Wallabia Research Articles

Resolving kangaroo phylogeny and overcoming retrotransposon ascertainment bias

Reconstructing phylogeny from retrotransposon insertions is often limited by access to only a single reference genome, whereby support for clades that do not include the reference taxon cannot be directly observed. Here we have developed a new statistical framework that accounts for this ascertainment bias, allowing us to employ phylogenetically powerful retrotransposon markers to explore the radiation of the largest living marsupials, the kangaroos and wallabies of the genera Macropus and Wallabia. An exhaustive in silico screening of the tammar wallaby (Macropus eugenii) reference genome followed by experimental screening revealed 29 phylogenetically informative retrotransposon markers belonging to a family of endogenous retroviruses. We identified robust support for the enigmatic swamp wallaby (Wallabia bicolor) falling within a paraphyletic genus, Macropus. Our statistical approach provides a means to test for incomplete lineage sorting and introgression/hybridization in the presence of the ascertainment bias. Using retrotransposons as “molecular fossils”, we reveal one of the most complex patterns of hemiplasy yet identified, during the rapid diversification of kangaroos and wallabies. Ancestral state reconstruction incorporating the new retrotransposon phylogenetic information reveals multiple independent ecological shifts among kangaroos into more open habitats, coinciding with the Pliocene onset of increased aridification in Australia from ~3.6 million years ago.

Speciation Generates Mosaic Genomes in Kangaroos.

The iconic Australasian kangaroos and wallabies represent a successful marsupial radiation. However, the evolutionary relationship within the two genera, Macropus and Wallabia, is controversial: mitochondrial and nuclear genes, and morphological data have produced conflicting scenarios regarding the phylogenetic relationships, which in turn impact the classification and taxonomy. We sequenced and analyzed the genomes of 11 kangaroos to investigate the evolutionary cause of the observed phylogenetic conflict. A multilocus coalescent analysis using ∼14,900 genome fragments, each 10 kb long, significantly resolved the species relationships between and among the sister-genera Macropus and Wallabia. The phylogenomic approach reconstructed the swamp wallaby (Wallabia) as nested inside Macropus, making this genus paraphyletic. However, the phylogenomic analyses indicate multiple conflicting phylogenetic signals in the swamp wallaby genome. This is interpreted as at least one introgression event between the ancestor of the genus Wallabia and a now extinct ghost lineage outside the genus Macropus. Additional phylogenetic signals must therefore be caused by incomplete lineage sorting and/or introgression, but available statistical methods cannot convincingly disentangle the two processes. In addition, the relationships inside the Macropus subgenus M. (Notamacropus) represent a hard polytomy. Thus, the relationships between tammar, red-necked, agile, and parma wallabies remain unresolvable even with whole-genome data. Even if most methods resolve bifurcating trees from genomic data, hard polytomies, incomplete lineage sorting, and introgression complicate the interpretation of the phylogeny and thus taxonomy.

Leaf odour cues enable non-random foraging by mammalian herbivores.

