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Invasive alien species may cause substantial changes and damaging impacts in the ecosystems they invade. Here, we document the current distribution and ecological interactions with native biota of the relatively recently introduced wasp, Vespula vulgaris, in the southern part of the Cape Horn Biosphere Reserve. We conducted surveys and field studies in four different habitats on Navarino Island: evergreen, deciduous and mixed forests, and shrublands. The spread of V. vulgaris through the island since its first detection has led to it occupying suitable habitats for nesting and foraging, both in urban and rural settings. The presence of V. vulgaris on islands and remote areas of the CHBR is likely the result of marine human movement through the channels withing the reserve. Wasp foraging composition was different on each of the four studied habitats, yet strongly linked to each habitat’s resources, indicating the inherent ability of V. vulgaris of exploiting surrounding resources efficiently. The lack of natural competitors and availability of multiple resources as allowed V. vulgaris to rapidly become a common pest in urban and rural settings in the southern extreme of South America. In this context, we believe that eradication would be impossible, although it would be possible to control populations at localized scales with proper planning and long-term management. Our results can act as a base for management planning, and we strongly recommend social engagement and dialog with pertinent governmental institutions to achieve this challenging task.

The Cape Horn Biosphere Reserve, one of the last wild areas of the planet, is not exempt from the pressures of global change, such as non-native species introductions. During 2018 and 2019 we studied the Robalo river basin in order to update the diversity and distribution of fishes. Here, we report for the first time the native and endangered "Peladillas" Aplochiton taeniatus and the non-native coho salmon Oncorhynchus kisutch. The coexistence of native and non-native fishes poses a challenge for the management and conservation of aquatic biota from the Cape Horn Biosphere Reserve.

Background The study of altitudinal gradients provides insights about species diversity, distribution patterns and related drivers. The Magellanic sub-Antarctic ecoregion has a steep elevational gradient, peaking at around 1,000 m a.s.l., and marked changes in temperature and landscape composition can be observed over relatively short distances. Methods This study assessed freshwater macroinvertebrate diversity associated with lakes and ponds along the altitudinal gradient of a Magellanic sub-Antarctic watershed. Results A monotonic decline in species richness was observed with increasing elevation, with simpler and more even community composition at higher altitude. This pattern differs from the mid-peak trend found in streams of the same watershed. Functional feeding group structure also diminished with increasing elevation. Discussion The study provides a descriptive baseline of macroinvertebrate community structure associated with lentic freshwater ecosystems in the Magellanic sub-Antarctic ecoregion, and confirms that elevation has substantial effects on community structure, function and environmental features, even in these relatively low elevation mountain ranges. The harsh environmental conditions of this ecoregion increase freshwater macroinvertebrate development time, as well as decreasing habitat availability and food supply, supporting simple but well adapted communities. In conjunction with previous research, this study provides a watershed-scale platform of information underpinning future long-term research in the region.