Planigale ingramilong-tailed planigale

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Geographic Range

Planigale ingrami, long-tailed planigale, is found in northern Australia in the northeastern part of the Northern Territory, Mackay and Townsville in Queensland, and south to Brunette Downs. ("Long-tailed Planigale", 2007; Davey, 1970; Grizmek, et al., 2005)

Habitat

Long-tailed planigales live in a variety of habitats. They are commonly found in clay soil woodlands, black soil plains, and the grasslands of Australia’s "Top End", which are seasonally flooded during the monsoon from December to the end of March. The grasslands in that region develop dry, deep cracks in the soil during the eight-month dry season. Long-tailed planigales use these cracks to hide from predators and hunt for invertebrates and other small animals. They will also hide under tussocks of grass. ("Long-tailed Planigale", 2007; Davey, 1970; Grizmek, et al., 2005)

Physical Description

Long-tailed planigales are the smallest living marsupials. Long-tailed planigales weigh 4.2 to 4.3 grams and are 55 to 65 mm in length. Long-tailed planigales are mouse-like marsupials with flat heads and pointed muzzles. Their fur is grey-brown with yellow hues and their bellies are lighter in color. They have long bare tails which make up just under half of their total length. The central pads on their feet are smooth and not serrated. Their hind limbs are bigger than their front limbs, allowing them to lean back or stand in a semi-crouched position. There is no sexual dimorphism in long-tailed planigales. ("Long-tailed Planigale", 2007; Davey, 1970; Grizmek, et al., 2005; Hume, 1999; "AnAge entry for Planigale ingrami", 2007; Tyndale-Biscoe and Renfree, 1987)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    4.3 g
    0.15 oz
  • Range length
    55 to 65 mm
    2.17 to 2.56 in
  • Average length
    59 mm
    2.32 in
  • Average basal metabolic rate
    0.0650 cm3.O2/g/hr

Reproduction

Males and females have multiple mates. (Grizmek, et al., 2005)

Little is known about reproduction in long-tailed planigales. They breed year round, but mostly during the wet season. Populations living in different parts of Australia typically give birth during different parts of the year. They give birth to 4 to 8 young per litter in the northern part of their range and up to 12 per litter in the southern part of their range. Young are nursed for up to 90 days, the first 6 weeks of which is spent in the mother's pouch. After weaning long-tailed planigales are independent. ("Long-tailed Planigale", 2007; Fisher, et al., 2001; Grizmek, et al., 2005; "AnAge entry for Planigale ingrami", 2007; Lee and Cockburn, 1985; Nowak, 1999; Tyndale-Biscoe and Renfree, 1987)

  • Breeding interval
    Breeding intervals in long-tailed planigales are unknown.
  • Breeding season
    Long-tailed planigales living in the Northern Territories give birth December to March. Long-tailed planigales living in Queensland give birth in September.
  • Range number of offspring
    4 to 12
  • Average weaning age
    90 days
  • Average time to independence
    3 months

Like all marsupials, Planigale ingrami give birth to underdeveloped young. The young spend six weeks in their mother's pouch, after which they spend six weeks hidden in in a grassy nest or under bark while their mother searches for food. ("Long-tailed Planigale", 2007)

  • Parental Investment
  • pre-fertilization
    • provisioning
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female

Lifespan/Longevity

Long-tailed planigales live for up to 1.3 years in the wild. ("AnAge entry for Planigale ingrami", 2007)

  • Average lifespan
    Status: wild
    1.3 years

Behavior

Long-tailed planigales forage constantly. Females are quiet and timid if disturbed, whereas males are active and will run quickly for cover. Long-tailed planigales are nocturnal, and go into a daily torpor which lasts 2 to 4 hours to conserve energy. (Davey, 1970; Grizmek, et al., 2005; Hume, 1999)

Home Range

Home ranges of long-tailed planigales are not reported in the literature.

Communication and Perception

Long-tailed planigales are likely to use chemical and auditory cues, like most mammals. However, there is little information on communication in planigales in the literature.

