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The Heath Monitor (Varanus rosenbergi ) is a lizard that grows up to a metre in length, preying on smaller reptiles, juvenile birds and eggs; it is frequently observed on warmer days basking in the sunlight or scavenging on roadkill. The Black Tiger Snake (Notechis ater) is also found on Kangaroo Island. Another reptile particularly associated with this locale is the Kangaroo Island Copperhead (Austrelaps labialis).
The most notable mammal present is the endemic Kangaroo Island Kangaroo (Macropus fuliginosus fuliginosus), the icon for whom the island was named upon European discovery in 1802. A smaller marsupial present on the island is the Tammar Wallaby (Macropus eugenii). An endemic dasyurid is the Critically Endangered Kangaroo Island Dunnart (Sminthopsis aitkeni), which is found only in the west of the island in Eucalyptus remota/E. cosmophylla open low mallee, E. baxteri low woodland or E. baxteri/E. remota low open woodland. The Common Brush-tailed Possum (Trichosurus vulpecula) is a widespread folivore native to Australia.
Monotremes are also represented on the island. There is also an introduced population of the Duck-billed Platypus (Ornithorhynchus anatinus) in the western part of the island in Flinders Chase National Park. The Short-beaked Echidna (Tachyglossus aculeatus) is also found moderately widespread on Kangaroo Island.
Chiroptera species on Kangaroo Island include the Yellow-bellied Pouched Bat (Saccolaimus flaviventris), which species is rather widespread in Australia and also occurs in Papua New Guinea. Australia's largest molossid, the White-striped Free-tail Bat (Tadarida australis) is found on Kangaroo Island. Another bat found on the island is the Southern Forest Bat (Eptesicus regulus), a species endemic to southern Australia (including Tasmania).
Several anuran species are found on Kangaroo island: Brown Tree Frog (Litoria ewingii), Spotted Marsh Frog (Limnodynastes tasmaniensis), Painted Spadefoot Frog (Neobatrachus pictus), and Brown Toadlet (Pseudophryne bibroni), in addition to the Brown Froglet (Crinia signifera).
The Glossy Black Cockatoo (Calyptorhynchus lathami) is found on the island, especially in the western part, where its preferred food, fruit of the Drooping Sheoak, is abundant. The Kangaroo Island Emu (Dromaius baudinianus) became extinct during the 1820s from over-hunting and habitat destruction due to burning.
Marine mammals that are observed on the island include the Australian Sea Lion (Neophoca cinerea) and New Zealand Fur Seal (Arctocephalus forsteri), each species of which is native to Kangaroo Island, and abundant at Admiral's Arch as well as at Seal Bay.
Kangaroo Island is not so adversely impacted by alien species grazers as parts of the mainland. No rabbit species are present on the island, and introduced (but escaped) Domestic Goats (Capra hircus) and pigs (Sus scrofa) have generated only minor issues. However, a Koala (Phascolarctos cinereus) population introduced to the island in the 1920s has caused significant damage to certain woodland communities, especially to Manna Gum trees.
Der Rosenberg-Waran oder auch Rosenberg’scher Waran (Varanus rosenbergi) ist eine in Australien endemische Art der Schuppenkriechtiere aus der Gattung der Warane (Varanus). Die Erstbeschreibung erfolgte 1957 durch den deutschen Herpetologen Robert Mertens. Das Art-Epitheton ehrt den deutschen Naturforscher, Geograph und Zoologen Hermann von Rosenberg. Der Rosenberg-Waran gehört zu den am besten erforschten australischen Waranarten.
Der Rosenberg-Waran kann bis zu 150 cm lang werden, wobei die auf dem australischen Festland lebenden Exemplare generell kleiner sind als die Tiere auf den vorgelagerten Inseln. Die Länge des Schwanzes beläuft sich auf das 1,3- bis 1,8fache der Kopf-Rumpf-Länge. Die Rückenseite der Tiere ist dunkel. Die Bauchseite ist vom Kinn bis zum Hinterleib hell und mit einem dunklen Netz- oder Streifenmuster überzogen. Der Kopf ist schwarz mit hellen Flecken und weist einen schwarzen Schläfenstreifen mit hellen Rändern auf. Die Kopfschuppen sind glatt und klein. Das Nasenloch befindet sich seitlich und liegt der Schnauzenspitze näher als dem Auge. Hals und Rumpf sind durch etwa 15 schmale, engständige, schwarze Querstreifen auf bräunlichem Grund gekennzeichnet. Der Schwanz zeigt bräunliche Querstreifen auf schwarzem Grund. Die Schwanzspitze ist entweder ebenfalls gestreift oder einfarbig-schwarz. Die Schwanzwurzel ist zylindrisch, der hintere Teil des Schwanzes ist relativ stark seitlich abgeflacht. Der Rumpf weist 160 bis 210 Schuppenreihen auf.
