Macropus Fuliginosus Research Articles

Host and geographically related genetic variation in species of Cloacina (Nematoda: Strongyloidea) from western and eastern grey kangaroos, Macropus fuliginosus and M. giganteus (Marsupialia: Macropodidae).

Host and geographically related genetic variation in species of Cloacina (Nematoda: Strongyloidea) from western and eastern grey kangaroos, Macropus fuliginosus and M. giganteus (Marsupialia: Macropodidae).

Chronic phalaris toxicity in macropods is widespread and peaks in July in Victoria, Australia.

Phalaris aquatica is pasture species introduced into Australia during early European settlement. Consumption of the plant can cause the neurological condition chronic phalaris toxicity (CPT) in sheep and cattle. In recent years, there has been an increase in reports of CPT in macropods, which has raised concerns regarding its impacts on their welfare. Currently, little is known about the distribution or seasonal patterns of this disease in wildlife, information pivotal in assessing its potential risks. Between 2021 and 2022, we conducted a survey targeting government bodies, veterinary businesses and wildlife organisations to investigate the locations and time of occurrence of CPT in macropods in the state of Victoria, Australia. We received 13 survey responses, 12 verbal reports, a full record of investigated cases from a university veterinary school and cases from a wildlife rescue organisation. Over the period of 11 years, Victoria had 918 cases of CPT recorded in macropods from 36 local government areas, with cases concentrated centrally just north of the state capital of Melbourne and July (midwinter) being the month with the highest case count (n = 220). There was a significant positive correlation between case count and both the abundance of kangaroos (Macropus giganteus and Macropus fuliginosus) (P < 0.01) and the abundance of P. aquatica (P = 0.009), and a significant negative correlation between annual case count and average rainfall of March (P = 0.016) and April (P = 0.02). Understanding these relationships will assist land and wildlife managers in predicting the risk and magnitude of disease outbreaks of CPT each in Victoria.

Functional interactions between coat structure and colour in the determination of solar heat load on arid living kangaroos in summer: balancing crypsis and thermoregulation

Interactions of solar radiation with mammal fur are complex. Reflection of radiation in the visible spectrum provides colour that has various roles, including sexual display and crypsis, i.e., camouflage. Radiation that is absorbed by a fur coat is converted to heat, a proportion of which impacts on the skin. Not all absorption occurs at the coat surface, and some radiation penetrates the coat before being absorbed, particularly in lighter coats. In studies on this phenomenon in kangaroos, we found that two arid zone species with the thinnest coats had similar effective heat load, despite markedly different solar reflectances. These kangaroos were Red Kangaroos (Osphranter rufus) and Western Grey Kangaroos (Macropus fuliginosus).Here we examine the connections between heat flow patterns associated with solar radiation, and the physical structure of these coats. Also noted are the impacts of changing wind speed. The modulation of solar radiation and resultant heat flows in these coats were measured at wind speeds from 1 to 10 m s−1 by mounting them on a heat flux transducer/temperature-controlled plate apparatus in a wind tunnel. A lamp with a spectrum like solar radiation was used as a proxy for the sun. The integrated reflectance across the solar spectrum was higher in the red kangaroos (40 ± 2%) than in the grey kangaroos (28 ± 1%). Fur depth and insulation were not different between the two species, but differences occurred in fibre structure, notably in fibre length, fibre density and fibre shape. Patterns of heat flux within the species’ coats occurred despite no overall difference in effective solar heat load. We consider that an overarching need for crypsis, particularly for the more open desert-adapted red kangaroo, has led to the complex adaptations that retard the penetrance of solar radiation into its more reflective fur.

