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Macropus

Macropus is a genus of herbivorous marsupials belonging to the family Macropodidae and subfamily Macropodinae, endemic to Australia.^[1] The name Macropus derives from the Greek words makros ("long") and pous ("foot"), referring to the elongated hind limbs and feet adapted for efficient hopping locomotion at speeds exceeding 50 km/h.^[2] Following a 2019 taxonomic revision, the genus now includes only two extant species of large kangaroos: the eastern grey kangaroo (Macropus giganteus) and the western grey kangaroo (Macropus fuliginosus), previously part of a broader complex that encompassed wallaroos and certain wallabies now classified in the genera Osphranter and Notamacropus.^[3] These species exhibit sexual dimorphism, with males typically larger than females, and females possess a forward-opening abdominal pouch containing four teats for nursing underdeveloped young (joeys).^[2] They are primarily grazers and browsers, relying on grasses, forbs, and shrubs for sustenance.^[4] The eastern grey kangaroo (Macropus giganteus), one of the largest marsupials, has males reaching up to 90 kg in weight.^[5] These animals inhabit diverse ecosystems, from arid deserts and grasslands to open woodlands and coastal regions, often forming social groups known as mobs for foraging and protection.^[4]

Taxonomy

Etymology and History

The genus name Macropus derives from the Ancient Greek terms makros (μακρός), meaning "long" or "large", and pous (πούς), meaning "foot", a reference to the notably elongated hind feet of its members.^[6] The genus Macropus was established in 1790 by the English naturalist George Shaw, with Macropus giganteus (the eastern grey kangaroo) designated as the type species. Early taxonomic efforts prior to Shaw's work had been initiated by German scientists in the 1770s, but Shaw's description formalized the genus based on specimens from Australia.^[6] In the early 19th century, European naturalists such as Coenraad Jacob Temminck and René Lesson expanded classifications within Macropus, incorporating a broader array of kangaroo-like marsupials from newly collected specimens, leading to initial inclusions of species now recognized in separate genera.^[7] This period saw significant taxonomic debate due to morphological variations observed in preserved samples, with Macropus encompassing diverse forms until more refined distinctions emerged later in the century.^[8] A major taxonomic revision occurred in 2019, when molecular and morphometric analyses by Celik et al. recommended elevating the subgenera Osphranter and Notamacropus to full genus status, thereby restricting Macropus sensu stricto to just two extant species (noting that traditional classifications included approximately 14 species across the three subgenera).^[3] This change, building on earlier proposals from 2015, was accepted by the Australian Faunal Directory, reflecting updated phylogenetic evidence from genetic and skeletal data.^[9]

Extant Species

The genus Macropus comprises two extant species of large kangaroos, both characterized by their robust build and adaptation to open habitats, though they exhibit distinct morphological and ecological traits.^[8] The eastern grey kangaroo (Macropus giganteus) features a pelage ranging from light to dark grey, with the underparts notably paler for camouflage in varied light conditions.^[8] Males typically stand 1.7–2 m tall when upright and weigh up to 90 kg, reflecting sexual dimorphism where males are significantly larger than females (three subspecies recognized: M. g. giganteus, M. g. tasmaniensis, M. g. melanops). This species inhabits open forests, woodlands, and sclerophyll habitats across eastern Australia, extending to Tasmania, where it thrives in areas with annual rainfall exceeding 250 mm and up to subalpine elevations.^[10] In contrast, the western grey kangaroo (Macropus fuliginosus) displays a darker, sooty grey fur with a blackish face and paws, providing better concealment in the denser scrub of its range; the underparts are paler, similar to its eastern counterpart.^[11] Adult males measure 1.6–2 m in height and weigh up to 72 kg, showing comparable dimorphism but slightly smaller overall size than M. giganteus (two subspecies recognized: M. f. fuliginosus, M. f. melanops).^[12]^[12] It occupies open woodlands, grasslands, and coastal heathlands in southwestern and southern Australia, from Shark Bay southward to the South Australian border and including Kangaroo Island, favoring semi-arid to temperate zones with grassy understories.^[13] Key differences between the species include fur color variation, with M. fuliginosus exhibiting a more uniformly dark, sooty tone suited to its westerly habitats, compared to the lighter, variable grey of M. giganteus.^[11] Additionally, M. fuliginosus demonstrates a regional adaptation through high tolerance to fluoroacetate, a toxin prevalent in southwestern Australian plants like those in the genus Gastrolobium, enabling it to exploit food sources lethal to other macropods including M. giganteus.