Der Rosenberg-Waran kommt ausschließlich in Australien vor. Sein Verbreitungsgebiet erstreckt sich dort in einem relativ schmalen Streifen entlang der Küste, vom Südwesten Western Australias bis in den Südosten South Australias. Isolierte Populationen existieren in Victoria und New South Wales. Auch einige Inseln vor der Küste des südlichen Australiens, z. B. Kangaroo und Reevesby Island, sind vom Rosenberg-Waran bewohnt. Vermutlich wurde er auf einigen Inseln gezielt ausgesetzt, um dort die Schlangen zu dezimieren.
Außer auf Kangaroo Island ist der Rosenberg-Waran generell selten.
Seinen englischen Trivialnamen „heath goanna“ (Buschwaran) verdankt der Rosenberg-Waran dem Umstand, dass er im Buschland nahe der Küste lebt. Daneben kommt er aber auch in baumbestandenem und bewaldetem Gelände vor.[1]
Die Tiere sind tagaktiv und ziehen sich für gewöhnlich ein bis zwei Stunden vor Sonnenuntergang in einen Unterschlupf zurück. Dabei kann es sich um eine Erdhöhle, einen hohlen Baumstumpf oder um eine Felsspalte handeln. Ein Individuum verfügt innerhalb seines Reviers meist über mehrere solcher Unterschlupfe. Da sich die Reviere verschiedener Tiere überschneiden, kann es vorkommen, dass ein und derselbe Unterschlupf in verschiedenen Nächten von verschiedenen Tieren genutzt wird. Dass mehr als ein Tier in einem Unterschlupf übernachtet, ist eher ungewöhnlich. Die Erdhöhlen graben die Tiere oft selbst, nutzen aber auch Baue, die von Individuen anderer Arten gegraben worden sind.
Die Geschlechtsreife erreicht der Rosenberg-Waran mit zwei bis drei Jahren. Paarungszeit ist im Hochsommer, von Ende Dezember bis Anfang Februar. Die Paarung erfolgt im Revier des Weibchens und kann sich in seltenen Fällen bis zu drei Wochen hinziehen, bei mehreren Kopulationen pro Tag, wobei das Männchen erst nach einigen Tagen engem Kontakt zum Weibchen beginnt zu kopulieren. Die Eiablage erfolgt dann zwischen Ende Januar und Anfang März.[2]
In der freien Natur bevorzugen die Tiere zur Eiablage bevölkerte Termitenbauten der Art Nasutitermes exitiosus. Das Weibchen gräbt dabei ein Loch in die Wand des Termitenbaus, errichtet eine Art Kammer und legt dort ihre Eier hinein. Den Verschluss des Loches übernehmen dann die Termiten. Die Eier sind so außerordentlich gut vor Feinden geschützt. Zudem ist die Temperatur und die Luftfeuchtigkeit innerhalb eines Termitenbaus immer konstant (im Winter nicht weniger als 20 °C, bei Außentemperaturen von unter 15 °C), was den Eiern und den frisch geschlüpften Jungen optimale Entwicklungsbedingungen bietet. Das Weibchen bleibt nach der Eiablage noch einige Wochen in der Nähe des Nestes, sodass es sein Gelege im Notfall beschützen kann. Im September oder Oktober graben sich die Jungtiere durch die Wand nach draußen. Dabei erhalten sie sehr wahrscheinlich keine Hilfe von einem der Elterntiere, wie es beim Buntwaran (Varanus varius) beschrieben wird. Das Jungtier bleibt solange im Termitenbau, bis die Außentemperaturen ausreichend hoch sind und ernährt sich in dieser Zeit von den Termiten. Auch nutzt es danach den Bau noch einige Monate als Unterschlupf für die Nacht.[3]
Wie die meisten Warane ist auch der Rosenberg-Waran ein Jäger. Dabei ist er nicht wählerisch und frisst sowohl Käfer und Schaben als auch kleine Landwirbeltiere, vorwiegend Säuger und Reptilien. Auch plündert er Reptiliengelege. In einem Fall ist ein Rosenberg-Waran dabei beobachtet worden, wie er ein Jungtier des Kurzschnabeligels (Tachyglossus aculeatus) erbeutet hatte. Gelegentlich fressen Rosenberg-Warane auch Aas, beispielsweise überfahrene Tiere auf der Straße.