Hematological and Biochemical Parameters of Macropod Progressive Periodontal Disease in Wild Western Gray Kangaroos

Macropod progressive periodontal disease (MPPD), known as Lumpy Jaw, poses a persistent and potentially fatal threat in Western gray kangaroos when they are kept in captivity. Such a condition leads to the development of osteomyelitis and sepsis in Western gray kangaroos (Macropus fuliginosus). This case study presented the inaugural examination of hematological and biochemical aspects of MPPD with a progression toward sepsis in a captive environment. The primary objective of this research was to pinpoint hematological and biochemical indicators associated with severe MPPD in a Western gray kangaroo held in captivity. The study employed various methods, including clinical, radiographical, hematological, and biochemical analyses, as well as microbiological study methods. The case was a 2.5-year-old male wild Western gray kangaroo with fever (39.7 °C), dehydration, dyspnea, tachycardia, and involuntary jaw clenching due to stress and agitation. The kangaroo had a history of lethargy, anorexia, swelling of the soft tissues of the lower jaw on the left side, and tenderness during palpation. A radiograph of the head revealed mandible proliferative lesions. The hematological and biochemical examinations indicated an increase in the total count of leucocytes, level of neutrophils, number of erythrocytes, hematocrit level, and lymphopenia. Increased activity of alkaline phosphatase, amylase, and creatinine elevated azotemia. There was a decrease in the content of albumin, glucose, and total bilirubin. The bacteria, consisting of Fusobacteriaceae spp., Porphyromonadaceae spp., and Bacteroidaceae spp., were found and identified in all samples. However, this comprehensive diagnosis of MPPD based on clinical signs, radiography, and especially hematological and biochemical parameters of the septic process can be helpful in diagnosis and treatment.

Land use and dingo baiting are correlated withthe density of kangaroos in rangeland systems.

Rangelands worldwide have been subject to broadscale modification, such as widespread predator control, introduction of permanent livestock water and altered vegetation to improve grazing. In Australia, these landscape changes have resulted in kangaroos (i.e. large macropods) populations increasing over the past 200 years. Kangaroos are a key contributor to total grazing pressure and in conjunction with livestock and feral herbivores have been linked to land degradation. We used 22 years of aerial survey data to investigate whether the density of 3 macropod species in the southern rangelands of Western Australia was associated with: (i) land use, including type of livestock, total livestock, density of feral goats, type of land tenure, and kangaroo commercial harvest effort; (ii) predator management, including permitted dingo control effort, estimated dingo abundance, and presence of the State Barrier Fence (a dingo exclusion fence); and (iii) environmental variables: ruggedness, rainfall, fractional cover, and total standing dry matter. Red kangaroos (Osphranter rufus) were most abundant in flat, open vegetation, on pastoral land, where area permitted for dingo control was high, and numbers were positively associated with antecedent rainfall with a 12-month delay. Western grey kangaroos (Macropus fuliginosus) were most abundant on flat, agricultural land, but less abundant in areas with high permitted dingo control. Euros (Osphranter robustus) were most abundant in rugged pastoral land with open vegetation, where permitted dingo control was high. While environmental variables are key drivers of landscape productivity and kangaroo populations, anthropogenic factors such as land use and permitted dingo control are strongly associated with kangaroo abundance.

Molecular detection of two new putative species of gammaherpesvirus in petaurid possums.

A molecular survey of herpesviruses in Australian native mammals was conducted, spanning 260 individuals from 27 species. Among the herpesviruses detected, a putative new gammaherpesvirus species was detected in the yellow-bellied glider (Petaurus australis), and another in the critically endangered Leadbeater's possum (Gymnobelideus leadbeateri). In addition, the known host range of the putative species macropodid gammaherpesvirus 3 (MaHV-3) is herein extended to the western grey kangaroo (Macropus fuliginosus). These findings expand our understanding of herpesviruses in Australian mammals and may inform biosecurity protocols for captive and translocated populations.

