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Late-Holocene mammal fauna from southern Australia reveals rapid species declines post-European settlement: Implications for conservation biology
Abstract
The arrival in Australia of Europeans and the species they brought with them initiated a sharp decline in native mammalian biodiversity. Consequently, one-third of the original or pre-European terrestrial mammal fauna is now extinct or threatened with extinction. Although the distributional ranges of many Australian mammals have contracted markedly, modern distributions are frequently used as baselines for conservation management and understanding ecological requirements. However, these often poorly reflect pre-European distributions, particularly in areas where biodiversity declines were rapid and occurred soon after European arrival. Here we analyse two late Holocene mammalian assemblages from Fleurieu Peninsula, South Australia, and reconstruct the pre-European terrestrial non-volant mammal fauna. The region was previously estimated to have lost perhaps 30% of its original terrestrial non-volant mammal fauna, but our results indicate a loss of almost 50%. We provide the first local records of the murids Mastacomys fuscus, Pseudomys australis, P. gouldii, P. novaehollandiae and P. shortridgei, and confirm the past occurrence of the now-extinct Conilurus albipes. Our study contributes new knowledge of species biogeography and ecology and will help refine restoration targets.
... Historically, M. fuscus was more widespread than today. The species has been found in numerous fossil assemblages across South Australia, Victoria and south-eastern New South Wales, and several fossil sites occur outside the species' current recognised distribution and habitat, e.g., McEacherns Cave and McEacherns Deathtrap Cave (Kos, 2003a(Kos, , 2003b) Mount Gambier (Thomas, 1922), Kangaroo Island (McDowell et al., 2013;McDowell et al., 2015;Adams et al., 2016), Naracoorte Caves (Reed and Bourne, 2000), Rapid Bay (Fusco et al., 2016) and the Southern Flinders Ranges (Liddle et al., 2018) in South Australia, and the Wellington Caves (Lydekker, 1885;Dawson and Augee, 1997;Green and Osborne, 2003), Jenolan Caves (Morris et al., 1997) and Wombeyan Caves (Ride, 1960;Andrews and Cook, 1990;Calaby and Wimbush, 1964), Yarrangobilly Caves (Bilney, 2020) and Wee Jasper (Theden-Ringl et al., 2020) in New South Wales. The fossil record suggests M. fuscus once occupied a wider range of drier habitat types (<700 mm rainfall) at lower elevations (<100 m) compared with its current distribution (Bilney et al., 2010;Fusco et al., 2016;Menkhorst, 1995). ...
... The species has been found in numerous fossil assemblages across South Australia, Victoria and south-eastern New South Wales, and several fossil sites occur outside the species' current recognised distribution and habitat, e.g., McEacherns Cave and McEacherns Deathtrap Cave (Kos, 2003a(Kos, , 2003b) Mount Gambier (Thomas, 1922), Kangaroo Island (McDowell et al., 2013;McDowell et al., 2015;Adams et al., 2016), Naracoorte Caves (Reed and Bourne, 2000), Rapid Bay (Fusco et al., 2016) and the Southern Flinders Ranges (Liddle et al., 2018) in South Australia, and the Wellington Caves (Lydekker, 1885;Dawson and Augee, 1997;Green and Osborne, 2003), Jenolan Caves (Morris et al., 1997) and Wombeyan Caves (Ride, 1960;Andrews and Cook, 1990;Calaby and Wimbush, 1964), Yarrangobilly Caves (Bilney, 2020) and Wee Jasper (Theden-Ringl et al., 2020) in New South Wales. The fossil record suggests M. fuscus once occupied a wider range of drier habitat types (<700 mm rainfall) at lower elevations (<100 m) compared with its current distribution (Bilney et al., 2010;Fusco et al., 2016;Menkhorst, 1995). Several researchers (e.g., Ride, 1956;Watts and Aslin, 1981;Happold, 2008;Schulz et al., 2019;Menkhorst, 1995;Green and Osborne, 2003;Menkhorst et al., 2008) attribute this to the cooler, wetter conditions of the late Pleistocene, suggesting the modern distribution of M. fuscus had been limited by climate change. ...
... Several researchers (e.g., Ride, 1956;Watts and Aslin, 1981;Happold, 2008;Schulz et al., 2019;Menkhorst, 1995;Green and Osborne, 2003;Menkhorst et al., 2008) attribute this to the cooler, wetter conditions of the late Pleistocene, suggesting the modern distribution of M. fuscus had been limited by climate change. However, recent radiometric dating has shown many of these fossil deposits actually accumulated during the Holocene, suggesting the species may have suffered a rapid range contraction in response to anthropogenic ecosystem modifications consequent to European settlement (Fusco et al., 2016;Tammone et al. in press). As threatening processes are still in effect, M. fuscus will probably continue to decline unless conservation management actions are enacted (Seebeck and Menkhorst, 2000;Green and Osborne, 2003;Green et al., 2008;Happold, 2008;Menkhorst et al., 2008;Seebeck, 1971;McDowell et al., 2013;Menkhorst, 1995;Hocking and Driessen, 2000;Bilney et al., 2010). ...
Global ecosystems underwent major changes through the Quaternary, as climates cycled from cool and dry glacial conditions to relatively warm and humid interglacial conditions. How these changes affected the diversity and composition of small-mammal communities is mostly unknown, especially for the southern-temperate regions of Australia. We used fossil assemblages from owl regurgitates to investigate changes in small mammals from Tasmania's forest environments over the last 20,000 years, encompassing the transition from cold glacial conditions of the Last Glacial′ Maximum (LGM) into the warmer Holocene. During the early part of this period, Tasmania was connected to mainland Australia via a low-elevation land bridge, but was transformed into a large island by rising sea levels during the Late Pleistocene – Holocene transition. Despite these changes, the regional small-mammal fauna appears to have been persistent over this entire period, with no loss of species. However, the relative abundance of most species changed dramatically, apparently in response to habitat changes, which also provoked substantial shifts in community composition and diversity. A strong indicator of the magnitude of change is Mastacomys fuscus, a graminivorus specialist murid, which dominated the assemblage prior to and during the LGM, but declined as temperature and sea level rose during the Late Pleistocene – Holocene. In contrast, the generalist rodent Pseudomys higginsi, along with the small forest-dependent marsupials Cercartetus spp. and Antechinus spp., became more common during the Holocene. The continued survival of these species to the present, despite divergent environmental needs, implies that Tasmania's complex geomorphology provided multiple refugia that conferred resilience in the face of environmental change.
... Quaternary fossil deposits often provide a high temporal resolution of paleontological evidence (Palombo, 2018), thus potentially rendering fine-scale information on how faunal communities reacted to changing climatic regimes at the time of deposition (see, e.g., Lundelius, 1960;Faunmap Working Group, 1996;Bell et al., 2010;Prideaux et al., 2010;Thorn et al., 2017). Observing faunal dynamics and records of extant species outside of their current distribution provides insights into the underlying causes and consequences of local extinctions or range shifts, which may be related to climate change and/or human impacts (e.g., Kemp and Hadly, 2016a;Fusco et al., 2016). This information provides a baseline through which modern species distributions and communities can be evaluated from a conservational perspective (Kemp and Hadly, 2016b), allowing predictions on their dynamics into the future. ...
... Besides climatic changes, human impacts potentially influenced distributions and abundances of small vertebrates during the late Pleistocene to Holocene of Australia. The youngest sedimentary bed we analyzed (1.8 ka) provides a record pre-dating European settlement, thus differences to the modern fauna might be caused by impacts of European settlers on the environment (e.g., Fusco et al., 2016). In particular, we report several unidentified morphotypes that occurred in both arid and wet periods, but do not resemble any extant species found in the area today. ...
... The presence of unidentified lizard morphotypes and locally extinct mammal species in both arid and wet periods might indicate that climatic changes did not affect these species' distributions throughout the late Pleistocene/Holocene. Instead, their absence in the vicinity of the cave today suggests a potential influence of European settlement on the fauna of MDC (see also Kos, 2003b). As described by Fusco et al. (2016) for the Fleurieu Peninsula (located northwest of MDC in South Australia), European settlement drastically altered local vegetation (see also Dodson, 2001) and surface hydrology (Harding, 2005), leading to a decrease of wetland vegetation in the area. These environmental changes probably led to higher intensity fires and consequently a loss of local terrestrial non-volant mammal biodiversity of almost 50% (Fusco et al., 2016). ...
The Quaternary Period is characterized by dramatic global climatic changes. Quaternary fossil deposits, which can offer excellent stratigraphic resolution, provide a unique opportunity to understand how fauna respond to past environmental change. Here, we test if the herpetofauna of McEachern’s Deathtrap Cave, a late Pleistocene to Holocene pitfall trap deposit from Victoria, Australia, shows climate-related shifts in taxonomic relative abundance through time. During the last 14,000 years, southeastern Australia experienced pronounced periods of aridity, while temperatures remained relatively stable. We show that the stratigraphic layers of this deposit are characterized by different relative abundances of reptile subfamilies, and that changes in subfamily abundance between layers correlate with known shifts to aridity, based on the percentage of C4 grasses present in the region. We further identify 13 lizard morphotypes from the fossil deposit and compare this diversity with the present-day lizard fauna. Our analyses indicate that gradual changes in community structure, which are typically observed in southeastern Australian vertebrate communities during the Pleistocene–Holocene transition, can partly be explained by changing aridity. These findings represent an important contribution to understanding Quaternary community change in Australia, particularly because evidence of faunal succession of reptile and amphibian communities in Victoria is lacking. Our results further demonstrate the utility of the Australian herpetofaunal fossil record for detecting community responses to past climate change on relatively shallow timescales and at higher levels of taxonomic identification.
