Антехинус: Австралияның шағын сүтқоректі жануарлары

Genus of marsupials

Antechinus (// ('ant echinus')) is a genus of small dasyurid marsupial endemic to Australia. They resemble mice with the bristly fur of shrews.

They are also sometimes called 'broad footed marsupial mice', 'pouched mice', or 'Antechinus shrews'. However, the majority of those common names are considered either regional or archaic; the modern common name for the animal is antechinus.

Antechinus have short fur and are generally greyish or brownish in colour, varying with species. A few species of New Guinean Antechinus were recognised, but they have been reclassified into the genus Murexia. The interspecific relations of the genus Antechinus are still under review. Generally, the clades are formed by species with similar geographic distributions. A. minimus (swamp antechinus)
A. swainsonii (Tasmanian dusky antechinus)
A. vandycki (Tasman Peninsula dusky antechinus)
A. adustus (rusty antechinus)
A. bellus (fawn antechinus)
A. flavipes (yellow footed antechinus)
A. leo (cinnamon antechinus)
A. mysticus (buff footed antechinus)

Antechinus are mainly insectivorous, but the exact composition of their diet can vary by species and habitat. Antechinus mainly eat beetles, insect larvae and spiders. Amphipods, millipedes and centipedes are also quite common in their diets. It has been reported that Antechinus also eat vertebrates, mainly small reptiles, such as skinks, or mammals, such as feathertail gliders. This is likely to occur most commonly when the Antechinus are food stressed. They are also classified as opportunists because they feed on most of the prey available to them However, they do show preference for some prey, i. e. beetles, spiders and larvae, especially when they are not food stressed. The larger species of Antechinus, such as A. swainsonii, are completely ground dwelling and forage in the leaf litter. The males experience mass mortality after mating, with male survival only observed in very rare cases. The gestation period varies by species between 25 and 35 days. The breeding season is in winter or early spring, from July to September. The timing of the breeding season changes very little at the same location between different years. This reproductive isolation may have led to sympatric speciation. Males have been selected to be ready before the females to ensure the maximum amount of time for mating.

Antechinus do not have a complete pouch, as in other marsupials, but simply a flap of skin covering the teats. The males mate with a number of females and the litters have a number of fathers. An increase in free corticosteroids is thought to allow males to utilise their reserve energy and maximise their reproductive effort, even though the increase usually proves fatal. Many marsupials undergo torpor as well as some birds and placental mammals. Unlike hibernation, daily torpor is not simply reliant on ambient air temperatures. Antechinus can move into torpor on summer days with temperatures in the range of Going into torpor allows them to greatly reduce metabolic rates, sometimes up to 80% However, going into torpor during the night is not uncommon. Increasing body temperature after torpor is energetically costly and reduces some of the metabolic savings. The main threats to these species, indeed all species of Antechinus, are habitat destruction and introduced animals. Deforestation and habitat destruction removes the complex understorey habitat which Antechinus require for protection from predators and for food. Antechinus also nest in tree hollows, which only form in senescent trees. Introduced predators also threaten Antechinus populations with foxes and cats predating upon Antechinus. Pigs, cattle and horses trample their habitats. Changed fire regimes since European arrival have resulted in more intense bushfires which can negatively impact Antechinus populations by destroying understorey vegetation and removing most of their preferred food. Climate change threatens several high altitude species, especially those in northern Queensland.