Der Deutsche Robert Mertens beschrieb die Art 1957 als Unterart des Gould-Warans (Varanus gouldii). Später erhob der Australier Glen Milton Storr diese Unterart in den Artstatus, da er feststellte, dass in den Regionen, in denen Rosenberg- und Gould-Waran sympatrisch vorkommen, keine Mischlinge dieser Arten zu finden sind.[4] Rosenberg- und Gould-Waran sind sich äußerlich sehr ähnlich, unterscheiden sich aber dadurch, dass letztgenannter eine einfarbig-helle Schwanzspitze und eine etwas andere Bauchzeichnung besitzt.[4]
Da die Vertreter der isolierten Populationen im Osten des Verbreitungsgebietes deutlich längere Schwänze haben als die Vertreter der westlichen Population, wird vermutet, dass beide Populationen eigenständige Arten sind.[5]
Innerhalb der Warane (Gattung Varanus) wird der Rosenberg-Waran in die Untergattung Varanus (Varanus) und innerhalb dieser in die gouldii-Artgruppe gestellt.
Der Rosenberg-Waran oder auch Rosenberg’scher Waran (Varanus rosenbergi) ist eine in Australien endemische Art der Schuppenkriechtiere aus der Gattung der Warane (Varanus). Die Erstbeschreibung erfolgte 1957 durch den deutschen Herpetologen Robert Mertens. Das Art-Epitheton ehrt den deutschen Naturforscher, Geograph und Zoologen Hermann von Rosenberg. Der Rosenberg-Waran gehört zu den am besten erforschten australischen Waranarten.
The Rosenberg's monitor (Varanus rosenbergi) is an Australian 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 sometimes abundant.[1]
The species was first described by German herpetologist Robert Mertens in 1957,[3] named and recognized as a subspecies of Varanus gouldii; a revision of Western Australian monitors published in 1980 elevated the taxon to species status.[4][5] It is now considered to be a member of the V. gouldii species complex.[6] The holotype was collected at the Stirling Range in Southwest Australia.[7][8] The specific name, rosenbergi, is in honor of German naturalist Hermann von Rosenberg.[9]
The infrageneric classification of the species allies it to other taxa of the subgenus Varanus (Varanus).[5] A geographically remote population in the eastern states has distinct characteristics that may represent a cryptic species.[1] A description published as Pantherosaurus kuringai in 1985 is regarded as a synonym for this species.[10][7]
The common names include the heath monitor or the southern heath monitor,[1] along with those names that are a legacy of their description as the sand goanna Varanus gouldii.
Like most other monitor lizards, these are fast-moving predators with long tails, stout limbs and clawed feet. They resemble the closely related and widespread 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.[8]
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.[4] Fat layers in V. rosenbergi constitute around 7.6% of body weight, allowing energy reserves to be stored throughout the body and tail.[5] 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.[11]
The comparative ratio of head and body lengths between the sexes, often evident in the monitor subgenus Odatria, is not easily discernible in this species and their subgenus Varanus.[12]
Reproductive behaviour, including guarding of nest sites, extends over a four-month period of a sexually active adult's year.[13] 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.
