Fat-tailed dunnart [1] | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Mammalia |
Infraclass: | Marsupialia |
Order: | Dasyuromorphia |
Family: | Dasyuridae |
Genus: | Sminthopsis |
Species: | S. crassicaudata |
Binomial name | |
Sminthopsis crassicaudata (Gould, 1844) | |
Fat-tailed dunnart range |
The fat-tailed dunnart (Sminthopsis crassicaudata) is a species of mouse-like marsupial of the Dasyuridae, the family that includes the little red kaluta, quolls, and the Tasmanian devil.
It has an average body length of 60–90 millimeters (2.4–3.5 in) with a tail of 45–70 millimeters (1.8–2.8 in). Its ear length is 14–16 millimeters (0.55–0.63 in). One of the smallest carnivorous marsupials, its weight varies between 10–20 grams (0.35–0.71 oz). The tail becomes fat a few milimeters from the proximal end and remains so right up to the tip. The dunnart has trichromat vision, similar to that of some other marsupials as well as primates, but unlike most mammals, which have dichromat vision.
The range of S. crassicaudata in Australia is in diverse habitats except for the Kimberley region of Western Australia and the northern Northern Territory like Arnhem Land and Kakadu National Park, but avoids the Wannon and Mallee scrub habitats in Victoria. In the northeast of Victoria, the species can also be found in grassy woodlands and samphire shrublands. The subspecies S. c. crassicaudata is found in the Epping Forest National Park in Queensland. S. c. ferruginea is found around Lake Eyre in South Australia. S. c. centralis is found in Killalpannina (as Killalpanima, Lake Eyre East), near Etadunna, South Australia. Fat tailed dunnarts can be found in most deserts in Australia, e.g. the Simpson Desert and Gibson Desert.
The habitats in which the species can be found include sparse grasslands, open shrublands and farmlands where there is considerable bare land. The impact of unimproved farming has been positive for this species as the type of habitat created is suitable to this dunnart's requirements, but intensive agriculture is seen as a negative factor for the species.
This species breeds from July to February, with the young in the pouch from July to April (Morton 1978b). Gestation is for 13 days and the young remain in the pouch for 70 days with litter size on average 7.5 with a 33% infant death rate. They generally have two litters per year with females not breeding for the first year. The average life span of the females is 18 months, and males 15 months.
The fat-tailed dunnart's diet includes insects such as beetles, spiders, small reptiles, and amphibians. It stores fat reserves in its carrot-shaped tail for times of food shortage.
The fat-tailed dunnart is often eaten by other carnivores, including invasive foxes and cats, as well as other feral animals that live among its environment.
The dunnart can survive in extreme, semi-arid environments. This is due to various physiological and behavioral characteristics. First, this marsupial is nocturnal and functions within a 24-hour circadian rhythm. [3] During the nighttime it is protected from high temperatures that cause energy loss. While awake, it spends the majority of its time feeding. Every night it consumes approximately its own body weight of food. [3] During periods of food shortage it decreases its duration of activity while also increasing its intensity of feeding. [4] It uses specialized, sharp teeth to grind its prey into fine pieces. This increases its ability to obtain nutrients from its prey. It has a high rate of digestion and can use fat stored in its tail as an energy source. [3]
Another survival technique that it uses is daily torpor. It lowers its body temperature and metabolic rate, [5] in order to reduce energy expenditure. Torpor is unaffected by alterations in photoperiod but is greatly affected by environmental conditions. Two conditions must occur in order for the fat-tailed dunnart to use daily torpor: low ambient temperatures and food shortage. [3] [6] There are seasonal variations in torpidity. They use it more often in the winter because food is scarce and it requires more energy to maintain a high constant body temperature. During torpor, the body temperature can drop as low as 14.6 °C. [5] [7] This species does not use torpor for extended periods of time, thus the heart rate is variable and does not reach a steady state, such as seen in long-term torpidators. This species is unique in that it can use torpor during development and reproduction. Even during lactation a female is capable of entering daily torpor without affecting the offspring. [8] [9]
Coupled with the daily torpor is a process called re-warming. The re-warming process demands a high amount of energy in order to raise the body temperature. [9] After awaking from a torpid state, these marsupials actively seek out areas in which they can bask in the sun to aid in this process. [10]
Nesting is also used as a behavioral survival technique. During times of cold temperatures, the fat-tailed dunnart shares nests with rodent species such as the house mouse, ( Mus musculus ), to conserve heat. This is unusual because the fat-tailed dunnart preys upon these mice during less extreme conditions. [3] Group nesting is observed only during times of non-breeding. [11]
In August 2022, it was announced that the University of Melbourne will partner with Texas-based biotechnology company Colossal Biosciences to attempt to re-create the thylacine using the fat-tailed dunnart, one of its closest living relatives, and return it to Tasmania. [12] [13] [14] [15] [16] [17]
Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are natively found in Australasia, Wallacea, and the Americas. One of the defining features of marsupials is their unique reproductive strategy, where the young are born in a relatively undeveloped state and then nurtured within a pouch on their mother's abdomen.
