Predators learning to avoid toxic invasive prey: a study on individual variation among free-ranging lizards

Within all wild populations, individuals vary in ways that affect their vulnerability to threatening processes. Understanding that variation may clarify mechanisms of population persistence and/or evolution. In Australia, Yellow-spotted Monitors (Varanus panoptes), decline by >90% when toxic Cane Toads (Rhinella marina) invade an area. Taste-aversion training (exposing animals to non-lethal toads) can buffer impacts; but does pre-existing behavioural variation also influence survival? An individual’s fate can be predicted from its behaviour during aversion-training trials. Lizards presented with small toads either consumed them, rejected them, or fled. When Cane Toads invaded our study site, mortality was lower in lizards that ‘consumed’ (aversion-trained) than in those that ‘fled’ (untrained), but even lower in lizards that ‘rejected’ toads outright. Thus, animals reluctant to consume toads in trials survived despite never being aversion-trained. In this system, lizard vulnerability is driven by boldness, behavioural responses to novel prey types, and the opportunity to learn aversion.

Management of Adult Inpatient Otolaryngologic Consultations During the COVID-19 Pandemic: A Proposed Tier-Based Triage System

The coronavirus disease 2019 (COVID-19) pandemic has placed tremendous strain on health care systems, leading to unprecedented challenges and obstacles in the delivery of patient care. Otolaryngologists are frequently called on for inpatient consultations for an array of pathologies, ranging from chronic benign conditions to acutely life-threatening processes. Professional otolaryngologic societies across the world have proposed limiting patient care to time-sensitive and urgent matters; however, limited literature is available to describe how this transient change in philosophy may translate to clinical practice. Here we present a structured algorithm that allows for rapid triage of otolaryngologic consults during the ongoing pandemic, in efforts to minimize infectious spread and protect clinicians while preserving high-quality patient care. Considerations for managing these consults are presented, with a commentary on practical and ethical considerations.

Landscape management of the mahogany glider (Petaurus gracilis) across its distribution: subpopulations and corridor priorities

Key threatening processes to biodiversity include habitat loss and fragmentation, with populations restricted to small fragments of habitat being more prone to extinction. The mahogany glider (Petaurus gracilis) is endemic to sclerophyll woodland forests between Tully and Ingham in north Queensland and is one of Australia’s most endangered arboreal mammals due to these processes. The aim of this study was to identify the degree of habitat fragmentation of the remaining remnant vegetation of the mahogany glider, identify subpopulations within its distribution and identify key wildlife corridors for restoration to facilitate the movement of this species within and between subpopulations. Ten glider subpopulations, spread over 998 habitat fragments, were identified, of which only five subpopulations may currently be considered to be viable. To assist in providing habitat connectivity between and within the subpopulations, 55 corridors were identified for restoration that had an average length of 8.25 km. The average number of gaps greater than 30 m was 3.4 per corridor, with the average length of these gaps being 523 m. This study confirmed a high degree of habitat fragmentation across the distribution of the mahogany glider and highlighted the need to strengthen the remaining subpopulations by restoring habitat connectivity between the remaining habitat fragments.

Testing the decline of the New Holland mouse (Pseudomys novaehollandiae) in Victoria

Many Australian rodent species have become extinct or undergone substantial range contractions since European invasion. Limited and haphazard survey efforts across much of Australia mean we are unsure of many species’ current and former ranges, hampering our ability to identify and remedy causes of decline. The New Holland Mouse (NHM; Pseudomys novaehollandiae) is an endangered rodent species native to south-east Australia that is suspected of undergoing rapid and dramatic range contractions and local extinctions in recent decades. Here, I reassess the species’ distribution across Victoria using extensive survey efforts and, subsequently, provide a summation of potential key threatening processes. In only 40 years, the NHM has been lost from seven of the 12 isolated areas where it once occurred in Victoria. Habitat loss and fragmentation, invasive predators, and potentially disease and genetic inbreeding have likely contributed to the species’ rapid and continuing decline. Conservation priorities include ongoing monitoring and research, cat and fox control, exclusion of rabbit poison-baiting, targeted fire and habitat management, and reintroduction to historically occupied regions where threatening processes have been mitigated.

