Christopher R. Dickman

The University of Sydney · School of Biological Sciences

Effective conservation of Australasian marsupials requires detailed knowledge of their food habits and activity patterns. Ancestral marsupials were probably nocturnal insectivores. Food habits of extant fauna are studied by techniques such as direct observations, analysis of prey remains in stomach contents or feces, field experiments, eDNA, stable...

This chapter introduces the book by telling how the history of research on American and Australasian marsupials has developed up to now. It focuses on the main disciplines that aim to study the diversity of marsupials and other metatherians, from the past to today. These disciplines are taxonomy, systematics, biogeography, ecology, and conservation...

Predation by feral cats (Felis catus) has caused the extinction of many native species in Australia and globally. There is growing evidence that the impacts of feral cats can be amplified in post‐fire environments, as cats are drawn to hunt in or around recently burnt areas and are also more effective hunters in open habitats. In 2018–2019, we esta...

The arid and semiarid regions of Australia encompass about three quarters of the continent. This vast area – the arid zone – is characterized by very varied habitats and landscapes and inter-annual extremes of rainfall that drive dramatic shifts in primary productivity. Arid zone marsupials use morphological, behavioral, and physiological adaptatio...

Expert elicitation can be valuable for informing decision-makers on conservation and wildlife management issues. To date, studies eliciting expert opinions have primarily focused on identifying and building consensus on key issues. Nonetheless , there are drawbacks of a strict focus on consensus, and it is important to understand and emphasize diss...

The availability of natural habitats is decreasing due to increases in the human population and inexorable urban spread. Although many marsupials cannot live in urban environments and others occur in areas removed from intensive human activity, some marsupials persist and even fare well in towns and cities or in disturbed habitats within the built...

Roaming domestic cats (Felis catus) are recognised as a threat to wildlife globally. Yet management of pet cats in urbanised areas is not regularly mandated, and management of feral cats in urbanised areas is rarely implemented. Mounting evidence emphasises the value of urban environments as hot spots of wildlife activity, which as the human popula...

Australasia is home to many iconic species of marsupials, most found nowhere else. The region also leads the world in marsupial declines and extinctions. There are many causes of marsupial decline with focus in this chapter on habitat loss and habitat fragmentation. While habitat loss and habitat fragmentation are typically considered together, the...

Global change drivers, such as anthropogenic nutrient inputs, are increasing globally. Nutrient deposition simultaneously alters plant biodiversity, species composition and ecosystem processes like aboveground biomass production. These changes are underpinned by species extinction, colonisation and shifting relative abundance. Here, we use the Pric...

Introduction of the domestic cat and red fox has devastated Australian native fauna. We synthesized Australian diet analyses to identify traits of prey species in cat, fox and dingo diets, which prey were more frequent or distinctive to the diet of each predator, and quantified dietary overlap. Nearly half (45%) of all Australian terrestrial mammal...

Under the Ecosystem Exploitation Hypothesis ecosystem productivity predicts trophic complexity, but it is unclear if spatial and temporal drivers of productivity have similar impacts. Long-term studies are necessary to capture temporal impacts on trophic structure in variable ecosystems such as deserts. We sampled ants and measured plant resources...

Species interactions play a fundamental role in ecosystems. They affect where species can live, how their population sizes fluctuate through time, and how environmental perturbations cascade through communities. But few ecological communities have complete data describing such interactions, which is an obstacle to understanding how ecosystems funct...

The 2021 annual forum of the Royal Zoological Society of NSW raked over the ashes of the unprecedented “Black Summer” bushfires of 2019–2020 in eastern and southern Australia to assess how forest ecosystems and their constituent fauna had fared. This paper provides an overview of the 21 studies that were presented at the forum, now as papers in thi...

Free-roaming domestic cats (i.e., cats that are owned or unowned and are considered ‘at large’) are globally distributed non-native species that have marked impacts on biodiversity and human health. Despite clear scientific evidence of these impacts, free-roaming cats are either unmanaged or managed using scientifically unsupported and ineffective...

Australia’s 2019–20 mega-fires burnt 79% of the Greater Blue Mountains World Heritage Area, prompting an urgent need for rapid on-ground post-fire assessments of flora and fauna to aid in post-fire recovery. This project aimed to determine spatial patterns in populations and assemblages of vertebrates, vertebrate temporal activity, and the diet of...