Food Habits

Long-tailed planigales feed on many invertebrates that are often close to their same size, including insect larvae, and small vertebrates such as Leggadina. They are aggressive predators, pouncing on and often biting their prey multiple times to kill it. They hunt at night and their main diet consists of grasshoppers and crickets. They have been observed eating only the meaty part of the insects, leaving the head and wings. Because of their flat head and small body shape, long-tailed planigales can easily reach into the hiding spots of their prey, which hide in the same cracked soil and leaf litter that the planigales do. ("Long-tailed Planigale", 2007; Davey, 1970; Grizmek, et al., 2005)

  • Animal Foods
  • mammals
  • reptiles
  • insects
  • terrestrial non-insect arthropods

Predation

Long-tailed planigales use their small stature and flat skull to their advantage, they conceal themselves in cracks in soil, leaf litter, and other small crevices to hide and escape from predators. The brownish color of their fur helps them blend in with their surroundings, making it harder for predators to spot them. Common predators are larger animals such as cane toads (Rhinella marina), domestic cats (Felis silvestris), and various types of snakes. (Harris and Barrett, 2006)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

Long-tailed planigales may help to control populations of the small animals that they prey on. (Davey, 1970; Grizmek, et al., 2005)

Economic Importance for Humans: Positive

Long-tailed planigales are important members of their native ecosystems.

Economic Importance for Humans: Negative

There are no known negative affects of Planigale ingrami on humans.

Conservation Status

There are three recognized sub-species: Planigale ingrami ingrami, Planigale ingrami brunnea, and Planigale ingrami subtilissima, little planigales.

Neither P. i. ingrami nor P. i. brunnea are endangered, but P. i. subtilissima are on the U.S. Federal list as endangered.

Other Comments

Other common names for Planigale ingrami are northern planigales, Ingram's planigales, and flat-headed planigales.

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Kristen Olson (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon.

Glossary

Australian

Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.

World Map

acoustic

uses sound to communicate

bilateral symmetry

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.

carnivore

an animal that mainly eats meat

chemical

uses smells or other chemicals to communicate

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

endothermic

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.

forest

forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.

insectivore

An animal that eats mainly insects or spiders.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

polygynandrous

the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

tactile

uses touch to communicate

temperate

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).

terrestrial

Living on the ground.

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

year-round breeding

breeding takes place throughout the year

References

Joao Pedro de Magalhaes. 2007. "AnAge entry for Planigale ingrami" (On-line). AnAge. Accessed December 05, 2007 at http://www.genomics.senescence.info/species/entry.php?species=Planigale_ingrami.

Creative Commons licence. 2007. "Long-tailed Planigale" (On-line). BIRD: linking the biodiversity community. Accessed January 01, 2007 at http://bird.net.au/bird/index.php?title=Long-tailed_Planigale.

Archer, M. 1982. Carnivorous Marsupials Volume 1. Mosman, N.S.W, Australia: Royal Zoological Society of New South Wales.

Armati, P., C. Dickman, I. Hume. 2006. Marsupials. New York: Cambridge University Press.

Davey, K. 1970. Australian Marsupials. Hong Kong: Lansdowne Press Pty. Ltd..

Fisher, D., I. Owens, C. Johnson. 2001. "The ecological basis of life history variation in marsupials" (On-line). Echological Archives. Accessed December 05, 2007 at http://esapubs.org/archive/ecol/E082/042/appendix-A.htm.

Grizmek, B., N. Schlager, D. Olendorf. 2005. "Answers.com" (On-line). Long-Tailed Planigale. Accessed January 01, 2007 at http://www.answers.com/topic/long-tailed-planigale-1?cat=technology.

Harris, J., S. Barrett. 2006. "A Miniscule Marsupial" (On-line). ABC North West Queensland. Accessed January 01, 2007 at http://www.abc.net.au/northwest/stories/s1697199.htm.

Hume, I. 1999. Marsupial Nutrition. New York, NY: Cambridge University Press.

Lee, A., A. Cockburn. 1985. Evolutionary Ecology of Marsupials. New York: Cambridge University Press.

Nowak, R. 1999. Walker's Mammals of the World Volume 1, Sixth Edition. Baltimore, Maryland: Johns Hopkins University Press.

Stonehouse, B., D. Gilmore. 1977. The Biology of Marsupials. Baltimore: University Park Press.

Tyndale-Biscoe, H., M. Renfree. 1987. Reproductive Physiology of Marsupials. New York, NY: Cambridge University Press.

Van Deusen, H. 1969. Feeding Habits of Planigale (Marsupialia, Dasyuridae). Journal of Mammalology, Vol. 50 No. 3: 616-618.