Fossil Record

The genus Macropus is known from a diverse fossil record in Australia, encompassing at least 11 recognized extinct species from the Pleistocene epoch, with subsequent discoveries suggesting the total may reach 13. These fossils, primarily from the late Pleistocene, document the genus's adaptation and diversification amid fluctuating climates and landscapes. Remains are dated to between approximately 2 million and 10,000 years ago, aligning with the Quaternary period's progression toward greater aridity across the continent.^[14] Notable among these extinct forms are large-bodied species that exemplify the genus's size variation, such as Macropus titan, estimated to have reached a body mass of around 150 kg and standing up to 2.1 meters tall, making it one of the largest confirmed members of Macropus. An even more massive unnamed Macropus species, discovered at the South Walker Creek locality in Queensland, is estimated at 274 kg, surpassing all other known kangaroos in scale and highlighting the potential for extreme gigantism within the genus.^[15]^[16] Key fossil sites contributing to this record are concentrated in southern Australia, including Lancefield Swamp in Victoria, where mass-death assemblages of megafauna including Macropus remains have been dated to about 42,000–46,000 years ago, and the Naracoorte Caves in South Australia, which preserve a range of Pleistocene vertebrate fossils from karst deposits spanning 500,000 years. These localities have yielded skeletal elements like femora, dentaries, and teeth that inform on the paleobiology of extinct Macropus taxa.^[17]^[18] Evolutionary trends evident in the Macropus fossil record include morphological adaptations to arid environments during the Quaternary, such as enhanced hindlimb proportions for efficient locomotion in open grasslands and dietary shifts reflected in dental wear patterns suited to tougher, drier forage. Gigantism in certain species, as seen in M. titan and the unnamed South Walker Creek form, likely arose in response to climatic cooling and drying, enabling larger body sizes to exploit sparse resources and reduce predation risk in expanding savanna habitats.^[19]^[20]

Physical Description

Morphology

Members of the genus Macropus exhibit a distinctive body plan adapted for efficient terrestrial locomotion, characterized by elongated hind limbs that are significantly longer and more muscular than the forelimbs, a bulkier pelvic girdle compared to the pectoral girdle, and a center of mass positioned toward the pelvic region to facilitate hopping.^[7] The forelimbs are reduced in size and strength, featuring a simple manus with five digits of roughly equal length and no opposable thumb, primarily suited for grasping vegetation and grooming rather than locomotion or weight-bearing.^[7] A long, muscular tail, often comprising half to the full length of the head-body, provides balance during movement and additional propulsion at slower speeds, while remaining non-prehensile and covered in hair.^[21]^[7] Specialized hind limb features include an elongated femur, tibia, and fibula, with the fourth digit enlarged for primary weight support and the first digit absent; the second and third digits are syndactylous (fused), aiding in grooming and reducing drag during strides.^[7] The hind feet are large and elongated, with a narrow plantar surface and padded soles that enhance traction and energy efficiency in bounding; tarsal joint modifications limit motion primarily to flexion-extension for stability.^[21] Powerful biarticular ankle extensor muscles, such as the gastrocnemius and plantaris, connect to long, compliant tendons analogous to the Achilles tendon in other mammals, enabling elastic energy storage and release during jumps—recovering up to 50% of mechanical energy in larger species.^[21] These adaptations collectively support sustained bipedal hopping as the primary mode of travel. Cranially, Macropus species possess a skull with a pronounced sagittal crest along the midline, providing anchorage for the temporalis jaw muscles to generate forceful bites, and a deep masseteric fossa for masseter muscle attachment.^[22]^[7] The dentition follows a diprotodont pattern with a dental formula of I 3/1, C 1/0, PM 2/2, M 4/4 (totaling 32-34 teeth), featuring large lower incisors for cropping vegetation and high-crowned (hypsodont) molars with transverse ridges suited for grinding fibrous plant material.^[7] Sensory adaptations include medium-sized eyes positioned for wide lateral and some binocular vision, with notably large ocular structures in species like Macropus eugenii supporting crepuscular activity patterns by enhancing low-light detection.^[23] Sensitive mystacial vibrissae (whiskers) around the slit-like nares and muzzle serve for close-range tactile exploration, aiding in foraging and navigation in dim conditions.^[7]

Size and Sexual Dimorphism

Members of the genus Macropus exhibit considerable variation in adult body size across species, with head-body lengths typically ranging from 0.45 to 1.6 m and tail lengths adding 0.35 to 1.05 m.^[7]^[24] Body weights for adults generally fall between 4 and 90 kg, influenced by species, sex, and environmental factors, with the largest individuals recorded in species like the red kangaroo (M. rufus) reaching up to 90 kg and standing over 2 m tall.^[7]^[24] Sexual dimorphism is pronounced in Macropus, particularly in larger species, where males are typically 1.5 to 2 times heavier than females and exhibit broader heads, thicker necks, and more developed forearm musculature adapted for agonistic interactions such as boxing.^[25]^[26] In extreme cases, such as the red kangaroo and common wallaroo (M. robustus), adult males can weigh up to six times more than females, a disparity linked to intense male-male competition for mating access.^[7] Females, by contrast, are smaller overall, an adaptation that may support higher reproductive efficiency through reduced energy demands during gestation and lactation.^[27] Growth in Macropus species follows a biphasic pattern, with rapid development occurring during the pouch phase, where joeys increase in size exponentially over 6-10 months depending on the species.^[28] Post-weaning, growth slows, and sexual dimorphism emerges as males continue to expand in mass and linear dimensions at a faster rate than females; males typically attain maximum size between 4 and 6 years of age, coinciding with full skeletal maturity and peak muscle development.^[28]^[29] Compared to the related genus Notamacropus, which includes smaller wallabies weighing 4-20 kg and measuring 0.5-1 m in head-body length, Macropus species are notably larger, reflecting adaptations to open habitats that favor greater body size for efficient locomotion and thermoregulation.^[7]^[30] However, extant Macropus forms are smaller than some extinct macropod relatives, such as species in the genus Procoptodon, which exceeded 100 kg.^[26]

