Global correlates of range contractions and expansions in terrestrial mammals

Understanding changes in species distributions is essential to disentangle the mechanisms that drive their responses to anthropogenic habitat modification. Here we analyse the past (1970s) and current (2017) distribution of 204 species of terrestrial non-volant mammals to identify drivers of recent contraction and expansion in their range. We find 106 species lost part of their past range, and 40 of them declined by >50%. The key correlates of this contraction are large body mass, increase in air temperature, loss of natural land, and high human population density. At the same time, 44 species have some expansion in their range, which correlates with small body size, generalist diet, and high reproductive rates. Our findings clearly show that human activity and life history interact to influence range changes in mammals. While the former plays a major role in determining contraction in species’ distribution, the latter is important for both contraction and expansion.

Understanding why many species ranges are contracting while others are stable or expanding is important to inform conservation in an increasingly human-modified world. Here, Pacifici and colleagues investigate changes in the ranges of 204 mammals, showing that human factors mostly explain range contractions while life history explains both contraction and expansion.

Geographic distribution ranges of terrestrial mammal species in the 1970s

Here we provide geographic distribution ranges for 205 species of terrestrial non-volant mammals in the 1970s. We selected terrestrial non-volant mammals because they are among the most studied groups, have greater availability of historical distribution data for the 1970s decade, and also show the largest range contractions compared to other taxonomic groups. Species belong to 52 families and 16 orders. Range maps were extracted from scientific literature including published papers, books, and action plans. For Australian species, due to the absence of published maps, we collated occurrence data from individual data sets (maintained by museums and government agencies) and converted these into polygonal range maps. Taxonomic and geographic biases towards more studied (charismatic) species are inevitably present. Among the most abundant orders, the highest percentage representation is for Carnivora (55 species, corresponding to 21% of species in the order), Cetartiodactyla (24 species, 10% of the order), and Perissodactyla (six species, 38% of the order). In contrast, the percentage representation is low for Rodentia (66 species, 3% of species in the order), Primates (19 species, 4%), and Eulipotyphla (6 species, 1%). The proportional representation of less speciose orders is highly variable. The data set offers the opportunity to measure the recent (1970-2019) change in the distribution of terrestrial mammal species, and test ecological and biogeographical hypotheses about such change. It also allows us to identify areas where changes in species distribution were largest. No copyright or proprietary restrictions are associated with the use of this data set other than citation of this Data Paper.

Metrics of progress in the understanding and management of threats to Australian birds

Although evidence-based approaches have become commonplace for determining the success of conservation measures for the management of threatened taxa, there are no standard metrics for assessing progress in research or management. We developed 5 metrics to meet this need for threatened taxa and to quantify the need for further action and effective alleviation of threats. These metrics (research need, research achievement, management need, management achievement, and percent threat reduction) can be aggregated to examine trends for an individual taxon or for threats across multiple taxa. We tested the utility of these metrics by applying them to Australian threatened birds, which appears to be the first time that progress in research and management of threats has been assessed for all threatened taxa in a faunal group at a continental scale. Some research has been conducted on nearly three-quarters of known threats to taxa, and there is a clear understanding of how to alleviate nearly half of the threats with the highest impact. Some management has been attempted on nearly half the threats. Management outcomes ranged from successful trials to complete mitigation of the threat, including for one-third of high-impact threats. Progress in both research and management tended to be greater for taxa that were monitored or occurred on oceanic islands. Predation by cats had the highest potential threat score. However, there has been some success reducing the impact of cat predation, so climate change (particularly drought), now poses the greatest threat to Australian threatened birds. Our results demonstrate the potential for the proposed metrics to encapsulate the major trends in research and management of both threats and threatened taxa and provide a basis for international comparisons of evidence-based conservation science.

Degrees of population-level susceptibility of Australian terrestrial non-volant mammal species to predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis catus)