Incubation periods of V. rosenbergi broods are around seven months, or longer at Kangaroo Island, which is regarded as an extended period when compared to other squamates and may be a response to the cooler climate of its range.[14] In September and October, the hatchlings emerge from the mound, possibly with digging assistance from the adult; this parenting behaviour has inferred from the habits of other monitors without being directly observed in V. rosenbergi. A study observing this species at Kangaroo Island found that hatchlings emerged at the point of the parents entry to the nest, and able to excavate themselves from their birthplace. Their emergence corresponds with increasing warmth of the temperature outside the termitaria, and the hatchlings are observed at basking in the sunshine at the exterior and reoccupying the nest site during cold nights.[15]
They are highly active carnivores, able to pursue large prey, and opportunistic generalists whose diet includes birds, reptiles, mammals, eggs, and carrion.[11][5] Analysis of the island population in South Australia revealed third of their diet is invertebrates, primarily species of Acrididae, Areneidae, Blattoidea and Coleoptera, with mammals and reptiles combined being the greater portion of animals that were eaten. Some amphibians, mostly Limnodynastes species of frogs, and a small proportion if birds were also found to have been captured and consumed, but invertebrates would be found during its regular foraging activities through soft soils and detritus. This goanna has been observed eating road kill, including possums and wallabies, and consumption of these may account for a significant proportion of the mammal component of their diet. The native rat species Rattus fuscipes is likely pursued and caught, but the recorded consumption of Macropus fuliginosus, the western grey kangaroo, and brush-tail possum Trichosurus vulpecula is likely the discovery of their carcasses.[5]
Water is obtained from prey when seasonal rainfall is low, and supplemented by drinking free water when available. Living in a sometimes saline environment, they are able to expel excess salts—primarily sodium chloride and a smaller amount of potassium—through gland structures at the nostrils. In winter months the water required by the goanna may be supplemented from free water or by pulmocutaneous exchange of moisture.[5]
The darker coloration of V. rosenbergi, a form of melanism, allows a greater degree of thermoregulation of their body in the cooler southern climates. They periodically bask in the sun throughout the day, or when the opportunity arises, laying in the soil if it is warm or clambering on to branches to avoid a net heat loss; heath monitors are mostly found in their burrows during the coldest parts of the year. Females may continue to be active at night, maintaining a body temperature 20 °C greater than the ambient temperature.[15][5]
Varanus rosenbergi conserves its energy requirements during cooler seasons of the year, entering a state of torpor, but demonstrates the ability to voluntarily arouse itself during these periods.[16]
The species will climb a tree to evade capture.[17]
The distribution range of the species is in the south of the Australian continent, all occurrences are recorded below the southern 30° line of latitude. The range in Southwest Australia is south of Mussel Pool, to the northeast of the state's capital Perth, and inland from the southern coast in a range that extends close to Bendering, Norseman, Balladonia and then east to Eucla and South Australia.[4] Varanus rosenbergi is most common in the west, locally abundant in favourable habitat, and deeply fragmented in the east; isolated groups near Canberra and Sydney may represent a separate species.[1] A subpopulation, with individuals somewhat larger in size, is found on Kangaroo Island, and a mainland population in South Australia is considered rare.[4] The eastern states included in records of the species occurrence at New South Wales, the Australian Capital Territory and Victoria.[1]
The heath monitor is found in habitat close to sea level and at elevations below 1500 metres asl.[1] The population in New South Wales, isolated and suspected to be a sister species, is found at high elevations that include occurrences above the snow-line in the mountainous regions of eastern Australia.[1] The individual range of V. rosenbergi is comparatively large.[5]
The distribution range overlaps with Varanus gouldii and individuals of these species are sometimes sympatric, especially at southern areas of the Western Australian wheatbelt and on the Swan Coastal Plain; the species do not hybridize.[4] The named distribution range of the widespread population of V. gouldi, due to a historically uncertain taxonomic description, was revised to exclude the southern coastal areas were this species occurs.[4]
The favoured types of habitat Varanus rosenbergi is associated with plant communities are most often sandy heathland, open woodland or sclerophyll forest, although the species is known to occur in other vegetation types.[1] The near coastal areas it inhabits are frequently saline environments.[5] Subalpine environments in the southernmost parts of its range such as Naas Valley, ACT, sometimes encounters snowfall.[18] Heath monitors excavate burrows for refuge, or occupy rocky fissures and hollow trees.
