Western brush wallabies are endemic to Australia, with the current range confined to the southwestern coastal region of Western Australia.
Biogeographic Regions: australian (Native )
Found in the southwest region of Western Australia.
Western brush wallabies are gray with slight brown variation in color on the neck and back. The alternative common name, black-gloved wallabies, is derived from the black coloring on the fore- and hind limbs. The most distinctive features of western brush wallabies, and those that are most useful for distinguishing it from western grey kangaroos (Macropus fuliginosus), are facial characters. They have two unique white stripes that extend from each of the ears to the end of the rostrum. The pinnae are also black on the exterior and a slightly lighter white or buff color in the interior. The chest is gray, the ventral portion of the abdomen is buff, and the tail has a black crest at its most distal end. Some individuals also have a faint black banded patterning on their dorsal side. Western brush wallabies can further be distinguished from the western grey kangaroos by their smaller size, significantly shorter forelimbs, and distinct gait: they move quickly with the head kept low and the tail extended rather than in an upright posture.
The second largest native mammal in southwest Western Australia, individuals range from 7 to 9 kg and have been reported up to 1530 mm in length. The tail comprises a large portion of this measurement and is between 540 and 970 mm long. Not including the tail, the head and body measurement ranges from 450 to 525 mm. Although size varies within the species, there is no significant observable sexual dimorphism.
As with other macropodids, the hind limbs of western brush wallabies are adapted to fast, powerful, hopping locomotion. The hind foot is slender and lacks a hallux. The second and third digits are fused to form a syndactylous digit, and the fourth digit is elongated and robust. The fourth digit bears the bulk of the energy transferred from the leg to the ground during hopping. Macropodids tend to exhibit a secondary form of slow 'pentapedal' locomotion, whereby the tail is used in conjunction with the forelimbs to support the weight of the body while the hind legs are swung forward.
Basal metabolic rate of Macropus irma is unknown, but marsupials in general tend to have lower basal metabolic rates than eutherian mammals. Some authors have suggested that this is correlated with saltatorial locomotion, which requires less energy than other forms of sustained locomotion.
Range mass: 7 to 9 kg.
Range length: 830 to 1530 mm.
Other Physical Features: endothermic ; homoiothermic; bilateral symmetry
Sexual Dimorphism: sexes alike
Preferred habitat for Macropus irma is open forest or woodlands with seasonally wet sites and low vegetation. This species is often found in dry schlerophyll forests, such as jarrah, and areas of mallee and heathland scrub. It is rarely found in wet schlerophyll forests and is not found in ecosystems characterized by a thick understory, such as karri forests.
Habitat Regions: temperate ; terrestrial
Terrestrial Biomes: savanna or grassland ; forest ; scrub forest
Habitat and Ecology
Little detailed information has been documented about the diet of Macropus irma, but individuals appear to prefer native grasses and can survive without access to free water for extended periods of time. Wallaby stomachs are divided into four chambers and their ability to ferment and extract nutrients from high-fiber food sources, such as grasses, makes them successful herbivores. Western brush wallabies generally graze for sustenance in open areas.
Plant Foods: leaves
Primary Diet: herbivore (Folivore )
Western brush wallabies are preyed on by red foxes and may influence vegetation through their herbivory. Marsupial mammals are vulnerable to mycobacterial infections and Mycobacterium avium has been noted as a significant disease risk for Macropus irma, particularly among captive populations.
- Mycobacterium avium
The two primary predators of Macropus irma are introduced red foxes (Vulpes vulpes) and humans (Homo sapiens. Native predators of young may include large snakes and monitor lizards.
- red foxes (Vulpes vulpes)
- humans (Homo sapiens)
Life History and Behavior
Wallabies in general often communicate with hoarse growls and cough-like vocalizations, particularly to communicate aggression. It has been noted that several wallabies also express alarm by stamping their feet on the ground. Soft clucking is common in males attempting to attract mates and for females interacting with their young. The use of pheromones to check females as they approach estrus has also been observed in Macropus eugenii. Western brush wallabies have not been well studied, so specific information is currently unavailable.
Communication Channels: visual ; acoustic ; chemical
Other Communication Modes: pheromones
Perception Channels: visual ; tactile ; acoustic ; chemical
The lifespan of Macropus irma has not been widely documented in wild populations or in captivity, and Macropus irma has historically been uncommon in reserves. The closely related Macropus eugenii, however, lives to be about 11 years old, a fairly common age range for most mid-sized macropodids.
