Lasiorhinus Latifrons Research Articles

How much time, effort and money is spent caring for wombats?

Wildlife care and rehabilitation are undertaken by thousands of volunteers throughout Australia every year. Bare-nosed (Vombatus ursinus) and southern hairy-nosed wombats (Lasiorhinus latifrons) regularly come into care, with the demands on wombat carers and the numbers of wombats increasing. Understanding the burdens placed on wombat carers and rehabilitators will provide information to wildlife managers to assess the risks to wombats and document the concerns of wildlife carers. Data were collected via an online quantitative and qualitative survey using Qualtrics. The survey was distributed through Facebook groups to wombat carers and rehabilitators and received 22 responses. The survey confirmed that caring for wombats is time-consuming and expensive, particularly when raising wombat joeys. Both adult and juvenile wombats were brought into care; the most common reasons were vehicle collisions, sarcoptic mange, and injuries resulting from dog or wombat attacks. Despite the significant financial and mental health costs to wombat carers, in most cases, carers thought young wombats that came into care were successfully rehabilitated and re-introduced into their natural habitat. Our study provides insights into the issues facing wombats, the people that care for wombats, and the wider carer sector.

Digging for answers: defining the external architecture of the southern hairy-nosed wombats’ (Lasiorhinus latifrons) subterranean excavations

The southern hairy-nosed wombat (Lasiorhinus latifrons) is a large, nocturnal, herbivorous, burrowing marsupial, endemic to the semi-arid and arid regions of southern Australia. The active burrow of L. latifrons is used as the primary feature in population estimations. Therefore, accurate identification of an active burrow is vital, especially when other burrow-like structures exist. Entrance attributes such as width, height, the length and angle of the path leading to the entrance, and signs of wombat activity are indistinguishable between the different structures, making differentiation between them impossible without inspecting the structure beyond the entrance. Structures leading from entrances were identified in the field as possible burrows, blinds, and go-throughs. An unmanned aerial vehicle provided accurate images from immediately above 12 active wombat warren systems in the mid-north of South Australia, to support ground-truthing for mapping and verification of these structures. Active possible burrows (APB) were found to occur in proportionally lower numbers than the active non-burrow structures (ANBS) of blinds and go-throughs, varying in proportion from as high as 1:2 to as low as 1:11 (APB:ANBS). Defining an active burrow and other tunnels leading from an entrance increases accuracy in burrow identification used in population estimations, while recognising the existence of additional architectural features is vital to understanding the functional potential of L. latifrons as an ecosystem engineer.

ConservationBots: Autonomous aerial robot for fast robust wildlife tracking in complex terrains

AbstractRadio tagging and tracking are fundamental to understanding the movements and habitats of wildlife in their natural environments. Today, the most widespread, widely applicable technology for gathering data relies on experienced scientists armed with handheld radio‐telemetry equipment to locate low‐power radio transmitters attached to wildlife from the ground. Although aerial robots can transform labor‐intensive conservation tasks, the realization of autonomous systems for tackling task complexities under real‐world conditions remains a challenge. We developed ConservationBots—small aerial robots for tracking multiple, dynamic, radio‐tagged wildlife. The aerial robot achieves robust localization performance and fast task completion times—significant for energy‐limited aerial systems while avoiding close encounters with potential, counterproductive disturbances to wildlife. Our approach overcomes the technical and practical problems posed by combining a lightweight sensor with new concepts: (i) planning to determine both trajectory and measurement actions guided by an information‐theoretic objective, which allows the robot to strategically select near‐instantaneous range‐only measurements to achieve faster localization, and time‐consuming sensor rotation actions to acquire bearing measurements and achieve robust tracking performance; (ii) a bearing detector more robust to noise; and (iii) a tracking algorithm formulation robust to missed and false detections experienced in real‐world conditions. We conducted extensive studies: simulations built upon complex signal propagation over high‐resolution elevation data on diverse geographical terrains; field testing; studies with wombats (Lasiorhinus latifrons; nocturnal, vulnerable species dwelling in underground warrens) and tracking comparisons with a highly experienced biologist to validate the effectiveness of our aerial robot and demonstrate the significant advantages over the manual method.

Microbial biogeography of the wombat gastrointestinal tract.