Searching for food is the first critical stage of foraging, and search efficiency is enhanced when foragers use cues from foods they seek. Yet we know little about food cues used by one major group of mammals, the herbivores, a highly interactive component of most ecosystems. How herbivores forage and what disrupts this process, both have significant ecological and evolutionary consequences beyond the animals themselves. Our aim was to investigate how free-ranging mammalian herbivores exploit leaf odour cues to find food plants amongst a natural and complex vegetation community. Our study system comprised the native "deer equivalent" of eastern Australian forests, the swamp wallaby Wallabia bicolor, and seedlings of Eucalyptus, the foundation tree genus in these ecosystems. We quantified how foraging wallabies responded to odour cues from plants manipulated in several ways: varying the quantity of visually concealed leaves, comparing damaged vs. undamaged leaves, and whole plants vs. those with suppressed cues. The rate of discovery of leaves by wallabies increased with odour cue magnitude, yet animals were extremely sensitive to even a tiny odour source of just a few leaves. Whole seedlings were discovered faster if their leaves were damaged. Wallabies found whole seedlings and those with suppressed visual cues equally rapidly, day and night. Seedlings with very little odour were discovered mainly by day, as nocturnal foraging success was severely disrupted. This study shows how leaf odour attracts mammalian herbivores to food plants, enabling non-random search for even tiny odour sources. As damaged leaves enhanced discovery, we suggest that the benefit of attracting natural enemies to invertebrate herbivores feeding on plants (potential "cry for help") may be offset by a cost-increased browsing by mammalian herbivores. This cost should be incorporated into multi-trophic plant-animal studies. Finally, the breakdown in capacity to find plants at night suggests substantial but unrecognized foraging costs to herbivores when abiotic factors, such as cold temperatures or pollution, reduce or degrade plant odour cues. We predict that an increasingly polluted world will alter the foraging success of mammalian herbivores, with significant ecological ramifications given that browsing can shape ecosystems.

Type specimens of non-fossil mammals in the Australian Museum, Sydney

The Australian Museum (AM) Mammal Collection represents one of the most significant world collections from the Australo-Pacific region, with over 50,000 mammal specimens of some 650 species from the region. The Collection contains about 882 primary (name bearing) and secondary mammal type specimens, representing 210 proposed names (species and subspecies), 124 of which are currently recognized as valid taxa. All are of taxa originating from the Australian region, Indonesia, Melanesia and the south-west Pacific. The 205 primary type specimens comprise 145 holotype specimens (on which 149 names are based), seven lectotypes, two neotypes; 33 syntypes of 18 taxa; and 18 specimens suspected to be syntypes of 11 taxa. Primary type material of the 185 named taxa represent 4 monotremes, 62 marsupials, 2 canids, 9 cetaceans, 68 rodents and 40 bats. The 677 secondary type specimens comprise 659 paratypes, 15 paralectotypes, and three suspected paralectotypes. This is the first published list of non-fossil mammal types in the AM Collection since the publication of Krefft’s catalogue in 1864. Individual accounts are presented discussing type status of 233 taxa by their originally proposed names, which includes taxa for which the type series has not been located since publication of the name. Registration data are given, with additional information not included in the published description, along with new information on many taxa proposed in the 19th century. Photographs of the primary type specimens of 43 taxa are provided, many of which are the first published images. New insights and a summary of current information is given for 14 taxa for which type material has not been located in world collections but we believe might have originally been lodged in the AM. Type material of seven taxa named by Krefft, Gray and Ramsay (all suspected junior synonyms), were identified in the AM Collection and are reported here for the first time since their original publication. These are: holotypes of Canis familiaris var. papuensis Ramsay, 1879, and Macleayius australiensis Gray, 1865 (= Eubalaena australis (Desmoulins, 1822)); syntypes of Pteropus rufus Ramsay, 1891 (= Pteropus neohibernicus Peters, 1876), Cuscus chrysorrhous var. goldiei Ramsay, 1877 (= Spilocuscus maculatus goldiei (Ramsay, 1877)), and Antechinus allanii Krefft, 1872 (= Antechinus cf. stuartii Macleay, 1841); and suspected syntypes of Halmaturus mastersii Krefft, 1871 (= Wallabia bicolor mastersii), and Phascolomys assimilis Krefft, 1872 (= Vombatus ursinus (Shaw, 1800)). The registration numbers of likely syntypes of two forgotten names, Antechinus brevicaudatus Krefft, 1872 (= ?Antechinus spp.), and Phalangista rufescens Krefft, 1872 (= Trichosurus spp.) have been located in the old specimen registers, the specimens have not yet been found in the Collection. The type series of many taxa proposed by Krefft and Ramsay are not fully defined and syntypes could remain unrecognized in the many institutions to which they extensively exchanged specimens during the 19th century. No nomenclatural actions are taken in this paper.

