Varanus rosenbergi

Rosenberg's monitor refers to Varanus rosenbergi, an Australia species of varanid reptile found in southern regions of the continent. They are large and fast predators with rugged bodies and long tails, having a combined length up to 1.5 metres, that will consume any smaller animal that is pursued and captured or found while foraging.They occur in the Australian Capital Territory, New South Wales, South Australia, Victoria, where it may be rare or locally common, and more frequently observed in Western Australia, where it is sometime abundant. The species was first described by German herpetologist Robert Mertens in 1957, named and recognised as a subspecies of Varanus gouldii; a revision of Western Australian varanids published in 1980 elevated the taxon to species status. The holotype was collected at the Stirling Range in Southwest Australia.The specific name, rosenbergi, is in honor of German naturalist Hermann von Rosenberg. The infrageneric classification of the species allies it to other taxa of the subgenus Varanus (Varanus).A geographically remote population in the eastern states has distinct characteristics that may represent a cryptic species.A description published as Pantherosaurus kuringai in 1985 is regarded as a synonym for this species. The common names include the heath monitor or the southern heath monitor, along with those names that are a legacy of their description as the sand goanna Varanus gouldii. A reptilian species related to other monitors and goannas of the genus Varanus, fast-moving reptilian predators with long tails, stout limbs and clawed feet. They resemble the wide spread sand goanna Varanus gouldii, to which they were previously allied as a subspecies, but distinguished by darker coloration overall, especially the markings at the tail tip and underside and the distinct black banding at the back and neck.Dull and vaguely defined yellow stripes appear across most of the tail's length, sometimes interrupting the blackish colour of its end.The feet and limbs are also very dark, and spotted with a creamy or brownish colour. The dark tone at the head is marked with yellow dots above the mouth, and the yellowish cream background colour of the underside displays a blackish reticular pattern. The largest specimens are those found at Kangaroo Island, near the coast of South Australia, these are also darker than those on the mainland and possess a greater number of scale rows at the ventral side.Fat layers in V. rosenbergi constitute around 7.6% of body weight, allowing energy reserves to be stored throughout the body and tail.This monitor can reach a length of 1.5 metres. It is dark gray with yellow and white spotting and black bands on its body and all the way down the tail. The juvenile is tinged with orange. The comparative ratio of head and body lengths between the sexes, often evident in the varinid subgenus Varanus (Odatria), is not easily discernible in this species and their subgenus Varanus. Reproductive behaviour, including guarding of nest sites, extends over a four month period of a sexually active adult's year. Rosenberg's monitors mate over a 12-day period in January. In February and March, the female digs into an active termite mound, creating a spherical nest chamber beneath the hardened shell—found under the loose outer layer of the mound—by collapsing the internal structure of tunnels and chambers. The depth of the monitor's nest is around 700 millimetres, taking the parent several days to complete, the thickness of the termitarium's cemented shell is approximately 140 mm and the overlying friable surface 100 mm. The species lays a brood of up to 14 eggs, then redeposits the excavated material to cover her entry; the termites reform the shell of their mound over the course of several days.