The reproductive habits of Varanus rosenbergi are closely associated with termite constructions, the above ground nest-mounds of some species, and is thought to rely on these to produce offspring.[1] The use of termitaria provides the newly hatched progeny the favourable conditions within the nest, warmth and regulated humidity, when conditions outside retard the activity of adults. Several other monitor species adopt termitaria as nest sites, those utilized by V. rosenbergi offer regular internal temperatures for most of the year, usually around 30° Celsius, and do not fall below 20 °C at the coolest times of the year.[15]
Varanus rosenbergi is known to be host to nine species of intestinal nematodes, parasites known as roundworm, and is recorded near undisturbed habitat with high infection rates of Abbreviata, physalopteroid species of the Spirurida order.[19] Individuals often carry blood-feeding ticks lodged to their skin, these are found around the cloaca or base of the tail or seeking areas of high blood flow at the head and neck by the female tick when pregnant. The infestation rate in the southwest region is around half of the adults and is absent in juveniles, the Kangaroo Island population has a higher rate, around 85% of those surveyed carrying the species Aponomma fimbriatum.[5]
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South Australia, Kangaroo Island
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South Australia, Kangaroo Island
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South Australia, Kangaroo Island
South Australia, Kangaroo Island
Western Australia, Stirling Range
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Western Australia
Western Australia, Cape Arid National Park
Juvenile
The Rosenberg's monitor (Varanus rosenbergi) is an Australian 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 sometimes abundant.
Varanus rosenbergi Varanus generoko animalia da. Narrastien barruko Varanidae familian sailkatuta dago.
Varanus rosenbergi Varanus generoko animalia da. Narrastien barruko Varanidae familian sailkatuta dago.
Le Varan de Rosenberg (Varanus rosenbergi), est une espèce de sauriens de la famille des Varanidae[1].
Cette espèce est endémique d'Australie. Elle se rencontre en Nouvelle-Galles du Sud, dans le sud-ouest du Victoria, en Australie-Méridionale et dans le sud de l'Australie-Occidentale[1].
Cette espèce est nommée en l'honneur d'Hermann von Rosenberg[2].
Il varano di Rosenberg (Varanus rosenbergi Mertens, 1957), o varano del mallee, è una specie della famiglia dei Varanidi originaria delle regioni orientali, meridionali e occidentali dell'Australia.
Il varano di Rosenberg può raggiungere gli 1,5 m di lunghezza[3]. È molto simile al varano di Gould, dal quale si differenzia solamente per la colorazione più scura, tanto che in passato veniva considerato una sua sottospecie.
L'areale di questa specie è ristretto alle regioni meridionali dell'Australia, al di sotto dei 30° di latitudine sud. Essa è diffusa nelle regioni costiere di Australia Occidentale, Australia Meridionale e nel sud-ovest del Victoria. Piccole popolazioni disgiunte si incontrano anche nei pressi di Sydney e di Canberra.
Il varano di Rosenberg si accoppia a gennaio, in un periodo della durata di 12 giorni. In febbraio-marzo la femmina crea, scavando in un termitaio, una camera-nido circolare. In essa depone fino a 14 uova. In settembre-ottobre i piccoli emergono dal termitaio, generalmente aiutati dalla madre[3][4].
Il varano di Rosenberg (Varanus rosenbergi Mertens, 1957), o varano del mallee, è una specie della famiglia dei Varanidi originaria delle regioni orientali, meridionali e occidentali dell'Australia.
Varanus rosenbergi[2] este o specie de reptile din genul Varanus, familia Varanidae, descrisă de Mertens 1957.[3][4] A fost clasificată de IUCN ca specie cu risc scăzut.[1] Conform Catalogue of Life specia Varanus rosenbergi nu are subspecii cunoscute.[3]
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Acest articol referitor la o reptilă este un ciot. Puteți ajuta Wikipedia prin completarea sa. Varanus rosenbergi este o specie de reptile din genul Varanus, familia Varanidae, descrisă de Mertens 1957. A fost clasificată de IUCN ca specie cu risc scăzut. Conform Catalogue of Life specia Varanus rosenbergi nu are subspecii cunoscute.
Varanus rosenbergi là một loài thằn lằn trong họ Varanidae. Loài này được Mertens mô tả khoa học đầu tiên năm 1957.[2]
Bài viết liên quan đến bộ bò sát có vảy này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Varanus rosenbergi là một loài thằn lằn trong họ Varanidae. Loài này được Mertens mô tả khoa học đầu tiên năm 1957.
