AimBiological invasions are a substantial threat to Antarctic biodiversity and a priority conservation policy focus for Antarctic Treaty Parties and the sovereign states of surrounding islands. Key to their strategies is prevention, including assessment of establishment risk for alien species. Despite establishment of some of the worst globally invasive species across the Antarctic region, assessments of establishment potential of these species are non‐existent. Here, we address this deficit and determine whether these invasive species constitute a significant conservation threat to the broader Antarctic region both now and in response to future regional climate change.LocationAntarctica and the Southern Ocean islands (45°–90° S).MethodsWe used ensemble species distribution models to assess the current and future climate suitability of the Antarctic region for 69 of the worst globally invasive species and 24 insect and plant species that have already established somewhere in the region.ResultsThe Antarctic continent is unsuitable for all of the worst globally invasive species under current conditions, but areas of the Antarctic Peninsula are predicted to become climatically suitable for up to six globally invasive species within the next century. By contrast, all Southern Ocean islands are presently climatically suitable for additional non‐native species, with the threat increasing in the future.Main conclusionsOur findings demonstrate that climate, which is often cited as a key barrier to alien species establishment, may afford some protection to continental Antarctica, but that this protection is not currently extended to the Southern Ocean islands. Furthermore, existing climatic barriers to alien species establishment will weaken as warming continues across the region. This not only illustrates the value of applying distribution modelling methods to this largely ice‐covered region, but demonstrates how these methods can be used to inform targeted surveillance of introduction pathways and sites that have the highest risk of establishment of invasive alien species.

SignificanceHow climate change and biological invasions interact to affect biodiversity is of major concern to conservation. Quantitative evidence for the nature of climate change–invasion interactions is, however, limited. For the soil ecosystem fauna, such evidence is nonexistent. Yet across the globe, soil-dwelling animals regulate belowground functioning and have pronounced influences on aboveground dynamics. Using springtails as an exemplar taxon, widely known to have species-specific effects on below- and aboveground dynamics, we show that across a wide latitudinal span (16–54°S), alien species have greater ability to tolerate climate change-associated warming than do their indigenous counterparts. The consequences of such consistent differences are profound given globally significant invasions of soil systems by springtails.

Summary1. More than 50% of the global human population lives in urban settings, which, for urban agglomerations with >1 million inhabitants, span a 30°C range in mean annual temperature and 4000 mm annual precipitation range. 2. Although the biodiversity impacts of urbanization are most commonly investigated at the assemblage level, these impacts are mediated through organismal physiology and behaviour. 3. At the individual level, mechanistic models, which provide an explicit means to understand how organisms meet the requirements of heat, water and nutrient balance, offer a useful way to assess physiological and behavioural responses to urban environments and their consequences for population dynamics. 4. Physiological determinants of assemblage variation can usefully be investigated by examining entry, exit and transformation rules. These are biases in the processes that determine which individuals join or leave a population or assemblage, and processes that act on individuals, which remain part thereof. 5. Direct evidence for physiological adaptation (broadly construed as phenotypic plasticity, genotypic change or some interaction between them) to urban environments is remarkably limited, owing largely to low numbers of investigations, given that most studies that have been conducted reveal some form of adaptation. 6. A warming tolerance approach, applied to insects globally, demonstrates that transposing sampled populations to the nearest urban area reduces warming tolerance by several degrees, though this effect is on average more marked for the Southern than the Northern Hemisphere. The lowest warming tolerance is found between 30 and 35°N or S, suggesting that in the absence of mitigation, the urban heat island effect of cities here will have the most pronounced impacts on insect populations. 7. Physiological approaches offer a useful means for understanding the urban-rural gradient across a wide range of climatically variable settings during a period of background environmental change.