... From early records of naturalists like Cleland and Black who identified the land surrounding Victor Harbour had few remaining remnants in the paddocks (confined to useable sections of land) or along roadways (Paton and Crompton, 2013). The waterways which ran into Victor Harbour being the Inman and Hindmarsh Rivers were a means to drain swamps and thus alter vegetation communities (Fusco et al. 2015). In particular, Allocasuarina pusilla noted to grow in association with Allocasuarina striata and Allocasuarina muelleriana along the creek line at Back Valley (Paton and Crompton, 2013). ...
... The loss of vegetation via European colonisation on the Fleurieu Peninsula is estimated to be as high as 42% (Harding, 2005;Fusco et al., 2015). Only 13% of the remaining vegetation is intact (Crossman et al., 2011). ...
... The region floristic importance often underestimated due to increased urbanisation/introduced species according to Crossman et al. (2011), and Bardsley and Sweeney (2010) as 50% of the state native floristic species occur in this region. European arrival into South Australia has had a substantial impact on the vegetation as acknowledged by Bardsley et al. (2015), Bickford et al. (2008), Fusco et al. (2015) and Crossman et al. (2011). What is not acknowledge as frequently is the Aboriginal presence on the landscape which involved fire stick farming (Bickford and Gell, 2005). ...
Identifying the cause of a threatened species can aid in how best to formulate recovery actions. Recovery can be based on broad concepts and may not reflect a specific community or species requirements. Urban sprawl and intensification of land are known as threatening processes. How a threatening process interacts with a threatened species can aid in the recovery efforts. In South Australia, the species Allocasuarina robusta provides an opportunity to understand how past land usage may direct recovery efforts. Information on past land usage can involve identifying and using data from multiple repositories. The investigation focused on the relationship between changes in land use and herbarium data to understand a relationship between a common and threatened species. As a species evolves and adapts, the conservation practices used, including the methods used for identifying future actions, needs to be reflective of a changing environment. A changing environment can have consequences to biodiversity, creating several issues for a land manager. Traditional species recovery techniques can slow the threatening process down. Sometimes these threats may be visible like grazing from fauna (native and introduced). The threat to Allocasuarina robusta is a change in land use originating from anthropogenic activities. Supplementary planting with tube stock is a well-grounded practice, but the implications from this practice may need further investigation. Natural regeneration is crucial for long term population survival, but in Allocasuarina robusta, this is not occurring. The Allocasuarina robusta investigation aims to explore the relationships between herbarium data and land-use histories to guide future recovery efforts.
... Conservation efforts are essential to remediate Australia's damaged ecosystems and examining fossil assemblages may greatly improve conservation management outcomes. However, the interpretive value of fossil assemblages rests largely on how well we understand the ecology of native species (McDowell et al. 2012;Fusco et al. 2016). Here we investigate a fossil assemblage sampled from Mair's Cave in the southern Flinders Ranges, South Australia, to explore the proximal pre-European biodiversity and seek insight into the ecological flexibility of some of Australia's native mammals. ...
... Mastacomys fuscus has been found in fossil assemblages across south-eastern Australia, indicating that its distribution was once much more extensive than it is today (Ride 1956;Calaby and Wimbush 1964;Hope et al. 1977;McDowell et al. 2015;Adams et al. 2016;Fusco et al. 2016). Several researchers (Calaby and Wimbush 1964;Watts and Aslin 1981;Green and Osborne 2003;Belcher and Leslie 2011;Milner et al. 2015) have hypothesised that its range contracted during the late Pleistocene and/or early Holocene in response to increasing aridity. ...
... Several researchers (Calaby and Wimbush 1964;Watts and Aslin 1981;Green and Osborne 2003;Belcher and Leslie 2011;Milner et al. 2015) have hypothesised that its range contracted during the late Pleistocene and/or early Holocene in response to increasing aridity. However, radiocarbon-dated fossil assemblages from Kangaroo Island (McDowell 2013;McDowell et al. 2015;Adams et al. 2016), Fleurieu Peninsula (Fusco et al. 2016) and south-eastern Australia (Bilney et al. 2010) indicate that M. fuscus occupied said regions within the last few hundred years. Consequently, its range appears to have contracted following European settlement and is not related to climatic change (Fusco et al. 2016). ...
Many Australian mammal species have suffered significant declines since European colonisation. During the first century of settlement, information on species distribution was rarely recorded. However, fossil accumulations can assist the reconstruction of historical distributions. We examine a fossil vertebrate assemblage from Mair's Cave, one of few known from the southern Flinders Ranges, South Australia. The Mair's Cave assemblage was dominated by mammals but also included birds and reptiles. Of the 18 mammals recovered, two have not previously been recorded from the southern Flinders Ranges, at least one is extinct and seven are recognised as threatened nationally. Characteristics of the assemblage suggest that it was accumulated by a Tyto owl species. Remains of Tyto delicatula and a larger unidentified owl were recovered from the assemblage. Most mammals identified from the assemblage presently occupy Australia's semiarid zone, but a single specimen of the broad-toothed rat (Mastacomys fuscus), which primarily occurs in high-moisture, low-temperature environments was also recovered. This suggests either that the southern Flinders Ranges once experienced higher past precipitation, or that M. fuscus can tolerate a broader climatic range than its current distribution suggests. Our study contributes new knowledge on the biogeography and ecology of several mammal species, data useful for helping to refine restoration targets.
... Understanding past biogeographical patterns is essential for developing accurate projections of species distributions across the landscape now and into the future, information fundamental for conservation efforts under a rapidly changing climate (McGuire & Davis, 2014). As such, sampling of vertebrate records from different types of caves across a variety of regions is a crucial first step for conservation palaeobiology approaches (Fusco, McDowell & Prideaux, 2016). ...
... post-European colonisation), but was never recorded alive prior to its local extirpation. If so, then ecological surveys used to determine the geographic range contraction of modern small-bodied mammals since European colonisation substantially underestimate the true historic geographic range of their occurrence, and the complete range of habitat tolerances of a given species (Fusco, McDowell & Prideaux, 2016). ...
Fossils from caves in the Manning Karst Region, New South Wales, Australia have long been known, but until now have never been assessed for their palaeontological significance. Here, we report on late Quaternary faunal records from eight caves in the region. Extinct Pleistocene megafaunal taxa are recognised in two systems and include giant echidnas (Tachyglossidae gen. et sp. indet.), devils ( Sarcophilus laniarius ), koalas ( Phascolarctos stirtoni ), marsupial ‘lions’ ( Thylacoleo carnifex ), and kangaroos ( Macropus giganteus titan ). Some caves contain skeletal remains of introduced exotics such as sheep and dogs, but also provide a rich record of small-bodied native species including Eastern Bettongs ( Bettongia gaimardi ), Eastern Chestnut Mice ( Pseudomys gracilicaudatus ), and White-footed Rabbit Rats ( Conilurus albipes ). These endemics are either locally extirpated or have suffered total extinction in the historic period. Their skeletal and dental remains were recorded as unmineralised surface specimens in the caves, indicating that they are recent in age. Extant populations have never been recorded locally, thus, their probable loss from the region in historic times had gone unnoticed in the absence of palaeo-evidence. Our findings suggest that the supposed habitat tolerances of such species have been substantially underestimated. It is highly likely that modern populations have suffered niche contraction since the time of European colonisation of the continent. The local extirpations of several species of digging mammal has likely led to decreased functionality of the current ecosystem.
... However, faunal declines were rapid and commenced soon after Europeans arrived. Thus, existing faunal baselines that are heavily reliant on historical records may not adequately represent the original faunal assemblages (Ride 1968;Bilney et al. 2010;McDowell 2014;Fusco et al. 2016). Consequently, biodiversity losses that occurred since European colonisation are typically underestimated. ...
... Consequently, biodiversity losses that occurred since European colonisation are typically underestimated. Holocene fossils have been used to extend our knowledge of the pre-European biogeography of Australia's original mammal fauna and how this has changed through time (Bilney et al. 2010;McDowell et al. 2012;Bilney 2014;McDowell 2014;Fusco et al. 2016). Combining fossil records with historical records provides more complete baselines and can potentially contribute to conservation management. ...
Context. Establishing appropriate faunal baselines is critical for understanding and abating biodiversity declines. However, baselines can be highly reliant on historical records that come from already disturbed ecosystems. This is exemplified in the Murray–Darling Depression bioregion of Australia, where European settlement (and accompanying marked land-management changes and the introduction of many species) triggered rapid declines and losses of native species, often before their documentation.
Aims. We aim to establish the mammal fauna present when Europeans settled the Murray Mallee and Murray–Darling Depression bioregion and determine the extent of mammal loss since European settlement.
Methods. We describe a dated vertebrate assemblage from Light’s Roost in the lower Murray Mallee region of South Australia. We compare our data with those of modern fauna surveys and historical records to document the extent of change in the mammal fauna since European settlement.
Key results. Radiocarbon ages showed that the assemblage was accumulating, at a minimum, within an interval from 1900 to 1300 years ago. Since this time, the Murray–Darling Depression has lost half of its flightless terrestrial mammals. Species lost include the mulgara (Dasycercus blythi/cristicauda), which places this taxon within only 40 km of Lake Alexandrina, the hitherto-disputed type locality for D. cristicauda. Fossils provided the principal evidence for nearly half of the Murray Mallee fauna and over three-quarters of the fauna are represented in the fossil record.
Conclusions. Late Holocene assemblages provide important archives of species biogeography and diversity. Our revised faunal baseline indicated that the pre-European fauna of the Murray–Darling Depression was more diverse than hitherto understood and its reduction appears largely caused by the impacts of European settlement.
Implications. Baselines for species distributions derived from historical records and modern faunal surveys are likely to be incomplete and warrant revision, particularly for smaller and more cryptic species. Deficiencies in regional records mask the extent of mammal declines caused by European colonisation and associated agricultural practices, and thus vulnerability to anthropogenic disturbance.