The mating system of western brush wallabies is not well documented. However, Tammar wallabies (Macropus eugenii) are morphologically similar, have a partially overlapping range, are closely related, and have been more extensively studied. Macropus eugenii has a polygynous mating system with clear male dominance hierarchies. Reproductive success is closely correlated with physical size and presumably with success in agonistic interactions. The majority of first copulations with females are achieved by alpha males, with the majority of the offspring also sired by the alpha males that secure the first copulation. Females usually mate with more than one male and subsequent copulations have been observed with males other than the alpha. Tammar wallabies also engage in a variety of behaviors to enhance reproductive success and secure mates. Males mate-guard pre- and post-copulation, check females, and intervene in consortships developing between a female and another male. Alpha males tend to engage in all of these sexual behaviors with greater frequency than lower-ranking males, making social stratification in Macropus eugenii distinct. Males of several macropodid species also make a clucking sound when courting females to attract a mate.
It is, however, important to note that there are distinguishing features between Macropus eugenii and Macropus irma that may have implications for how closely the western brush wallaby mating system resembles that of Tammar wallabies. For instance, Macropus eugenii is sexually dimorphic, common in polygynous species, but Macropus irma does not exhibit sexual dimorphism.
There is little information available in the literature on reproduction in western brush wallabies. Females give birth to a single offspring usually in April or May. The newborn then spends up to 7 months in the pouch attached to one of the mother's 4 teats, after which point it leaves the pouch to suckle occasionally while it accompanies the mother on foot. Embryonic diapause, a period during which hormonal signals delay embryonic development, is common among macropodids and has been noted in Macropus irma. In other closely related seasonal breeders such as Tammar wallabies, females enter post-partum oestrus after giving birth and mate shortly thereafter. The fertilized ovum resulting from this copulation enters embryonic diapause at the blastocyst stage and reenters active embryonic development once the pouch young vacates. The age of sexual maturity is not well known in western brush wallabies, but Macropus eugenii females and males are sexually mature at 8 months and 24 months, respectively.
Breeding interval: Breeding interval in western brush wallabies is not documented and may vary by seasonal and unpredictable conditions, such as the availability of food.
Breeding season: Females typically give birth in April or May.
Average number of offspring: 1.
Key Reproductive Features: iteroparous ; seasonal breeding ; gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization ; viviparous ; embryonic diapause
Western brush wallabies give birth to a single offspring. The female then spends a 7 month period carrying the newborn in her pouch and continues to suckle even after it vacates. Furthermore, a female cannot gestate another fertilized egg until after her current suckling offspring is weaned, meaning that she is fully invested in one offspring at a time both physiologically and behaviorally. The reproductive life of Macropus irma has not been formally observed and recorded, but characteristic features of closely related species, such as the polygynous mating system of Macropus eugenii and the tendency for Macropus eugenii males to copulate with multiple females in succession, suggests that parental investment may be almost exclusively maternal for western brush wallabies
Parental Investment: altricial ; female parental care ; pre-fertilization (Provisioning, Protecting: Female); pre-hatching/birth (Provisioning: Female, Protecting: Female); pre-weaning/fledging (Provisioning: Female, Protecting: Female)
After successful fox baiting programs instated to elevate population count after the 1970's, Macropus irma has been classified as a species of Least Concern. It has a large, stable population and a relatively wide distribution, including multiple protected areas.
US Federal List: no special status
CITES: no special status
IUCN Red List Assessment
Red List Category
Red List Criteria
Relevance to Humans and Ecosystems
There are no known adverse effects of Macropus irma on humans.
In the early stages of European settlement, Macropus irma was traded in large numbers for fur. Records indicate annual individual sales as high as 122,000 in 1923.
Positive Impacts: body parts are source of valuable material
Western brush wallaby
The western brush wallaby (Macropus irma), also known as the black-gloved wallaby, is a species of wallaby found in the southwest coastal region of Western Australia. The wallaby's main threat is predation by the introduced red fox (Vulpes vulpes). The IUCN lists the western brush wallaby as Least Concern, as it remains fairly widespread and the population is believed to be stable or increasing, as a result of fox control programs.
The western brush wallaby has a grey colour with distinctive white colouring around the face, arms and legs (although it does have black gloves as its alternative common name implies). It is an unusually diurnal macropod that eats mainly grass.
The western brush wallaby was classified as M. irma in 1837. Synonyms include Halmaturus irma  and M. manicatus contributed by Jay Gould in 1852. It also goes by the common names of the Kwoora  or the black-gloved wallaby. The western brush wallaby falls under the order Diprotodontia which is composed of marsupials with only one pair of incisors in the lower jaw (although a second, non-functional pair may be present), three pairs of uppers incisors, and no lower canine teeth. All of these characteristics of the teeth are clear adaptions for an herbivorous diet. The western brush wallaby is in the superfamily Macropodoidea, the suborder Phalangerida, and the subgenus Notamacropus. They are part of the largest family of marsupials, Macropodidae, which are believed to have become secondarily terrestrial after descending from arboreal marsupials.