Speciation in the genus Cloacina (Nematoda: Strongylida): species flocks and intra-host speciation.

Sequences of the first and second internal transcribed spacers (ITS1 + ITS2) of nuclear ribosomal DNA were employed to determine whether the congeneric assemblages of species of the strongyloid nematode genus Cloacina, found in the forestomachs of individual species of kangaroos and wallabies (Marsupialia: Macropodidae), considered to represent species flocks, were monophyletic. Nematode assemblages examined in the black-striped wallaby, Macropus (Notamacropus) dorsalis, the wallaroos, Macropus (Osphranter) antilopinus/robustus, rock wallabies, Petrogale spp., the quokka, Setonix brachyurus, and the swamp wallaby, Wallabia bicolor, were not monophyletic and appeared to have arisen by host colonization. However, a number of instances of within-host speciation were detected, suggesting that a variety of methods of speciation have contributed to the evolution of the complex assemblages of species present in this genus.

Consistent patterns of vehicle collision risk for six mammal species

The occurrence and rate of wildlife-vehicle collisions are related to both anthropocentric and environmental variables, however, few studies compare collision risks for multiple species within a model framework that is adaptable and transferable. Our research compares collision risk for multiple species across a large geographic area using a conceptually simple risk framework.We used six species of native terrestrial mammal often involved with wildlife-vehicle collisions in south-east Australia. We related collisions reported to a wildlife organisation to the co-occurrence of each species and a threatening process (presence and movement of road vehicles). For each species, we constructed statistical models from wildlife atlas data to predict occurrence across geographic space. Traffic volume and speed on road segments (also modelled) characterised the magnitude of threatening processes.The species occurrence models made plausible spatial predictions. Each model reduced the unexplained variation in patterns and distributions of species between 29.5% (black wallaby) and 34.3% (koala). The collision models reduced the unexplained variation in collision event data between 7.4% (koala) and 19.4% (common ringtail possum) with predictor variables correlating similarly with collision risk across species.Road authorities and environmental managers need simple and flexible tools to inform projects. Our model framework is useful for directing mitigation efforts (e.g. on road effects or species presence), predicting risk across differing spatial and temporal scales and target species, inferring patterns of threat, and identifying areas warranting additional data collection, analysis, and study.

Oesophageal and stomach nematode communities in three sympatric macropodid species in coastal and montane environments in southeastern New South Wales

ABSTRACTThe parasitic nematode communities are described from the oesophagi and stomachs of eastern grey kangaroos, Macropus giganteus (Shaw), red-necked wallabies, Notamacropus rufogriseus (Desmarest) and swamp wallabies, Wallabia bicolor (Desmarest) (Marsupialia: Macropodidae) from coastal and montane habitats in southeastern New South Wales. The number of nematode species recorded for each macropodid species was similar to that recorded in previous studies in Victoria. Overall diversity of nematode communities was greatest in N. rufogriseus and greater in montane than in coastal localities in both N. rufogriseus and M. giganteus. Community similarity between coastal and montane localities was highest in N. rufogriseus compared to M. giganteus and W. bicolor. Few nematode species were shared between host species. There were more significant differences in species prevalences than intensities of infection in M. giganteus between coastal and montane localities, less so for N. rufogriseus but these were not calculated for W. bicolor due to small montane sample size. Community differences between macropodid species were attributable primarily to host-specific parasite species. This is the first comparison of helminth communities in macropodids in a replicated study in different habitats at similar latitudes.