Carrion is an ubiquitous resource that drives the dynamics of scavenger populations and shapes the structure and composition of their communities. Corvids (Family: Corvidae) are among the most common scavengers globally, facilitating carcass discovery by other species and contributing to carcass biomass removal. Here, we examine how environmental f...

Ecological models predict that the effects of mammalian herbivore exclusion on plant diversity depend on resource availability and plant exposure to ungulate grazing over evolutionary time. Using an experiment replicated in 57 grasslands on six continents, with contrasting evolutionary history of grazing, we tested how resources (mean annual precip...

Global change drivers such as anthropogenic nutrient inputs simultaneously alter biodiversity, species composition, and ecosystem functions such as aboveground biomass. These changes are interconnected by complex feedbacks among extinction, colonization, and shifting relative abundance. Here, we use a novel temporal application of the Price equatio...

Populations of many animal species decline after fire, with some individuals killed during the fire and others succumbing to impoverished conditions in the post-fire environment. For individuals that survive a fire, an ability to exploit scarce resources in the burnt landscape is particularly important. In this study, we compared the numbers, survi...

Aim Introduced predators negatively impact biodiversity globally, with insular fauna often most severely affected. Here, we assess spatial variation in the number of terrestrial vertebrates (excluding amphibians) killed by two mammalian mesopredators introduced to Australia, the red fox (Vulpes vulpes) and feral cat (Felis catus). We aim to identif...

Australia has suffered more modern mammal extinctions than any nation. Among the list of extinct species is the blue-grey mouse (Pseudomys glaucus), a rodent known from just three specimens (two from southern Queensland and one from northern New South Wales). We investigated circumstances of collection for the three specimens referred to this speci...

An important but understudied modality for eavesdropping between predators and prey is olfaction, especially between non-mammalian vertebrate predators and their prey. Here we test three olfactory eavesdropping predictions involving an apex reptilian predator, the sand goanna Varanus gouldii, and several species of its small mammalian prey in arid...

Ecosystem engineers are typically seen as organisms whose activities modulate the availability of resources for other species. A new study shows that Brandt's vole engineers its local environment specifically to reduce its own risk of being killed by predatory birds.

Urban environments provide the only or best habitats that are left for wildlife in many areas, promoting increased interest in urban conservation and a need to understand how wildlife cope with urban stressors, such as altered predator activity and human disturbance. Here, we used filmed giving-up density experiments to investigate behavioral copin...

Wildlife are increasingly being found in urban habitats, and likely rely on some resources in suburban household yards, which exposes them to the effects of yard management and human and pet activities. We compared the relationships between these potential disturbances and benefits to the number of different types of wildlife sighted by householder...

Both fire and predators have strong influences on the population dynamics and behaviour of animals, and the effects of predators may either be strengthened or weakened by fire. However, knowledge of how fire drives or mediates predator-prey interactions is fragmented and has not been synthesised. Here, we review and synthesise knowledge of how fire...

Millions of native animals around the world are rescued and rehabilitated each year by wildlife rehabilitators. Triage and rehabilitation protocols need to be robust and evidence-based, with outcomes consistently recorded, to promote animal welfare and better understand predictors of wildlife survival. We conducted a global systematic review and me...

After environmental disasters, species with large population losses may need urgent protection to prevent extinction and support recovery. Following the 2019–2020 Australian megafires, we estimated population losses and recovery in fire‐affected fauna, to inform conservation status assessments and management. Temperate and subtropical Australia. 20...

Aim: Comprehensive, global information on species' occurrences is an essential biodiversity variable and central to a range of applications in ecology, evolution, biogeography and conservation. Expert range maps often represent a species' only available distributional information and play an increasing role in conservation assessments and macroeco...

Carrion is a vital resource in terrestrial ecosystems, supporting complex networks of interacting consumer organisms. The insect community attending carrion forms a vital part of this food web, but the functional roles of insects as scavengers can be altered by invasive species via the effects of predation and competition. European wasps (Vespula g...

Global change drivers such as anthropogenic nutrient inputs simultaneously alter biodiversity, species composition, and ecosystem functions such as above ground biomass. These changes are interconnected by complex feedbacks among extinction, invasion, and shifting relative abundance. Here, we use a novel temporal application of the Price equation t...

Earth's rapidly warming climate is propelling us towards an increasingly fire-prone future. Currently, knowledge of the extent and characteristics of animal mortality rates during fire remains rudimentary, hindering our ability to predict how animal populations may be impacted in the future. To address this knowledge gap, we conducted a global syst...