... Of the two, P. australis currently has a more central and arid Australian distribution. Its significant range reduction in the last 100 years has been previously noted (Breed & Ford 2007, Medlin 2008, Fusco et al. 2016, Leggett et al. 2018. Our records suggest an even greater range reduction, certainly since the Holocene but also post-European settlement. ...
Late Pleistocene to Holocene-aged microfaunal assemblages are rarely reported in Australia despite their critical importance for palaeoecological studies, as well as their bearing on the megafaunal extinction debate. Capricorn Caves, central-eastern Queensland, hosts three Late Pleistocene to Holocene deposits containing significant faunal records. Excavations were conducted on these deposits over several seasons, with analyses of recovered material ongoing. Here, we report interim results and explore their implications for our understanding of the microfaunal record of central eastern Queensland. Fern Chamber was previously dated using U-series to the Holocene (>7.6 ± 0.2 ka). Honeymoon Suite was dated to >6.4 ± 0.2 ka using U-series. However, new charcoal dates from the deposit span approximately 7.5–15.5 ka, although the association between charcoal and fauna is unresolved. The fauna is likely Holocene. Colosseum Chamber is the oldest of the deposits, and new single-grain luminescence ages and age-depth modelling suggest that the deposit likely spans MIS 1–4. We use abundant fragmentary rodent remains to examine palaeoenvironmental change over this period. Carbon and oxygen isotope analyses of rodent incisor fragments reveal broad diets within the rodent community, and significant differences in precipitation between glacial and interglacial conditions. Rodent long bone histological analyses indicate significant differences in bone metabolism at the family level between the MIS 3 and 2 samples, but not MIS 1. We suggest that these data support evidence for a mid-Holocene arid anomaly in the region, and increased aridity through the Holocene relative to the terminal Pleistocene. The sites contain at least 10 small mammal species either globally extinct or locally extirpated, including the Capricorn rabbit-rat (Conilurus capricornensis), the white-footed rabbit-rat (Conilurus albipes), the plains mouse (Pseudomys australis), Gould’s mouse (Pseudomys gouldii), Forrest’s mouse (Leggadina forresti), the long-tailed hopping mouse (Notomys longicaudatus), swamp rat (Rattus lutreolus), the white-tailed rat (Uromys caudimaculatus), the narrow-nosed planigale (Planigale tenuirostris), the Liverpool Plains striped bandicoot (Perameles fasciata), the Cape York brown bandicoot (Isoodon peninsulae), and the southern brown bandicoot (Isoodon obesulus). We also record significant range contractions for frogs (Philoria sp., Neobatrachus sp.) and earless dragons (Tympanocryptis sp.). This study demonstrates that significant changes in the microfaunal community of tropical Queensland occurred between the Late Pleistocene and the late Holocene. It also reinforces how poorly recorded native faunas are from the late Holocene through the historical period, to today. Such records underpin and are thus vital for modern biodiversity conservation efforts.
Julien Louys [j.louys@griffith.edu.au], Australian Research Centre for Human Evolution, Griffith University, Brisbane, Australia; Jonathan Cramb [jonathan.cramb@qm.qld.gov.au], Queensland Museum, Brisbane, Australia; Kyle Ferguson [k.ferguson81@outlook.com.au], School of Earth and Environmental Science, The University of Queensland, Brisbane, Australia; Justine Kemp [j.kemp@griffith.edu.au], Australian Research Centre for Human Evolution, Griffith University, Brisbane, Australia; Rachel Wood [rachel.wood@arch.ox.ac.uk], School of Archaeology and Anthropology, Australian National University, Canberra, Australia and Oxford Radiocarbon Accelerator Unit (ORAU), University of Oxford, Oxford, UK; Justyna J. Miszkiewicz [j.miszkiewicz@uq.edu.au], School of Social Science, University of Queensland, Brisbane, Australia and Naturalis Biodiversity Center, Leiden, the Netherlands; Nathalia R. Dias Guimarães [ndg0601@gmail.com], School of Archaeology and Anthropology, Australian National University, Canberra, Australia; Penny Higgins [pennilyn.higgins@gmail.com], EPOCH Isotopes, 6606 E Townline Road, Williamson, NY 14589, USA; Kenny J. Travouillon [Kenny.Travouillon@museum.wa.gov.au], Western Australian Museum, Perth, Australia; Scott A. Hocknull [scott.hocknull@qm.qld.gov.au], Geosciences, Queensland Museum, Brisbane, Australia; Gregory E. Webb [g.webb@uq.edu.au], School of Earth and Environmental Science, The University of Queensland, Brisbane, Australia; Gilbert J. Price [g.price1@uq.edu.au], School of Earth and Environmental Science, The University of Queensland, Brisbane, Australia.
... Furthermore, many of the mammals, common and hunted over the preceding 6000 years, are now extinct, locally extinct or on endangered lists. This fauna from these sites documents an ecological and cultural world that no longer exists (Fusco et al., 2016;Menkhorst, 2009;Wilson et al., 2022). ...
Ngaut Ngaut (Devon Downs) and Tungawa (Fromm’s Landing) 2 and 6 are located in the Gorge Section of the Lower Murray River. They were excavated more than 60 years ago. Unusually, they preserved fauna over the 6000 or 7000 years of occupation. Assessing this record, it is concluded that Aboriginal agents were responsible for the middens in these rockshelters. Following this, Ngaut Ngaut and the Tungawa sites are compared in terms of their dating, stratigraphy and changes in the fauna through time. While the majority of species are present throughout at all three sites, there are shifts in the number of animals in concert with Holocene environmental changes. After 3000 BP, the trend is to increased attention being given to resources from the riparian and river zones and away from the dryland Murray Plains. An increase in shellfish and the presence of crayfish gastroliths support this contention. Nearby Tartanga Island provides a record of Holocene sedimentary changes in the Murray River associated with altered sea level and flood regimes, particularly the deposition of the Monoman and Coonambidgal formations. The latter creating a landscape of highly productive swamps and backwaters. The information from these legacy excavations supports the conclusion that a shift in the locus of Aboriginal hunting and gathering activities accompanied mid- and late-Holocene environmental changes on the Lower Murray River.
... We contend that such waterless plains are artefacts of TO-LM, but were probably not maintained for the free-water-dependent large macropods, rather the mammalian Traditional Owner food resources in Table 3. Woylies (Bettongia penicillata) were recorded from the southern Murray mallee (Menkhorst & Beardsell 1982). Represented in Murray River archaeological sites, Bettongia penicillata were a consistent feature of Aboriginal hunting over the past 6000 years, but have not been recorded on the Murray Plains since shortly after European settlement (Fusco et al. 2015). These species can persist, without drinking free water and can occupy habitats such as at Woornoonoomal (Strahan 1998a) (Table 3). ...
The nineteenth century mass mammal extinctions in the semi-arid zone of the Murray‒Darling basin, southeastern Australia, are examined in the context of prior traditional land management. A model of grassland dynamics reveals a multi-trophic level productive pulse one to five years post-fire, followed by senescence and increasing flammability. Traditional Owner patch burning of grassland optimized human and mammalian food (including tubers, seeds and fungi) and decreased fire risk. Over at least 40 000 years, the persistence and abundance of fauna responded to this energetically closed self-reinforcing management. In 1830, depopulation (disease, massacres and displacement) effectively ended traditional management, an ecologically traumatic event that extinguished these productivity pulses. Associated mammal populations of c. 20 species collapsed, and all eco-engineering and mycophagous species, such as bilbies, bettongs and bandicoots, rapidly disappeared. Traditional land management increased productivity, habitat heterogeneity and reduced wildfire risk, underpinning mammal abundance. This has remained unrecognized by most mammalogists and land managers. Blaming extinctions predominantly on the additions by Europeans (introduction of ungulates, feral grazers and predators etc.), disastrous as they were, fails to acknowledge the initial cause of rarity, i.e. loss of productivity, habitat and niches when traditional management was subtracted from country. As ecosystems continue to degrade, understanding the primary cause is fundamental to improved management. Although too late for extinct species, respect for, and inclusion of, traditional land management knowledge provides a direction for future land management.
... The Holocene climate has been of significant interest to researchers who study not only climate (Briner 2016;Kotlia and Wünnemann 2019), but also mammals (Fusco et al. 2016;Backwell et al. 2018), vegetation (Revelles et al. 2015;Woodbridge et al. 2018), and the environment (Daggers et al. 2018). This research can improve our understanding of climate change. ...
We reconstructed the Holocene climate in the study area using data from a BZ section in the Baiyangdian paleo-lake. Samples were analyzed for multiple proxies for climate conditions, including grain size, magnetic susceptibility (MS), and carbonate content, which were combined with accelerator mass spectrometry (AMS) 14C data. The results show that from 10.0 to 6.3 kyr BP, the study area experienced an interval of increasing precipitation and rising water level at Lake Baiyangdian. For a very short period, ~ 8.4 kyr BP, the extent of the lake reached the sampling point. The climate during this stage was relatively humid. The water level dropped abruptly at 6.5 kyr BP as a result of a weak monsoon event. From 6.3 to 2.9 kyr BP the climate became humid once again. The continuous lacustrine sediment of the strata indicated that the water level of Lake Baiyangdian expanded rapidly during this period and reached the sampling point. After 2.9 kyr BP, the climate in the region changed again from humid to dry. The abrupt increase in MS after ~1 kyr BP (993 AD) is consistent with records of human activities in local chronicles, which indicates that the environment in the study area was influenced by human activities. Through a comparison of the BZ section and the East Asian summer monsoon (EASM) records, we found that precipitation in the study area was controlled by the EASM. A series of cold Holocene events were clearly recorded by the sediment in the BZ section, and these events are synchronous with the North Atlantic ice-rafting events (IRD). The connection between the characteristics of the BZ section and the EASM and IRD indicate that climate evolution in the study area was strongly affected by EASM and IRD.
