Parantechinus apicalissouthern dibbler

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Geographic Range

Although once widespread throughout southwest Australia, today Parantechinus apicalis is only found in small populations on the mainland. Two larger populations have recently been found inhabiting Boullanger and Whitlock Islands in Jurien Bay in Western Australia. (Miller, et al., 2003; Woolley, 1991)

Habitat

Southern dibblers on Whitlock Island prefer dense vegetation such as dunal scrubland and succulent heath. This may be due to the protection it provides from predators or an increased abundance of insect prey. Interestingly, when released from captivity into the wild they take refuge in seabird burrows. On Boullanger Island there seemed to be no preference of habitat as the entire island is fairly regular and has no trees. (Bencini, et al., 2001; Miller, et al., 2003; Mills and Bencini, 2000)

Physical Description

Southern dibblers are small, with males averaging 145 mm in length and 60 to 100 g. Male southern dibblers found on the mainland are generally heavier than island individuals. Females are smaller at 140 mm average and 40 to 75 g. They have pointed snouts, long whiskers, and strong jaws with sharp teeth. There are also grooves on the pads of their feet which function in providing good traction. These, along with sharp claws, allow them a good grip on trees and rocks. Parantechinus apicalis has rather coarse fur with a freckled appearance. The fur is brownish grey above and grayish white with yellow underneath. They have hairy tapering tails and distinctive white rings around large eyes. (Moro, 2003; Strahan, 1983; Woolley, 1991)

  • Sexual Dimorphism
  • male larger
  • Range mass
    40 to 100 g
    1.41 to 3.52 oz
  • Range length
    140 to 145 mm
    5.51 to 5.71 in

Reproduction

Typical behaviors prior to and during mating include sniffing of the cloacal and facial regions and rump by both the male and female. This behavior is common and increases in intensity as the female approaches estrous. Chases and attempted mountings are frequent. The male may chase the female or vice versa. Often the animals vocalize when they are chasing or attempting mountings. Mountings are initiated by the male and there are many attempts that are unsuccessful. Chasing and unsuccessful mountings may occur up to 15 days prior to copulation. Successful mountings involve the male clasping the female in a neck-grip and a single copulation may continue for a few hours. (Strahan, 1983; Wolfe, et al., 2000)

Paranechinus apicalis will mate throughout March and April. Although females are only able to breed once annually, males may be able to breed in multiple seasons. The gestation period for southern dibblers is long compared to other small dasyurids, 44 to 53 days. Once females give birth they carry up to eight young in a shallow pouch. The young are dependent on the female for 3 to 4 months and usually disperse in September and October, reaching sexual maturity in 10 to 11 months. (Collins, 1973; Miller, et al., 2003; Moro, 2003; Strahan, 1983; Woolley, 1988; Woolley, 1991)

  • Breeding interval
    Southern dibblers breed once yearly.
  • Breeding season
    Breeding occurs from March to April.
  • Average number of offspring
    8
  • Average number of offspring
    8
    AnAge
  • Range gestation period
    44 to 53 days
  • Range time to independence
    3 to 4 months
  • Range age at sexual or reproductive maturity (female)
    10 to 11 months
  • Range age at sexual or reproductive maturity (male)
    10 to 11 months

The extent of parental investment in southern dibblers involves the female carrying and protecting her young in a shallow pouch. She provides food and protection until the young reach independence and disperse in 3 to 4 months. (Strahan, 1983)

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

Lifespan/Longevity

In captivity and in the wild Parantechinus apicalis individuals live 2 to 3 years. Interestingly, on Boullanger Island males display semelparity where they die immediately after the breeding season. Extremely high energy demands during the breeding season, elevated levels of free corticosteroids in the blood, and related disease such as ulcers, anemia, and parasite infestation ultimately cause the death of males. Because mainland males survive for multiple breeding seasons, this male die-off could be environmentally determined. One possible explanation is the effect of nesting seabirds including bridled terns and white-faced storm petrels on resources. Seabirds affect nutrients in the soil; post-breeding survival is significantly higher on Whitlock Island which has many seabirds, 18 times more nutrients in the soil and a larger amount of insects. (Dickman and Braithwaite, 1992; Kraaijeveld, et al., 2003; Mills and Bencini, 2000; Strahan, 1983; Wolfe, et al., 2004; Woolley, 1991)