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To forage efficiently in a patchy environment animals must make informed decisions concerning in 36 which patches to forage, for which the behaviour of other animals often provides informative cues. 37However, other individuals may differ in the quality or relevance of information that they provide, 38 and accordingly animals are expected to be selective with respect to whom they copy. Such 39 selectivity may include the biasing of copying towards older, larger or more experienced 40conspecifics. This study investigated whether the ability of nine-spined sticklebacks (Pungitius 41 pungitius) to exploit public information, that is, to judge the relative profitability of food patches 42 solely on the basis of the relative feeding activity of others, is influenced by their own body size and 43 that of the individuals from whom they copy. Individual observer fish, classed as either small or 44 large, were trained that two discrete foraging patches differed in their relative quality, one being 45 rich and the other poor ('personal information'). They then watched two shoals of either small or 46 large demonstrator conspecifics feeding at the two patches ('public information'), but with relative 47 profitability of the patches reversed compared to training, before being given the opportunity to 48 make a patch choice. Our results show that the effectiveness of this public demonstration is clearly 49 contingent on the size of the demonstrators, with subjects of both size classes copying the patch 50 choice of large demonstrators significantly more than they copied the patch choice of small 51 demonstrators. This study reinforces the view that animal social learning is directed along particular 52 pathways, with individuals predisposed by selection to copy particular categories of individual 53 Efficient foraging in a patchy environment requires animals to make informed decisions concerning 71 in which patches to forage and how long to spend at each patch. Relevant information capable of 72 guiding such decision making can be obtained either directly, via sampling, or indirectly, by 73 attending to social cues produced intentionally or inadvertently by other individuals (Giraldeau 74 1997; Kendal et al. 2005). Social learning, learning through observing others, reduces the costs 75 associated with learning asocially, and potentially allows for faster location and resource estimation 76 of patches, but can be costly if inappropriate or outdated information is acquired (Boyd & 77 Richerson 1985; Valone 2007). 78The use of social learning may, however, be more complex than originally envisaged. Both 79 evolutionary game theory and population genetic models lead to the prediction that animals ought 80 to be highly selective with respect to the circumstances under which they rely on social learning and 81 the individuals from whom they learn (Boyd & Richerson 1985; Giraldeau et al. 2002). Animals 82 should exhibit specific adaptive 'social learning strategies' that enhance the efficiency of asocial 83 learning by selec...

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Simultaneously investigating variation in species richness and turnover for indigenous and introduced communities holds great promise as a means to understand the relative contributions of ecological processes to community structure. Such insight will advance understanding of the ways in which environmental change may affect future community dynamics. Using a recently developed multi‐site turnover metric, zeta diversity (ζ), we explored species turnover patterns across indigenous and introduced insect and vascular plant communities of the Southern Ocean Islands. In addition, we used updated species occurrence and high‐resolution environmental data to reexamine previously described patterns and drivers of species richness across the region. Species richness variation in indigenous insect and vascular plant communities was largely explained by island isolation and temperature, whereas human visitation frequency was strongly associated with introduced species diversity of both groups. Indigenous communities of both plants and insects had faster rates of species turnover across sites and less inter‐island connectivity than their introduced counterparts. Zeta diversity analyses suggested that stochastic processes were more influential than niche‐related processes on the observed patterns of turnover of indigenous insects. Meanwhile, turnover patterns of introduced insects and indigenous and introduced vascular plants were indicative of the dominance of niche‐related processes. These outcomes highlight very different diversity patterns across indigenous and alien communities and indicate that different ecological processes may underlie diversity variation across these islands and taxonomic groups.

Southern Ocean Islands are globally significant conservation areas. Predicting how their terrestrial ecosystems will respond to current and forecast climate change is essential for their management and requires high-quality temperature data at fine spatial resolutions. Existing datasets are inadequate for this purpose. Remote-sensed land surface temperature (LST) observations, such as those collected by satellite-mounted spectroradiometers, can provide high-resolution, spatially-continuous data for isolated locations. These methods require a clear sightline to measure surface conditions, however, which can leave large data-gaps in temperature time series. Using a spatio-temporal gap-filling method applied to high-resolution (~1 km) LST observations for 20 Southern Ocean Islands, we compiled a complete monthly temperature dataset for a 15-year period (2001–2015). We validated results using in situ measurements of microclimate temperature. Gap-filled temperature observations described the thermal heterogeneity of the region better than existing climatology datasets, particularly for islands with steep elevational gradients and strong prevailing winds. This dataset will be especially useful for terrestrial ecologists, conservation biologists, and for developing island-specific management and mitigation strategies for environmental change.