By Kristen Olson
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. (Creative Commons licence, 2007; Davey, 1970; Grizmek, Schlager, and Olendorf, 2005)
Biogeographic Regions:
australian 
(native ).
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. (Creative Commons licence, 2007; Davey, 1970; Grizmek, Schlager, and Olendorf, 2005)
These animals are found in the following types of habitat:
temperate ; terrestrial .
Terrestrial Biomes:
savanna or grassland ; forest .
Physical Description
(0.15 oz)
(2.17 to 2.56 in; avg. 2.32 in)
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. (Creative Commons licence, 2007; Davey, 1970; Grizmek, Schlager, and Olendorf, 2005; Hume, 1999; Joao Pedro de Magalhaes, 2007; Tyndale-Biscoe and Renfree, 1987)
Some key physical features:
endothermic ; homoiothermic; bilateral symmetry .
Sexual dimorphism: sexes alike.
Reproduction
Breeding intervals in long-tailed planigales are unknown.
Long-tailed planigales living in the Northern Territories give birth December to March. Long-tailed planigales living in Queensland give birth in September.
Males and females have multiple mates. (Grizmek, Schlager, and Olendorf, 2005)
Mating systems:
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. (Creative Commons licence, 2007; Fisher, Owens, and Johnson, 2001; Grizmek, Schlager, and Olendorf, 2005; Joao Pedro de Magalhaes, 2007; Lee and Cockburn, 1985; Nowak, 1999; Tyndale-Biscoe and Renfree, 1987)
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. (Creative Commons licence, 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. (Joao Pedro de Magalhaes, 2007)
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, Schlager, and Olendorf, 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. (Creative Commons licence, 2007; Davey, 1970; Grizmek, Schlager, and Olendorf, 2005)
Primary Diet:
carnivore (eats terrestrial vertebrates, insectivore , eats non-insect arthropods).
Animal Foods:
mammals; reptiles; insects; terrestrial non-insect arthropods.
Predation
- cane toads (Bufo marinus)
- domestic cats (Felis silvestris)
- snakes (Serpentes)
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. (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, Schlager, and Olendorf, 2005)
Economic Importance for Humans: Negative
There are no known negative affects of Planigale ingrami on humans.
Economic Importance for Humans: Positive
Long-tailed planigales are important members of their native ecosystems.
Conservation Status
IUCN Red List: [link]:
Not Evaluated.
US Federal List: [link]:
Endangered.
CITES: [link]:
No special 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.
For More Information
Find Planigale ingrami information at
Contributors
Tanya Dewey (editor), Animal Diversity Web, University of Michigan Museum of Zoology.
Kristen Olson (author), University of Oregon. Stephen Frost (editor, instructor), University of Oregon.