  • Range lifespan
    Status: wild
    1 to 3 years
  • Range lifespan
    Status: captivity
    2 to 3 years
  • Typical lifespan
    Status: wild
    2 to 3 years
  • Typical lifespan
    Status: captivity
    2 to 3 years

Behavior

Southern dibblers are active at both dawn and dusk hunting for large insects. If necessary, they can jump or climb trees in order to catch their prey. During the day they take shelter and rest in logs or between rocks. In reintroduced populations they form groups which vary around 100 individuals. (Cooper and Withers, 2004; Fisher and Dickman, 1993; Moro, 2003)

Home Range

No information on home range sizes in southern dibblers is was found.

Communication and Perception

Southern dibblers do vocalize, but vocalization is usually only heard during mating and plays no role in the attraction of mates. There is no other information on how P. apicalis communicates, perceives its environment, or attracts mates, but related species rely heavily on sight and smell. (Wolfe, et al., 2000)

Food Habits

Parantechinus apicalis is primarily insectivorous, eating whatever insects they can find. Being a generalist in this way may be advantageous due to fluctuating environmental conditions. Specifically P. apicalis has been found to eat grasshoppers (Orthoptera), cockroaches (Blattaria), beetles (Coleoptera), termites (Isoptera), and ants (Hymenoptera). Plant material, such as the berries of Rhagodia baccata, make up around 20% of its diet. Members of this species show no significant differences in their diet during different seasons. (Bencini, et al., 2001; Miller, et al., 2003)

  • Animal Foods
  • insects
  • Plant Foods
  • fruit
  • nectar

Predation

The color of the fur of southern dibblers is their best camouflage. They are also able to move easily and with speed through dense vegetation and, for these reasons, have few natural predators. Mainland populations are heavily preyed upon by introduced red foxes and feral cats. (Moro, 2003)

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

On the mainland southern dibblers prey on insects and are often prey to larger mammals. On the islands southern dibblers face little danger of predation but compete with introduced house mice for food. (Miller, et al., 2003)

Economic Importance for Humans: Positive

There are no known positive affects of Parantechinus apicalis on humans. They are a member of a unique fauna and may be of ecotourist interest because of their rarity.

Economic Importance for Humans: Negative

There are no known adverse affects of Parantechinus apicalis on humans.

Conservation Status

In 1902 southern dibblers were thought to be extinct but were rediscovered in 1967. They have been threatened by human development, habitat destruction and burning, and the introduction of foxes and cats. Southern dibblers are presently undergoing extensive conservation efforts including successful translocations of captive-bred individuals to Escape Island. Although this project is fairly new, initial success is high with three generations surviving after the initial relocation. (Bencini, et al., 2001; Mills and Spencer, 2003; Moro, 2003; Wolfe, et al., 2004)

Contributors

Tanya Dewey (editor), Animal Diversity Web.

Megan Coughlin (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Australian

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

World Map

acoustic

uses sound to communicate

altricial

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.

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

crepuscular

active at dawn and dusk

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.

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

ecotourism

humans benefit economically by promoting tourism that focuses on the appreciation of natural areas or animals. Ecotourism implies that there are existing programs that profit from the appreciation of natural areas or animals.

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.

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.

polygynandrous

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

polymorphic

"many forms." A species is polymorphic if its individuals can be divided into two or more easily recognized groups, based on structure, color, or other similar characteristics. The term only applies when the distinct groups can be found in the same area; graded or clinal variation throughout the range of a species (e.g. a north-to-south decrease in size) is not polymorphism. Polymorphic characteristics may be inherited because the differences have a genetic basis, or they may be the result of environmental influences. We do not consider sexual differences (i.e. sexual dimorphism), seasonal changes (e.g. change in fur color), or age-related changes to be polymorphic. Polymorphism in a local population can be an adaptation to prevent density-dependent predation, where predators preferentially prey on the most common morph.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

semelparous

offspring are all produced in a single group (litter, clutch, etc.), after which the parent usually dies. Semelparous organisms often only live through a single season/year (or other periodic change in conditions) but may live for many seasons. In both cases reproduction occurs as a single investment of energy in offspring, with no future chance for investment in reproduction.

sexual

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

social

associates with others of its species; forms social groups.