Interrelationships between fire, habitat, and mammals in a fragmented heathy woodland

Altered fire regimes threaten biodiversity, but there is limited understanding of the mechanisms driving population declines. Relationships between mammal occurrence and time since fire can be unclear because mammals respond directly to changes in habitat structure rather than time since fire per se, and patterns of regeneration can be highly variable. Previous studies have examined how mammals respond to time since fire and habitat structure separately, but rarely considered the three factors together. Furthermore, fires may interact with other threats such as habitat loss and fragmentation, also rarely incorporated into fire studies but known to influence mammal communities. Understanding each of these mechanisms and how they interact is critical for using fire effectively in conservation.We simultaneously related ground-dwelling mammal species activity to habitat structure, habitat structure to post-fire vegetation growth stage, and species activity to growth stage and landscape structure (extent of heathy woodland vegetation) using structural equation models (SEMs). This allowed us to find direct effects of growth stage on mammals, indirect effects mediated by habitat structure, and additional effects of landscape structure.Understorey cover, litter depth, and coarse woody debris responded to growth stage and were important contributors in all SEMs. Four of seven mammal species responded to at least one habitat structure variable. None of the mammal species were related directly to growth stage, but mammals were indirectly related to growth stage through the mediating influence of habitat structure. For example, western grey kangaroos were linked to recently burnt sites, but only through their negative association with litter depth. Extent of heathy woodland vegetation was also an important driver of mammal activity and was related to all but one species; two species showed a positive relationship, and four negative.Important relationships between fire and ground-dwelling mammals may be overlooked unless changes in important habitat resources are also considered. Fire management planning for fauna conservation should incorporate habitat responses as mammal responses to the fire regime may be mediated by fire-driven changes in resources. Knowing how time since fire affects important habitat structures can improve the effectiveness of using fire to manipulate these to support mammal species. Our results will help land managers understand direct and indirect effects of fire in a landscape where multiple drivers threaten biodiversity, and guide the use of prescribed fire to promote aspects of habitat structure that benefit mammals.

Using Remote Sensing to Estimate Understorey Biomass in Semi-Arid Woodlands of South-Eastern Australia

Monitoring ground layer biomass, and therefore forage availability, is important for managing large, vertebrate herbivore populations for conservation. Remote sensing allows for frequent observations over broad spatial scales, capturing changes in biomass over the landscape and through time. In this study, we explored different satellite-derived vegetation indices (VIs) for their utility in estimating understorey biomass in semi-arid woodlands of south-eastern Australia. Relationships between VIs and understorey biomass data have not been established in these particular semi-arid communities. Managers want to use forage availability to inform cull targets for western grey kangaroos (Macropus fuliginosus), to minimise the risk that browsing poses to regeneration in threatened woodland communities when grass biomass is low. We attempted to develop relationships between VIs and understorey biomass data collected over seven seasons across open and wooded vegetation types. Generalised Linear Mixed Models (GLMMs) were used to describe relationships between understorey biomass and VIs. Total understorey biomass (live and dead, all growth forms) was best described using the Tasselled Cap (TC) greenness index. The combined TC brightness and Modified Soil Adjusted Vegetation Index (MSAVI) ranked best for live understorey biomass (all growth forms), and grass (live and dead) biomass was best described by a combination of TC brightness and greenness indices. Models performed best for grass biomass, explaining 70% of variation in external validation when predicting to the same sites in a new season. However, we found empirical relationships were not transferrable to data collected from new sites. Including other variables (soil moisture, tree cover, and dominant understorey growth form) improved model performance when predicting to new sites. Anticipating a drop in forage availability is critical for the management of grazing pressure for woodland regeneration, however, predicting understorey biomass through space and time is a challenge. Whilst remotely sensed VIs are promising as an easily-available source of vegetation information, additional landscape-scale data are required before they can be considered a cost-efficient method of understorey biomass estimation in this semi-arid landscape.