Most herbivorous mammals have symbiotic microbes living in their gastrointestinal tracts that help with harvesting energy from recalcitrant plant fibre. The bulk of research into these microorganisms has focused on samples collected from faeces, representing the distal region of the gastrointestinal (GI) tract. However, the GI tract in herbivorous mammals is typically long and complex, containing different regions with distinct physico-chemical properties that can structure resident microbial communities. Little work has been done to document GI microbial communities of herbivorous animals at these sites. In this study, we use 16S rRNA gene sequencing to characterize the microbial biogeography along the GI tract in two species of wombats. Specifically, we survey the microbes along four major gut regions (stomach, small intestine, proximal colon, distal colon) in a single bare-nosed wombat (Vombatus ursinus) and a single southern hairy-nosed wombat (Lasiorhinus latifrons). Our preliminary results show that GI microbial communities of wombats are structured by GI region. For both wombat individuals, we observed a trend of increasing microbial diversity from stomach to distal colon. The microbial composition in the first proximal colon region was more similar between wombat species than the corresponding distal colon region in the same species. We found several microbial genera that were differentially abundant between the first proximal colon (putative site for primary plant fermentation) and distal colon regions (which resemble faecal samples). Surprisingly, only 10.6% (98) and 18.8% (206) of amplicon sequence variants (ASVs) were shared between the first proximal colon region and the distal colon region for the bare-nosed and southern hairy-nosed wombat, respectively. These results suggest that microbial communities in the first proximal colon region—the putative site of primary plant fermentation in wombats—are distinct from the distal colon, and that faecal samples may have limitations in capturing the diversity of these communities. While faeces are still a valuable and effective means of characterising the distal colon microbiota, future work seeking to better understand how GI microbiota impact the energy economy of wombats (and potentially other hindgut-fermenting mammals) may need to take gut biogeography into account.

The behavioral responses of a nocturnal burrowing marsupial (Lasiorhinus latifrons) to drone flight.

The use of drones in wildlife research and management is increasing. Recent evidence has demonstrated the impact of drones on animal behavior, but the response of nocturnal animals to drone flight remains unknown. Utilizing a lightweight commercial drone, the behavioral response of southern hairy‐nosed wombats (Lasiorhinus latifrons) to drone flights was observed at Kooloola Station, Swan Reach, South Australia. All wombats flown over during both day and night flights responded behaviorally to the presence of drones. The response differed based on time of day. The most common night‐time behavior elicited by drone flight was retreat, compared to stationary alertness behavior observed for daytime drone flights. The behavioral response of the wombats increased as flight altitude decreased. The marked difference of behavior between day and night indicates that this has implications for studies using drones. The behavior observed during flights was altered due to the presence of the drone, and therefore, shrewd study design is important (i.e., acclimation period to drone flight). Considering the sensory adaptations of the target species and how this may impact its behavioral response when flying at night is essential.

Host reproductive cycle influences the pouch microbiota of wild southern hairy-nosed wombats (Lasiorhinus latifrons)

BackgroundMarsupials are born much earlier than placental mammals, with most crawling from the birth canal to the protective marsupium (pouch) to further their development. However, little is known about the microbiology of the pouch and how it changes throughout a marsupial’s reproductive cycle. Here, using stringent controls, we characterized the microbial composition of multiple body sites from 26 wild Southern Hairy-nosed Wombats (SHNWs), including pouch samples from animals at different reproductive stages.ResultsUsing qPCR of the 16S rRNA gene we detected a microbial community in the SHNW pouch. We observed significant differences in microbial composition and diversity between the body sites tested, as well as between pouch samples from different reproductive stages. The pouches of reproductively active females had drastically lower microbial diversity (mean ASV richness 19 ± 8) compared to reproductively inactive females (mean ASV richness 941 ± 393) and were dominated by gram positive bacteria from the Actinobacteriota phylum (81.7–90.6%), with the dominant families classified as Brevibacteriaceae, Corynebacteriaceae, Microbacteriaceae, and Dietziaceae. Three of the five most abundant sequences identified in reproductively active pouches had closest matches to microbes previously isolated from tammar wallaby pouches.ConclusionsThis study represents the first contamination-controlled investigation into the marsupial pouch microbiota, and sets a rigorous framework for future pouch microbiota studies. Our results indicate that SHNW pouches contain communities of microorganisms that are substantially altered by the host reproductive cycle. We recommend further investigation into the roles that pouch microorganisms may play in marsupial reproductive health and joey survival.

