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.
- Biogeographic Regions
- australian
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.
- Habitat Regions
- temperate
- terrestrial
- Terrestrial Biomes
- savanna or grassland
- forest
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.
- Other Physical Features
- endothermic
- homoiothermic
- bilateral symmetry
- Sexual Dimorphism
- sexes alike
Reproduction
Males and females have multiple mates.
- Mating System
- polygynandrous (promiscuous)
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.
- Key Reproductive Features
- iteroparous
- seasonal breeding
- year-round breeding
- gonochoric/gonochoristic/dioecious (sexes separate)
- sexual
- viviparous
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.
- Parental Investment
-
pre-fertilization
- provisioning
-
protecting
- female
-
pre-hatching/birth
-
provisioning
- female
-
protecting
- female
-
provisioning
-
pre-weaning/fledging
-
provisioning
- female
-
protecting
- female
-
provisioning
Lifespan/Longevity
Long-tailed planigales live for up to 1.3 years in the wild.
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.
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.
- Primary Diet
-
carnivore
- eats terrestrial vertebrates
- insectivore
- eats non-insect arthropods
- 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 (
Bufo marinus
), domestic cats (
Felis silvestris
), and various types of snakes.
- Anti-predator Adaptations
- cryptic
Ecosystem Roles
Long-tailed planigales may help to control populations of the small animals that they
prey on.
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.
Additional Links
Contributors
Tanya Dewey (editor), Animal Diversity Web.
Kristen Olson (author), University of Oregon, Stephen Frost (editor, instructor), University of Oregon.
- Australian
-
Living in Australia, New Zealand, Tasmania, New Guinea and associated islands.
- native range
-
the area in which the animal is naturally found, the region in which it is endemic.
- 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.
- forest
-
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
- 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.
- 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.
- polygynandrous
-
the kind of polygamy in which a female pairs with several males, each of which also pairs with several different females.
- 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).
- seasonal breeding
-
breeding is confined to a particular season
- year-round breeding
-
breeding takes place throughout the year
- sexual
-
reproduction that includes combining the genetic contribution of two individuals, a male and a female
- viviparous
-
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
- nocturnal
-
active during the night
- motile
-
having the capacity to move from one place to another.
- sedentary
-
remains in the same area
- solitary
-
lives alone
- visual
-
uses sight to communicate
- tactile
-
uses touch to communicate
- acoustic
-
uses sound to communicate
- 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.
- carnivore
-
an animal that mainly eats meat
- insectivore
-
An animal that eats mainly insects or spiders.
References
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.
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 .