Context Over the last 230 years, the Australian terrestrial mammal fauna has suffered a very high rate of decline and extinction relative to other continents. Predation by the introduced red fox (Vulpes vulpes) and feral cat (Felis catus) is implicated in many of these extinctions, and in the ongoing decline of many extant species. Aims To assess the degree to which Australian terrestrial non-volant mammal species are susceptible at the population level to predation by the red fox and feral cat, and to allocate each species to a category of predator susceptibility. Methods We collated the available evidence and complemented this with expert opinion to categorise each Australian terrestrial non-volant mammal species (extinct and extant) into one of four classes of population-level susceptibility to introduced predators (i.e. ‘extreme’, ‘high’, ‘low’ or ‘not susceptible’). We then compared predator susceptibility with conservation status, body size and extent of arboreality; and assessed changes in the occurrence of species in different predator-susceptibility categories between 1788 and 2017. Key results Of 246 Australian terrestrial non-volant mammal species (including extinct species), we conclude that 37 species are (or were) extremely predator-susceptible; 52 species are highly predator-susceptible; 112 species are of low susceptibility; and 42 species are not susceptible to predators. Confidence in assigning species to predator-susceptibility categories was strongest for extant threatened mammal species and for extremely predator-susceptible species. Extinct and threatened mammal species are more likely to be predator-susceptible than Least Concern species; arboreal species are less predator-susceptible than ground-dwelling species; and medium-sized species (35 g–3.5kg) are more predator-susceptible than smaller or larger species. Conclusions The effective control of foxes and cats over large areas is likely to assist the population-level recovery of ~63 species – the number of extant species with extreme or high predator susceptibility – which represents ~29% of the extant Australian terrestrial non-volant mammal fauna. Implications Categorisation of predator susceptibility is an important tool for conservation management, because the persistence of species with extreme susceptibility will require intensive management (e.g. predator-proof exclosures or predator-free islands), whereas species of lower predator susceptibility can be managed through effective landscape-level suppression of introduced predators.

Havens for threatened Australian mammals: the contributions of fenced areas and offshore islands to the protection of mammal species susceptible to introduced predators

Context Many Australian mammal species are highly susceptible to predation by introduced domestic cats (Felis catus) and European red foxes (Vulpes vulpes). These predators have caused many extinctions and have driven large distributional and population declines for many more species. The serendipitous occurrence of, and deliberate translocations of mammals to, ‘havens’ (cat- and fox-free offshore islands, and mainland fenced exclosures capable of excluding cats and foxes) has helped avoid further extinction. Aims The aim of this study was to conduct a stocktake of current island and fenced havens in Australia and assess the extent of their protection for threatened mammal taxa that are most susceptible to cat and fox predation. Methods Information was collated from diverse sources to document (1) the locations of havens and (2) the occurrence of populations of predator-susceptible threatened mammals (naturally occurring or translocated) in those havens. The list of predator-susceptible taxa (67 taxa, 52 species) was based on consensus opinion from >25 mammal experts. Key results Seventeen fenced and 101 island havens contain 188 populations of 38 predator-susceptible threatened mammal taxa (32 species). Island havens cover a larger cumulative area than fenced havens (2152km2 versus 346km2), and reach larger sizes (largest island 325km2, with another island of 628km2 becoming available from 2018; largest fence: 123km2). Islands and fenced havens contain similar numbers of taxa (27 each), because fenced havens usually contain more taxa per haven. Populations within fences are mostly translocated (43 of 49; 88%). Islands contain translocated populations (30 of 139; 22%); but also protect in situ (109) threatened mammal populations. Conclusions Havens are used increasingly to safeguard threatened predator-susceptible mammals. However, 15 such taxa occur in only one or two havens, and 29 such taxa (43%) are not represented in any havens. The taxon at greatest risk of extinction from predation, and in greatest need of a haven, is the central rock-rat (Zyzomys pedunculatus). Implications Future investment in havens should focus on locations that favour taxa with no (or low) existing haven representation. Although havens can be critical for avoiding extinctions in the short term, they cover a minute proportion of species’ former ranges. Improved options for controlling the impacts of cats and foxes at landscape scales must be developed and implemented.

Did Zaglossus bruijnii occur in the Kimberley region of Western Australia?

A 2012 paper reported the discovery of a specimen of Zaglossus bruijnii with a label attached that recorded that it had been collected at Mount Anderson, in the south-west Kimberley region of Western Australia, in 1901. Based on several lines of evidence, I argue that this distinctive long-beaked echidna is not, and has not been, part of the Kimberley region’s modern mammal fauna. The simplest and most plausible explanation is that the tag on the specimen came from another animal.

Mammals on Western Australian islands: occurrence and preliminary analysis

We present a database of indigenous and non-indigenous terrestrial mammal records on Western Australian (WA) islands, updated from a database we published more than 20 years ago. The database includes records of 88 indigenous species on 155 islands, compared with 54 indigenous species on 141 WA islands in the paper by Abbott and Burbidge in CALMScience, Volume 1, pp. 259–324. The database also provides 266 records of 21 species of non-indigenous mammal species on 138 WA islands, more than double the number of records in the earlier review. Of the 33 threatened and near-threatened WA non-volant mammals, 16 occur naturally (and have persisted) on WA islands, five additional species occur on islands outside WA, 14 successful conservation translocations of 10 species have been undertaken to WA islands, and six species have been successfully translocated to 12 islands outside WA – two of which do not currently occur on WA islands. The house mouse now accounts for the largest number of extant records of non-indigenous species. Even with the increasing number of conservation translocations to mainland islands (fenced exclosures), WA islands remain essential for the effective conservation of several threatened and near-threatened mammals and many of the translocations to mainland islands have been sourced from islands.