Torquenema n. g., Wallabicola n. g., and Macropostrongyloides phascolomys n. sp.: New Genera and a New Species of Nematode (Strongylida: Phascolostrongylinae) Parasitic in Australian Macropodid and Vombatid Marsupials

Simple SummaryThis article describes two new genera of parasitic nematodes, Torquenema n. g. from the eastern grey kangaroo and Wallabicola n. g. from the swamp wallaby, and a new species, Macropostrongyloides phascolomys n. sp. from the caecum of the common wombat. The strongyloid nematodes belonging to the subfamily Phascolostrongylinae occur primarily in the large intestines of macropodid and vombatid marsupials. Current molecular evidence suggests that the two nematode species, Macropostrongyloides dissimilis and Paramacropostrongylus toraliformis, from macropodid marsupials are distant from their respective congeners. Furthermore, specimens of Macropostrongyloides lasiorhini from the large intestines of the southern hairy-nosed wombat (Lasiorhinus latifrons) and the common wombat (Vombatus ursinus) are genetically distinct. This study aimed to describe the new genera Torquenema n. g. (with T. toraliforme n. comb. as the type species) from the eastern grey kangaroo, Wallabicola n. g. (with W. dissimilis n. comb. as the type species) from the swamp wallaby and a new species Macropostrongyloides phascolomys n. sp. from the common wombat, using light and scanning electron microscopy.

Signatures of landscape and captivity in the gut microbiota of Southern Hairy-nosed Wombats (Lasiorhinus latifrons)

BackgroundHerbivorous mammals co-opt microbes to derive energy and nutrients from diets that are recalcitrant to host enzymes. Recent research has found that captive management—an important conservation tool for many species—can alter the gut microbiota of mammals. Such changes could negatively impact the ability of herbivorous mammals to derive energy from their native diets, and ultimately reduce host fitness. To date, nothing is known of how captivity influences the gut microbiota of the Southern Hairy-nosed Wombat (SHNW), a large herbivorous marsupial that inhabits South Australia. Here, using 16S rRNA gene sequencing, we characterized the faecal microbiota of SHNWs in captivity and from three wild populations, two from degraded habitats and one from an intact native grass habitat.ResultsWe found that captive SHNWs had gut microbiota that were compositionally different and less diverse compared to wild SHNWs. There were major differences in gut microbiota community membership between captive and wild animals, both in statistically significant changes in relative abundance of microbes, and in the presence/absence of microbes. We also observed differences in microbial composition between wild populations, with the largest difference associated with native vs. degraded habitat.ConclusionsThese results suggest that captivity has a major impact on the gut microbiota of SHNWs, and that different wild populations harbour distinct microbial compositions. Such findings warrant further work to determine what impacts these changes have on the fitness of SHNWs, and whether they could be manipulated to improve future management of the species.

Evaluation of olfactory and visual cues to deter southern hairy-nosed wombats (Lasiorhinus latifrons) from their burrows

Human–wildlife conflicts threaten a huge diversity of species and affect the livelihoods of millions of people. There is an increasing need to develop management strategies that meet the needs of humans and wildlife. A variety of conflict mitigation measures are available, but for many species like the southern hairy-nosed wombat (Lasiorhinus latifrons) their effectiveness has not been scientifically tested. Deterrents could provide a cost effective and efficient means of reducing wombat damage to agriculture. Anecdotal accounts suggest that ‘Blood & Bone’ (a plant fertiliser) and compact discs may deter wombats. This study aimed to assess their effectiveness in deterring free-living wombats from burrows on agricultural land using remote cameras to monitor changes in activity and behaviour before and after treatment application. Mixed-effects models revealed a significant decrease in the number of visits to burrows following the application of compact discs (P<0.01). ‘Blood & Bone’ did not deter wombats from burrows (P=0.81), but increased exploratory behaviour (P=0.01) and decreased travelling behaviour (P=0.05) were observed. This suggests that visual cues may be more effective in deterring wombats from burrows than olfactory cues, possibly because they are more easily detected from further away.

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.

Observations on the mortality of young southern hairy-nosed wombats (Lasiorhinus latifrons) in the Murraylands of South Australia

There are very few reports on mortality of young southern hairy-nosed wombats. We describe the appearance of six young wombats that died when rainfall was well below average in 2017–19. Some of the wombats appeared malnourished, and most died around the age of weaning, which we conclude is a vulnerable time for them. A crude and lower estimate of the mortality of wombats born in 2016 was 31%.