Distribution and Habitat

Geographic Range

The genus Macropus is endemic to Australia and New Guinea, with the majority of species distributed across the Australian mainland and the island state of Tasmania. One species, the agile wallaby (Macropus agilis), extends to southern New Guinea and nearby islands. Eastern species, such as the eastern grey kangaroo (Macropus giganteus), are distributed from northern Queensland through New South Wales and Victoria to southeastern South Australia, with a subspecies extending to Tasmania. Western species, including the western grey kangaroo (Macropus fuliginosus), occupy areas from northern Western Australia eastward to the Nullarbor Plain and into parts of South Australia and New South Wales, while the red kangaroo (Macropus rufus) spans most of the mainland interior, excluding the wetter coastal fringes in the southwest and southeast.^[5]^[13]^[31] Prior to European settlement around 1788, Macropus species maintained widespread distributions shaped by Indigenous fire-stick farming and hunting practices, which supported open habitats across much of the continent for over 65,000 years. Post-settlement, ranges have shown overall stability for large species, with habitat clearance for agriculture and pastoralism converting forests to grasslands that favored their expansion in some regions, though overhunting and localized degradation led to contractions, particularly in Tasmania for the forester kangaroo subspecies (M. giganteus tasmaniensis).^[32]^[33] No significant introduced populations of Macropus exist outside their native range in Australia and New Guinea, unlike certain smaller macropods translocated to New Zealand or Pacific islands. The central arid deserts, including the Nullarbor Plain and broader inland zones, act as formidable barriers to dispersal, isolating eastern and western lineages and driving genetic divergence, as evidenced by distinct mitochondrial and nuclear markers between species like the eastern and western grey kangaroos.^[32]^[34]

Habitat Preferences

Species of the genus Macropus predominantly inhabit open ecosystems such as eucalypt woodlands, grasslands, and savannas across Australia, where they require proximity to water sources for survival, particularly in semi-arid regions. These kangaroos generally avoid dense rainforests and climax forests, favoring instead landscapes that combine grassy foraging areas with scattered cover for protection. For instance, the eastern grey kangaroo (M. giganteus) selects semi-arid mallee scrub, open woodlands, and forests with grassy understories, while the red kangaroo (M. rufus) thrives in arid open plains and shrublands with occasional trees for shade.^[10]^[4] Adaptations to these habitats enable Macropus species to tolerate semi-arid and arid conditions, especially in western and central Australia, through efficient water conservation and behavioral thermoregulation. Western grey kangaroos (M. fuliginosus) and red kangaroos exhibit tolerance for low-rainfall areas by utilizing moisture from succulent vegetation and resting in shade during peak heat, reducing water loss. Eastern grey kangaroos seek shade more frequently under moderate temperatures, crouching to enhance convective cooling, and prefer diverse landscapes with heathlands and shrublands for shelter from predators and weather. All species utilize scattered eucalypts or shrubs for daytime refuge, with shade reducing solar exposure by up to 80%.^[35]^[36]^[37] Seasonal movements in Macropus are nomadic, driven by rainfall patterns, with individuals shifting to greener pastures during wet seasons and concentrating near permanent water in dry periods to access reliable resources. Red kangaroos, in particular, demonstrate high mobility, traveling up to hundreds of kilometers in response to pasture availability, while grey kangaroos exhibit more localized shifts within home ranges of varied sizes. These patterns ensure access to optimal conditions amid Australia's variable climate.^[4]^[38]^[39] Habitat fragmentation influences Macropus preferences toward ecotones, or edges between forested and open areas, which provide balanced opportunities for cover and visibility to evade predators. This edge preference is evident in grey kangaroos selecting cleared zones adjacent to woodlands, enhancing survival in patchy landscapes without venturing into uniform open or dense habitats.^[37]^[40]

