Dibblers are most active at dawn and dusk. They feed on ground-dwelling insects and other invertebrates but will also eat small lizards, small birds and small mammals. They are well adapted carnivores, with strong jaws and tiny sharp teeth, and are also incredibly agile and able to run through seemingly impenetrable undergrowth with ease. Not only are they well equipped for foraging in the undergrowth, but they can also run up trees and rocks. Their broad feet have claws on the toes, and grooves running along the feet pads which act as suckers (4).  Females have one oestrous cycle per year, and mating occurs in March or April (2). Following a gestation period of 44 days, the female gives birth to 8 young. The infants live and nurse in their mother's pouch for several weeks before growing too large (2).

The dibbler is one of the rarest mammals in the world (2). It is a small marsupial carnivore found in Australia. Like other members of the dasyurid family, it has a distinctive pointed snout, well developed canines, 6-7 sharp cheek teeth and broad feet bearing sharp claws (3). Its small mouse-like body is covered in coarse fur which is brownish-grey in colour, with distinctive white speckles. The tail is hairy and tapering, and there are distinctive white markings around the eyes (3). Females, like most marsupials, have pouches in which they carry the newborns until they are fully developed (3).

The Dibbler is endemic to south-western Australia. It occurs naturally in Fitzgerald River National Park and on the islands of Boullanger and Whitlock (Friend 2004). The species also occurs as translocated populations on Escape Island, Peniup, and Stirling Range National Park (Woolley 2008).

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.

Biogeographic Regions: australian (Native )

Historic Range:
Australia

This species is restricted to two small islands (Boullanger and Whitlock) off the southwest Western Australian coast. It also occurs on the Australian mainland in three widely separated areas (4).

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.

Range mass: 40 to 100 g.

Range length: 140 to 145 mm.

Other Physical Features: endothermic ; homoiothermic; bilateral symmetry ; polymorphic

Sexual Dimorphism: male larger

Habitat and Ecology

Systems

• Terrestrial

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.

Habitat Regions: temperate ; terrestrial

Terrestrial Biomes: desert or dune

Inhabits dense heath habitat and appears to prefer sites with sandy soils (4).

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.

Animal Foods: insects

Plant Foods: fruit; nectar

Primary Diet: carnivore (Insectivore )

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.

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.

Known Predators:

• red foxes (Vulpes vulpes)
• feral cats (Felis silvestris)

Anti-predator Adaptations: cryptic

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.

Communication Channels: visual ; acoustic ; chemical

Perception Channels: visual ; acoustic

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.

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.

Maximum longevity: 5.5 years (captivity) Observations: These animals are expected to live more than 3 years in the wild (Bernhard Grzimek 1990). One specimen lived 5.5 years in captivity (Richard Weigl 2005).

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.

Mating System: polygynandrous (promiscuous)

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.

Breeding interval: Southern dibblers breed once yearly.

Breeding season: Breeding occurs from March to April.

Average number of offspring: 8.

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.

Key Reproductive Features: semelparous ; iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); viviparous

Average number of offspring: 8.

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.

Parental Investment: altricial ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)

Year Assessed

Assessor/s

Reviewer/s

Justification

History

• 1996
  Endangered
• 1994
  Endangered
  (Groombridge 1994)
• 1990
  Indeterminate
  (IUCN 1990)
• 1988
  Indeterminate
  (IUCN Conservation Monitoring Centre 1988)
• 1986
  Indeterminate
  (IUCN Conservation Monitoring Centre 1986)
• 1982
  Indeterminate
  (Thornback and Jenkins 1982)

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.

US Federal List: endangered

CITES: no special status

IUCN Red List of Threatened Species: endangered

Current Listing Status Summary

Status: Endangered
Date Listed: 12/02/1970
Lead Region: Foreign (Region 10) 
Where Listed:


Population detail:

Population location: entire
Listing status: E

For most current information and documents related to the conservation status and management of Parantechinus apicalis, see its USFWS Species Profile

Classified as Endangered (EN B1+2ce) on the IUCN Red List 2003 (1).

Population

Population Trend

Major Threats

This species has been lost from 90% of its former range in Australia (4). It is not known why this marsupial is so rare, although surveys suggest various factors. Land clearing and habitat fragmentation are thought to be significant causes of its decline. In addition, the frequent burning of heathland and litter may reduce the availability of invertebrates in the area. Predation by introduced mammals such as foxes and cats are also considered a threat to this species (4).

Conservation Actions

In 1992 a recovery plan for this species was developed by the International Union for the Conservation of Nature and Natural Resources (IUCN), addressing the threats facing this species (4). Predation by foxes and cats has now been brought under control by The Department of Conservation and Land Management (CALM) and, in the last decade, dibbler numbers have started to increase (5). Perth Zoo has been working with CALM to establish a captive breeding stock of over 100 individuals of this species (6). They have also translocated a group of dibblers to Escape Island; a predator free island which has suitable habitat for this marsupial. Here, radio tracking devices and trapping practices will be used to monitor the populations (5). Considering that the dibbler was on the brink of extinction, this recovery plan has been a great success. It is however essential to maintain these conservation efforts as the dibbler is still regarded as a severely endangered animal (1).

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

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.

Positive Impacts: ecotourism