Bulldozers and Blueberries: Managing Fence Damage by Bare-Nosed Wombats at the Agricultural–Riparian Interface

Fence damage by bare-nosed wombats (Vombatus ursinus) can be a serious problem for farmers wishing to reduce herbivory by other herbivores on valuable crops. We investigated the effectiveness of exclusion fencing to prevent the incursion of unwanted native and feral herbivores and the use of swinging gates designed to allow wombats to pass through the fence without having to damage it. We also examined the temporal response of animals toward exclusion fencing and wombat gates. The 10-month study took place on the interface between natural riparian vegetation and a 22-ha blueberry (Vaccinium corymbosum) orchard in southeastern Australia. Following the testing of exclusion fencing (i.e., footing wire and flexible fence), we installed 6 swinging wombat gates at existing breach points within the exclusion fencing. Wombat gates were 0.6 m high × 0.5 m wide and constructed of 200 × 100 × 6 mm galvanized steel. We continually observed the response of wombats and other animals to both exclusion fencing and wombat gates using heat- and motion-sensing digital cameras. We made a total of 1,480 detections of the 3 target species—wombats, red foxes (Vulpes vulpes), and swamp wallabies (Wallabia bicolor)—in the study area between August 2007 and June 2008. Most were wombat detections (79%), followed by detections of swamp wallabies (12%) and foxes (8%). Wombats became accustomed to using the gates within 1 month, with an average exclusion rate of 48% in the first month after their installation. For the final 6 months of the project, the number of wombat detections showed an exclusion rate of approximately 25%. The swinging gates were equally consistent in excluding foxes and wallabies. The results of this study showed that swinging wombat gates were effective in regulating access by wombats while excluding other unwanted animals.

Skeletal fluorosis in marsupials: A comparison of bone lesions in six species from an Australian industrial site.

In this study we explored the prevalence, type, location and severity of skeletal lesions in six species of Australian marsupial (Macropus giganteus, Notamacropus rufogriseus, Wallabia bicolor, Phascolarctos cinereus, Trichosurus vulpecula and Pseudocheirus peregrinus) from high and low-fluoride environments. Lesions occurred to varying extents in all species, and lesion distribution varied with biomechanical differences in gait and mastication. Bone fluoride levels increased with severity of periosteal hyperostosis. The mean bone fluoride concentration of individuals lacking hyperostosis (across all species, from both high and low-fluoride environments) was 1100±260μgF-/g dry bone, compared to 4300±1200μgF-/g and 6300±1200μgF-/g in those with mild and severe grade hyperostosis, respectively. Multivariable modelling showed that the probability of observing a lesion varied across species, anatomical location, age and bone fluoride concentration (in a non-linear manner). The pathological changes reported in the marsupials are consistent with the range of fluoride-related lesions described in other mammals, and biomechanical differences among the studied marsupial species offer some explanation for the degree of interspecific variability in prevalence, type, anatomical location, and severity of the lesions.

The influence of evolutionary history and body size on partitioning of habitat resources by mammalian herbivores in south-eastern Australia

Habitat use is the most common dimension along which sympatric species partition resources to reduce competition. We conducted faecal pellet counts at Wilsons Promontory National Park, Victoria, to examine habitat use by an assemblage of mammalian herbivores with disparate evolutionary histories and varying body size: introduced European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus), and native eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor) and common wombat (Vombatus ursinus). Overlap in habitat use was low between four pairs of species, suggesting spatial partitioning of resources to reduce the potential for interspecific competition. More generally, however, overlap in habitat use was high, particularly between native and introduced grazers. These results indicate the potential for competition if resources were limiting and suggest that assemblages of species with independent evolutionary histories have inherently less resource partitioning to facilitate coexistence than assemblages of species with common evolutionary histories. Despite evidence of high overlap in habitat use between native and introduced species at a broad scale, and variation in the competitive ability of species, coexistence was likely facilitated by niche complementarity, including temporal and fine-scale partitioning of spatial resources. There was no relationship between body size and the diversity of habitats used. In contemporary assemblages of native and introduced species, evolutionary history is likely to have a strong influence on resource partitioning.

