The next frontier: assessing the feasibility of eradicating mammalian pests from Auckland Island. (Special Issue: Restoration of New Zealand subantarctic islands.)

Auckland Island, the fifth largest island in New Zealand, is the only island in New Zealand's subantarctic region where introduced mammalian pests remain (pigs, Sus scrofa;mice, Mus musculus;cats, Felis catus). The island has unique biodiversity and is a key site for progressing New Zealand's goal to be free of several introduced predators by 2050. Recent island eradication successes have rekindled interest in eradicating pests from Auckland Island, and for the first time considering all three pests in one project. Over a 3-year period, we tested the feasibility of eradicating pigs, mice and cats by looking at what it would take to succeed, rather than what we could practically deliver with the tools we currently have. We proposed adaptations to current methods and used an evidence-based approach by undertaking large-scale field trials to test uncertainties and emerging technologies in-situ. We gathered data and evaluated proposed methods against five established principles of eradication while considering the logistics and infrastructure requirements of the project. Eradicating pigs, mice and cats from Auckland Island is worthwhile and feasible but dependent on further development of emerging technologies and capabilities for efficient delivery with an acceptable level of risk. Three eradication operations are required with specific sequencing and timing, supported by initial establishment of infrastructure. The project needs a large investment spread over 8 to 10 years to yield permanent and internationally important benefits with low ongoing cost to sustain. The feasibility study exposed the project's scale and was used to inform decision makers, who postponed the work in 2020 in response to the economic impacts of COVID-19. The study focusses future preparations on identified planning issues and dependencies to progress project readiness in anticipation of it being launched when economic conditions allow.

A global perspective on the influence of the COVID-19 pandemic on freshwater fish biodiversity. (Special Issue: Conservation and ecological impacts of the COVID-19 pandemic.)

The COVID-19 global pandemic and resulting effects on the economy and society (e.g., sheltering-in-place, alterations in transportation, changes in consumer behaviour, loss of employment) have yielded some benefits and risks to biodiversity. Here, we considered the ways the COVID-19 pandemic has influenced (or may influence) freshwater fish biodiversity (e.g., richness, abundance). In many cases, we could only consider potential impacts using documented examples (often from the media) of likely changes, because anecdotal observations are still emerging and data-driven studies are yet to be completed or even undertaken. We evaluated the potential for the pandemic to either mitigate or amplify widely acknowledged, pre-existing threats to freshwater fish biodiversity (i.e., invasive species, pollution, fragmentation, flow alteration, habitat loss and alteration, climate change, exploitation). Indeed, we identified examples spanning the extremes of positive and negative outcomes for almost all known threats. We also considered the pandemic's impact on freshwater fisheries demand, assessment, research, compliance monitoring, and management interventions (e.g., restoration), with disruptions being experienced in all domains. Importantly, we provide a forward-looking synthesis that considers the potential mechanisms and pathways by which the consequences of the pandemic may positively and negatively impact freshwater fishes over the longer term. We conclude with a candid assessment of the current management and policy responses and the extent to which they ensure freshwater fish populations and biodiversity are conserved for human and aquatic ecosystem benefits in perpetuity.

Restricted human activities shift the foraging strategies of feral pigeons (Columba livia) and three other commensal bird species. (Special Issue: Conservation and ecological impacts of the COVID-19 pandemic.)

Invasive species are a growing concern with increasing global connectivity. Feral pigeons (Columba livia) are widespread and invasive, thus their effective control is of keen international interest. The COVID-19 pandemic has offered an unprecedented opportunity to investigate the impact of a nation-wide Circuit Breaker (restricted human activities) in Singapore on first, the abundance of the feral pigeons and three urban commensals-the Javan myna (Acridotheres javanicus), common myna (A. tristis), and house crow (Corvus splendens) in different food source types;and second, the activity budgets of feral pigeons. A significant and progressive decline in feral pigeon abundance was observed in open food centres and feeding hotspots after the Circuit Breaker was implemented. While the house crow and common myna were less affected, the Javan myna abundance increased moderately at refuse collection centres during the Circuit Breaker and decreased significantly in green spaces after the Circuit Breaker. Changes in food abundance could also predict changes in feral pigeon abundance and its effect was greatest in feeding hotspots. A greater proportion of feral pigeons was observed foraging and moving with a smaller proportion seen resting with probable consequences on their reproductive capacity. Our study also cautions against drawing inferences on biological responses due to similar social restrictions without careful consideration of other ecological factors, like average flock size and time of the day, which also affected the proportion of pigeons foraging on natural versus anthropogenic food. In summary, our results advocate a food limitation approach to control the feral pigeon populations.

Lockdown policy effects on invasive species: a perspective. (Special Issue: Invasive alien species and biodiversity: impacts and management.)

Changes in human activities caused by the COVID-19 pandemic can have multiple effects on biodiversity but there is limited knowledge of how this can impact invasive alien species (IAS). Societal measures against the spread of COVID-19 can have both short-term and long-term consequences on IAS. In the short-term, reduced human disturbance on natural habitats can increase the activity of IAS and accelerate their spread. Furthermore, management agencies have reduced control activities, sometimes allowing IAS to thrive, and ongoing monitoring programs have been interrupted, hindering rapid identification and management of biological invasions. Long-term impacts could include global modifications to wildlife trade and increased releases of captive-bred species because of the fear of zoonotic diseases and also greater public awareness of the risks of pathogens being spread among animal populations. Long-term collection and sharing of data are crucial to modulate IAS management during and after the lockdowns.