Keeping Australia’s islands free of introduced rodents: the Barrow Island example

Islands are important reservoirs of endemic and threatened species, but anthropogenic influences have impacted their biotas. Australia has over 8000 islands, both continental and oceanic, but because of considerably increased traffic, both tourist and commercial, many of these islands have been and are subject to increased threats from invasive species. The invasive Black Rat Rattus rattus is of particular concern as it can negatively impact mammal, bird, reptile, invertebrate and plant populations. Barrow Island, in northwest Western Australia, is an island requiring particular protection from Black Rats as it is a Class A nature reserve with many unique and threatened taxa that is subject to major disturbances from activities associated with oil extraction and a large liquefied natural gas processing plant. Strict quarantine is currently imposed on all materials and persons being sent to the island and there is an intense on-island surveillance programme. So far the protocols used have prevented Black Rats establishing on this island, but such a level of biosecurity is clearly impossible for all islands. In this paper we discuss the effectiveness of quarantine inspections and surveillance together and alone in protecting high-risk, high-value Australian islands against introduced rodents and we document eradication costs for other islands. World-wide, it has only been possible so far to eradicate rats from relatively small islands, mostly with no non-target indigenous mammals and larger islands only where there are no non-target indigenous mammals. Models based largely on economic considerations have suggested it is more cost effective to use surveillance alone without quarantine for Black Rats on Barrow Island and that if rats become widespread (an estimated 4% risk), it may be more cost effective not to attempt eradication. Such models provide useful guidance for managers where biodiversity values are relatively low or where there are no non-target species, but for Barrow island we argue for continuation of quarantine as well as surveillance and an increased level of quarantine controls at the point of departure on all people, vessels and aircraft visiting other vulnerable Australian islands.

Unforeseen consequences of a misidentified rodent: case study from the Archipelago of the Recherche, Western Australia

Since 1953, it has been assumed that Rattus rattus occurred on Woody Island, Archipelago of the Recherche, Western Australia, and that R. fuscipes was locally extinct. Recent trapping and identification, including sequencing of mitochondrial DNA, has confirmed the persistence of R. fuscipes. The apparent misidentification of the 1950 specimen and failure to collect vouchers since has led to unforeseen consequences, including a proposal to eradicate the Rattus population.

Is Australia ready for assisted colonization? Policy changes required to facilitate translocations under climate change

Assisted Colonization (AC) has been proposed as one method of aiding species to adapt to the impacts of climate change. AC is a form of translocation and translocation protocols for threatened species, mostly for reintroduction, are well established in Australia. We evaluate the information available from implementation of translocations to understand how existing policies and guidelines should be varied to plan, review and regulate AC. While the risks associated with AC are potentially greater than those of reintroductions, AC is likely to be the only available method, other than germplasm storage and establishment of captive populations, of conserving many taxa under future climate change. AC may also be necessary to maintain ecosystem services, particularly where keystone species are affected. Current policies and procedures for the preparation of Translocation Proposals will require modification and expansion to deal with Assisted Colonization, particularly in relation to risk management, genetic management, success criteria, moving associated species and community consultation. Further development of risk assessment processes, particularly for invasiveness, and guidelines for genetic management to maintain evolutionary potential are particularly important in the context of changing climate. Success criteria will need to respond to population establishment in the context of new and evolving ecosystems, and to reflect requirements for any co-establishment of interdependent species. Translocation Proposals should always be subjected to independent peer review before being considered by regulators. We conclude that consistent approaches by regulators and multilateral agreements between jurisdictions are required to minimize duplication, to ensure the risk of AC is adequately assessed and to ensure the potential benefits of AC are realized.