... Australia is a megadiverse and sparsely populated continent with an unenviable extinction rate (Fusco et al., 2016;Woinarski et al., 2015). The observatory samples a range of habitats that include some of Australia's most remote areas, where little is known about species distributions and survey effort is typically limited. ...
Fauna surveys are traditionally manual, and hence limited in scale, expensive, and labour intensive. Low‐cost hardware and storage mean that acoustic recording now has the potential to efficiently build scale in terrestrial fauna surveys, both spatially and temporally. With this aim, we have constructed the Australian Acoustic Observatory. It provides a direct and permanent record of terrestrial soundscapes through continuous recording across Australian ecoregions, including those periodically subject to fire and flood, when manual surveys are dangerous or impossible. The observatory comprises 360 permanent listening stations deployed across Australia. Groups of four sensors are deployed at each of 90 sites, placed strategically across ecoregions, to provide representative datasets of soundscapes. Each station continuously records sound, resulting in year‐round data collection. All data are made freely available under an open access licence. The Australian Acoustic Observatory is the world’s first terrestrial acoustic observatory of this size. It provides continental‐scale environmental monitoring of unparalleled spatial extent, temporal resolution, and archival stability. It enables new approaches to understanding ecosystems, long‐term environmental change, data visualization and acoustic science that will only increase in scientific value over time, particularly as others replicate the design in other parts of the world.
... In areas that have been significantly affected by recent human activity, however, quantitative assessments of species abundance and diversity in modern faunas may be misleading, as they may have been shaped by rapid anthropogenic changes to surrounding environments (e.g. Fusco et al., 2015;Stegner, 2016). As a result, for studies aimed at assessing the consequences of natural (i.e. ...
Abstract
Temporal differences in fossil assemblages of small mammals can generate important insights into associated environmental conditions. Moreover, by
including modern assemblages in such comparisons, it may also be possible to identify the effects of recent human colonization on mammal communities
and their habitats. To explore potential signals of European colonization in northwestern Patagonia, we compared fossil and modern assemblages of
small mammals from two newly characterized paleontological sites in the Limay Valley region of Río Negro Province, Argentina. The material analyzed
consisted of 18 species of small-bodied terrestrial mammals identified from a sample of 27,992 specimens. Fossil assemblages dating from 6453 to 1002
calibrated years before present were relatively stable in taxonomic composition and displayed only minor differences in relative species abundances. In
contrast, the modern assemblages examined were clearly distinct, containing a different suite of numerically dominant taxa and lacking three previously
abundant grassland species that are presumed to have gone extinct in the vicinity of our study sites. We suggest that these changes reflect substantial
post-colonization modifications of surrounding landscapes, including establishment of pine plantations, changes in fire regimes, and introductions of
livestock and invasive species of plants. If correct, this supposition raises important concerns regarding the use of modern assemblages as a baseline for
reconstructing paleoenvironmental conditions. To avoid potential misinterpretations associated with the use of modern faunal assemblages, we suggest
two potential alternative strategies for inferring temporal changes in environmental conditions.
... Thus, fossil and museum specimens, as well as extant individuals, from sites on mainland South Australia (e.g. within the Fleurieu Peninsula (Fusco et al., 2016) and Naracoorte Cave World Heritage area (Macken and Reed, 2013)), as well as western Victoria (such as Fern Cave, Swain's Cave, McEachern's Cave, and Glenelg; Jones et al., 2001) and the continental islands of the Bass Strait (King, Flinders, Deal, and Cape Barren Islands; Hope, 1974;Peacock et al., 2018), need to be genotyped in the future. ...
Spotted-tailed quolls ( Dasyurus maculatus) – cat-sized, carnivorous marsupials – occupied Kangaroo Island (KI), South Australia, for over 50,000 years but became locally extinct following European settlement of the island in 1836. As the largest mammalian predator on KI when the Europeans colonised it, spotted-tailed quolls would have played a significant role in maintaining healthy ecosystem function. The reintroduction of spotted-tailed quolls to KI could redress some of these ecological benefits and would establish a refuge population of the species, which is considered endangered by the Australian government. However, before a reintroduction could be considered, the genetic relationship between KI’s spotted-tailed quolls and the currently recognised extant subspecies needs to be established. While subspecies are difficult to differentiate by skeletal morphology, they are genetically distinct. Here, we extracted ancient DNA from five left dentaries excavated from Kelly Hill Cave (KI) that were morphologically identified as D. maculatus. Following genetic confirmation of these identifications, we sequenced a 450-bp region of the mitochondrial D-loop to determine the subspecific genetic affiliation(s) of KI’s D. maculatus, and therefore the subspecies that may be the most appropriate candidate for reintroduction. We find that all five specimens are most closely related to the Tasmanian subspecies, but form a distinct monophyletic clade that may represent a new subspecies. Further research (including genotyping spotted-tailed quoll specimens from mainland South Australia and Western Victoria) is required before decisions are made regarding the sourcing of individuals for reintroduction to KI.
... The vast majority of the fossil and subfossil specimens of Chaeropus described herein were derived from owl roost deposits. Such deposits can be used to reconstruct late Quaternary range reductions and extinctions of small fauna associated with European arrival and land use (Fusco et al. 2016). Further survey, sampling, and excavation of surface owl scats in caves and rock shelters situated in the ranges of Chaeropus indicated in Figure 1 may thus also provide further evidence of the timing and nature of extinction of these species. ...
The Pig-footed Bandicoot, Chaeropus ecaudatus, an extinct arid-adapted bandicoot, was named in 1838 based on a specimen without a tail from the Murray River in New South Wales. Two additional species were later named, C. castanotis and C. occidentalis, which have since been synonymised with C. ecaudatus. Taxonomic research on the genus is rather difficult because of the limited material available for study. Aside from the types of C. castanotis and C. occidentalis housed at the Natural History Museum in London, and the type of C. ecaudatus at the Australian Museum in Sydney, there are fewer than 30 other modern specimens in other collections scattered around the world. Examining skeletal and dental characters for several specimens, and using a combination of traditional morphology, morphometrics, palaeontology and molecular phylogenetics, we have identified two distinct species, C. ecaudatus and C. yirratji sp. nov., with C. ecaudatus having two distinct subspecies, C. e. ecaudatus and C. e. occidentalis. We use palaeontological data to reconstruct the pre-European distribution of the two species, and review the ecological information known about these extinct taxa.
... The results of our investigations provide new evidence highlighting both the array and severity of the changes that took place and demonstrate that biological changes may not correspond directly with climatic events, but rather to geomorphological changes that may delay a direct response. Because these prehistoric changes in biodiversity were doubtless extreme, it is disconcerting that such transformations in the past are proving to be less severe than modern anthropogenic impacts that include cultivation, livestock grazing, CO 2 emissions, water diversion, and the introduction of invasive plants and animals (Freeman et al., 2014;Fusco et al., 2016;Jones, 2000;McDowell, 2014;Morris and Rowe, 2014;Schmitt, 2004). These novel impacts are increasing, can develop rapidly, and often co-occur, and it is not surprising that their commonly adverse effects on mammalian community energy flow and diversity are proving to be unanticipated and complex (Rowe et al., 2011;Terry and Rowe, 2015). ...
Comparisons of Bonneville basin small-mammal skeletal assemblages from low-elevation caves with a collection from an upper piedmont rock shelter support Oviatt et al.’s hypothesis that early-Holocene moisture may have been the result of groundwater discharge rather than precipitation and runoff. After cool and moist late-Pleistocene environs were replaced by warmer and drier Holocene climates, low-elevation small-mammal communities increased in taxonomic richness and evenness and continued to support large numbers of rodent and leporid species well-adapted to mesic contexts. At the same time, the more upland small-mammal community along the Bonneville shoreline on the basin’s margin experienced declines in richness and evenness and the extirpation of a number of mesic-adapted mammals. Overall differences in the composition of these early-Holocene assemblages suggest the basin bottom sustained moist and energetically auspicious habitats considerably longer than regional adjacent uplands, and it is possible that this low-elevation moisture was the result of Pleistocene Lake Bonneville groundwater discharge.
... richness cannot be high), but as MAP increases, the effects of other variables that can also influence richness, especially nutrient availability (Bell, 1982;Olff et al., 2002), become important and allow for richness to take on a broader range of values. Variance may also be introduced by local extinctions in historical times, primarily due to landscape transformation and introduction of invasive species (Fusco et al., 2016), resulting in lower richness in some modern communities than predicted by precipitation. The lack of a significant positive correlation between richness and geographical area may reflect habitat homogeneity within the National Parks, such that increasing area does not sample new habitats and new sets of species (Travouillon and Legendre, 2009). ...
The precipitation history of southwest Australia since the Last Glacial Maximum (LGM) has important implications for understanding southern hemisphere climate dynamics. Previously reported environmental records indicating more open vegetation during the LGM have been interpreted in terms of aridity, but such changes can be explained by alternative mechanisms. To provide new evidence concerning the region's Quaternary precipitation history, we examine temporal changes in large mammal richness at four southwest Australian fossil sites: Devil's Lair, Tunnel Cave, Witchcliffe Rock Shelter and Rainbow Cave. Large mammal richness is correlated strongly with mean annual precipitation across 53 modern Australian communities. Extending this relationship to the fossil record, a steady increase in richness from the LGM to the onset of the Holocene at both Devil's Lair and Tunnel Cave is consistent with increased precipitation through time. This supports previous interpretations of a more arid LGM and implies regional heterogeneity in the position of the southern hemisphere westerlies. A reduction in richness during the last 1000 years is unlikely to be the result of precipitation change and may be related to more frequent burning of the landscape by hunter-gatherers in an effort to increase availability of large prey.
... One tenth of the known 273 species of Australian mammals have become extinct in the past 200 years, with another 21% of our endemic land mammals on the threatened list (Woinarski et al 2015). In some regions, like the Fleurieu Peninsula of South Australia, subfossil remains suggest that up to 50% of the original terrestrial land mammal fauna have become extinct since the arrival of Europeans (Fusco et al. 2015). ...
