Myrmecobius fasciatus

Geographic Range

Since the beginning of European settlement in Australia, the abundance of numbats has declined dramatically. Previously occupying most of southern Australia, including New South Wales and Victoria, and parts of Western Australia and the Northern Territory, numbat are now extinct in approximately 99% of its former range. Only two natural populations remain, the Dryandra and Perup sites, both located in Western Australia. Reintroduced populations can be found in Dragon Rocks Nature Reserve, Batalling State Forest, Tutanning Nature Reserve, and Boyagin Nature Reserve (all located in Western Australia), Yookamurra Sanctuary (located in South Australia), and Scotia Sanctuary (located in New South Wales).

• Biogeographic Regions
• australian australian
  • introduced introduced
  • native native

• Other Geographic Terms
• island endemic island endemic

Habitat

When numbats were abundant, they occupied semi-arid and arid woodlands (composed of flowering trees and shrubs of the genera Eucalyptus and Acacia ) and grasslands (composed of grasses of the genera Triodia and Plectrachne ). Now, they can only be found in eucalypt woodlands, which are located at an elevation of approximately 317m, in the wettest periphery of the former range because of the abundance of old and fallen trees. The logs of eucalypt woodlands play a great role in aiding in the survival of numbats. At night, the numbats seek shelter inside hollow logs, and during the day, numbats can avoid predators, especially birds and foxes, by staying hidden within the darkness of the logs. During mating seasons, logs provide numbats an area for their nesting sites. Most importantly, the heartwood of the majority of trees in eucalypt woodlands are eaten by termites, which are the base of the numbat's diet. Numbats depend on sufficient presence and availability of termites so much so that the presence of termites restricts the habitat of numbats to areas only where termites can be found. If areas are too wet or too cold, termites will not flourish, and, thus, neither will numbats.

• Habitat Regions
• temperate temperate
• terrestrial terrestrial

• Terrestrial Biomes
• forest forest

Physical Description

Numbats are small, slender carnivorous marsupials, weighing between 300 g and 752 g, and measuring 175 mm to 290 mm body length and 120 mm to 210 mm tail-length. The head is relatively small and flat with an elongated, pointed snout and a slim, sticky tongue that has the capability to extend to at least 100 mm. The coat is composed of short, stiff, reddish-brown or grey-brown hair, which is marked by four to eleven white bands running across the back and rump, giving each individual a unique, distinct appearance. A single dark stripe, accentuated by a white band below it, crosses each side of the face and travels through each eye. The hair on the tail tends to be slightly longer than the hair on the body. Tails do not differ greatly among numbats; they tend to be brown in color interspersed with white with an orange-brown color on the underside. The hair on the ventral side, or abdomens, of numbats are white. The eyes and ears are located high on the head, and the erect ears are twice as long as broad. The forefeet, which bear five toes, and the hind feet, which bear four toes, all have strong, sharp claws. Unlike other mammals, numbats do not have proper teeth but instead have blunt “pegs” because they do not chew their food. In female numbats, there is no trace of a proper pouch; instead, skin folds, which are covered in short crimped, golden hair, enclose the young when suckling from one of the four nipples found on the abdomen. In addition to the skin folds, females and males differ from one another in body mass, with males tending to weigh slightly more than females. Females weigh between 320 g and 678 g, averaging 478 g. While males weigh between 300 g and 715 g, averaging 597 g. When young, newborn numbats range in length from less than 20 mm to 75 mm, and the snout is extremely shortened. When the young reach the length of approximately 30 mm, a light downy coat arises, and this coat eventually bears the characteristic white stripes when the numbat is about 55 mm in length.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

Leading up to the mating season, which occurs from December to January, male numbats secrete an oily substance from their sternal gland, which is located at the top of the chest. Turning the fur red, this pungent oil is rubbed over surfaces of logs and rocks by the male. In addition to advertising to females that the male is looking for a mate, the smell also warns other males to stay away from his territory. When a male desires a certain female, he will follow her and pay particularly close attention to her cloacal region by sniffing it. Both the male and female will vocalize to one another, producing sounds that are composed of a series of soft clicks. Numbats vocalize only during two different periods in their life (during the breeding season and during infancy when communicating with the mother); however, breeding vocalizations are significantly different than baby numbat vocalizations. If a female rejects male advances, loud altercations will take place. The female will produce low, throaty, aggressive growls with her mouth closed. At times, the male will attempt to mount the aggravated female, which will lead to them tumbling together on the ground with the female growling. The male may still try to pursue the female by chasing her, or he may stop his advances all together. After copulation, which ranges in time from less than one minute to an hour, the male may leave immediately in order to mate with another female, or he may stay in the den (hollow logs, burrows, and nests composed of bark, grass, and leaves) until the mating season ends. However, after the reproductive season finishes, the male will leave the female. The female then cares and tends to the young by herself. Numbats are polygynous, meaning males mate with more than one female; thus, during the next breeding season, the male will mate with a different female.