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.

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.

References

Bencini, R., C. McCulloch, H. Mills, A. Start. 2001. Habitat and diet of the dibbler (Parantechinus apicalis) on two islands in Jurien Bay, Western Australia. Wildlife Research, 28: 465-468. Accessed March 18, 2006 at www.publish.csiro.au/journals/wr.

Collins, L. 1973. Monotremes and Marsupials. Washington: Smithsonian Institution Press.

Cooper, C., P. Withers. 2004. Influence of season and weather on activity patterns of the numbat (Myrmecobius fasciatus) in captivity. Australian Journal of Zoology, 52: 475-485. Accessed March 18, 2006 at http://www.publish.csiro.au/journals/ajz.

Dickman, C., R. Braithwaite. 1992. Postmating mortality of males in the dayurid marsupials, Dasyurus and Parantechinus. Journal of Mammalogy, 73(1): 143-147. Accessed March 18, 2006 at http://www.jstor.org.

Fisher, D., C. Dickman. 1993. Body size-prey relationships in insectivorous marsupials: tests of three hypotheses. Ecology, 74(6): 1871-1883. Accessed March 18, 2006 at http://www.jstor.org.

Kraaijeveld, K., F. Kraaijeveld-Smit, G. Adcock. 2003. Does female mortality drive male semelparity in dasyurid marsupials?. Proc. R. Soc. Lond. B (Suppl.), 270: 251-253.

Miller, S., R. Bencini, H. Mills, D. Moro. 2003. Food availability for the dibbler (Parantechinus apicalis) on Boullanger and Whitlock Islands, Western Australia. Wildlife Research, 30: 649-654. Accessed March 18, 2006 at www.publish.csiro.au/journals/wr.

Mills, H., B. Spencer. 2003. Polymorphic microsatellites identified in an endangered dasyurid marsupial, the dibbler (Parantechinus apicalis). Molecular Ecology Notes, 3: 218-220.

Mills, H., R. Bencini. 2000. New evidence for facultative male die-off in island populations of dibblers, Parantechinus apicalis. Australian Journal of Zoology, 48: 501-510. Accessed March 18, 2006 at http://www.publish.csiro.au/journals/ajz.

Moro, D. 2003. Translocation of captive-bred dibblers Parantechinus apicalis (Marsupialia: Dasyuridae) to Escape Island, Western Australia. Biological Conservation, 111: 305-315. Accessed March 18, 2006 at http://www.elsevier.com/locate/biocon.

Strahan, R. 1983. The Australian Museum Complete Book of Australian Mammals. London-Sydney-Melbourne: Angus and Robertson Publishers.

Twigg, L., G. Martin, A. Eastman, D. King, W. Kirkpatrick. 2003. Sensitivity of some Australian animals to sodium fluoroacetate (1080): additional species and populations, and some ecological considerations. Australian Journal of Zoology, 51: 515-531. Accessed March 18, 2006 at http://www.publish.csiro.au/journals/ajz.

Wolfe, K., H. Mills, M. Garkaklis, R. Bencini. 2004. Post-mating survival in a small marsupial is associated with nutrient inputs from seabirds. Ecology, 85(6): 1740-1746.

Wolfe, K., H. Robertson, R. Bencini. 2000. The mating behavior of the dibbler, Parantechinus apicalis, in captivity. Australian Journal of Zoology, 48: 541-550. Accessed March 18, 2006 at http://www.publish.csiro.au/journals/ajz.

Woolley, P. 1988. Reproduction in the ningbing antechinus (Marsupialia: Dasyuridae): field and laboratory observations. Australian Wildlife Research, 15: 149-56.

Woolley, P. 1991. Reproductive pattern of captive Boullanger Island dibblers, Parantechinus apicalis (Marsupialia: Dasyuridae). Wildlife Research, 18: 157-63.