Little is known about the behaviour of the western brush wallaby, however much of their behavior is consistent with that of other members of the Macropodidae family.
Although quite small, the western brush wallaby's coloring resembles the larger kangaroos of the region. The western brush wallaby's head and body length usually falls around 1.2 m. Their tail length, which ranges from 54–97 cm, is proportionally long to their smaller body size. The adult western brush wallaby weighs anywhere from 7.0-9.0 kg. Their coloring consists of a pale to mid gray coat with a distinct white facial stripe. Other distinct features include black and white ears, black hands and feet, and crest of black hairs on the tail. The size of the male and female are quite similar.
The western brush wallaby is a herbivore, although there is disagreement on whether it is a browser, eating mainly leaves, or a grazer, eating mainly grass, as there has not been extensive research done. It is a diurnal animal, which is somewhat unusual for macropods, and is active during dawn and dusk, making it crepuscular. It rests during the hottest part of the day and at night either singly or in pairs, taking shelter in bushes and small thickets . The wallabies will consume most species of plants, with the Carpobrotus edulis, Cynodon dactylon, and Nuytsia floribunda being the common dietary items. One source suggests that the wallaby’s diet is made up of 3-17% of grasses and sedges, 1-7% forbs, and 79-88% browsing material (mainly the leaves of low shrubs). The stomach is divided into four compartments where microorganisms can ferment the fibrous plant material. They appear to be able to survive without free water.
Although decades of research have been done in regards to the reproductive behavior of the western brush wallaby, their habits are relatively unknown. The young are usually born during April and May. Females, like all marsupials, have a well-developed forwardly opening pouch containing four teats. The female gives birth to one young a time, with two rarely occurring. Gestation lasts from three to five weeks. After birth, the young enter the lactation period for seven months, until October or November. After vacating the pouch the young wallaby goes through a weaning period during which it will stick its head in the pouch temporarily attach itself to a teat.
Like all others in the Macropodidae family, the western brush wallabies are characterized by powerful hind limbs and long hind feet. It runs by weaving or sidestepping, utilizing its powerful hind-limbs, while keeping its head low and its tail extended straight, making it very speedy.
The western brush wallaby resembles peramelemorphs in having syndactyl second and third toes on the hind-foot, where the two small digits are fused together except at the tip, where a pair of slender claws protrudes. Macropods are uniquely “pentapedal” meaning that at slow speeds they move by moving the weight of the body onto their forelimbs and their down-turned tail while the hind-limbs swing forward. This movement makes for a rather awkward slow gait. When moving quickly the fourth toe, which is the longest and strongest, is aligned with the axis of the foot and plays an important role in the hopping motion while the tail functions in keeping its balance.The hind-legs cannot move backwards nor can they move independently of each other (unless swimming or on its side) allowing for a more energy efficient hopping. The forelimbs of macropods are small and weakly developed.
Distribution and habitat
The western brush wallaby is found in the southwest coastal region of Western Australia from Kalbarri all the way down to Cape Arid, particularly centralized near the Swan River. They are found in some areas of mallee and heathland and are uncommon in wet sclerophyll forests. There are none in the true Karri forests because of the thick undergrowth present. They prefer tall open forests that supply good grazing. They particularly favor open, seasonally damp flat areas with low grasses and open scrubby brushes. This type of open habitat contributes to the speediness of the animal as it moves low to the ground.
Population and conservation status
Exotic species have had a tremendous effect on Australia as it is, in ecological terms, an island not a continent and islands experience an unparalleled rate of extinction. In the 1970s the population the western brush wallaby began to decline as the population of the red fox dramatically increased. The red foxes particularly targeted the juvenile wallabies as soon as they left their mother's pouch. According to a survey taken in 1970 in the Jarrah Forests of the Darling Range, there were 10 individuals per 100 square kilometers; another survey was taken 1990 and the population had declined to 1 per 100 square kilometers. The population of the Western Grey Kangaroo, who only differs from the wallaby in its large size, was also monitored during this time; the kangaroo's population remained constant during the twenty years.
Kinnear's pioneering work in the 1990s provided the Department of Environment and Conservation of Western Australia with an effective method of controlling the foxes using meat and egg baits with “1080”, an environmentally-friendly toxin. His method proved successful and significantly contributed to the recovery of the western brush wallaby along with several other animal populations. Currently there are about 100,000 animals. Due to this recovery the western brush wallaby been moved from the IUCN Near Threatened list to the Least Concern list.
Although fox control measure has helped the population stabilize considerably, due to habitat clearing for farming the population is still fragmented and their range greatly reduced.
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