The immense size, varied land systems, different climatic regimes, and great antiquity of the Australian landmass have fostered the development of an extraordinarily rich and endemic biota. Yet, despite the importance of this unique natural heritage, evidence is mounting that Australia’s living systems are under increasing assault. On land, the maj...

Human activity can impose additional stressors to wildlife, both directly and indirectly, including through the introduction of predators and influences on native predators. As urban and adjacent environments are becoming increasingly valuable habitat for wildlife, it is important to understand how susceptible taxa, like small prey animals, persist...

Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus , have had extensive impacts on Australian biodiversity. In this study, we collate information on consumption of Australian birds by the fox, paralleling a recent study reporting on birds consumed by cats. We found records of consumption by foxes on 128 nativ...

Public opposition has shaped management of wild animals in Australia, but public interest in dingo control has been minimal. We hypothesised that this is due to lack of awareness of dingo management practices, in part because using the term “wild dogs” to describe management renders “dingoes” invisible, framing the issue as one of control of introd...

Significance Disentangling the effects of rainfall timing and magnitude on animal and plant populations is essential to reveal the biological consequence of diverse climate change scenarios around the world. We conducted a 10-y, large-scale, manipulative experiment to examine the bottom-up effects of changes in rainfall regime on the population dyn...

Two introduced carnivores, the European red fox Vulpes vulpes and domestic cat Felis catus, have had, and continue to have, major impacts on wildlife, particularly mammals, across Australia. Based mainly on the contents of almost 50,000 fox dietary samples, we provide the first comprehensive inventory of Australian mammal species known to be consum...

Eucoleus aerophilus (syn. Capillaria aerophila) is a zoonotic trichuroid nematode parasite of dogs, cats and wild carnivores with a global distribution. The main reservoir species in Europe is the red fox, where it has been detected in up to 97% of animals surveyed. Despite the burgeoning feral cat and fox population in Australia, there is a paucit...

Software for realistically simulating complex population genomic processes is revolutionizing our understanding of evolutionary processes, and providing novel opportunities for integrating empirical data with simulations. However, the integration between simulation software and software designed for working with empirical data is currently not well...

Pet cats (Felis catus) often have negative effects on wildlife. This is of growing concern in urban areas as these are increasingly becoming hotspots of native wildlife activity, and as the human population increases, so too does the pet cat population. To maintain biodiversity in urban areas, further knowledge on pet cat behaviour and impacts is r...

Fire has long been a part of the Australian environment and remains a potent force in shaping the adaptations of species, the dynamics of populations, and the structure of ecological communities. However, the fire regime is changing. Fire seasons are longer, wet vegetation types that do not usually burn are now at risk, and fire intensity and sever...

Context. Invasive species are a major cause of biodiversity loss across much of the world, and a key threat to Australia's diverse reptile fauna. There has been no previous comprehensive analysis of the potential impact of the introduced European red fox, Vulpes vulpes, on Australian reptiles. Aims. We seek to provide an inventory of all Australia...

Similar to many Australian mammal species, the kowari (Dasyuroides byrnei), a marsupial 'micro-carnivore' restricted to the gibber plains of central Australia, persists under the threat of extinction. The kowari has experienced a significant contraction from its historical range and is now extinct in the Northern Territory, with scattered populatio...

The red fox Vulpes vulpes is one of the world’s most widespread carnivores. A key to its success has been its broad, opportunistic diet. The fox was introduced to Australia about 150 years ago, and within 30 years of its introduction was already recognised as a threat to livestock and native wildlife. We reviewed 85 fox diet studies (totalling 3169...

An important but understudied modality for eavesdropping between predators and prey is olfaction, especially between non-mammalian vertebrate predators and their prey. Here we test three olfactory eavesdropping predictions involving an apex reptilian predator, the sand goanna Varanus gouldii , and several species of its small mammalian prey in arid...

An important but understudied modality for eavesdropping between predators and prey is olfaction, especially between non-mammalian vertebrate predators and their prey. Here we test three olfactory eavesdropping predictions involving an apex reptilian predator, the sand goanna Varanus gouldii , and several species of its small mammalian prey in arid...

