The most notable mammal found on Kagaroo Island 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), Brown Toadlet (Pseudophryne bibroni) and Brown Froglet (Crinia signifera).
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 found on Kangaroo Island. Another reptile particularly associated with this locale is the Kangaroo Island Copperhead (Austrelaps labialis).
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.
The Kangaroo Island dunnart (Sminthopsis aitkeni) is a dark sooty-grey coloured dunnart species first described in 1969, with paler underparts of its body. It has an average body length of 170–198 mm, a snout to anus length of 80–93 mm, a tail measurement of 90–105 mm, a hind foot of 17.5 mm, ear length of 18 mm and a weight of 20–25 grams. The thin tail is also gray, but lighter on the bottom. The tail is longer than the body. Kangaroo Island dunnarts are dimorphic, with males larger than females.
The Kangaroo Island dunnart is listed as Critically Endangered by International Union for Conservation of Nature (IUCN). The population was believed to be less than 500 before the 2019–2020 Australian bushfires.[3] Following the fires, it is believed that only about 50 individuals exist.[4]
This dasyurid is found only on the western half of Kangaroo Island in South Australia, the island's only endemic mammal. The species inhabits mallee heath on laterite soils. It is believed that the Kangaroo Island dunnart originally lived over the whole island. Today, there are six sites in which Kangaroo Island dunnarts have been found. All are either in the Flinders Chase National Park or the Ravine des Casoars Wilderness Protection Area, both on the western part of the island. Recent attempts to locate Kangaroo Island dunnarts on the eastern portion of the island have failed.
The Kangaroo Island dunnart is nocturnal. Their diet consist of invertebrates. Studies of their feces showed that the major component of their diet is ants and spiders. Scorpions, beetles, and grasshoppers are also eaten.
Little is known of the Kangaroo Island dunnarts' behaviour. However, they are believed to be polyestrous, breeding twice a year. Based on trapping of juveniles, it is believed they breed in mid-September to October and again in November to December. Their gestation period is approximately 12 days. Little is known about parental care. It is thought that males only live for one mating season, whereas females may live to breed for two seasons.
The Kangaroo Island dunnart is listed as critically endangered on the IUCN Red List of Threatened Species.[1] The Australian government first developed a recovery plan in 2011.[5] As recently as the early 2000s, the wildlife research community was uncertain as to whether the species population in the wild was actually so low, or whether they were just particularly well concealed.[6] Before the 2019–2020 bushfires, it was believed that there were fewer than 500 individuals.
The Kangaroo Island dunnart is believed to have had a range of the entire island at one time. Today, it has only been found on six sites on the western portion of Kangaroo Island. The population decrease has been attributed to several causes. Habitat loss is believed to be a primary cause. Although no clear habitat preference has been identified, Kangaroo Island dunnarts seem to be dependent on some low vegetation. The eastern portion of Kangaroo Island has been largely converted from the natural habitat for agricultural and grazing purposes. About 50% of Kangaroo Island's natural habitat has been cleared and Kangaroo Island dunnarts have not been found in the cleared regions. Also, tree dieback caused by Phytophthora cinnamomi, a water mould, has also affected Kangaroo Island dunnart populations. Feral cats may also be a factor in the decreased population.
Kangaroo Island dunnart populations are considered particularly vulnerable due to their small range, since a single event can negatively affect a large proportion of the population. Forest fire is a major concern and the major fires in 2019–2020 destroyed much of their remaining habitat.[7] In May 2019, months prior to the start of the 2019–2020 bushfires, a workshop on the status of the dunnart was held on Kangaroo Island that included government representatives as well as scientists and landowners. The minutes from that meeting provided considerable information on the Kangaroo Island dunnart's status prior to the bushfires.[8] The population was devastated by the bushfires, which likely wiped out a majority of an individuals; however, dunnarts have still been sighted in burnt and unburnt areas following the fires, raising hopes for recovery.[4][9]
The Kangaroo Island dunnart (Sminthopsis aitkeni) is a dark sooty-grey coloured dunnart species first described in 1969, with paler underparts of its body. It has an average body length of 170–198 mm, a snout to anus length of 80–93 mm, a tail measurement of 90–105 mm, a hind foot of 17.5 mm, ear length of 18 mm and a weight of 20–25 grams. The thin tail is also gray, but lighter on the bottom. The tail is longer than the body. Kangaroo Island dunnarts are dimorphic, with males larger than females.
The Kangaroo Island dunnart is listed as Critically Endangered by International Union for Conservation of Nature (IUCN). The population was believed to be less than 500 before the 2019–2020 Australian bushfires. Following the fires, it is believed that only about 50 individuals exist.