Adaptations of large marsupials to survival in winter snow cover: locomotion and foraging

The small extent of seasonally snow-covered Australian mountains means that there has not been a great selective pressure on the mammalian fauna for adaptations to this environment. Only one large marsupial, the common wombat (Vombatus ursinus (Shaw, 1800)), is widespread above the winter snowline. In the past 20 years, with snow depth and duration declining, the swamp wallaby (Wallabia bicolor (Desmarest, 1804)) has become more common above the winter snowline. The red-necked wallaby (Macropus rufogriseus (Desmarest, 1817)) is common in alpine Tasmania where seasonal snow cover is neither as deep nor as long-lasting as on the mainland, but has only been recorded regularly above the winter snowline in the mainland Snowy Mountains since 2011. This study examines morphological aspects of locomotion of these three herbivorous marsupials in snow. The wombat is the best adapted to snow, with quadrupedal gait and an expanded home range allowing it to locate and feed on the same plant groups as it does at lower elevation. Wallabies are poorly adapted to locomotion in snow, but the browsing swamp wallaby is able to maintain its dietary habit by feeding on exposed shrubs in deep snow, whereas the red-necked wallaby, which depends more on grazing, appears constrained to areas where snow is shallow.

Livestock guardian dogs as surrogate top predators? How Maremma sheepdogs affect a wildlife community.

Use of livestock guardian dogs (LGDs) to reduce predation on livestock is increasing. However, how these dogs influence the activity of wildlife, including predators, is not well understood. We used pellet counts and remote cameras to investigate the effects of free ranging LGDs on four large herbivores (eastern gray kangaroo, common wombat, swamp wallaby, and sambar deer) and one mesopredator (red fox) in Victoria, Australia. Generalized mixed models and one‐ and two‐species detection models were used to assess the influence of the presence of LGDs on detection of the other species. We found avoidance of LGDs in four species. Swamp wallabies and sambar deer were excluded from areas occupied by LGDs; gray kangaroos showed strong spatial and temporal avoidance of LGD areas; foxes showed moderately strong spatial and temporal avoidance of LGD areas. The effect of LGDs on wombats was unclear. Avoidance of areas with LGDs by large herbivores can benefit livestock production by reducing competition for pasture and disease transmission from wildlife to livestock, and providing managers with better control over grazing pressure. Suppression of mesopredators could benefit the small prey of those species. Synthesis and applications: In pastoral areas, LGDs can function as a surrogate top‐order predator, controlling the local distribution and affecting behavior of large herbivores and mesopredators. LGDs may provide similar ecological functions to those that in many areas have been lost with the extirpation of native large carnivores.

Olfactory and visual plant cues as drivers of selective herbivory

Food quality is an important consideration in the foraging strategy of all animals, including herbivores. Those that can detect and assess the nutritional value of plants from afar, using senses such as smell and sight, can forage more efficiently than those that must assess food quality by taste alone. Selective foraging not only affects herbivore fitness but can influence the structure and composition of plant communities, yet little is known about how olfactory and visual cues help herbivores to find preferred plants. We tested the ability of a free‐ranging, generalist mammalian browser, the swamp wallaby Wallabia bicolor, to use olfactory and visual plant cues to find and/or browse differentially on Eucalyptus pilularis seedlings grown under different nutrient conditions. Low‐nutrient seedlings differed from high‐nutrient seedlings, having lighter coloured leaves, red stems and lower biomass and nitrogen content. In the absence of visual cues, wallabies used odour to differentiate vials containing cut seedlings. They visited and investigated patches with high‐nutrient seedling odour most, followed by patches with low‐nutrient seedling odour, and patches with no added odour least. However, when visual and olfactory cues of seedlings were present, wallabies reversed their foraging response and were more likely to browse low‐ than high‐nutrient seedlings. This browsing difference, in turn, disappeared when long‐range visual cues were reduced by pinning seedlings horizontal to the ground. We suggest that visual cues overrode the effects of olfactory cues on browsing patterns of intact seedlings. Our study shows that herbivores can respond to odours of higher nutrient plants but in ecologically realistic scenarios they use a variety of visual and olfactory cues, with a context‐dependent outcome that is not always selection of high nutrient food. Our results demonstrate the importance of testing the sensory abilities of herbivores in realistic multi‐sensory settings to understand their function in selective foraging.

