The long-tailed mouse (Pseudomys higginsi) is found on the island of Tasmania and is the only species of rodent endemic to Tasmania. Fossils have been found on the Australian mainland in Victoria and Eastern New South Wales that date back to the late Pleistocene. (Driessen et al., 1999)
Pseudomys higginsi prefers areas with high annual rainfall such as rainforests and wet sclerophyll forests. They also can be found in wet scrub and eucalyptus scrub, but are rare or absent in dry forests, grasslands and low alpine vegetation. They are found between sea level and eleations of about 1,200 m. They create tunnels and runways in wet and shaded habitats under the moss-covered forest floor. They are known to retreat to holes in rotting stumps and logs. Pseudomys higginsi have been found in open to dense vegetation areas and also in undergrowth areas devoid of cover 0.5 m from the ground. (Driessen et al., 1999; Strahan, 1995)
Pseudomys higginsi has soft fur that is grayish-brown above and white below. The young are more uniformly colored. The bicolor tail has the same coloration as the body. The tail is about 170 mm long, the head and body is about 130 mm long, and the hind foot length is about 33 mm. The slender, tapered tail is carried in a curved shape well above ground while in locomotion. Some P. higginsi have a white tip on the tail. The tail is likely used for balance. The hind feet and tail lengths are relatively longer than other species in the genus. Long-tailed mice weigh 60 to 70 g. The face is pointed and the eyes are set forward. The ears are large and rounded at 24 mm and when pressed forward will cover the eyes. The iris is dark brown and the nostril is pink and naked. There are four nipples prominent on the abdomen. The upper incisors are 4 mm above the gums and the anterior of the tooth is orange. The lower incisors are pale yellow and are 6 mm long. The cheek teeth are rooted and can be aged by wear. The dental formula is 1/1 0/0 0/0 3/3 = 16. There is no sexual dimorphism between male and females, however many female measurements slightly exceed male measurements. (Stoddart et al. 1993, Driessen et al. 1999)
The mating system and behavior of this mouse have not been characterized.
Pseudomys higginsi has a breeding season from November to April. The long-tailed mouse raises one to two litters in a season each with a litter size of 3 to 4 offspring. Gestation lasts for 30 to 34 days. Spontaneous ovulation occurs with an estrous cycle of about 10 days in adults. Population numbers increase after an extreme rainfall season. (Strahan, 1995; Driessen et al., 1999)
Young P. higginsi are born in natal fur with a head and body length one-third the size of the mother. The incisors erupt before birth and are directed inward. These inward incisors are used for firm attachment to mother’s teat. If there is danger, the mother can hurry away and not lose her young, who remain attached to the teats. The incisors will wear to normal rodent-like teeth as the young grow into adults.
At eight days P. higginsi can crawl even though their eyes aren't open yet. The eyes open at 15 days and the ears unfold at 18 days. The tail is short at birth but grows rapidly to equal head and body length by 18 days of age.
The mother leaves young in the nest while she forages. Neonates and are wholely dependent on the mother until 25 days, and at 33 days they are independent. The hind feet triple in size the first 5 weeks (35 days) to reach adult size. By 40 days P. higginsi is near adult size except for the tail, which grows until the 75th day. The first molt occurs at 50 days with the final adult coat at 100 days.
(Strahan, 1995; Driessen et al., 1995)
As in all mammals, the female cares for the young by nursing them. P. higginsi mothers leave their altricial young in a nest while they go out to forage. The young are weaned around 33 days of age.
Maximum lifespan of P. higginsi in the wild is about 18 months. (Strahan, 1995)
Pseudomys higginsi is most active at night but may forage during the day. These mice are inquisitive and active creatures. If they are alarmed they will explode from the area and leap about 30cm in any direction. When P. higginsi is relaxed, they will stand in a bipedal stance, however they are not bipedal in locomotion but are more quadrupedal. They are kept easily in captivity and are very nervous and defensive when first captured. Hoarding is rare in captive animals but has been observed in lactating females. (Driessen et al., 1999)
The home range of a male is ca. 2,630 square meters and the female’s homerange is ca. 2,080 square meters. (Driessen et al., 1999)
Long-tailed Mice are opportunistic feeders and their main foods are monocotyledons, subterranean fungi, fruits of shrubs, and invertebrates. In the spring mosses and ferns are common and in the summer monocotyledons and dicotyledons are common. They will not have to drink water if succulent food is eaten. (Strahan 1995, Driessen et al. 1999)
Masked owls and Eastern quolls are the main predators of P. higginsi. Before settlement, it was determined that 44% of the masked owl's diet was P. higginsi but now it is only about 1%. This suggests that there was a higher abundance of long-tailed mice in the past. (Driessen et al., 1999). Specific anti-predator behaviors have not been reported for these mice, However, if they are alarmed they will explode from the area and leap about 30cm in any direction. This could be an adaptation to avoid the sharp talons of a predator.
Pseudomys higginsi has an overlapping range with the velvet-furred swamp rat (Rattus lutreolus velutinus) in wet sclerophyll forests, and interspecific competition for space has been noticed. It is believed that swamp rats restrict access of P. higginsi to better microhabitat and food supply. (Monamy et al. 1999, Driessen et al. 1999)
Becuase of their dietary habits, these mice likely affect both the populations of predators and the plant community. They are likely seed dispersers.
Pseudomys higginsi has several ectoparasites that may affect humans and/or pets. The most conspicuous is the mite Laelaps calabyi. Other ectoparasites include a tick Ixodes tasmani, several fleas Pygiopsylla hoplia, Acanthopsylla rothschildi, and Stephanocircus pectinipes and a louse Hoplopleua calabyi. (Driessen et al., 1999)
Although this mouse is not thought to be as common as it once was, it is not under threat of extinction.
Other common names of P. higginsi include Higgins' Mouse, Tasmanian Mouse, Tasmanian Pseudo-rat, and Long-tailed Rat. Pseudomys comes from the combined form of Greek pseudes meaning false and Latin mys (plural mus) meaning mouse. The name higginsi came from a physician and natural history dealer resident of Tasmania named E.T. Higgins. (Strahan 1995, Driessen et al. 1999)
Janet King (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor), University of Wisconsin-Stevens Point.
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
uses smells or other chemicals to communicate
animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.
parental care is carried out by females
union of egg and spermatozoan
fertilization takes place within the female's body
animals that live only on an island or set of islands.
having the capacity to move from one place to another.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
an animal that mainly eats all kinds of things, including plants and animals
rainforests, both temperate and tropical, are dominated by trees often forming a closed canopy with little light reaching the ground. Epiphytes and climbing plants are also abundant. Precipitation is typically not limiting, but may be somewhat seasonal.
scrub forests develop in areas that experience dry seasons.
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
Dreissen, M., R. Rose. 1999. *Pseudomys higginsi*: Mammalian Species. American Society of Mammalogists, 623: 1-5.
Monamy, V., B. Fox. 1999. Habitat selection by female *Rattus lutreolus* drives asymmetric competition and coexsistence with *Pseudomys higginsi*. Journal of Mammalogy, 80: 232-242.
Stoddart, M., G. Challis. 1993. Habitat use and body form of the long-tailed mouse (*Pseudomys higginsi*). Wildlife Research, 20: 735-738.
Strahan, R. 1995. Family Rodentia *in* Mammals of Australia. Washington, D.C: Smithsonian Institution Press.