Behavior and Ecology

Locomotion

Macropus species exhibit a distinctive hopping gait that transitions from pentapedal progression at low speeds to bipedal bounding at higher velocities. At slower paces, typically below 5 m/s, individuals employ all four limbs and the tail in a coordinated sequence, with the tail acting as a fifth limb to provide support, propulsion, and power equivalent to the combined forelimbs.^[41] This pentapedal motion allows for stable movement in confined spaces, resembling a quadrupedal walk augmented by tail assistance. As speeds increase, the gait shifts to bipedal hopping, where the forelimbs are held aloft and propulsion relies primarily on the elongated hindlimbs, enabling strides of up to 9 m.^[42] The energy efficiency of this locomotion stems from elastic energy storage in the Achilles tendons and digital flexor tendons of the hindlimbs, which recycle mechanical energy to minimize metabolic costs during sustained activity. In red kangaroos (Macropus rufus), oxygen consumption remains nearly constant at around 1.25 ml O₂ kg⁻¹ s⁻¹ across hopping speeds from 2 to 6.4 m/s on level ground, allowing travel over long distances without proportional increases in fatigue.^[43] This mechanism, supported by tendon strains that store and return up to 70% of the energy needed for each hop, contrasts with the rising metabolic demands seen in quadrupedal runners and facilitates efficient foraging over arid landscapes.^[44] Maximum speeds reach 60–70 km/h in short bursts for predator evasion, with red kangaroos capable of maintaining averages of ~40 km/h for several minutes.^[45]^[46] Daily foraging travels typically span several kilometers (median ~6 km for red kangaroos), depending on resource availability and environmental conditions.^[38] Beyond hopping, Macropus individuals can walk on all fours using the pentapedal gait in tight enclosures and demonstrate swimming proficiency via alternating fore- and hindlimb strokes to keep the head above water, often as an escape response during floods.^[47] These capabilities are enabled by specialized hindlimb morphology, including long femora and tibiae adapted for powerful extension.^[48] Macropus species, such as the eastern grey kangaroo (M. giganteus) and western grey kangaroo (M. fuliginosus), typically live in fluid social groups known as mobs, consisting of 10 or more individuals, though average sizes range from 3 to 10 with occasional aggregations up to 50 in resource-rich areas.^[10]^[49] These groups feature a core of adult females and their young, with membership that is dynamic and open, allowing transient associations among males and subadults; dominant adult males often lead or associate closely with the group to maintain access to females.^[5]^[49] Interactions among males in Macropus mobs are characterized by ritualized agonistic behaviors to establish dominance, including upright "boxing" postures where opponents grasp forelimbs and deliver powerful kicks with hind legs aimed at the opponent's abdomen or torso.^[50] These displays, observed in species like the red kangaroo (M. rufus), rarely result in serious injury and serve primarily to assess strength for hierarchical positioning rather than direct resource competition.^[50] Communication is supplemented by vocalizations, such as guttural coughing growls emitted by aggressive males to signal dominance or alarm, which can alert group members to potential threats.^[49]^[10] Foraging in Macropus occurs predominantly as grazers, with individuals consuming grasses, forbs, herbs, and occasionally shrubs, selecting nutrient-rich vegetation like new growth during dry seasons to optimize intake.^[5]^[51] Activity peaks at dawn and dusk in a crepuscular pattern, with daily foraging bouts lasting 6-10 hours, during which adults ingest ~0.4–0.8 kg of dry matter for smaller individuals (~25 kg), scaling with body size up to ~2 kg for larger adults depending on availability.^[49]^[52] Group foraging enhances efficiency by allowing shared exploitation of patches, though individuals may disperse briefly before regrouping. Predation avoidance in Macropus relies on collective vigilance within mobs, where larger group sizes reduce per-individual scanning time due to the "many-eyes" effect, enabling faster detection of predators like dingoes (Canis dingo).^[53] Sentinels or alert individuals emit cough-like vocalizations or thumping foot stomps to warn the group, prompting evasive hopping that leverages their locomotion for rapid escape.^[49]^[53] This social strategy is particularly pronounced in open habitats, balancing foraging needs with risk mitigation.^[54]

Reproduction and Life History

Breeding Systems

Macropus species exhibit a promiscuous polygynous mating system, in which dominant males secure mating opportunities with multiple females through competitive interactions and guarding behaviors.^[29] During courtship, males approach receptive females, engaging in sniffing of the cloacal region to assess estrus, followed by persistent following and ritualized displays such as grooming and boxing to establish dominance.^[55]^[29] This system is influenced by sexual dimorphism, where larger male size aids in male-male competition for access to females.^[10] Breeding in Macropus is largely aseasonal under favorable environmental conditions, though it often peaks during wet seasons when food resources are abundant, leading to higher female fertility.^[4] A key physiological adaptation is embryonic diapause, where a fertilized embryo remains dormant in the uterus for several months, allowing delayed implantation until the previous young vacates the pouch.^[7] This mechanism enables superfetation, permitting a female to conceive a new embryo while one is already in diapause or developing, thus maximizing reproductive output in variable habitats.^[56] Gestation in Macropus typically lasts 30-36 days, varying slightly by species, after which a tiny newborn weighing approximately 1 gram emerges and instinctively crawls into the mother's pouch to attach to a teat.^[4]^[7] Generally, only one young is born per pregnancy, though the diapause process supports overlapping reproductive cycles.^[7] Males possess specialized scent glands that secrete an oily, strongly odorous substance used for marking territory and attracting females during courtship.^[49] Vocalizations, including growls and coughs, also play a role in male displays and competition for mates, signaling dominance in multi-male groups.^[57] In such groups, sperm competition occurs as multiple males may mate with a female, with dominant individuals achieving higher paternity success through pre- and post-copulatory mechanisms.^[58]^[59]