Carrion consumption by the swamp wallaby (Wallabia bicolor)

Macropodids are predominantly herbivores and their dentition reflects their foraging strategy. The swamp wallaby (Wallabia bicolor) is considered to be a generalist browser, consuming a wide diversity of plants, from forbs, shrubs, grasses and sedges. However, there is some evidence that swamp wallabies are opportunists. Here, I document the consumption of the wing of a dead seabird by a swamp wallaby, the first detailed case of this species consuming carrion, and discuss other records of animal consumption in the Macropodiformes.

The gastro-intestinal helminth parasites of the swamp wallaby, Wallabia bicolor (Desmarest) (Marsupialia: Macropodidae), and their regional distribution

ABSTRACTThe gastro-intestinal helminth parasite community of the swamp wallaby, Wallabia bicolor (Desmarest) (Marsupialia: Macropodidae) is reviewed based on published and previously unpublished data, covering its entire geographical range. The diversity recorded is higher than in previous studies and with substantial differences between northern and southern parasite communities. This difference is attributable in part to host-specific parasite species, but is due mainly to species acquired from sympatric macropodid hosts, which differ substantially between northern and southern regions. Additionally, helminth species were identified with primarily southern distributions but with occurrences at a low prevalence in northern regions. Diversity was greater in southern populations of the host. It is predicted that additional helminth parasites are likely to be found in W. bicolor, but that these will be either species with a highly localised distribution, of which several have already been reported, or occasional transfers from related confamilial hosts. The study emphasises the significance of examining the parasites of a host over its entire geographical range rather than at more local scales.

Follow your nose: leaf odour as an important foraging cue for mammalian herbivores.

Studies of odour-driven foraging by mammals focus on attractant cues emitted by flowers, fruits, and fungi. Yet, the leaves of many plant species worldwide produce odour, which could act as a cue for foraging mammalian herbivores. Leaf odour may thus improve foraging efficiency for such herbivores in many ecosystems by reducing search time, particularly but not only, for plants that are visually obscured. We tested the use of leaf odour by a free-ranging mammalian browser, the swamp wallaby (Wallabia bicolor) to find and browse palatable tree seedlings (Eucalyptus pilularis). Wallabies visited patches non-randomly with respect to the presence of seedlings. In the absence of visual plant cues, they used leaf odour (cut seedlings in vials) to find patches earlier, and visited and investigated them more often than control patches (empty vials), supporting the hypothesis that wallabies used seedling odour to enhance search efficiency. In contrast, the grey kangaroo (Macropus giganteus), a grazer, showed no response to seedling odour. When the availability of seedling visual and olfactory cues was manipulated, wallabies browsed seedlings equally quickly in all treatments: upright (normal cues), pinned to the ground (reduced visual cues), and upright plus pinned seedlings (double olfactory cues). Odour cues play a critical role in food-finding by swamp wallabies, and these animals are finely tuned to detecting these cues with their threshold for detection reached by odours from only a single plant. The global significance of leaf odour in foraging by mammalian herbivores consuming conifers, eucalypts, and other odour-rich species requires greater attention.

Diet of dingoes and other wild dogs in peri-urban areas of north-eastern Australia.

Knowledge of the resource requirements of urban predators can improve our understanding of their ecology and assist town planners and wildlife management agencies in developing management approaches that alleviate human-wildlife conflicts. Here we examine food and dietary items identified in scats of dingoes in peri-urban areas of north-eastern Australia to better understand their resource requirements and the potential for dingoes to threaten locally fragmented populations of native fauna. Our primary aim was to determine what peri-urban dingoes eat, and whether or not this differs between regions. We identified over 40 different food items in dingo scats, almost all of which were mammals. Individual species commonly observed in dingo scats included agile wallabies, northern brown bandicoots and swamp wallabies. Birds were relatively common in some areas but not others, as were invertebrates. Dingoes were identified as a significant potential threat to fragmented populations of koalas. Dietary overlap was typically very high or near-identical between regions, indicating that peri-urban dingoes ate the same types or sizes of prey in different areas. Future studies should seek to quantify actual and perceived impacts of, and human attitudes towards, peri-urban dingoes, and to develop management strategies with a greater chance of reducing human-wildlife conflicts.