• Mating System
• polygynous polygynous

The reproductive cycles of numbats are seasonal, with the female producing one litter per year. The female is polyestrous, which means she has several estrous cycles during a single breeding season. Thus, females that have failed to conceive or have lost their young may conceive again with a subsequent mate. Males too have a distinct fertility cycle; the sperm appear in early December, decline in February, and are absent by March. Females first breed when they are 12 months of age, and males are sexually mature at 24 months. After a gestation period of 14 days, female numbats give birth to four young in January or February. The underdeveloped young, which are about 20 mm long, travel to the mother's nipples. Unlike most marsupials, female numbats lack a pouch to house the young. Instead, the four nipples are covered by crimped, golden hair that differs greatly from the long white hair on her chest. There, the young entwine their forelimbs in the specialized crimped hair of the mammary area and attach to her nipples for up to six months until the young have grown so large that the mother cannot walk properly. By late July or early August, the young are detached from the nipples and are placed in the nest. Although detached from the nipples, they continue to suckle until they are approximately nine months of age. In late September, the young begin to forage for themselves, becoming independent and moving to a territory of their own by November.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous
• post-partum estrous

Males play no part in post-breeding parental investment, leaving females to care for the young alone. After females give birth, the underdeveloped young immediately travel to the mother's nipples and attach. The litter size usually consists of four numbats so that all nipples are occupied. Due to the fact that there is no pouch, the young survive by holding onto the mother only by their oral attachment to the nipples and by entwining their forelimbs into the crimped hair of the mammary area, also known as skin folds. The young stay attached to the mother for approximately six to seven months. By this time, the young are so big that they cause the mother to walk abnormally; thus, she removes them from her body and places them in a log or burrow. Provisioning and protecting her young, the mother consistently returns to the log or burrow to suckle them until they are eight or nine months of age. Over the next two months, the young begin to investigate the area outside their nest, encountering their first predators and eating termites. The mother weans them from her milk between ten and eleven months of age. By the twelfth month, the juveniles leave their mother to find their own territory, forage for themselves, and breed.

• Parental Investment
• altricial altricial
• female parental care female parental care
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female
• pre-independence
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

The average lifespan for male or female numbats in the wild is four to five years, as compared to seven years for a female and eleven years for a male in captivity. The lifespan for those in the wild is quite short because numbats are constantly preyed on by foxes, raptors, and cats. Therefore, their longevity is limited by the injuries incurred from their predators and their constant expenditure of energy in trying to survive. In addition, when captive-bred numbats are released in the wild, they lack the basic knowledge and skills to avoid their predators. This is demonstrated by the research at Perth Zoo in Western Australia. In the year 2000, Perth Zoo implemented an experimental training program where young captive-bred numbats were exposed to a raptor while loud noises and bird alarm calls were sounded. The results suggest that these trained numbats had a higher survival rate over the first 5 months after release than the untrained numbats. Due to training programs, as well as fox-and-cat-control programs, the mortality rate of numbats in the wild (recorded in the year 2011) has dropped to a fairly low rate.

Behavior

Numbats are very unusual marsupials in that they are diurnal, or active only in the daytime. The diurnal activity is due to its termite diet. Because numbats are not powerful enough to break into termite mounds to get to their prey, they have to feed during the day when there is a great abundance of active termites in the shallow galleries.

Numbats also exhibit seasonal patterns related to photoperiod, prey abundance, and reproduction. During the spring and summer seasons, numbats are active for a longer time during a 24 period. Wandering and feeding in mid-morning and in the late afternoons, numbats only takes a short "rest" during mid-day when it takes shelter in a hollow log. However, during autumn and winter, numbats are active later in the morning and returns to their shelter earlier in the afternoon, staying active during mid-day. These patterns reflect how numbats take advantage of the daylight to scour for termites, while also attempting to minimize thermoregulatory costs.