Demography and spatial requirements of the endangered northern quoll on Groote Eylandt

ContextAustralia has experienced the highest number of mammal extinctions of any continent over the past two centuries. Understanding the demography and spatial requirements of populations before declines occur is fundamental to confirm species trajectory, elucidate causes of decline and develop effective management strategies. AimsWe evaluated the demography and spatial requirements of a northern quoll, Dasyurus hallucatus, population on Groote Eylandt, Northern Territory. Groote Eylandt is considered a refuge for the species because key threatening processes are absent or limited; cane toads and introduced ungulates are absent, feral cats are infrequently detected and the fire regime is benign compared with mainland Northern Territory. MethodsWe conducted a 4-year capture–mark–recapture study to monitor growth, reproduction and survival of northern quolls within a 128-ha area, and we evaluated spatial requirements by attaching GPS units to both sexes. To assess the status of the Groote Eylandt population, we compared the demographics with existing data from mainland populations. Key resultsThe average density of northern quolls was 0.33ha−1. However, there was a 58% decline in female density, primarily between 2012 and 2013, corresponding with a decrease in female body mass. Females survived and bred in up to 3 years and adult survival rates did not vary among years, suggesting that juvenile recruitment drives population fluctuations. Male quolls were semelparous, with die-off occurring in the months following breeding. The median female and male home ranges were 15.7ha and 128.6ha respectively, and male ranges increased significantly during breeding, with 1616ha being the largest recorded. ConclusionsThe northern quoll population on Groote Eylandt had a higher density, female survival and reproductive success than has been previously recorded on the mainland. However, a marked decline was recorded corresponding with a decrease in female mass, indicating below-average rainfall as the likely cause. ImplicationsGroote Eylandt remains a refuge for the endangered northern quoll. However, even in the absence of key threatening processes, the population has declined markedly, highlighting the impact of environmental fluctuations. Maintaining the ecological integrity of Groote Eylandt is imperative for population recovery, and managing threats on the mainland over appropriate spatial scales is necessary to increase population resilience.

Risk Control Through Evaluation of Catastrophic Scenarios

In sectors where pipelines cross areas exposed to severe hazards or where the consequences are serious, traditional analyses based on the Risk Analysis Matrix (RAM) do not reflect the effect of the works and actions taken for risk control. That condition induces the idea of ineffectiveness or uselessness of the works and actions taken for protection and reinforcement. In this paper, for those situations it is proposed the analysis of hypothetical scenarios to determine which of them can become catastrophic, in order to assess which situations can trigger a catastrophe, and in consequence to take actions regarding them and thus to avoid the catastrophic situation. The suggested method consists in proposing scenarios of damages, corresponding an event of loss of product containment of a hydrocarbon transport system. In those scenarios, the following consequences of the oil spill are determined: the behaviour of the product, its route, the site of rupture, the possible threats that affect it, and the triggers of the threatening processes. Critical or catastrophic scenarios are selected and the chain of events regarding them is determined as detailed as possible. When analysing that chain, it is possible to find actions that may modify it, such as the control of the route so that it does not reach the sensitive elements, the strengthening of the pipeline to bear the hazards, the reinforcement of the ground to prevent the action of the hazards and to avoid that the hazard takes place. It must be determined how to protect the exposed elements and how to handle the spilled product to avoid the affectation of the elements mentioned above. For this point, it is important to know the infrastructure of the Contingency Plan and therefore to evaluate the possibility of strengthening it.

Urokinase-Type Plasminogen Activator System in Norm and in Life-Threatening Processes (Review)

The multifunctional urokinase-type plasminogen activator system (uPA-system) includes serine proteinase — uPA or urokinase, its receptor (uPAR) and two inhibitors (PAI-1 and PAI-2). The review discusses the structural features and involvement of the system components in the development of life-threatening processes including carcinogenesis, inflammation, neurogenesis and fibrinolysis, in regulation of which the destruction of extracellular matrix (ECM), cell mobility and signaling inside and outside the cell play a decisive role. uPA triggers the processes by activating the plasminogen and its convertion into plasmin involved in the activation of matrix metalloproteinases (MMPs) in addition to the regulation of fibrinolysis. MMPs can hydrolyze all the major ECM components and therefore play a key role in invasion, metastasis, and cell mobility. MMPs activates a cassette of biologically active regulatory molecules and release them from ECM. uPAR, PAI-1 and PAI-2 are responsible for regulation of the uPA activity. In addition, being a signaling receptor, uPAR along with MMPs lead to the stimulation of a number of signaling pathways that are associated with the regulation of proliferation, apoptosis, adhesion, growth and migration of cells contributing to tumor progression, inflammation, chemotaxis, and angiogenesis. Effective participation of the uPA system components in ECM destruction and regulation of intracellular and extracellular signaling pathways demonstrates that the system significantly contributes to the regulation of various physiological and pathological processes.