Our knowledge of the conservation status of reptiles, the most diverse class of terrestrial vertebrates, has improved dramatically over the past decade, but still lags behind that of the other tetrapod groups. Here, we conduct the first comprehensive evaluation (~92% of the world's ~1714 described species) of the conservation 1 Joint senior authors...

In addition to feeding on animal remains, many scavengers also function as predators. Carcasses may therefore affect local animal communities by attracting facultative scavengers and increasing predation risk for other species in the vicinity of the carcasses. This risk may be elevated in low productivity environments, especially where humans incre...

Determining the factors that drive the distributions of threatened species is often critical for informing effective conservation management actions. Species distribution models can be used to distinguish common habitat features shared by limited historical records and identify other areas where a species might persist. In this study, we built a sp...

Feral individuals of the cat Felis catus are recognised internationally as a threat to biodiversity. Open, non‐insular systems support a large proportion of the world’s biodiversity, but the population‐level impacts of feral cats in these systems are rarely elucidated. This limits prioritization and assessment of the effectiveness of management int...

The impacts of wildfire upon biodiversity can be compounded by other factors. There is some evidence that feral cats Felis catus may move to, or occur in increased abundance in, recently burnt areas. As such, wildlife that have survived fire may be at increased predation risk, in part because the burnt landscape offers less shelter from predation....

Achieving conservation goals, such as coexistence between wildlife and humans, requires an evidence-based understanding of the factors that shape conservation contexts. For addressing conflict between humans and wildlife, this means understanding the barriers and opportunities to changing human behaviors toward wildlife. Here, we develop a Theory o...

Understanding wild animal responses to stressors underpins effective wildlife management. In order for responses to stressors to be correctly interpreted, it is critical that measurements are taken on wild animals using minimally invasive techniques. Studies investigating wild animal responses to stressors often measure either a single physiologica...

Invertebrates dominate the animal world in terms of abundance, diversity and biomass, and play critical roles in maintaining ecosystem function. Despite their obvious importance, disproportionate research attention remains focused on vertebrates, with knowledge and understanding of invertebrate ecology still lacking. Due to their inherent advantage...

A Correction to this paper has been published: https://doi.org/10.1038/s41467-021-20985-z.

Aichi Target 12 of the Convention on Biological Diversity (CBD) contains the aim to ‘prevent extinctions of known threatened species’. To measure the degree to which this was achieved, we used expert elicitation to estimate the number of bird and mammal species whose extinctions were prevented by conservation action in 1993–2020 (the lifetime of th...

Human activities are transforming grassland biomass via changing climate, elemental nutrients, and herbivory. Theory predicts that food-limited herbivores will consume any additional biomass stimulated by nutrient inputs (‘consumer-controlled’). Alternatively, nutrient supply is predicted to increase biomass where herbivores alter community composi...

Context. Cats are the definitive or primary host for pathogens that cause diseases in people and livestock. These cat-dependent diseases would not occur in Australia if cats had not been introduced, and their ongoing persistence depends on contacts with cats. Toxoplasma gondii is a protozoan parasite that cycles between cats and any other warm-bloo...

Climate variability has been widely documented to have bottom-up effects on the population dynamics of animals 1,2 , but the mechanisms underlying these effects have been rarely investigated through field manipulative experiments that control for confounding factors ³ . Here, we examined the effects of different rainfall patterns (i.e. timing and a...

Research and management attention on the impacts of the introduced domestic cat (Felis catus) on Australian fauna have focussed mainly on the feral population. Here, we summarise the evidence for impacts of predation by pet cats on Australian wildlife. We collate examples of local wildlife population decline and extirpation as a result, at least in...

ContextWe recently estimated the numbers of reptiles, birds and mammals killed by cats (Felis catus) in Australia, with these assessments providing further evidence that cats have significant impacts on Australian wildlife. No previous studies have estimated the numbers of frogs killed by cats in Australia and there is limited comparable informatio...

Context. Recent global concern over invertebrate declines has drawn attention to the causes and consequences of this loss of biodiversity. Feral cats, Felis catus, pose a major threat to many vertebrate species in Australia, but their effect on invertebrates has not previously been assessed. Aims. The objectives of our study were to (1) assess the...

Ancestral dingoes arrived in Australia at some time, or times, during the Holocene, heralding a period of long and uneasy coexistence with the human inhabitants of the continent. For the first Australians, dingoes became a valued and integral part of the culture but also exacted diverse social and economic costs. For early Europeans and later arriv...