectares and decrease to 5% of their normal size in winter. A monitor's range of action apparently remains fairly constant over its life.
Even if spotted monitor lizards are primarily loners, their areas of activity overlap strongly. Occasionally several specimens are found on the same tree or feed on the same carcass. On the other hand, typical Waran commentary fights have also been observed with the colored monitor. Other monitor lizards usually fight these fights for a resource such as carrion or a reproductive partner; In the case of the colored monitor, however, there are only sparse observations about this behavior, the reason for the disputes is therefore only insufficiently known for this species.
nutrition
The spotted monitor is a carnivore whose prey includes mammals, birds, reptiles, reptile eggs, and insects. Nor does he disdain carrion. Obviously arboreal marsupial (make in largely untouched forests possums ) as the Ordinary pseudocheiridae ( Pseudocheirus peregrinus ) the bulk of the food, and the rest of the food in particular consists of carrion of bottom-dwelling marsupials like wallabies and insects of all stages of development. In contrast, in habitats that have been changed by humans, many of the usual prey animals are missing, and the spotted monitor includes many introduced animal species ( neozoa ) such as rabbits in its diet. In particular, the carrion of these introduced mammals as well as animals perished in traffic ( roadkills ) then dominate the diet. They also rummage through rubbish for food in cities and at campsites, which can lead to health problems for the lizard.
The Buntwaran is an active hunter and examined large areas lambent for prey and carrion from. Tree-dwelling mammals are easy prey for the well-climbing spotted monitor, as they are nocturnal and the lizard can easily attack them. Since, as with all monitor lizards, the skull is kinetic , the colored monitor can devour large prey whole - sometimes up to 42% of its own body weight.
literature
- RL Earley, O. Attum, P. Eason: Varanid combat: perspectives from game theory. In: Amphibia-Reptilia. 23, 2002, pp. 469-485.
- A. Gillet, R. Jackson: Human Food Scrap Ingestion in Two Wild Lace Monitors Varanus varius. In: Biawak. 4 (3), 2010, 2010, pp. 99-102.
- F. Guarino: Spatial ecology of a large carnivorous lizard, Varanus varius (Squamata: Varanidae). In: Journal of the Zoological Society. 258, 2002, pp. 449-457.
- F. Guarino: Habitat Selection by a Large Carnivorous Lizard, Varanus varius. In: Mertensiella. 16 ( Advances in Monitor Research III ), 2007, pp. 247-254.
- R. Hoser: Lace monitors (Varanus varius) in the wild and in captivity in Australia, with reference to a collection of seven adults held in captivity for eight years. In: Monitor - Journal of the Victorian Herpetological Society. 10 (1), 1998, pp. 22-30, 35-36.
- T. Jessop, J. Urlus, T. Lockwood, G. Gillespie: Preying Possum: Assessment of the Diet of Lace Monitors (Varanus varius) from Coastal Forests in Southeastern Victoria. In: Biawak. 4 (2), 2010, pp. 59-63.
- M. Rogner: Echsen 2. Ulmer Verlag, 1994, ISBN 3-8001-7253-4 .
- B. Weavers: Varanus varius. In: ER Pianka, DR King (Ed.): Varanoid Lizards of the World. Indiana University Press, 2004, ISBN 0-253-34366-6 , pp. 488-502.
- S. Wilson, G. Swan: A complete guide to reptiles of Australia. 3. Edition. New Holland Publishers, Sydney / Auckland / London / Cape Town 2010, ISBN 978-1-877069-76-5 .
Individual evidence
- ↑ Hoser (1998): 30; Weavers (2004): 492; Wilson & Swan (2004): 402.
- ↑ Weavers (2004): 492; Wilson & Swan (2010): 402.
- ↑ Weavers (2004): 493; Wilson & Swan (2010): 402.
- ↑ Hoser (1998): 30; Rogner (1994): 36; Weavers (2004): 493; Wilson & Swan (2010): 402.
- ↑ Guarino (2002): 451-452, 454; Weavers (2004): 494-496.
- ^ Weavers (2004): 495-496.
- ↑ Guarino (2002): 449, 452-454; Weavers (2004): 500.
- ↑ Earley et al. (2002): Guarino (2004): 454.
- ↑ Jessop et al. (2010): 59-60; Gillet & Jackson (2010); Weavers (2004): 497.
- ↑ Jessop et al. (2010): 61-62; Weavers (2004): 496-498.