Numbats are solitary animals, except for mothers caring for their young and males and females sharing a nest temporarily during the breeding season. The young numbats of a litter play with one another, running and chasing until they reach 10 months of age. Once they leave the home range, they establish their own territory, which they maintain for life.

When numbats roam, they walk or trot with a jerky movement. Occasionally they will stop to feed, while continuing to scan their surroundings for predators. When sitting, they take on the appearance of dasyurids , small carnivorous marsupials of Australia. Sitting vertically on their hind feet, numbats will keep their forepaw raised in alert. When excited or stressed, numbats arche their tail over their back and erect their fur. If feeling disturbed or threatened, they take off into a bounding run, reaching speeds up to 32 km per hour, until they reache a hollow log or burrow. After pausing briefly to look into the shelter before it enters, numbats press their body firmly against the inner wall and grasps the sides with their claws to prevent any attempt of extraction. Once the threat has passed, they come out of hiding head first and continue on.

• Key Behaviors
• terricolous
• fossorial fossorial
• diurnal diurnal
• crepuscular crepuscular
• motile motile
• sedentary sedentary
• solitary solitary
• territorial territorial

Home Range

Numbats maintain an individual home range of approximately 50 hectares. Members of the same sex are excluded from these ranges; however, males and females may have overlapping territories. Sheltering at night in hollow logs and burrows, or nests composed of bark, grass, and leaves at times, numbats use a large number of sanctuaries within a certain home range. Numbats tend to select logs that area approximately 8 cm in diameter, and they dig burrows that are straight shafts about 1 m long, 15 to 23 cm in diameter, and 10 to 60 cm below ground. These logs and burrows provide numbats with a perfect living environment, buffering temperatures, humidity, and other environment conditions. For example, the logs and burrows tend to be on average 5 degrees Celsius warmer than outside temperatures during winter, as well as cooler during summer, which provide an adequate environment for young as well as aiding in reducing thermoregulatory costs.

Communication and Perception

Numbats produce a variety of vocalizations. During breeding season, if a female and male are both interested in one another, they vocalize by producing a series of soft clicks. However, if a male approaches a female and she rejects his advances, she will produce growling vocalizations that may lead to loud altercations. A similar vocalization that resembles these growling sounds can also be heard from numbats that are being handled or disturbed. Differing slightly, these distressed low-throaty growls are produced with the mouth closed, along with a repetitive "tut tut tut." Another type of vocalization is the hissing growls produced by numbats that are protecting their territory against foreign numbats. Besides the breeding season and stressful situations, the only other time one tends to hear vocalizations produced by numbats are when a mother is caring for her young. Once the young have emerged from the log or burrow, the mother communicates with them by soft chirping sounds.

The numbat relies heavily on sight, hearing, and smell when perceiving their environment. Constantly on alert when roaming and feeding, the numbat detects threats from predators primarily by sound (hearing the predator's approach) and vision (seeing their approach). When feeding, the numbat only uses smell. The numbat's incredibly keen sense of smell allows them to locate termite galleries, brimming with prey, despite the fact that some galleries are as far as 50 mm below the surface of the soil. Smell is also used during breeding season. When a male has found a female, he smears an oily, foul-smelling substance from his sternal gland around the female numbat's territory, which wards off other males.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• scent marks scent marks

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

Food Habits

Numbats diets consist primarily of termites , although they ingest some predator ants by accident while eating termites. Eating approximately 15,000 to 20,000 termites per day, numbats have evolved several morphological features in order to be successful in obtaining and feeding on termites. The elongated snout is used for getting into logs and small holes in the ground to search for termites. Their nose is extremely sensitive, sensing the presence of termites by smell and small vibrations in the ground. A long, thin tongue, which is coated with saliva, allows numbats to gain access to the termite passageways, also known as galleries, and quickly withdraw several termites that have adhered to the sticky saliva. The saliva is produced from a pair of quite enlarged and complex salivary glands. The forefeet and hind feet bear razor-sharp claws, which allow numbats to dig rapidly into termite galleries in the soil. Their mouths are filled with 47 to 50 blunt "pegs," instead of proper teeth as in other mammals, because numbats do not chew the termites.