Development Stages

The development of Macropus joeys begins immediately after birth, with the underdeveloped newborn crawling unaided into the mother's pouch and latching onto a teat within minutes, where it remains attached for approximately 70-100 days as the teat swells to secure it in place.^[60]^[29] During this pouch life, which lasts 6-11 months depending on the species, the joey is nourished by milk whose composition changes dynamically to support sequential growth stages, starting with high-carbohydrate, low-protein milk for initial organ development and shifting to higher protein and lipid content in mid-lactation for rapid tissue growth and energy needs.^[61] For instance, in red kangaroos (Osphranter rufus, formerly Macropus rufus), early milk is dilute with elevated oligosaccharides for gut maturation, while later phases feature approximately 13% lipids to fuel emerging mobility.^[61] Joeys typically begin brief emergences from the pouch around 5-7 months to explore and graze, detaching from the teat but returning for nursing, with these excursions becoming more frequent as they develop fur and thermoregulatory abilities.^[60]^[29] In the juvenile phase, joeys achieve permanent emergence from the pouch at around 8-10 months, though they continue to suckle intermittently; for example, in western grey kangaroos (Macropus fuliginosus), this occurs at approximately 320 days, while in red kangaroos it is near 235 days.^[29]^[60] Weaning follows between 12-18 months, marking the transition to full independence in foraging, with young-at-foot joeys following their mothers closely during this period to learn grazing behaviors and avoid predators.^[60]^[29] This phase emphasizes physical conditioning for hopping locomotion and social integration into mob dynamics, lasting until sexual maturity. Sexual maturity in Macropus varies by sex and species, with females typically reaching it at 18-24 months—such as 20-36 months in western grey kangaroos—while males mature later at 2-4 years, often delayed until they achieve sufficient size for breeding competition, as seen in eastern grey kangaroos (Macropus giganteus) where males mature around 4 years.^[29]^[62] Lifespan in the wild averages 6-8 years due to predation and environmental stresses, though maximum recorded ages reach 12 years for females; in captivity, individuals can live up to 20 years with veterinary care and consistent nutrition.^[63]^[64] Post-pouch parental care involves continued nursing of young-at-foot for several months, with mothers providing protection and grooming while the juveniles follow during foraging; alloparenting is rare but documented through adoption of pouch young in eastern grey kangaroo mobs, where females may nurse non-offspring following misdirected care or loss of their own joey.^[29]^[65] This extended maternal investment supports juvenile survival until dispersal, often triggered by the birth of a new sibling via embryonic diapause reactivation.^[60]

Conservation and Threats

Population Status

Species within the genus Macropus, including the eastern grey kangaroo (M. giganteus), western grey kangaroo (M. fuliginosus), and red kangaroo (M. rufus), are classified as Least Concern on the IUCN Red List due to their wide distributions and large populations across Australia.^[66]^[12]^[67] Population trends are generally stable or increasing, supported by habitat management practices that enhance forage availability in rangelands and agricultural zones.^[68] Abundance estimates vary by species and region, reflecting their adaptability to diverse environments. For instance, the eastern grey kangaroo population in Queensland was estimated at approximately 10.7 million individuals in 2024, while in New South Wales, surveys indicated over 7.4 million across key zones in 2024.^[69]^[70] The western grey kangaroo numbered around 1 million in New South Wales' western plains in 2024, with additional populations in South Australia and Western Australia contributing to a national total exceeding 2 million and estimated around 4-5 million based on recent assessments.^[70]^[71] Densities can reach up to 100 individuals per km² in optimal habitats, such as well-watered grasslands.^[72] Population dynamics are characterized by high reproductive rates that compensate for natural mortality, enabling rapid recovery from environmental stressors like drought. Females typically produce one young per year, with embryonic diapause allowing flexibility in breeding timing, resulting in growth rates of 8-14% annually under favorable conditions.^[73] Monitoring occurs primarily through annual aerial surveys across commercial harvest zones in states like New South Wales, Queensland, and South Australia, providing reliable estimates with adjustments for visibility biases.^[74]^[68] Regional variations show higher densities in protected areas, where reduced human activity supports larger groups, compared to fragmented habitats near urban edges. For example, populations in South East Queensland have experienced local declines due to habitat fragmentation, with some subpopulations at risk of further reduction from development pressures.^[75] In contrast, densities in conserved rangelands often exceed 50 individuals per km², underscoring the influence of intact habitats on abundance.^[72]