Poor welfare outcomes resulting from poor management decisions in a translocation of western grey kangaroos (Macropus fuliginosus)

There is often considerable social media commentary on whether remnant kangaroo populations in urban areas should be euthanased or translocated. Here, we describe a translocation program in Western Australia where kangaroos were herded into a temporary enclosure, darted, sedated, and translocated to a site in the State Forest east of the Swan Coastal Plain where they were released after 24 h. Prior to darting and after being initially herded into a temporary holding enclosure, kangaroos were repeatedly released from the enclosure by members of the public. Sixty-three of 154 adult kangaroos and 20 of 52 pouched young (40.3%) died or were euthanased before being released from the translocation release enclosure. The total volume of the sedative Zoletil (mL kg−1) injected into kangaroos as a sedative was significantly higher in those that survived than those that died. The primary conclusion from this management program was that the western grey kangaroos were susceptible to capture myopathy and distressed animals are at a greater risk of not surviving a translocation program. In our professional judgement, from an animal welfare perspective, these kangaroos should have been euthanased and not translocated. Such scientific advice and professional experience should inform future decisions regarding management of remnant kangaroo populations.

Understanding Australia’s unique hopping species: a comparative review of the musculoskeletal system and locomotor biomechanics in Macropodoidea

Kangaroos and other macropodoids stand out among mammals for their unusual hopping locomotion and body shape. This review examines the scaling of hind- and forelimb bones, and the primary ankle extensor muscles and tendons. We find that the scaling of the musculoskeletal system is sensitive to the phylogenetic context. Tibia length increases with positive allometry among most macropodoids, but negative allometry in eastern grey kangaroos and isometry in red kangaroos. Femur length decreases with stronger negative allometry in eastern grey and red kangaroos than among other macropodoids. Muscle masses scale with negative allometry in western grey kangaroos and with isometry in red kangaroos, compared to positive allometry in other macropodoids. We further summarise the work on the hopping gait, energetics in macropodoids, and stresses in the musculoskeletal system in an evolutionary context, to determine what trade-offs may limit locomotor performance in macropodoids. When large kangaroos hop, they do not increase oxygen consumption with speed, unlike most mammals, including small hopping species. We conclude that there is not enough information to isolate the biomechanical factors that make large kangaroos so energy efficient. We identify key areas for further research to fill these gaps.

Understanding the spatiotemporal dynamics of understorey biomass in semi-arid woodlands of south-eastern Australia

When managing grazing pressure for conservation, understanding forage dynamics is essential. In south-eastern Australia, ongoing grazing is inhibiting regeneration in several semi-arid woodland communities. Western grey kangaroos (Macropus fuliginosus (Desmarest, 1817)) have been identified as a key component of total grazing pressure. They are thought to switch from grass to lower-quality browse, including tree seedlings, when grass biomass falls below 400 kg ha−1. One static threshold may not adequately capture the spatial and temporal hazard associated with kangaroo grazing, and this study aimed to explore how grassy biomass varies across a case-study landscape. Understorey biomass and species composition data were collected in the field on seven occasions between December 2016 and May 2019. We used Generalised Linear Mixed Models (GLMMs) to describe the influence of environmental and herbivory variables on total (live and dead) understorey, live understorey, and grass (live and dead) biomass. Canopy cover showed the strongest influence on understorey biomass, with more biomass found in open sites than in woodland. Understorey biomass levels were lowest in summer and autumn. Grass biomass, in particular, fell below the 400 kg ha−1 forage-switch threshold in wooded areas during this time. We anticipate that an increased understanding of understorey biomass dynamics will inform managers as to when and where to focus management efforts to promote regeneration and sustained recovery of these semi-arid woodlands. Results of this study suggest that conducting management efforts before the summer/autumn decline in understorey biomass, particularly in woodlands, is critical in reducing the browsing risk to seedlings.