The behaviour and social development of young southern hairy-nosed wombats (Lasiorhinus latifrons)

Little is known about the ethology and behavioural ecology of young wombats. Observations of young southern hairy-nosed wombats (Lasiorhinus latifrons) that were still with their mothers revealed that they have an extensive ethogram that includes autonomous and social play, and precocial aggressive and defensive behaviours. The behaviour of one wombat was observed for 5–7 nights at monthly intervals from when it was first seen above ground with its mother (at an estimated age of 7–9 months). In the first 3 months it played often, and it remained within 25m of the natal burrow. Thereafter, the frequency of play declined, and it followed its mother further from the natal burrow. Five months after it was first seen it became independent of its mother when she moved to another warren. Nearly all the young wombat’s social encounters and interactions were with the group of wombats that occupied two warrens that included the natal burrow. At the time of the study, in 1975, only two of the nine juvenile and subadult wombats that were present at the warrens when the study started were still there 15 months later, which suggests that many young wombats disperse.

A quick drink: the response of southern hairy-nosed wombats (Lasiorhinus latifrons) to rainfall

This paper describes opportunistic observations of the response of wombats to rainfall. Within a few minutes after heavy showers of rain wombats congregated to drink at an area of exposed calcrete (limestone) where water had accumulated. The wombats interacted socially much more than is typical for wombats. This event demonstrates a level of understanding of their environment and of the availability of a transient resource that has not been documented previously.

The population status of southern hairy-nosed wombats (Lasiorhinus latifrons). II. Landscape factors affecting distribution and abundance

The southern hairy-nosed wombat has a fragmented distribution across the arid and semiarid regions of southern South Australia and south-eastern Western Australia. Its distribution and abundance are highly patchy, with large clusters of warrens in some areas but few to no warrens in adjacent areas. In order to understand why this occurs, we mapped the species’ distribution and correlated the locations of over 8130 data points (5349 presence points and 2781 absence points) with environmental and landscape data. Overall, the wombat distribution is influenced by rainfall, with no wombats in areas where the mean annual rainfall is <154mm. Abundance is greatest in areas where rainfall is >227mm per annum. At the regional/local scale, warrens are found only in areas where the soil clay content is between 9 and 40%, and warren abundance is higher in open vegetation classes (saltbush/bluebush shrublands, grasslands) than in closed vegetation (mallee woodlands with shrubby understorey). Over-riding all of these environmental influences are anthropogenic land-use practices: although 38% of the wombats are located in protected areas and 51% are located on grazing land, they are virtually absent from croplands (~2%).

The population status of southern hairy-nosed wombats (Lasiorhinus latifrons). I. Distribution and abundance

There is disagreement within the community regarding whether the distribution and abundance of southern hairy-nosed wombats (Lasiorhinus latifrons) is increasing or decreasing. On one hand, farmers and graziers within areas where wombats can be found have consistently claimed that wombat numbers have increased in recent decades. Conversely, conservation groups, including the International Union for the Conservation of Nature (IUCN), claim that the wombat population is experiencing a species-wide decline, and recently upgraded its conservation status to ‘Near Threatened’. To resolve this disparity, we used a combination of field surveys and the analysis of satellite imagery to map the species-wide distribution and to estimate the overall population abundance of southern hairy-nosed wombats. We found that the wombat population has grown substantially since the last major surveys in the 1980s; however, the growth has not been uniform. While the population group in the Gawler Ranges has experienced marked population growth, there has been only relatively modest growth in the Murraylands. On the Yorke Peninsula, while the overall population numbers do not appear to have changed, some colonies have disappeared entirely. We also found a substantial population of wombats in Western Australia that had not been previously reported.