Human Impacts and Protection

Human activities have significantly altered the habitats of Macropus species through agricultural expansion and urbanization, leading to fragmentation and loss of native grasslands and woodlands essential for their survival.^[76] Vehicle collisions pose a substantial mortality risk, particularly for larger species like the eastern grey kangaroo (Macropus giganteus), with road networks intersecting their movement paths and resulting in high incidences of fatalities.^[77] Additionally, limited culling programs are implemented in agricultural areas to mitigate crop damage, though these are regulated to prevent overexploitation.^[78] In the 19th century, intensive hunting by European settlers drastically reduced Macropus populations, driven by demand for hides, meat, and sport, which nearly led to local extinctions in some regions.^[79] Regulations introduced in the 1970s shifted management toward sustainability, establishing commercial harvesting frameworks to control numbers while allowing recovery.^[80] Climate change has intensified these pressures by exacerbating droughts, which reduce forage availability and increase starvation risks for Macropus species across arid and semi-arid Australia.^[81] Macropus species are protected under Australian federal and state legislation, including the Environment Protection and Biodiversity Conservation Act 1999 and state-specific acts like New South Wales' Biodiversity Conservation Act 2016, which prohibit unauthorized harm or trade.^[82] Sustainable harvesting is enforced through annual quotas, typically set at 10-20% of estimated populations for commercial and damage mitigation purposes, monitored by state wildlife agencies.^[83] Conservation initiatives include the development of habitat corridors in national parks and peri-urban areas to facilitate movement and gene flow, reducing isolation from fragmentation.^[84] Kangaroos hold profound cultural and spiritual significance for Indigenous Australians, symbolizing connection to Country and featured in Dreamtime stories, which bolsters community-led conservation efforts.^[31] Their iconic status in national identity, as emblems of Australian biodiversity and resilience, fosters widespread public support for protection programs and sustainable management.^[32]