Plant Tannins and Essential Oils Have an Additive Deterrent Effect on Diet Choice by Kangaroos

Tannins and essential oils are well recognised as antiherbivore compounds. We investigated the relative effectiveness of the polyphenol, tannin, and the essential oils, 1,8-cineole and pine oil, as feeding deterrents against western grey kangaroos. Both groups of secondary metabolites are naturally abundant in many Australian plants. These three metabolite groups were incorporated separately or together into standard pellets for presentation to kangaroos, and their behaviour (sequence of food choice and feeding time) and amounts consumed were observed. The control (with no secondary metabolites) was much preferred. There was a sharp reduction in the ingestion of pellets containing tannins, 1,8-cineole or pine oil. Combinations of the metabolites resulted in almost no consumption. In association with tannin, pellets containing either 1,8-cineole or pine oil were as effective deterrents as both combined. There was a strong correlation between time spent feeding on the different diets and the amount of food consumed, although the rate of intake was markedly slower when secondary metabolites were present. Behavioural observations showed that the amount of food ingested is initially guided by the presence/absence of essential oils, apparently detected by smell, and later by the presence/absence of tannins, by taste. Both groups of secondary metabolites work in concert by stimulating different senses that minimise herbivory by marsupials, such as the western grey kangaroo, and help to explain their abundance in the Australian flora.

Assessing the spatial and temporal organization of Red Kangaroo, Western Grey Kangaroo and Eastern Grey Kangaroo populations in eastern Australia using multivariate autoregressive state‐space models

SummaryTo identify patterns in the temporal dynamics and spatial organization of kangaroo subpopulations that are commercially harvested, we fitted multivariate autoregressive state‐space (MARSS) models to time series of kangaroo abundance from the main harvest zones of eastern Australia (1990–2019 for New South Wales and 1984–2019 for Queensland). We found that the responses of most populations to process variation, that is variation due to environmental or demographic stochasticity were correlated and that populations responded synchronously to environmental changes. Furthermore, we examined the influence of the covariates lagged rainfall, Southern Oscillation Index (SOI) and harvest rate on kangaroo abundance. We found that lagged rainfall had a positive influence, SOI and harvest rate had negative influences but the influence of covariates was not consistent across species or between subpopulations. In terms of population spatial structure, the analysis identified two subpopulations of Red Kangaroo (Osphranter rufus) in New South Wales and four subpopulations of grey kangaroos (a combination of Eastern Grey Kangaroo (Macropus giganteus) and Western Grey Kangaroo (Macropus fuliginosus)), which appeared to be associated with a rainfall gradient from east‐west. In Queensland, separate subpopulations were identified in each of the three main harvest management zones for both Red Kangaroo and Eastern Grey Kangaroo. The implications of these results for the management of commercially harvested kangaroos are discussed.

Advances in aerial survey methods for macropods in New South Wales and Queensland

SummaryThis paper describes advances made to aerial surveys of macropods in New South Wales and Queensland. Regular aerial surveys of macropods across large areas of Australia’s arid and semi‐arid rangelands were established as a response to concerns for the species’ conservation. They became integral to the harvest management of the four macropod species – Eastern Grey Kangaroo (Macropus giganteus), Western Grey Kangaroo (M. fuliginosus), Red Kangaroo (Osphranter rufus) and Common Wallaroo (O. robustus). Harvest quotas are set as a proportion of population size, requiring absolute estimates of abundance. Counts were made in strip transects from fixed‐wing aircraft, but required correction for animals that are missed. In New South Wales and Queensland, counts are now made using line transect sampling, providing survey‐specific correction. Helicopters are used in more rugged and timbered areas and where Common Wallaroo can be more frequently found and harvested. Mark‐recapture distance sampling is used in more open country that can be surveyed using fixed‐wing aircraft and improves the accuracy of density estimates by accounting for animals missed on the transect line. Macropod populations are likely to be surveyed in the future by airborne imagery and by drones, but the technology needs further development. Spatial models could usefully provide small‐scale density estimates and address non‐random sampling.