Australasia has a unique fauna of living vertebrates, which include the oldest known species on the planet (the lungfish Neoceratodus) as well as many diverse, highly endemic families of fish, amphibians, reptiles, birds and mammals. The origin of most of the Australian vertebrate fauna has developed from two phases. Firstly, when Australia was subsumed within the greater Gondwana landmass, migration of animals from one region to another was possible by a land connection. Many of our most primitive forms of reptiles and mammals probably entered the country at this time, such as varanids, madtsooid snakes, monotremes and basal marsupials. Secondly, following the breakup of Gondwana, the isolation of Australia for its last 40 million years and subsequent changing climatic conditions drove the radiation of marsupial, reptile and amphibian families within the continent. The gradual aridification of central Australia further divided the landmass into discrete regional areas characterised by rainfall, vegetation, and climatic zones.
Two new fossil deposits from caves of the Broken River area, northeast Queensland, provide the first regional records of vertebrate species turnover and extinction through the late Quaternary. Fossil assemblages from Big Ho and Beehive Caves are dominated by small-bodied vertebrates, especially mammals. They represent owl roost deposits, although limited presence of larger-bodied taxa such as macropodids may be the result of occasional pitfall trapping. U-series dating demonstrates that Big Ho dates to the penultimate glacial cycle (c. 165 ka) and Beehive to the early Holocene (c. 8.5 ka). A total
of 34 mammalian taxa were identified; within the two deposits, seven taxa are unique to Big Ho and another seven are found only in Beehive. The deposits also preserve five extinct fossil taxa (bandicoots and rodents) that add to a growing list of small-bodied species known to have suffered extinction in the late Quaternary. The deposits further yield the remains of four species of bandicoots and rodents (Chaeropus yirratji, Notomys longicaudatus, Conilurus albipes, and Pseudomys gouldii) that suffered extinction post-
European colonization. These new fossil records represent significant increases in the known geographic and temporal range of several species and begin to fill an important gap in our understanding of the faunal history of tropical northeast Australia.
A limestone cave on the lower slopes of the southeastern Australian high country reveals a deep, stratified deposit dated from ca. 14,000 to 2000 cal. BP and rich in predominantly non-cultural faunal remains. Located in a sensitive ecological area between the Australian Alps and the Southern Tablelands, the site provides a valuable chronological archive for the interpretation of local environmental change using the faunal record as a proxy, in particular native rodents and other small mammals. Inferred palaeoenvironmental trends include the cessation of periglacial conditions in the surrounding ranges during the Terminal Pleistocene; a shift to warmer conditions and the establishment of forest and wetland habitats from around 13,500 to 10,000 cal. BP, with a significant decline in cold-adapted species at ca. 11,500 cal. BP and a period of significant taxon fluctuation and extinctions corresponding to a possible peak in warm and moist conditions (a ‘Holocene Optimum’), beginning around 8000 cal. BP and lasting perhaps 1500 to 2000 years. Complications to the relatively steady and continuous chronostratigraphy, formed from an AMS radiocarbon sequence from sedimentary charcoal, arose from the presence of several teeth of extinct sthenurine megafauna. These were resolved with direct U-series analysis to establish their much greater antiquity and comparison of the sthenurine teeth with teeth of extant macropodids from the same deposit through fluoride absorption analysis, which also identified the megafauna teeth as anomalous to the sequence. The site provides an important case study for the interpretation of megafauna remains in stratified sedimentary deposits, especially for sites that appear to contain evidence for the co-occurrence of megafauna and humans in primary contexts.
The three large forest owls of southeastern Australia, the Powerful Owl Ninox strenua, Sooty Owl Tyto tenebricosa and Masked Owl T. novaehollandiae, often occur sympatrically but little is known about how they partition their habitat. The places where owls obtain their food and what they eat may have a crucial bearing on our understanding of their habitat requirements. Totals of 1,672 prey items from 47 Powerful Owl territories, 1,466 items from 28 Sooty Owl territories, and 175 items from six Masked Owl territories (or locations) were analysed. There was virtually no overlap between the diets of the Powerful Owl and Masked Owl. The Powerful Owl preyed almost exclusively on arboreal mammals, most of which weighed 50–100% of adult owl body weight, supplemented by diurnal birds. In contrast, the Masked Owl preyed almost exclusively on small terrestrial and scansorial mammals, most of which weighed 3–20% of adult owl body weight, supplemented by diurnal birds. At any one site, both owls appeared to specialise on just one or two prey species. The diet of the Sooty Owl was strikingly different by its generalist nature, comprising , at any one site, a wide range of arboreal and terrestrial or scansorial mammals, mostly weighing 2–100% of adult owl body weight. The Sooty Owl appeared to take any available small and medium-sized mammals and foraged throughout its more limited habitat (rainforest, tall moist eucalypt forest) from the forest canopy to the ground. Geographical variation in owl diets was related to differences in the availability of potential prey. All three species were found to survive and breed successfully in the coastal and foothill forests of southeastern New South Wales on a diet composed principally of prey species that are not dependent on old-growth forest.
1.Small mammal community composition is almost universally estimated from conventional trapping, which is logistically difficult to scale up for landscape-level assessments. Owl pellets may be a more effective alternative for measuring small mammal community composition over large geographic areas due to the relative ease and low cost of field collections. However, owl pellets may introduce sampling biases that differ from those associated with conventional trapping. A thorough comparison to conventional traps is required before owl pellets can be widely adopted as an alternative research tool for small mammal studies.2.We conducted a literature review of owl diet-prey availability studies to: (1) compare small mammal community composition between owl pellets and trapping when the two methods were used simultaneously, and (2) assess the influence of owl genus and habitat type on community composition estimated by these two methods. We used data from 27 published studies, which allowed for 32 comparisons between owl pellets and trapping conducted simultaneously. These studies included 15 owl species from five common genera from different major habitats.3.Rarefied estimates showed that owls consistently sampled identical or higher species richness compared to conventional trapping. Richness estimates rarefied to the lowest sample size per study were not statistically identical (μΔrichness = 0.20 ± 0.09 SE, P = 0.30); on average 0.95 ± 0.13 SE additional species were identified from pellets compared to trapping. Measures of species dominance and evenness estimated from both methods were statistically identical (μΔ1-D = 0.02 ± 0.03 SE; μΔPIE = 0.004 ± 0.04 SE). Species lists, relative species composition, and species rank order abundance were in moderate agreement between sampling methods (Jaccard = 0.62 ± 0.04 SE; Bray-Curtis = 0.53 ± 0.04 SE; Spearman Rho = 0.41 ± 0.07 SE). Linear regression and AIC model selection showed that the performance of pellets versus traps did not differ based on owl genus or habitat type.4.Small mammal community composition estimated via pellets was better represented compared to estimates from conventional trapping. Composition metrics from the two methods were consistent and not affected by owl genera or habitat type. Thus, owls are an effective alternative for landscape-level assessments of small mammal communities.This article is protected by copyright. All rights reserved.
ABSTRACT: It is widely accepted that most larger Australian vertebrates were extinct by 40 ka. The reliability of
<20-ka radiocarbon (14C) ages on charcoal stratigraphically associated with sthenurine (short-faced) kangaroo
tooth fragments from Seton Rockshelter, Kangaroo Island, have therefore proven contentious. Some researchers
have argued these fossils were in situ, while others have claimed they were reworked. To address this we obtained
new 14C ages on bones from the site. These bone ages are not only consistent with earlier charcoal ages, but are in
near-perfect stratigraphic order, providing strong support for the site’s stratigraphic integrity. Our analyses indicate
units aged 21�17 ka were primarily accumulated by Tasmanian devils (Sarcophilus harrisii) and owls (Tyto
species), after which humans became the primary accumulation agent. The tight chronology, faunal trends and
current lack of evidence for older layers from which specimens could have been reworked suggest the sthenurine
remains may be in situ. However, because attempts to directly date sthenurine material failed, we cannot
confidently assert that they survived to this time. Therefore, Seton Rockshelter may be best excluded from the
Pleistocene extinction debate until the site can be re-excavated and more conclusive evidence collected, including
more complete or directly datable sthenurine remains.
A major concern in modern conservation biology is the loss of biodiversity. Such loss has, however, been common throughout the history of life. The source of the modern concern is that biodiversity loss is thought to be exacerbated by anthropogenic (human) causes in general, a top-down ecological process. But contrary to the ecologically noble savage notion, today is not different in kind from the past. Humans have depleted and extirpated populations and species for thousands of years. Climate change has also reduced biodiversity throughout history, such as when primary productivity is reduced by increased aridity in a bottom-up ecological process. The paleozoological record provides examples of normal background fluctuation in biodiversity and indicates bottom-up processes have been commonplace and top-down (particularly anthropogenic) causes can be distinguished from them in zooarchaeological collections. Both the loss and gain of species and of morphological variants can be tracked in the paleozoological record. Given that instances of biodiversity decrease on many continents at the end of the Pleistocene were coincident with climatic warming, the threat to modern biodiversity of modern global warming driven by anthropogenic processes is quite real.