Numbats daily diet of termites, which corresponds to approximately 10% of the body weight of an adult numbat, includes the genera Heterotermes , Coptotermes , Amitermies , Microcerotermes , Termes , Paracapritermes , Nasutitermes , Tumulitermes , and Occasitermes , usually in proportion to their relative abundance. Due to the fact that Coptotermes and Amitermies are the most common termite species in numbat habitat, these two genera are the most commonly eaten. However, numbats do have preferences; some lactating females prefer Coptotermes species at certain periods of the year, and some numbats have refused to eat Nasutitermes species during the winter.

In "Fauna of Australia," by J.A. Friend, author J.H. Calaby (1960) describes feeding in numbats. Numbats use scent to locate termite galleries and begin to dig out the insects with both feet rapidly. Numbats use their tongue to pick up exposed termites and may leave to find another gallery or dig in the same gallery once termites are no longer exposed. Numbats also turn over leaves and sticks with their teeth to expose and prey upon termites.

• Primary Diet
• carnivore carnivore
  • insectivore insectivore

• Animal Foods
• insects

Predation

Numbats fave several predators on a daily basis. The three primary predators of the numbat are red foxes , raptors , and feral cats . Unfortunately, because of their small size, they are easy prey for these predators. Even the smaller species of these predators, such as little eagles , which ranges in size from 45 cm to 55 cm, can effortlessly overpower numbats. At times, numbats are also taken by snakes , such as carpet pythons , and large lizards , such as sand goannas . Due to the fact that the number of these predators are overly elevated in fragmented woodlands, the populations of numbats have decreased rapidly since they are constantly being preyed upon.

Numbats have several adaptations for predator avoidance. It primarily avoids detection while roaming on the forest floor by the composition of its hair color, which camouflages with the surrounding brush. The erect ears located high on the head and the eyes located on the opposite sides of their head allow numbats to hear or see predators coming towards them. If numbats sense danger or encounters a predator, they will freeze and keep very still until the danger has passed. If pursued, numbats will run to shelter and grasp the sides of the enclosure. At times, numbats may also try to ward off predators by producing low-throaty growls along with a repetitive "tut tut tut."

• Anti-predator Adaptations
• cryptic cryptic

Ecosystem Roles

Numbats play an important role in controlling termite populations. Numbats feed on approximately 20,000 termites daily. The termite species consumed are based on their abundance. Although uncommon, ants can also be found in the termite diet, but these ants are incidentally consumed while numbats are feeding on termites. In addition, numbats invariably ingests debris (at least 0.33 g of dirt for every gram of organic matter) that adheres to the tongue along with the termites.

Numbats are hosts for many species of endo- and ectoparasites. Three nematodes ( Beveridgeiella calabyi , Beveridgeiella inglisi , Mulusentis myrmecobius ), have been found in the alimentary tract of numbats. A new species of acanthocephalan ( Mulusentis myrmecobius ) uses arthropods as intermediate hosts; thus, numbats are infected by this acanthocephalan by feeding on infected termites. Several ectoparasites have also been found on numbats, including mites ( Mesolaelaps australiensis ), ticks ( Ixodes vestitus , Ixodes myrmecobii , Amblyomma triguttatum ), and fleas ( Echidnophaga myrmecobii , Echidnophaga perilis ).

• Ecosystem Impact
• creates habitat
• keystone species keystone species

Economic Importance for Humans: Positive

When numbats used to flourish throughout Southern Australia, parts of Western Australia, and the Northern Territory, Aboriginal natives hunted them for food. Known to these people as the "walpurti," numbats were captured by being chased into burrows and then dug up by hand in order to eat. However, due to the dramatic decrease in numbat populations, numbat are now a protected species that has become of great importance to scientists and environmental program agencies. By studying numbats, scientists are gaining a greater understanding of several different aspects of mammalogy, such as morphology, physiology, and ecology. A collection of up to two hundred specimens of numbats can be found in museums. This not only aids scientists in their research, but also benefits future generations that are interested in this species as well as mammals in general. Environmental program agencies have also benefited from numbats. Necessitating intensive work for over twenty years, a number of environmental program agencies, which were founded to save the numbats from extinction, have been provided long-term support for their recovery programs allowing program longevity. In addition to once being important to the Aboriginal people and currently to scientists and environmental program agencies, numbats assist in the control of the termite population in eucalypt woodlands, eating approximately 15,000 to 20,000 termites per day.

• Positive Impacts
• food food
• research and education
• controls pest population

Economic Importance for Humans: Negative

There are no known adverse effects of numbats on humans.