Scaling at different ontogenetic stages: Gastrointestinal tract contents of a marsupial foregut fermenter, the western grey kangaroo Macropus fuliginosus melanops

Prominent ontogenetic changes of the gastrointestinal tract (GIT) should occur in mammals whose neonatal diet of milk differs from that of adults, and especially in herbivores (as vegetation is particularly distinct from milk), and even more so in foregut fermenters, whose forestomach only becomes functionally relevant with vegetation intake. Due to the protracted lactation in marsupials, ontogenetic differences can be particularly well investigated in this group. Here, we report body mass (BM) scaling relationships of wet GIT content mass in 28 in-pouch young (50 g to 3 kg) and 15 adult (16–70 kg) western grey kangaroos Macropus fuliginosus melanops. Apart from the small intestinal contents, in-pouch young and adults did not differ in the scaling exponents (‘slope’ in log-log plots) but did differ in the scaling factor (‘intercept’), with an implied substantial increase in wet GIT content mass during the out-of-pouch juvenile period. In contrast to forestomach contents, caecum contents were elevated in juveniles still in the pouch, suggestive of fermentative digestion of milk and intestinal secretion residues, particularly in the caecum. The substantial increase in GIT contents (from less than 1 to 10–20% of BM) was associated mainly with the increase in forestomach contents (from 25 to 80% of total GIT contents) and a concomitant decrease in small intestine contents (from 50 to 8%), emphasizing the shifting relevance of auto-enzymatic and allo-enzymatic (microbial) digestion. There was a concomitant increase in the contents-to-tissue ratio of the fermentation chambers (forestomach and caecum), but this ratio generally did not change for the small intestine. Our study not only documents significant ontogenetic changes in digestive morpho-physiology, but also exemplifies the usefulness of intraspecific allometric analyses for quantifying these changes.

Mortality trends for five species of macropods from a single institution from 1995 to 2016.

Macropods are commonly kept and exhibited species worldwide. Mortality records were reviewed for five species of macropods housed at Cleveland Metroparks Zoo from 1995 to 2016. One hundred sixty-seven deaths occurred including Western grey kangaroo (Macropus fuliginosus) (n = 22), Bennett's wallaby (M. rufogriseus) (n = 64), red kangaroo (M. rufus) (n = 56), wallaroo (M. robustus) (n = 9), and Tammar wallaby (M. eugenii) (n = 16). The leading cause of death was trauma, followed by bronchopneumonia for all species. Gastric dilatation was identified as a concern for red kangaroo. Females lived longer than males across species and were overrepresented by the data set. Oral necrobacillosis and osteomyelitis were health concerns for macropods in this review. Mortality reviews are important as they identifying collection trends and influencing long-term care.

Predicting mammal responses to pyrodiversity: From microbats to macropods

Fire has shaped Australia's diverse mammal fauna for millennia. However, ongoing changes to fire regimes threaten native mammal populations, and a significant conservation challenge is to understand and promote desirable forms of pyrodiversity (variation in fire regimes). A way forward is to quantify how different aspects of pyrodiversity influence whole mammal assemblages and produce dynamic maps of species distributions to inform conservation. We aimed to determine and map how spatial and temporal variation in fire regimes correlates with a diverse mammal assemblage comprising macropods, microbats, rodents, small marsupials and a monotreme. We built species distribution models for 17 species against fire, climate and environmental covariates in fire-prone woodlands of semi-arid Australia. Spatial measures of fire included the area, diversity and configuration of landscape elements, and temporal measures included time since fire and fire frequency. Native mammals showed a variety of responses to pyrodiversity. Microbats were more likely to occur as time since fire increased, whereas rodents were correlated with recently burned areas. Small dasyurid marsupials were correlated with the area of older post-fire age-classes, while western grey kangaroo occurrence was positively associated with high diversity of post-fire ages. Our new approach, using predictive models to map mammal distributions in relation to spatial and temporal variation in fire regimes, provides outputs that managers can use to improve conservation planning. This enables the positive and negative effects of fire to be better understood and will assist in achieving desirable forms of pyrodiversity that meet the needs of whole mammal assemblages.