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Jul 7, 2008 · Macropods show levels of sexual size dimorphism that amongst mammals are second only to those found in Phocid seals (Weckerly 1998). They are ...
[29]
Growth of Grey Kangaroos and the Reliablility of Age Determination ...
Sexual dimorphism in patterns ofgrowth was not detected during pouch life but was exhibited by all species after the young vacated the pouch and grew towards ...
[30]
Western Gray Kangaroo (Macropus fuliginosus) Fact Sheet
Apr 29, 2025 · Males reach adulthood at 45-50 kg (99-110 lb) or about 5 years old ... age/full adulthood; reasons for this trend are unclear (Dawson 2013) ...Gestation And Birth · Life Stages · Mortality And Health
[31]
https://www.bushheritage.org.au/species/kangaroos
[32]
Control and Conservation of Abundant Kangaroo Species - PMC
A special breed of “kangaroo dog” was selected from the greyhound and a more powerful breed such as the mastiff. Of the sport, Oxley in 1820 [57] enthuses: “I ...
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Forester Kangaroo (Macropus giganteus tasmaniensis) - DCCEEW
Oct 10, 2021 · Before European settlement, the Forester Kangaroo occurred over parts of eastern, central and northern Tasmania. It has contracted in range ...
[34]
(PDF) Gradient analysis of macropod distribution in open forest and ...
Macropod communities are most diverse in eastern Australia. Patterns of macropod abundance along environmental gradients were examined from data collected ...Missing: barriers | Show results with:barriers
[35]
Western Gray Kangaroo (Macropus fuliginosus) Fact Sheet
Apr 29, 2025 · Habitat · Prefer areas with enough cover to provide shelter from weather and predators, and open, grassy areas where they can find food · Highest ...
[36]
A continent-wide analysis of the shade requirements of red and ...
Apr 5, 2016 · giganteus and M. fuliginosus may reflect adaptive differences in properties such as fur insulation. In addition to seeking more shade, M ...
[37]
A Study of Habitat Preferences in the Grey Kangaroo - ResearchGate
Generally preferring habitats with a mixture of quality grass and forested areas [28] , eastern grey kangaroos occupy home ranges of 8-269 ha [29,30] and ...
[38]
Home range of the red kangaroo Macropus rufus - ScienceDirect.com
Firstly, males of large size and commensurate high status would range further than females in order to maximise encounters with oestrous females. Secondly, red ...Missing: dimorphism | Show results with:dimorphism
[39]
Habitat Selection by Sex, Age and Reproductive Class in the Red ...
The optimum habitat appears to be areas of wet sclerophyll forest with a thick shrubby understorey in association with grassy areas. Although the species may be ...<|separator|>
[40]
Habitat separation in the grey kangaroos, Macropus giganteus ...
Habitat preferences of ... Macropus rufogriseus, the most diurnal species, occurred at comparatively low and uniform densities throughout th e study area.
[41]
The kangaroo's tail propels and powers pentapedal locomotion
Jul 1, 2014 · Kangaroos use their muscular tail to support, propel and power their pentapedal gait just like a leg. 1. Introduction. Kangaroos are well known ...
[42]
Why walk when you can jump? | Student Voices - Nature
Jun 29, 2012 · Energetics and biomechanics of locomotion by red kangaroos (Macropus rufus). Comparative Biochemistry and Physiology (Part B), 120, 41-49 ...
[43]
Energetics and biomechanics of locomotion by red kangaroos ...
As red kangaroos hop faster over level ground, their rate of oxygen consumption (indicating metabolic energy consumption) remains nearly the same.
[44]
[PDF] Energetics and biomechanics of locomotion by red kangaroos ...
As red kangaroos hop faster over level ground, their rate of oxygen consumption (indicating metabolic energy consumption) remains nearly the same.
[45]
PMC Search Update - PubMed Central - NIH
Sep 18, 2013 · A large kangaroo hops at an average speed of 40 km h−1 for several ... maximum in the deep zone and then decreased in the calcified zone.Missing: length | Show results with:length
[46]
(PDF) How kangaroos swim - ResearchGate
Aug 7, 2025 · When first submerged in water the kangaroos showed a diving reflex; they did not inhale water, and then maintained their heads and necks above the surface.
[47]
Functional morphology of the hindleg in two kangaroos Macropus ...
In this study the structures in the hindleg of the kangaroo which are potentially available for jumping were examined. Specimens of two species, Macropus ...
[48]
Behavior & Ecology - Western Gray Kangaroo (Macropus fuliginosus ...
Apr 29, 2025 · Forage 6-10 hours per day, often around dawn and dusk (Priddel 1986) · Spend about 20% less time foraging during the summer (may be due to ...Missing: habits | Show results with:habits
[49]
Boxing in Red Kangaroos, Macropos Rufus: Aggression or Play?
Formalized fights in red kangaroos, lacking resource conflict, are likely play-fighting, with the goal to push opponents off balance, not inflict injury.
[50]
Diet & Feeding - Western Gray Kangaroo (Macropus fuliginosus ...
Apr 29, 2025 · Western Gray Kangaroo (Macropus fuliginosus) Fact Sheet: Diet & Feeding ... Western gray kangaroo has a high tolerance to the plant toxin ...
[51]
Water use and feeding patterns of the marsupial western grey ...
Aug 6, 2025 · Water use and feeding patterns of the marsupial western grey kangaroo (Macropus fuliginosus melanops) grazing at the edge of its range in arid ...
[52]
Eastern Grey Kangaroo (Macropus giganteus) Vigilance Behaviour ...
Jul 27, 2019 · This is the first study to compare the vigilance behaviour between urban and non-urban populations of a large mammal across regions.
[53]
Predation-sensitive grouping and habitat use by eastern grey ...
A study of habitat preferences in the grey kangaroo (Macropus giganteus). Australian Wildlife Research, 8 (1981), pp. 245-254. View in Scopus Google Scholar.
[54]
courtship and mating
As with other species, the most common sexual interaction is the sexual checking of the female by males. The male approaches the female and sniffs her cloacal ...Missing: Macropus traits scent glands sperm competition
[55]
Macropod Reproduction (Kangaroo and Wallaby) | About the Roos
Kangaroos have a 28-day pregnancy, no placenta, and the baby climbs to the pouch. They can also suspend a second pregnancy until the first is gone.
[56]
Australian Journal of Zoology - CSIRO Publishing