A survey and critical review of wombat diets in captivity

Much of the literature on wombat diet is concerned only with the broad categories of consumed matter, and there is little about their specific nutritional requirements despite diet playing a major role in health. This study gathered information by surveying zoological parks and wildlife carers about current feeding regime, diet and the prevalence of nutritional or dental disorders of wombats held in captivity, with the aim of improving the diets of captive wombats, thus their health and welfare outcomes. Data on the composition, variation and basis of diets for 31 bare-nosed or common wombats (Vombatus ursinus) and 19 southern hairy-nosed wombats (Lasiorhinus latifrons) were gathered from 13 facilities. The nutritional values of diets fed to wombats in captivity were calculated and compared with known dietary requirements for bare-nosed wombats. Results demonstrate that the current diet of wombats held in captivity often consists of a high portion of fruits, vegetables and livestock feed, with the fruit and vegetable portions providing higher levels of simple carbohydrates and starch compared with natural grass diets. Generally, the facilities are providing diets that are exceeding reported maintenance energy and nitrogen requirements. Due to a lack of details provided regarding quantity and species of grasses fed, we could not provide an accurate ration calculation for the proportion of grasses in the diets. Some of the health concerns noted included insufficient weight gain, endoparasites, malocclusion and insufficient tooth wear. Further research is required to assess the requirements of reproductive, lactating and juvenile wombats; however, it is clear that wombats in captivity need to be fed larger volumes and varieties of grasses, forbs and sedges than they are currently being fed to maintain good health.

Translocation is not a viable conflict-resolution tool for a large fossorial mammal, Lasiorhinus latifrons

Abstract ContextThe translocation of southern hairy-nosed wombats (Lasiorhinus latifrons) has been suggested as a management tool to alleviate conflicts with the agricultural sector because of the damages caused by their burrowing activity. Translocation is widely used for removing problem animals from conflict areas, but its effectiveness is rarely adequately evaluated and often fails to resolve conflicts. Furthermore, translocations often result in low survival, extensive movement, and the non-establishment of translocated animals. AimsThe present study assessed the viability of translocation as a damage-mitigation tool for L. latifrons, by examining the (1) capture success of L. latifrons, (2) survival and establishment of translocated L. latifrons, and (3) reduction of L. latifrons activity at source sites. MethodsThirteen L. latifrons individuals were translocated from conflict zones on agricultural properties and released on a private grazing property >60km from capture sites. The behaviour of translocated L. latifrons individuals was monitored using GPS and/or VHF technology, and compared with that of 12 resident animals. Motion-sensor cameras monitored the source sites to determine recolonisation rates. Key resultsThe capture and removal of problem individuals were time-intensive and infeasible on a large scale. Post-release mortality was not observed, although nine translocated and nine resident L. latifrons individuals went missing soon after release. Translocated (n=4) L. latifrons displayed high site fidelity, but initially ranged further than residents (n=6), before settling into similar behaviour patterns. Lasiorhinus latifrons activity was not reduced at the source sites, with neighbouring wombats recolonising warrens within 1–2 weeks. ConclusionsTranslocation is not a suitable human–wombat conflict mitigation tool but may prove useful for restoring declining populations. ImplicationsThese findings support the growing body of evidence that translocating problem animals is not suitable for resolving conflicts and alternative methods such as the use of deterrents may be more appropriate.

Variation in the sex ratio of pouch young and adult hairy-nosed wombats (Lasiorhinus latifrons and Lasiorhinus krefftii)

Understanding the causes and consequences of biases in the sex ratio at birth and of adults in species of mammals that have unusual life histories may help us know whether sex ratios are adaptive responses to ecological and evolutionary forces and may be important in conserving endangered species. For example, have sex ratio biases at birth and in adults in species of mammals evolved as an adaptive response to environmental unpredictability? We investigated the sex ratio of populations of hairy-nosed wombats, Lasiorhinus latifrons, and the endangered Lasiorhinus krefftii. The social structure of Lasiorhinus includes male philopatry and female dispersal, which are unusual traits among mammals. Reproduction in these wombats is often curtailed by unpredictable droughts, and so wombats may be a suitable target group for understanding the causes and consequences of biases in mammalian sex ratios. The sex ratio in populations of adult L. latifrons reported in the scientific literature varied widely, but the mean percentage of females in the 10 studies examined was 54.9 with a 95% confidence interval of 50.3 to 59.5. In the population of L. latifrons that we monitored for nearly twenty years beginning in 1994, the percentage of adult females varied between 66 and 37% in a manner that suggested homeostasis. The growth of the population of critically endangered L. krefftii from 52 males and 29 females in 2000 to 79 males and 91 females in 2016 suggested that more females than males were born. The sex ratio of pouch young of L. latifrons was biased towards females at times. The mean percentage of female pouch young in 19 breeding seasons was 56.4 (95% confidence interval of 50.4–62.4). Variation in the sex ratio of pouch young was examined regarding theories of sex allocation. When the percentage of adult females in the population was lower (37–50%) and had been declining, L. latifrons mothers had more female than male pouch young, but the sex ratio of pouch young was about equal when the percentage of adult females was higher (53–66%). This pattern is partly consistent with Fisher’s principle, which is also known as the homeostatic hypothesis (HH). When the percentage of adult females was lower, the mothers of female pouch young were in better condition than the mothers of male pouch young, which is consistent with a reversed Trivers–Willard (TW) effect in part. The biases in the sex ratio of adult and pouch young wombats may be adaptive responses to their life history and to demographic and environmental cues. Wombats are unusual among mammals in that males are philopatric and females disperse. Hairy-nosed wombats (two species within the genus Lasiorhinus) exist tenuously in semi-arid environments because of infrequent reproduction, habitat degradation, and drought. L. krefftii is critically endangered. This study suggests that following severe droughts, a female bias in the sex ratio of pouch young and of adults may result in populations increasing more rapidly than if the sex ratio was equal. Agencies charged with managing and conserving wombats could make use of this knowledge by undertaking more comprehensive demographic monitoring of populations to evaluate their risk of extinction; a persistent male bias in adults may be a signal of an increased risk of extinction. The unpredictability of rainfall and drought across their distribution has resulted in variation in abundance and in genetic, ecological, and social parameters associated with wombat colonies, making these species valuable for exploring the causes and consequences of biases in mammalian sex ratios.