The broad-toothed rat (Mastacomys fuscus) is a small to medium-sized rodent found in south-eastern Australia. Recent surveys across the southern portion of its range indicate that the species is in decline, and climate change has been identified as a key threat to the localised persistence of this species. The present study reports on a rapid field survey across 14 high montane and subalpine sites (including moist tussock grassland, sedgelands, heathlands and bogs) in the southern Australian Capital Territory, Australia. M. fuscus scats were recorded along transects, and habitat, vegetation, distance to drainage lines and disturbance due to feral animals were recorded. Relative abundance of M. fuscus was positively related to specific vegetation types (heath, sedge and Poa) and site size. Conversely, relative abundance of M. fuscus was negatively related to disturbance due to feral animals, and distance from creek drainage lines. This study indicates that M. fuscus has specific habitat preferences and threats associated with environmental change and introduced species may threaten populations in the Australian Capital Territory
Ancient DNA is becoming increasingly recognised as a tool in conservation biology to audit past biodiversity. The widespread loss of Australian biodiversity, especially endemic mammal populations, is of critical concern. An extreme example occurred on Depuch Island, situated off the north-west coast of Western Australia, where an unidentified species of rock-wallaby (Petrogale sp.) became extinct as a result of predation by red foxes. Two potential candidate species, Petrogale lateralis and P. rothschildi, both have ranges adjacent to Depuch Island, making identification based on geography difficult. A museum bone (one of the only surviving Depuch Island specimens) was subjected to standard ancient DNA analyses and procedures. Mitochondrial DNA cytochrome b and hypervariable control region were targeted for species identification. Ancient DNA was successfully recovered from the bone: 200 base pairs (bp) of control region and 975 bp of the cytochrome b gene. Bayesian phylogenetic analyses were employed to model the Depuch Island rock-wallaby DNA sequences together with sequences of other rock-wallaby taxa from GenBank. Evidence suggests that of the two Petrogale lateralis subspecies proposed to have inhabited Depuch Island, Petrogale lateralis lateralis was identified as the most likely. The identification of the Depuch Island rock-wallaby population may assist in the reintroduction of an insurance population of Petrogale lateralis lateralis, which is becoming increasingly threatened on mainland Australia.
Introduction: Recent studies at sites in northern Australia have reported severe and rapid decline of several native mammal species, notwithstanding an environmental context (small human population size, limited habitat loss, substantial reservation extent) that should provide relative conservation security. All of the more speciose taxonomic groups of mammals in northern Australia have some species for which their conservation status has been assessed as threatened, with 53 % of dasyurid, 47 % of macropod and potoroid, 33 % of bandicoot and bilby, 33 % of possum, 30 % of rodent, and 24 % of bat species being assessed as extinct, threatened or near threatened. However, the geographical extent and timing of declines, and their causes, remain poorly resolved, limiting the application of remedial management actions.
Introduction: Recent studies at sites in northern Australia have reported severe and rapid decline of several native mammal species, notwithstanding an environmental context (small human population size, limited habitat loss, substantial reservation extent) that should provide relative conservation security. All of the more speciose taxonomic groups of mammals in northern Australia have some species for which their conservation status has been assessed as threatened, with 53 % of dasyurid, 47 % of macropod and potoroid, 33 % of bandicoot and bilby, 33 % of possum, 30 % of rodent, and 24 % of bat species being assessed as extinct, threatened or near threatened. However, the geographical extent and timing of declines, and their causes, remain poorly resolved, limiting the application of remedial management actions.
Material and methods: Focusing on the tropical savannas of northern Australia, this paper reviews disparate recent and ongoing studies that provide information on population trends across a broader geographic scope than the previously reported sites, and examines the conservation status and trends for mammal groups (bats, macropods) not well sampled in previous monitoring studies. It describes some diverse approaches of studies seeking to document conservation status and trends, and of the factors that may be contributing to observed patterns of decline.
Results and Discussion: Current trends and potential causal factors for declines. The studies reported demonstrate that the extent and timing of impacts and threats have been variable across the region, although there is a general gradational pattern of earlier and more severe decline from inland lower rainfall areas to higher rainfall coastal regions. Some small isolated areas appear to have retained their mammal species, as have many islands which remain critical refuges. There is now some compelling evidence that predation by feral cats is implicated in the observed decline, with those impacts likely to be exacerbated by prevailing fire regimes (frequent, extensive and intense fire), by reduction in ground vegetation cover due to livestock and, in some areas, by ‘control’ of dingoes. However the impacts of dingoes may be complex, and are not yet well resolved in this area. The relative impacts of these individual factors vary spatially (with most severe impacts in higher rainfall and more rugged areas) and between different mammal species, with some species responding idiosyncratically: the most notable example is the rapid decline of the northern quoll (Dasyurus hallucatus) due to poisoning by the introduced cane toad (Rhinella marina), which continues to spread extensively across northern Australia. The impact of disease, if any, remains unresolved.
Conservation Management Responses. Recovery of the native mammal fauna may be impossible in some areas. However, there are now examples of rapid recovery following threat management. Priority conservation actions include: enhanced biosecurity for important islands, establishment of a network of feral predator exclosures, intensive fire management (aimed at increasing the extent of longer-unburnt habitat and in delivering fine scale patch burning), reduction in feral stock in conservation reserves, and acquisition
Significance
The island continent of Australia harbors much of the world’s most distinctive biodiversity, but this review describes an extent of recent and ongoing loss of its mammal fauna that is exceptionally high and appreciably greater than previously recognized. The causes of loss are dissimilar to those responsible for most biodiversity decline elsewhere in the world.
We live amid a global wave of anthropogenically driven biodiversity loss: species and population extirpations and, critically,
declines in local species abundance. Particularly, human impacts on animal biodiversity are an under-recognized form of global
environmental change. Among terrestrial vertebrates, 322 species have become extinct since 1500, and populations of the remaining
species show 25% average decline in abundance. Invertebrate patterns are equally dire: 67% of monitored populations show 45%
mean abundance decline. Such animal declines will cascade onto ecosystem functioning and human well-being. Much remains unknown
about this “Anthropocene defaunation”; these knowledge gaps hinder our capacity to predict and limit defaunation impacts.
Clearly, however, defaunation is both a pervasive component of the planet’s sixth mass extinction and also a major driver
of global ecological change.
Desert rodents exhibit irruptive (boom–bust) population dynamics in response to pulses of primary productivity. Such unpredictable population dynamics are a challenge for monitoring population trends and managing populations, particularly for species in decline. We studied the population dynamics and occurrence of populations of the vulnerable plains mouse, Pseudomys australis (42-g body mass), during the low (bust) phase of the cycle in the Simpson Desert, Australia, to examine the use of refuges by the species and the predation pressure experienced from native and introduced predators. Specifically we investigated landscape-scale occurrence; body mass, reproduction, and population size; and presence of native and introduced predators. Our results demonstrate that P. australis contracted to discrete areas of the landscape (refuges) during the low phase and that these areas occupied a small proportion (~17%) of the range occupied during population peaks. Animals in refuge populations had comparable body mass, occurred at similar densities to populations during the boom phase, and continued to reproduce during dry conditions. Such refuges represented a significant concentration of biomass to predators in a resource-poor environment. Native predators were rare during the low phase, suggesting that refuges naturally experienced low predation levels. Two introduced predators, feral house cats and red foxes, persisted during the low phase and exploited refuge populations of P. australis, thus representing a significant threat to population persistence. We advocate a novel approach to management of rodents in arid systems that involves identifying the discrete parts of the landscape that function as drought refuges and then focusing threat management there. The relatively small size of these refuges increases the likelihood of cost-effective management.
Sinkholes and coastal caves located in, around and between the Coffin Bay and Lincoln National Parks were surveyed for pre-European fossils, which were collected from or just below the sediment surface. Twenty-four pre-European fossil samples, including eight already in the collections of the South Australian Museum, were analysed and 25 native and five introduced species of non-volant mammal were identified. Native and introduced species were often found together, indicating that the sites have accumulated mammal remains in both pre-and post-European times. Only four of the non-volant native mammals recovered are known to be extant in the study area today: Lasiorhinus latifrons, Macropus fuliginosus, Cercartetus concinnus and Rattus fuscipes. In contrast, 20 native species recorded have been extirpated and one (Potorous platyops) is now extinct. C. concinnus was recorded from only one of the fossil assemblages but is known to be widespread in the study area today. This may indicate recent vegetation change related to European land management practices and have implications for natural resource management in the area.
Notomys robustus sp. nov. is described from skulls found in whole and decomposed owl pellets from caves at Chambers Gorge in the Flinders Ranges, South Australia. The holotype was contained within a complete owl pellet, as were several paratypes. The species is distinguished by the unique conformation of the cusps of the upper first molar teeth. In adults, the anterodorsal region of the zygomatic arch is much wider than in any known species of Notomys. Since the original discoveries were made in 1976, the species has been found in more sites in the Flinders Ranges and at one other site near Mount Margaret in the Davenport Range, some 350 km northwest of the nearest Flinders Ranges site.
Thirty species of rodents are recorded from South Australia. At the time of
European settlement, the State probably supported at least 19 species of
native rodents. Eight additional species have been recorded only in subfossil
material. At least 11 species are now considered to be extinct and there have
been significant declines in all the other species as a result of over 150
years of European influence. In addition, three species have been introduced
to the State since European settlement. Over the last ten years, there has
been a significant increase in our understanding of the distribution and
ecology of what remains of the rodent fauna through a series of systematic,
site-based biological surveys, a significant increase in research on subfossil
and owl pellet remains, documentation of Aboriginal ecological knowledge and
ecological and distributional studies on three species. This paper describes
our current state of knowledge of the distribution, ecology and threats to the
South Australian rodent fauna and makes suggestions for future research and
conservation management.
Seton rock shelter (35⚬ 59'S, 137⚬ 03'E) is located in the southwest of Kangaroo Island, South Australia. Excavation of the late Pleistocene deposit in the rock shelter has provided a rich assemblage of mammal, bird and reptile remains dating from more than 16 000 BP to about 10 000 BP. Analysis of these remains shows that the late Pleistocene fauna of Kangaroo Island was more extensive than the depauperate island fauna of today. The disappearance of many species reflects a reduction in open vegetation probably due to a combination of climatic change, the separation of the island postglacially by rising sea level, and the disappearance of a human population within the last 5000 years. The deposit also provides evidence for the contemporaneity of man and one of the extinct Pleistocene kangaroos, Sthenurus cf. gilli, at 16 000 BP.