Interspecific variation in the diets of herbivores in an industrial environment: implications for exposure to fluoride emissions.

Atmospheric fluorides (gaseous and particulate) are deposited on, and absorbed by, vegetation. Ingested fluoride accumulates in calcified tissues of vertebrates, and if it is excessive, it may lead to dental and skeletal fluorosis. The prevalence, form and severity of the effects vary greatly between species. Foraging strategy can be an important determinant of fluoride exposure in herbivores, because foliar fluoride concentrations vary between plant species, for example, according to vertical and lateral position in the vegetation. We combined microhistological analysis of diet and analysis of foliar fluoride levels to examine interspecific variation in dietary fluoride exposure of macropodid marsupials (swamp wallaby Wallabia bicolor, red-necked wallaby Notamacropus rufogriseus and eastern grey kangaroo Macropus giganteus), in the buffer zone of an aluminium smelter in Victoria, Australia. Dietary niche differentiation between species was evident. The swamp wallaby and the red-necked wallaby were browsers or mixed feeders, depending on the classification system used. The eastern grey kangaroo was a grazer, consuming almost entirely grasses. However, foliar fluoride did not vary significantly between the main plant groups consumed. Our results indicate that interspecific variation in diet at this site is unlikely to explain variation in fluoride exposure.

A method for age estimation in the swamp wallaby (Wallabia bicolor)

We investigated molar progression as an index of age in the swamp wallaby (Wallabia bicolor) by examining a small sample of known-age specimens. We demonstrate a strong relationship between age and molar index in W. bicolor [log10(age, in days) = (MI + 4.6864)/2.2179, R2 = 0.93], which will facilitate more detailed investigation of this species.

Vegetation management influences habitat use by mammalian herbivores in shrub-encroached grassy woodland

Context Restoration of disturbed vegetation communities commonly involves altering vegetation composition and structure, attributes that can influence the suitability of habitat for fauna. Feedbacks may occur whereby changes to the vegetation affect mammalian herbivores, and unintended changes may prevent managers from achieving conservation goals. Aims To understand how vegetation management affects habitat use by five mammalian herbivores, namely eastern grey kangaroo (Macropus giganteus), swamp wallaby (Wallabia bicolor), common wombat (Vombatus ursinus), European rabbit (Oryctolagus cuniculus) and hog deer (Axis porcinus). Methods A management experiment (mechanical slashing of the encroaching shrub Leptospermum laevigatum) at Wilsons Promontory National Park, Australia, created slashed swales in addition to untreated dune and scrub woodland. In each vegetation stratum, we estimated the cover of L. laevigatum and quantified herbivore abundance by counting the standing crop of faecal pellets. Key results Relative to untreated vegetation, mechanical slashing of L. laevigatum substantially reduced cover of this species above 200 cm, but increased its cover below 30 cm. On the basis of faecal-pellet counts, multispecies use of managed and unmanaged parts of the landscape differed substantially, with the differences principally driven by higher abundance of European rabbits and eastern grey kangaroos at slashed sites. Conclusions The responses of three grazing species (kangaroo, rabbits and wombats) to vegetation management were predicted well by prior knowledge of diet and habitat preferences. This was not the case for the browser (swamp wallaby), nor for the grazer that consumes substantial amounts of browse in the study area (hog deer), and additional knowledge of the processes underlying their responses to vegetation change is required. Implications Our findings highlighted that vegetation management can influence herbivore abundances in the managed system. An improved understanding of these associations will allow vegetation management plans to incorporate herbivore responses.