The thylacine, also commonly known as the Tasmanian tiger or Tasmanian wolf, is an extinct carnivorous marsupial that was native to the Australian mainland and the islands of Tasmania and New Guinea. The thylacine died out in New Guinea and mainland Australia around 3,600–3,200 years ago, prior to the arrival of Europeans, possibly because of the introduction of the dingo, whose earliest record dates to around the same time, but which never reached Tasmania. Prior to European settlement, around 5,000 remained in the wild on Tasmania. Beginning in the nineteenth century, they were perceived as a threat to the livestock of farmers and bounty hunting was introduced. The last known of its species died in 1936 at Hobart Zoo in Tasmania. The thylacine is widespread in popular culture and is a cultural icon in Australia.
Dasyuromorphia is an order comprising most of the Australian carnivorous marsupials, including quolls, dunnarts, the numbat, the Tasmanian devil, and the extinct thylacine. In Australia, the exceptions include the omnivorous bandicoots and the marsupial moles. Numerous South American species of marsupials are also carnivorous, as were some extinct members of the order Diprotodontia, including extinct kangaroos and thylacoleonids, and some members of the partially extinct clade Metatheria and all members of the extinct superorder Sparassodonta.
The Dasyuridae are a family of marsupials native to Australia and New Guinea, including 71 extant species divided into 17 genera. Many are small and mouse-like or shrew-like, giving some of them the name marsupial mice or marsupial shrews, but the group also includes the cat-sized quolls, as well as the Tasmanian devil. They are found in a wide range of habitats, including grassland, underground, forests, and mountains, and some species are arboreal or semiaquatic. The Dasyuridae are often called the 'marsupial carnivores', as most members of the family are insectivores.
Torpor is a state of decreased physiological activity in an animal, usually marked by a reduced body temperature and metabolic rate. Torpor enables animals to survive periods of reduced food availability. The term "torpor" can refer to the time a hibernator spends at low body temperature, lasting days to weeks, or it can refer to a period of low body temperature and metabolism lasting less than 24 hours, as in "daily torpor".
Dunnart is a common name for species of the genus Sminthopsis, narrow-footed marsupials the size of a European mouse. They have a largely insectivorous diet.
Mulgaras are the six small rat-sized species in the genus Dasycercus. They are marsupial carnivores, closely related to the Tasmanian devil and the quolls, that live in deserts and spinifex grasslands of arid Australia. They are nocturnal, but occasionally "sunbathe" in the entrance of the burrow in which they dwell. Their kidneys are highly developed to excrete extremely concentrated urine to preserve water, as the animals rarely drink. They feed mostly on insects, but also eat reptiles and small mammals. They are seasonal breeders and breed from June to September. The pouch comprises two lateral folds of skin.
Antechinus is a genus of small dasyurid marsupial endemic to Australia. They resemble mice with the bristly fur of shrews.
The kultarr is a small insectivorous nocturnal marsupial inhabiting the arid interior of Australia. Preferred habitat includes stony deserts, shrubland, woodland, grassland and open plains. The kultarr has a range of adaptations to help cope with Australia's harsh arid environment including torpor similar to hibernation that helps conserve energy. The species has declined across its former range since European settlement due to changes in land management practices and introduced predators.
The subfamily Sminthopsinae includes several genera of small, carnivorous marsupials native to Australia: kultarrs, ningauis, dunnarts, and planigales.
Smintopsini is a tribe of marsupial in the family Dasyuridae.
The slender-tailed dunnart, also known as the common dunnart in Australia, is a dasyurid marsupial. It has an average body length of 7 to 12 centimeters (2.8–4.7 in) with a tail length of 5.5 to 13 centimetres (2.2–5.1 in). It weighs 25–40.8 grams for males and 16.5–25.4 grams for females.
The striped-faced dunnart is a small, Australian, nocturnal, "marsupial mouse," part of the family Dasyuridae. The species' distribution occurs throughout much of inland central and northern Australia, occupying a range of arid and semi-arid habitats.
The white-tailed dunnart, also known as the ash-grey dunnart, is a dunnart native to Australia.
The Julia Creek dunnart is a marsupial with a buffy brown upperside and white underside. This dunnart has a body length of 100–135 mm with a tail of 60–105 mm to make a total length of 160–240 mm. Its weight is between 40 and 70 g. The length of the hind foot is 22–24 mm. The species has a dark brown triangle colour from above and below the eye with the point at the nose, and another dark stripe on top of the skull. A healthy dunnart has a carrot-shaped tail filled with fat stores.
The fat-tailed false antechinus, also called the fat-tailed pseudantechinus and red-eared antechinus, is a member of the order Dasyuromorphia. It is an inhabitant of western and central Australia. Its species name, macdonnellensis, refers to the MacDonnell Ranges near Alice Springs, where it was first discovered.
The sandhill dunnart is a species of carnivorous Australian marsupial of the family Dasyuridae. It is known from four scattered semi-arid areas of Australia: near Lake Amadeus in Northern Territory, the central and eastern Eyre Peninsula in South Australia, the southwestern and western edges of the Great Victoria Desert in Western Australia, and at Yellabinna in South Australia.