Genetic monitoring of southern hairy-nosed wombats over two decades reveals that individuals can live for at least 18 years in the same warrens

Survival and growth rates are important demographic parameters to understand for long-term management of populations. Eighteen years have elapsed since non-invasive genetic methods were used to identify southern hairy-nosed wombats (Lasiorhinus latifrons), and determine space use and relatedness at Brookfield Conservation Park, South Australia. Because the species is long-lived (>30 years) and genetic methods can identify all or most wombats that use an area, it is possible to determine whether population size or warren use have changed and if any individuals are still alive. To this end, in April 2017 we collected hair from wombats from the same warrens as the earlier study using sticky tape suspended across burrows. We subjected DNA from selected hairs to 10 microsatellite loci and a Y-linked sex marker, and identified 76 wombats. Five wombats were detected 16–18 years before, and four of them were found in warrens that they had used previously. The number of tapes hit, wombats detected, and warrens used were greater than in April 2001 and similar to September 2001. This study illustrates that non-invasive sampling methods can be used to track free-ranging individuals in continuous habitat across decades, despite rapidly evolving genetic technology that can strand older datasets.

Environmental Factors Influencing Hairy‐Nosed Wombat Abundance in Semi‐Arid Rangelands

ABSTRACTUnderstanding environmental factors influencing the abundance of species is important for developing strategies to manage wildlife effectively. Long‐term studies provide the most reliable information upon which to base management decisions. This is particularly important when considering threatening processes, like drought and climate change, and a species' future security. We collected data on abundance of southern hairy‐nosed wombats (Lasiorhinus latifrons) on Kooloola Station in South Australia's Murraylands during nightly spot‐lighting excursions in winter and spring between 1993 and 2014. Wombat numbers declined significantly after the early‐mid 1990s, and were lowest in 2002–2003 in the middle of the millennium drought (late 1996–mid‐2010). Despite an observed decline in grazing competition from domestic sheep and rabbits (Oryctolagus cunniculus) after 2003 and above‐average rainfall in 5 of the next 11 years, the wombat population failed to recover to early–mid‐1990s levels, remaining at approximately 50% of estimated abundance pre‐drought. The study provides evidence that rainfall has a significant effect on southern hairy‐nosed wombat population size, most likely through improvements in the availability of palatable plant species. Historical information suggests that there was a change in the grass and herbaceous layer on Kooloola Station in the mid‐1970s from a pasture dominated by summer‐germinating native grass and forb species, the natural diet of the southern hairy‐nosed wombat, to one dominated by winter‐germinating introduced weeds. Several consecutive years of above‐average rainfall are needed before effective wombat population increase occurs and the size of yearly winter and spring rainfall events is strongly linked to population trends the following year. Historical information and first‐hand observations suggest that dietary components (either native grasses or introduced weed species) and level of grazing competition may also interact to affect wombat survival and population recovery from drought, although this requires further testing. Together with rainfall, these factors have important implications to develop appropriate conservation and management strategies for this species in a changing climate likely to be dominated by increased drought frequency and duration. © 2020 The Wildlife Society.