Conservation Status

Numbats are currently listed by the IUCN Red List and the US Fish & Wildlife Service as an endangered species. Decreasing in population by more than 20% within a short five years (between the years 2003 and 2008), numbat populations contain approximately less than 1,000 mature individuals globally. There are two native sites of the species, Dryanda and Perup of Western Australia. In Dryanda, populations have and continue to decrease dramatically for unknown reasons, declining from an estimated peak of 600 in 1992 to 50 in 2012 today. In Perup, populations are stable and possibly increasing in number. In reintroduced sites, there are 500 to 600 numbat individuals and populations seem stable; however, they are not self-sustaining and, thus, are not considered secure.

The introduction of several predators, specifically red foxes and raptors , have greatly added to the decline in numbat populations. The introduction of rabbits and rats may also have increased the number of feral cats in the habitat, which are another major predator of numbats. In addition to the increase in predators, changed fire regimes and habitat destruction in some areas have reduced the number of logs, which numbats use as shelter for resting, refugees from predators, and as a source of termites (the base of their diet).

A number of conservation actions have been taken. These include captive breeding, reintroduction programs, protected areas, and red fox control programs. Other objectives for recovery, as listed by Maxwell et al. (1996), are also being implemented, such as trying to increase the number of self-sustaining populations to at least nine and the number of individuals to over 4,000.

Additional Links

Encyclopedia of Life

Contributors

Angelique de la Riva (author), Sierra College, Jennifer Skillen (editor), Sierra College, Laura Podzikowski (editor), Special Projects.

References

Cooper, C., P. Withers. 2002. Metabolic physiology of the numbat (Myrmecobius fasciatus). Journal of Comparative Physiology. B , 172/8: 669-675. Accessed March 31, 2012 at http://www.ncbi.nlm.nih.gov/pubmed/12444465 .

Cooper, C. 2011. Myrmecobius fasciatus (Dasyuromorphia: Myrmecobiidae): Iss. 881. Mammalian Species (Online) , 43/879-883: 129-140. Accessed March 04, 2012 at http://www.bioone.org/doi/abs/10.1644/881.1 .

Fletcher, T., P. Spencer, T. Friend, S. Jackson. 2003. Numbats. Pp. chapter 4, 99-119 in Australian Mammals: Biology and Captive Management . Collingwood VIC, Australia: CSIRO Publishing.

Friend, J., D. Neil. 2003. Conservation of the Numbat (Myrmecobius fasciatus). Pp. 452-463 in Predators with Pouches: The Biology of Carnivorous Marsupials . Collingwood VIC, Australia: CSIRO Publishing.

Friend, J. 1989. Myrmecobiidae. Pp. chapter 22, 1-18 in Fauna of Australia Volume 1B . Canberra ACT, Australia: AGPS Canberra.

Friend, T., A. Burbidge. 2011. "Myrmecobius fasciatus" (On-line). IUCN Red List of Threatened Species. Accessed March 04, 2012 at http://www.iucnredlist.org/apps/redlist/details/14222/0 .

Harradine, N. 2012. "Numbat Numbers in Decline" (On-line). ABC News. Accessed May 03, 2012 at http://www.abc.net.au/news/2011-08-23/numbat-numbers-in-decline-feature/2851582 .

2005. "Annotated CITES Appendices and Reservations" (On-line pdf). Convention on International Trade in Endangered Species of Wild Fauna and Flora. Accessed March 30, 2012 at http://www.cites.org/eng/resources/pub/checklist08/Annotated_CITES_Appendices_and_reservations.pdf .

Zoological Society of London. 2012. "Numbat (Myrmecobius fasciatus)" (On-line). EDGE: Evolutionarily Distinct and Globally Endangered. Accessed March 31, 2012 at http://www.edgeofexistence.org/mammals/species_info.php?id=165 .

2012. "Numbat (Myrmecobius fasciatus)" (On-line). U.S. Fish and Wildlife Service. Accessed March 30, 2012 at http://ecos.fws.gov/speciesProfile/profile/speciesProfile.action?spcode=A044 .

Project Numbat Inc. 2012. "Numbats" (On-line). Project Numbat. Accessed March 31, 2012 at http://numbat.org.au/numbats/ .

Australian Marsupials and Monotremes Specialist Group, IUCN Survival Commission. The Action Plan for Australian Marsupials and Monotremes. Project No 500. Australia: Maxwell S., Burbidge A.A. and Morris K. 1996.