More commonly, head rubbing evoked hissing and snapping from the female. The male and female vocalisations recorded during courtship interactions were ...
[57]
Sperm competition and sexual selection in western grey kangaroos ...
It is suggested that dominant males invest heavily in large forelimb muscles, which aids in male-male competition, female coercion and increased attractiveness ...Missing: behavior courtship scent glands vocalizations
[58]
(PDF) Is there evidence for a trade-off between sperm competition ...
Aug 6, 2025 · Western grey kangaroos (Macropus fuliginosus) are found in large, labile mixed-sex groups, in which the males show a dominance hierarchy. Males ...Missing: vocalizations | Show results with:vocalizations
[59]
Reproduction & Development - Red Kangaroo (Osphranter rufus ...
Apr 29, 2025 · Young from blastocyst stage will have developed to birth stage within a day of the previous young's exit from the pouch.Missing: Macropus | Show results with:Macropus<|control11|><|separator|>
[60]
Marsupial and monotreme milk—a review of its nutrient and immune ...
Jun 23, 2020 · Milk is the primary source of sustenance for young marsupials and monotremes and its composition varies at different stages of development.
[61]
Composition of Milk from Red and Grey Kangaroos with Particular ...
Analysis of milk from red and grey kangaroos confirmed that the composition of milk from individual mammary glands changes with advancing age of the ...
[62]
Eastern Grey Kangaroo - Billabong Sanctuary
Eastern Grey Kangaroos mature at about 4 years of age, and females mature at about 18 months of age.<|control11|><|separator|>
[63]
Eastern Grey Kangaroo facts for wildlife tour guides
Nov 22, 2018 · Maximum recorded weight of a male Eastern Grey Kangaroo is 91kg (200 pounds) but most reach a max of around 66kg (145 pounds).
[64]
Macropus fuliginosus (western gray kangaroo) - Animal Diversity Web
They can be found in woodlands, open forests, coastal heathland, and open grassland areas. They have also been found near city areas and on golf courses. These ...
[65]
Adoption in Eastern Grey Kangaroos: A Consequence of ... - NIH
May 13, 2015 · Where pouch young were switched, all four mothers exclusively nursed the adopted young for at least 6 months and ceased care of their biological ...
[66]
[PDF] Eastern Grey Kangaroo Macropus giganteus – reject a proposal to list
6. Macropus giganteus is not listed as threatened under the Commonwealth Environmental Protection and Biodiversity Conservation Act 1999 and is listed as ' ...
[67]
[PDF] Western Grey Kangaroo Macropus fuliginosus
Average home range size varies from 83 to 897 ha, with males having larger home ranges than females (Priddel et al. 1988a; Arnold et al. 1992; Coulson 1993;.
[68]
[PDF] Red Kangaroo Macropus rufus – reject a proposal to list
Macropus rufus is endemic to Australia and is widely distributed across the continent, from the Western Australian coast to western New South Wales. (NSW) and ...
[69]
[PDF] Queensland Commercial Macropod Management Program Annual ...
Note: Population estimates are based on aerial surveys conducted in 2023, which were used to set the 2024 quotas. Population estimate figures are rounded to the ...
[70]
[PDF] 2025 Quota report: NSW Commercial Kangaroo Management ...
Dec 17, 2024 · This report provides the 2024 population estimates for red kangaroos. (Osphranter rufus), eastern grey kangaroos (Macropus giganteus), western ...
[71]
How kangaroos could be jeopardising conservation efforts across ...
Feb 5, 2021 · As part of the study, researchers found densities of kangaroos in the conservation areas were as high as 145 animals per sq km. Numbers ...<|separator|>
[72]
Stochastic demography and population dynamics in the red ...
Dec 11, 2009 · We analyse a stochastic environment model of the red kangaroo (Macropus rufus), a species inhabiting an environment characterized by ...
[73]
Population monitoring for kangaroo management.
Direct monitoring on a large scale is costly. Aerial surveys are conducted annually at best, and precision of population estimates declines with the area over ...
[74]
Quantifying trends and predictors of decline in eastern grey ...
Feb 20, 2018 · Eastern grey kangaroo populations have declined in many areas of the South East Queensland bioregion of Australia, a region that has ...
[75]
The impact of human activities on Australian wildlife - PMC
Increasing human population size and the concomitant expansion of urbanisation significantly impact natural ecosystems and native fauna globally.
[76]
What influences road mortality rates of eastern grey kangaroos in a ...
Dec 17, 2019 · Vehicle collisions most frequently impact large herbivores due to their larger home range compared to smaller animals, and higher population ...
[77]
[PDF] Managing kangaroos in New South Wales - Environment and Heritage
Thousands of kangaroos are hit by vehicles, while tens of thousands die from thirst and starvation during drought as part of the natural boom bust cycle. How to ...
[78]
Kangaroo hunting in colonial Australia - Pursuit
Mar 15, 2020 · A new book explores how the kangaroo became a quarry, a resource and a point of violent conflict between settlers and Australia's Aboriginal people.
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[PDF] History of Kangaroo Killing - Parliament of Australia
The State Government responded by introducing restrictive legislation to regulate the shooting of kangaroos and this brought stability back to the industry.
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Kangaroos at risk from climate change - Mongabay
Oct 16, 2008 · A 2°C-rise in temperature could trigger significant range contraction for kangaroos in Australia and put one species at high risk of extinction.
[81]
Kangaroo management in New South Wales
Apr 18, 2024 · Native animals are protected under the NSW Biodiversity Conservation Act 2016. It is an offence to harm, or to buy or sell kangaroos for ...
[82]
Harvest macropod damage mitigation permit quota information
Aug 14, 2025 · The Macropod Conservation Plan restricts the quota for damage mitigation permits to 2% of the estimated population for each species of harvest ...
[83]
[PDF] Guidance Note for managing kangaroos in Victoria's growth areas
In urban settings, nominating linear movement corridors is not an effective management approach on its own, but can be effective in combination with retention ...