The Southern Hemisphere SHCal04 radiocarbon calibration curve has been updated with the addition of new data sets extending measurements to 2145 cal BP and including the ANSTO Younger Dryas Huon pine data set. Outside the range of measured data, the curve is based upon the ern Hemisphere data sets as presented in IntCal13, with an interhemi-spheric offset averaging 43 ± 23 yr modeled by an autoregressive process to represent the short-term correlations in the offset.
The mainland portion of the Adelaide Geosyncline (Mount Lofty and Flinders Ranges) has been postulated as an important arid-zone climate refugium for Australia. To test the sensitivity of this putative Australian arid biome refugium to contemporary climate change, we compared Generalized Additive Modelling and MaxEnt distribution models for 20 vascular plant species. We aimed to identify shared patterns to inform priority areas for management. Models based on current climate were projected onto a hypothetical 2050 climate with a 1.5°C increase in temperature and 8% decrease in rainfall. Individual comparisons and combined outputs of logistic models for all 20 species showed range contraction to shared refugia in the Flinders Ranges and southern Mount Lofty Ranges. Modelling suggests the Flinders Ranges will experience species turnover while suitable climatic habitat will be retained in the Mount Lofty Ranges for the current suite of species. Fragmentation of the southern Mount Lofty Ranges poses management challenges for conserving species diversity with warming and drying. Although projected models must be interpreted carefully, they suggest the region will remain an important but threatened refugium for mesic species at a continental scale.
Australia’s native rodents are the most ecologically diverse family of Australian mammals. There are about 60 living species – all within the subfamily Murinae – representing around 25 per cent of all species of Australian mammals. They range in size from the very small delicate mouse to the highly specialised, arid-adapted hopping mouse, the large tree rat and the carnivorous water rat. Native Mice and Rats describes the evolution and ecology of this much-neglected group of animals. It details the diversity of their reproductive biology, their dietary adaptations and social behaviour. The book also includes information on rodent parasites and diseases, and concludes by outlining the changes in distribution of the various species since the arrival of Europeans as well as current conservation programs.
The Action Plan for Australian Mammals 2012 is the first review to assess the conservation status of all Australian mammals. It complements The Action Plan for Australian Birds 2010 (Garnett et al. 2011, CSIRO Publishing), and although the number of Australian mammal taxa is marginally fewer than for birds, the proportion of endemic, extinct and threatened mammal taxa is far greater. These authoritative reviews represent an important foundation for understanding the current status, fate and future of the nature of Australia. This book considers all species and subspecies of Australian mammals, including those of external territories and territorial seas. For all the mammal taxa (about 300 species and subspecies) considered Extinct, Threatened, Near Threatened or Data Deficient, the size and trend of their population is presented along with information on geographic range and trend, and relevant biological and ecological data. The book also presents the current conservation status of each taxon under Australian legislation, what additional information is needed for managers, and the required management actions. Recovery plans, where they exist, are evaluated. The voluntary participation of more than 200 mammal experts has ensured that the conservation status and information are as accurate as possible, and allowed considerable unpublished data to be included. All accounts include maps based on the latest data from Australian state and territory agencies, from published scientific literature and other sources. The Action Plan concludes that 29 Australian mammal species have become extinct and 63 species are threatened and require urgent conservation action. However, it also shows that, where guided by sound knowledge, management capability and resourcing, and longer-term commitment, there have been some notable conservation success stories, and the conservation status of some species has greatly improved over the past few decades. The Action Plan for Australian Mammals 2012 makes a major contribution to the conservation of a wonderful legacy that is a significant part of Australia’s heritage. For such a legacy to endure, our society must be more aware of and empathetic with our distinctively Australian environment, and particularly its marvellous mammal fauna; relevant information must be readily accessible; environmental policy and law must be based on sound evidence; those with responsibility for environmental management must be aware of what priority actions they should take; the urgency for action (and consequences of inaction) must be clear; and the opportunity for hope and success must be recognised. It is in this spirit that this account is offered. Winner of a 2015 Whitley Awards Certificate of Commendation for Zoological Resource.
If radiocarbon measurements are to be used at all for chronological purposes, we have to use statistical methods for calibration. The most widely used method of calibration can be seen as a simple application of Bayesian statistics, which uses both the information from the new measurement and information from the 14 C calibration curve. In most dating applications, however, we have larger numbers of 14 C measurements and we wish to relate those to events in the past. Bayesian statistics provides a coherent framework in which such analysis can be performed and is becoming a core element in many 14 C dating projects. This article gives an overview of the main model components used in chronological analysis, their mathematical formulation, and examples of how such analyses can be performed using the latest version of the OxCal software (v4). Many such models can be put together, in a modular fashion, from simple elements, with defined constraints and groupings. In other cases, the commonly used “uniform phase” models might not be appropriate, and ramped, exponential, or normal distributions of events might be more useful. When considering analyses of these kinds, it is useful to be able run simulations on synthetic data. Methods for performing such tests are discussed here along with other methods of diagnosing possible problems with statistical models of this kind.
Quantitative Paleozoology describes and illustrates how the remains of long-dead animals recovered from archaeological and paleontological excavations can be studied and analyzed. The methods range from determining how many animals of each species are represented to determining whether one collection consists of more broken and more burned bones than another. All methods are described and illustrated with data from real collections, while numerous graphs illustrate various quantitative properties.
Owls are important consumers of small vertebrates, and because they regurgitate pellets rich in bone, they may be important potential contributors of the concentrated remains of small vertebrates to the fossil record. Owls of three sizes, the large great horned owl ( Bubo virginianus ), the medium-sized barn owl ( Tyto alba ), and the small screech owl ( Otus asio ), were fed a common diet of mice. The bony contents of the pellets were analyzed to determine the amount of bone loss by digestion, bone completeness, and sites of bone breakage. For all three species, only about half the number of bones ingested were recovered in the pellets. Mandibles and femora were most abundant, and pelves and scapulae were the least abundant. Screech owls broke 80% of the cranial and limb elements, barn owls only 30%. Skulls fared poorly in great horned and screech owl pellets, while barn owls returned 80% of the skulls intact, with only the caudal portion of the cranium damaged; barn owls also returned articulated strings of vertebrae and complete paws. These results provide a baseline for the recognition of owls as agents of accumulation of small bones in the fossil record and suggest that the actions of ancient predators may be revealed by species-specific patterns of bone destruction of an assemblage of fossil prey species.
Remains derived from owl pellets are a major source of small-animal remains in paleontological and archaeological sites. Pellet remains are examined here to further develop workable strategies for extracting taphonomic information from microvertebrate assemblages. Study of the remains of three wild owl species yielded characteristic patterns of bone fragmentation and skeletal element representation. At the assemblage level, owl-derived assemblages are shown to differ quantitatively from other assemblages. The possible variability to be expected in owl-derived assemblages is examined and the patterns are contrasted with those produced by other depositional agents. The patterns can be useful in the identification of owl-deposited remains in some assemblages; however, overlap with patterns produced by other mechanisms may complicate analysis. -Author
The long Lake George record demonstrates that, under the temperate conditions of the Southern Tableland, sclerophyll vegetation and associated high fire activity existed during warm interglacial and interstadial climates. The glacial maxima, however, remained tree- as well as sclerophyll shrub-free; the lack of fuel accumulation in these largely open landscapes is confirmed by an absence of charcoal evidence. The last 140 000 yr record from Lynch's Crater, in the wet tropical climate of NE Queensland, reveals that peak development of sclerophyll vegetation and fire activity on the Atherton Tableland occurred during dry glacial climates, and that interglacials were marked by the expansion of rainforests which allowed little scope for fire activity. The history of vegetation and associated fire events is outlined for pre-aboriginal and aboriginal times, ie. before and after c.32,000 yr BP. Aboriginal man would probably have already acquired experience of fire-making, and his impact on the landscape would have been marked.-P.J.Jarvis after Author
Buccleuch, Bago and Maragle State Forests were surveyed for the broad-toothed rat Mastacomys fuscus as part of a strategic survey program for threatened species. Wetlands were surveyed for broad-toothed rats during summer-autumn 2003 and summer-autumn 2004. Broad-toothed rats were recorded from 15 of the 50 sites surveyed in Buccleuch, 9 of 34 sites in Bago and eight of eight sites surveyed in Maragle. Grazing, particularly by feral horses, appeared to be a major factor in the absence of broad-toothed rats from a number of sites. Drainage of large sites, with the associated changes in vegetation was also recorded from several sites.
Evidence of viable populations of Mastacomys fuscus was found in two areas, the Snowy Mountains region in southern New South Wales (including the higher parts of the Australian Capital Territory), and at Barrington Tops in the north. Evidence of M. fuscus was found at 196 of 231 sites at which searches were conducted for faecal remains within the Snowy Mountains region, and at 14 of 27 sites at Barrington Tops. Sites could be classified in six broad habitat types, all having two major components, protection from predators, and grass or sedge to provide food. All sites at which the species was detected were characterised by a mean annual precipitation of >1000mm, a mean annual temperature of <10°C and altitudes >1000m. The presence of M. fuscus could not be confirmed at sites at lower elevations. Only populations in the Snowy Mountains region, specifically those above the winter snowline (>1500m), may be considered secure in the short term.
Third volume of exhaustive seven-volume summary of all that is known of the birds of the Australian, New Zealand and Antarctic region.
[1028 pages, colour plates]
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The broad-toothed rat, Mastacomysfuscus, is a relict species surviving in isolated
colonies in New South Wales, Victoria, and Tasmania. It was much more widespread in
the Pleistocene to Recent and its decline was probably due to long-term environmental
changes.
A study was made on the only known colony in New South Wales, at Whites
River, Kosciusko State Park. Systematically, this population is not separable from the
modern Victolian subspecies, bvazenori. In this cold, wet, elevated habitat the rat and
other small mammals live along small creeks among shrubs and long grass which are
covered by snow during winter. The snow is held up by the shrubs and the microclimatic
conditions beneath the snow are relatively mild. In other localities the climate
is wet and cool to cold and the rat lives in shrub and grass communities.