Conservation status and biogeography of Australia's terrestrial mammals

This paper attempts to identify and explain patterns in the biogeography of Australia’s indigenous terrestrial mammals at the time of European settlement (before modern extinctions), and also compares species’ pre-European and current status by region. From subfossil, historical and contemporary sources, we compiled data on the past geographic range and present status of mammals for Australia’s 85 biogeographic regions. Of the 305 indigenous species originally present, 91 have disappeared from at least half of the bioregions in which they occurred before European settlement. Thirty-nine extant species ‘persist’ in less than 25% of their original bioregions; 28 of these are marsupials and 11 are rodents. Twenty-two of the original 305 species are extinct, a further eight became restricted to continental islands, and 100 have become extinct in at least one bioregion. Over the same period, 26 species of exotic mammals established wild populations and now occupy from one to 85 bioregions. When we classified the bioregions in terms of their original species composition, the 3-group level in the dendrogram approximated the Torresian, Eyrean and Bassian subregions proposed by Spencer in 1898, while the 4-group level separated southern semiarid Eyrean bioregions, including those in south-west Australia, from the arid Eyrean bioregions. The classification dendrogram showed geographically (and statistically) discrete clustering down to the 19-group level, suggesting that all four subregions can be further divided on the basis of their mammal faunas. Variation partitioning showed 66% of the biogeographical pattern can be explained by environmental factors (related to temperature and precipitation), the spatial position of each bioregion (a third-order polynomial of latitude and longitude), the area of each bioregion, and the richness of species in each bioregion. In addition to the marked distributional changes that indigenous mammals have experienced over the last 200 years, the 49% of variation explainable by temperature and precipitation implies further shifts with global climate change.

Translocation Of Mala (Lagorchestes Hirsutus) From The Tanami Desert, Northern Territory To Trimouille Island, Western Australia

In June 1998, 30 mala (Lagorchestes hirsutus undescribed central Australian subspecies) were translocated from a semi-captive colony in the Tanami Desert, Northern Territory to Trimouille Island, part of the Montebello Islands Conservation Park, off the Pilbara coast of Western Australia. Mala are ?Extinct in the Wild? according to IUCN (1994, 2000) Red List Categories and Criteria. The translocation was made possible by the eradication of black rats (Rattus rattus) and confirmation of the absence of feral cats (Felis catus), which were recorded on the island in the 1970s. Post-release monitoring up to October 2001 showed that mala were breeding and expanding the area occupied.

Comparison of the erythrocyte sedimentation rate measured in the eye casualty department by the Seditainer method with an automated system

PURPOSE

To compare a new automated system for the measurement of erythrocyte sedimentation rate (ESR) with the established manual Seditainer method.

METHODS

Two hundred and twelve patients undergoing investigation for giant cell arteritis or other systemic vasculitides had ESR measurements by both the established manual Seditainer and the new laboratory-based automated system. The results were compared by correlation coefficient and mean difference. The limits of agreement with confidence intervals were also calculated.

RESULTS

Across the range of results from 1 to 120 mm/h, the correlation coefficient was 0.844. The automated method had a mean negative bias of -9.8 mm/h (95% confidence interval: -12.2 to -7.4 mm/h). The wide scatter of results produced limits of agreement (+/- 2 standard deviations) between the two methods of -45 to 26 mm/h. There were seven results that were underestimated by the automated system which were clinically significant.

CONCLUSIONS

There is a wide degree of scatter between the two sets of results. The automated system has a negative bias when compared with the manual method. There is a propensity for the automated system to sporadically underestimate the true result, sometimes to a degree that is clinically significant. The authors therefore cannot recommend replacement of the manual Seditainer system at the present time.

The Ecology of the Western Swamp Tortoise Pseudemydura Umbrina (Testudines: Chelidae)

Western swamp tortoise (Pseudemydura umbrina) was rediscovered in Western Australia in 1954. It is a relict species of a monotypic genus, of very restricted range and specialized habitat. Population was estimated to be 13 to 45 and decreasing at 1 of its 2 native reserves and to be 10 to 45 and static at the other reserve. It does not use permanent water, but lives and feeds in ephemeral winter swamps and spends the other 6 to 9 months of the year in refuges in leaf litter, under fallen branches or in holes in the ground, in contact with the soil. The tortoise is carnivorous and in the wild takes only live aquatic organisms. Captive adults will not take meat until they have starved for many months. Stomach of 1 female (Edward, pers. commun.) had aquatic crustaceans, chiefly Eulimnadia sp., with insects and insect larvae, mainly Coleoptera and Diptera. Study of faeces confirmed that observation had shown that small tadpoles and an aquatic earthworm (Eodrilus cornigravei) were eaten also. Reproduction, growth, activity relative to body and water temperature, and desiccation rate, were noted. One adult female tortoise was eaten by a fox. Foxes and bandicoots (Isoodon obesulus) eat eggs of other tortoises and would eat those of P. umbrina. Hatchlings may be eaten by large wading birds such as straw-necked ibis (Threskiornis spinicollis) and white-faced heron (Notophoyx novaehollandiae).