Potential for dietary competition between the threatened black-flanked rock-wallaby and sympatric western grey kangaroo

An overabundance of western grey kangaroo (Macropus fuliginosus) can detrimentally impact agriculture and compete with threatened fauna for food resources. In Paruna Wildlife Sanctuary, south-western Western Australia, kangaroos are common and widespread. By contrast, the endangered black-flanked rock-wallaby (Petrogale lateralis lateralis) are spatially constrained to rock refuges. We investigated the potential for dietary competition between these two species by measuring the overlap in their diets, spatial overlap in their foraging patches, and comparing their diets with food resource availability. A combination of scat analysis, passive IR camera trapping and vegetation surveys were employed around rock outcrops used by rock-wallabies within the sanctuary. Rock-wallaby diets were dominated by forbs, overlapping 56% with kangaroo diet, which included mostly browse and forbs. Some of their shared preferred food resources were spatially and/or temporally limited, suggesting potential competition for these food plants. There was also a 33% spatial overlap of foraging patches between the two species. The dietary and spatial overlap detected between rock-wallabies and kangaroos suggest there is potential for resource competition, which may be exacerbated if kangaroo numbers increase. Future conservation actions include monitoring western grey kangaroo densities and food plant availability. Population control for kangaroos may be required, particularly for increasingly hot and dry years, as predicted under climate change.

Square salads: exploring the diet of the southern hairy-nosed wombat (Lasiorhinus latifrons) via DNA metabarcoding

Southern hairy-nosed wombats (Lasiorhinus latifrons) are large semi-fossorial marsupials that inhabit semiarid areas of southern South Australia and southeast Western Australia. Despite their size and prominence on the landscape, little is published about diet and foraging preferences. Further, it is unclear whether this wombat species’ diet overlaps with sympatric western grey kangaroos (Macropus fuliginosus), which are locally abundant across the southern hairy-nosed wombat’s distribution. Competition for food resources may be an added stressor in Murraylands populations where kangaroos are plentiful. Here, we identified diet items and dietary overlap of southern hairy-nosed wombats and western grey kangaroos. We accomplished this by opportunistically sampling fresh faecal pellets from both species at Brookfield Conservation Park in April 2017. We performed DNA metabarcoding via Illumina next generation sequencing of the faecal DNA using the plant ITS2 gene. We identified 10 genera in the wombat diet and 20 in the diet of kangaroos; diets of both species included native and introduced genera. Eight genera were shared between both marsupials. This work highlights the capabilities of non-invasive genetic sampling in concert with DNA metabarcoding to elucidate diet and dietary overlap between species.

Ontogenetic growth and the development of a unique fibrocartilage entheses in Macropus fuliginosus

Here we examine the bone histology of the femora and humeri of the Western Grey Kangaroo, Macropus fuliginosus. Our results reveal that bone modelling in response to ontogenetic growth and the development of tuberosities on the femur, and especially in the humerus, lead to a highly complex histology. We propose that the alternating fast and slow rates of bone deposition are seasonal, and are likely correlated with heterothermy related to ecological constraints during the summer months. In females, after the fourth growth mark in the femur, there is a distinctive change to a more lamellar textured bone deposition with sparse vascularisation, directly indicating a slowdown in growth. However, in males, the zones remain woven textured and well vascularised, which is indicative of continued fast growth. Here we also report the novel occurrence of a fibrocartilaginous entheses for the attachment of the m. quadratus femoris to the caudal femoral tuberosity. Using a combination of methodologies, we show that perimeter measurements of growth marks provide a reasonable estimation of the age of kangaroos. Additionally, we observed large individuals that have ceased diaphyseal appositional growth of the femur and the humerus, as well as fusion of the distal epiphyses of both bones, though the proximal epiphyses may remain unfused.