Mastacomys was bred in captivity for the first time. Four litters, one of which was
conceived in the wild, were born in captivity in December-March, and an advanced
pregnant female was trapped in February. A pregnant female was trapped in Victoria
in October. Evidence suggests a long gestation period, and it has small litters of
precocious young which attach tenaciously to the teats and are dragged around by the
mother, a habit widespread in the Pseudomyinae. Soon after the birth of the young
(presumably after post-partum meting) the female becomes dominant and savagely
attacks the male if he comes near her.
Photographs of a living Mastacomys are published for the first time.
Forested ecosystems of south-eastern Australia now differ physically, compositionally and functionally from their condition prior to European settlement. Understanding these changes, and how native species and entire ecosystems have responded, is crucial for biodiversity conservation and ecosystem management.Here I argue that a combination of limited historical information and a knowledge base biased towards modern ecological studies has resulted in a distorted perception of ecosystem condition, hindering the instigation of effective biodiversity conservation measures. This argument is based on recently obtained information about changes to the non-volant mammal community, which reveals relatively recent but underreported ecological changes, including major declines in species distribution and abundance, shifts in niche utilization and associated disruption of ecosystem functions. Ultimately, many mammal species are being denied the capacity to function to the extent they did historically. Following this re-assessment, it is evident that current forest management does not adequately address contemporary conservation dilemmas posed by detrimental ecosystem changes. This is especially salient when most of the factors responsible for causing changes to the mammal community are still active and include forest management and utilization activities. Therefore, additional conservation measures are essential to meet forest stewardship and biodiversity conservation obligations.For the health, functionality and sustainability of forested ecosystems, native mammal species must be capable of functioning to their ecological potential and occupy their original niche. This will be facilitated by the suppression of threatening processes (primarily exotic species), ensuring ecologically sensitive fire regimes and the reintroduction/translocation of missing species. The recovery or restoration of forest functionality based on mammal conservation should have wide-scale benefits for biodiversity conservation.
This review arose from the observation that 'long-term' ecological studies could be extended by orders of magnitude if palaeo-ecological data are incorporated. Summary European-settlement-related impacts over the past 200 years pose many challenges for the conservation and restoration of Australia's ecosystems. Landscape mod-ification, associated habitat loss and the introduction of exotic species have caused the extinction and mainland extirpation of numerous vertebrates. This process happened so quickly that many species became locally or functionally extinct before their presence was documented. A growing body of research on Holocene fossil accumulations is providing insights into the composition and biogeography of Australian ecosystems prior to European settlement. This review explores the similarities between palaeo-and neo-ecology and how Holocene (last 10,000 years) assemblages can be used by neo-ecologists, conservation managers and policy makers to identify and fill gaps in knowledge and contribute to the management and restoration of Australia's degraded ecosystems.
ABSTRACT
Islands have been a focus for the study of evolutionary and ecological processes since the time of Darwin and Wallace. In this study I examine faunal responses to climate change and isolation on Kangaroo Island (KI), South Australia, over approximately the last 50 thousand years (kyr). KI lies off the south coast of South Australia near the edge of the continental-shelf. It retains the largest proportion (47%) of uncleared natural vegetation in any of the agricultural districts of southern Australia and has been spared the introduction of rabbits and foxes. In addition, it is the only part of Australia that was not inhabited by Aboriginals at the time of European colonisation. Consequently, KI may retain the best-preserved natural ecology in southern Australia and is therefore vital for the conservation of southern Australia’s biodiversity.
Prior to isolation, land-bridge islands typically support diverse ‘mainland’ faunas that, once isolated, suffer elevated selection pressures and extinction rates. Therefore, island fossil records can provide detailed archives of how faunas responded to past environmental change and isolation and offer excellent potential analogues for predicting the long-term impacts of anthropogenic habitat fragmentation. KI was isolated from the mainland by rising sea-levels around 9 kyr ago. Here I examine variations in stable isotopes, sedimentology, geochemistry, chronology and non-volant mammalian fauna from a Late Pleistocene–Holocene fossil assemblage excavated from Kelly Hill Cave (KHC; CEGSA No. 5K1) in the Kelly Hill Caves complex. KI’s existing Late Pleistocene–Holocene fossil mammal assemblages are re-examined and pre-European faunas of Eyre and Yorke Peninsulas are also investigated.
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The KHC fossil assemblage spans from >20 to 7 kyr ago and records shifts in mammal community composition across the Last Glacial Maximum (LGM) and Holocene isolation. Total species richness did not vary greatly through the sequence, but relative abundances of ecologically divergent species varied greatly. Several heath species were abundant during the relatively cool, dry Late Pleistocene but declined with the onset of relatively warmer, wetter Holocene conditions. Arid zone species were most abundant during the LGM only and mallee/woodland species became more abundant during the Holocene. These patterns are supported by stable isotope and sedimentary records. The mammals excavated from KHC clearly responded to climate change, but only three species were extirpated from the sequence during the LGM. This bolsters an emerging view that Australia’s native fauna was highly resilient to climate change. A further four species disappear within 2 kyr of KI’s isolation, but all were previously rare. Nineteen species were extirpated from KI between 7 kyr ago and the Present, many of which were lost soon after isolation, which is consistent with the predictions of island biogeographic theory. As the fossil record between 7 kyr and Present is provided by nearby archaeological assemblages that doubtless have different collection biases, locating and analysing fossil deposits younger than 7 kyr will be an important focus of future studies.
Microfossil, sediment and documentary records provide a history of European land use and its impact on the vegetation of the Fleurieu Peninsula, South Australia. Two sedimentary cores were analysed for their fossil pollen and charcoal composition. Chronologies were established using a combination of 210Pb, 14C and microfossil markers. Primary and secondary evidence for the spatial expansion of land uses in the region were compiled providing local-, bioregional- and regional-scaled European settlement histories. The settlement and land-use histories of the major vegetation types in the region were different and were closely determined by the nature of the vegetation itself. The sedimentary and microfossil records indicate that wetland and terrestrial vegetation have undergone sequential changes of composition. There is evidence of a decline in fire-sensitive understorey species and the decline is likely due to intensive firing and grazing of scleropyllous woodlands and forests early in European settlement. Early-settlement native forestry practices were intensive, however they did not alter overstorey tree composition. Mid-twentieth-century wholesale vegetation clearance is clearly marked in the pollen record by a decline in Eucalyptus and increase in herbaceous species. Wetland vegetation was highly impacted by European land practices through changes to sediment inputs and hydrological conditions that began prior to catchment clearance, during the phase of intensive firing and grazing. Through the integration of multiscaled, ecosystem-specific historical settlement histories and palaeoecological analysis, correlations between past land uses and biotic responses can be confidently demonstrated.
In Australia mediteranean-type climates occur in southwestern Australia and in near coastal South Australia and adjacent western Victoria. These regions support species-rich sclerophyllous heaths and shrublands with the biodiversity particularly high in the southwest. Palynological records show that around the timne of the Last Glacial Maximum the climate was sufficiently severe that the vegetation of the southeastem regions was of a different character compared to today with grasses and Asteraceae more common everywhere. In the southwest the differences between Last Glacial Maximum and the Holocene were less pronounced and the tree and shrub genera Casuarina and Allocasuiarina were more prominent, and heathland and shrubland remaining the main vegetation type. Most of the records from the Last Glacial Maximun verify that common taxa in mediterranean-type climate environments today were present through that period in low niumbers. The modem chairacter of the vegetation developed arounid two key periods: the Pleistocene/Holocene boundary, and, to a much smaller degree, from the mid-Holocene, with the chaniges somewhat less in the southwest. The mid-Holocene period was mnarked by slightly wetter and waimer conditionis than present across all of southeastem Australia, yet most palynological records show little if any response in terrestrial vegetation in relation to this climate. The most significant Holocene changes appear to be a gradual decline in the importance of Casuarina, and changes in the abundance of Corymbia calophylla in the southwest. Many of the palynological records also have fossil charcoal histories and it is clear that, while there has been some regional variation. fire has been an important environmental feature of the regions throughout the Holocene. However, there are few indications that fire had any major role in vegetation change. What is clear is that European settlement, from about 150-180 years ago, wrought the greatest changes on vegetation, and possibly because of the parallel climate and environmental conditions the main invasive species have come from other mediterranean-type climate regions.
A fossil pollen and charcoal record from a cyperaceous swamp on the Fleurieu Peninsula, South Australia, was investigated to provide a history of pre and post-European settlement vegetation change. It was found that the swamp initiated sometime before 8220 calibrated years BP. High rates of peat development and the expansion of swamp species between 7000 BP and 4500 cal. BP indicated wet conditions at that time. The swamp became drier in the late Holocene and some peat may have been lost through deflation. Macroscopic charcoal and Typha pollen suggested that Aborigines deliberately burned the upland wetlands during the mid to late Holocene. Prior to European settlement climate changes generated community shifts in the terrestrial vegetation. The record revealed a transition from an early Holocene Eucalyptus woodland to an Allocasuarina wet-heath in the humid mid-Holocene, a community type with no modern analogue in the region. In the drier late Holocene, a Eucalyptus-dominated woodland returned. The impacts of European settlement were clearly seen in changes in sedimentation rates and in both terrestrial and wetland flora. Allocasuarina verticillata declined early in the European period and fire tolerant species were promoted, before the almost complete removal of native vegetation through broad scale land clearance and its replacement with nonnative pasture species. Compositional changes to the swamp flora were marked through the European phase with Acacia expanding early in settlement and later being replaced by Leptospermum, in response to changed fire and regional hydrological regimes. The impact of European land use is discussed in relation to Holocene climate-driven vegetation changes and aspects of Aboriginal land use.