Short-tailed monitor
| Short-tailed monitor | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Systematics | ||||||||||||
|
||||||||||||
| Scientific name | ||||||||||||
| Varanus brevicauda | ||||||||||||
| Boulenger , 1898 |
The short-tailed monitor lizard ( Varanus brevicauda ) is a species of monitor lizard ( Varanus ) native to Australia . It is the smallest known monitor lizard.
features
The short-tailed monitor reaches a total length of a maximum of 23 cm with a head-trunk length of 11.8 cm , usually they are fully grown with 7 to 11 cm KRL. The tail is quite short, the tail length is 87–116% of the KRL. The tail is round in cross section. Adult specimens weigh 8–17 g. The head, neck and limbs are also quite short and broad. It is striking that the short-tailed monitor lizard, despite its small size, has 31–35 presacral vertebrae, while other monitor lizard species usually only have 28–31.
The top of the body is reddish brown to brown and marked with dark brown spots. The underside of the body is white or pale brown. There is a slight temporal strip.
distribution and habitat
With the exception of the south, the short-tailed monitor inhabits all dry areas in Western Australia, the southern half of the Northern Territory as well as the northernmost South Australia and the westernmost Queensland. Black-tailed monitor lizards mainly inhabit Spinifex grasslands and sandy deserts.
Way of life
General
Short-tailed monitors are diurnal. They are particularly active in spring, but they hibernate in a burrow during autumn and winter. They are mostly ground dwellers, but can also climb in the Spinifex bushes and sometimes use their tails to grab. In the Spinifex they also seek protection from predators such as other monitor lizards.
The short-tailed monitor lizard is less active compared to other monitor lizards. According to studies, 14-25 m are covered during the day using the recovery method .
nutrition
The species reproduces insects, centipedes, spiders, small lizards and insect larvae as well as reptile eggs in the Spinifex landscapes. In a study, the stomach contents of 12 museum specimens consisted of 14.5% grasshoppers, 11% spiders, 7.6% lizards, 5.5% cockroaches, 3.5% reptile eggs, 3.5% insect larvae except caterpillars, 2.8% Insect eggs, 2.1% centipedes, 1.5% hymenoptera , 1.4% caterpillars, 1.4% scorpions, 0.7% pupae , 0.7% ants, 0.7% woodlice and 33.8% indeterminable Insects. Since the tails of nocturnal geckos were also found in the stomachs of diurnal short-tailed monitor lizards, one can assume that short-tailed monitor lizards penetrate the daytime hiding places of nocturnal lizards and attack the sleeping animals.
Reproduction
Males evidently reach sexual maturity at the earliest from 7 cm (age 10 months), females earliest from 8 cm KRL and 22 months of age (i.e. after 2 springs). Search the males in the mating season from September to October lambent for females. In November the females lay a clutch of usually 2-3 eggs. The young hatch in late January and February. They have a KRl of 4.2-4.5 cm at birth and weigh 2 g. The short-tailed monitor grows slowly.
Systematics
The first description of V. brevicauda was in 1898 by George Albert Boulenger . The specific epithet comes from Latin and means "short tail" (Latin brevis = short, cauda = tail). The syntypes come from the Sherlock River, Nicol Bay, Western Australia and are kept in the British Museum of Natural History. On the basis of the hemipenis morphology and general body structure, V. brevicauda can be assigned to the subgenus Odatria within Varanus . This summarizes all Australian dwarf monitor lizards. Molecular biological analyzes also came to this conclusion. According to Fitch et al. (2006) Varanus eremius is the sister group of V. brevicauda .
swell
- ER Pianka (2004): Varanus brevicauda . In: ER Pianka & DR King (Eds.): Varanoid Lizards of the World , pp. 312-317. Indiana University Press, Bloomington & Indianapolis. ISBN 0253343666
- ↑ after Pianka (2004) and there cite sources
- ^ A b D. R. King & ER Pianka (2007): Ecology of the Pygmy Monitor, Varanus brevicauda, in Western Australia. Mertensiella 16 ( Advances in Monitor Research III ), pp. 304-312
- ↑ Varanus brevicauda in The Reptile Database ; Retrieved January 18, 2011.
- ↑ AJ Fitch, AE Goodman & SC Donnellan (2006): A molecular phylogeny of the Australian monitor lizards (Squamata: Varanidae) inferred from mitochondrial DNA sequences . Australian Journal of Zoology 54, pp. 253-269