Aim: In ectotherms, the colour of an individual's cuticle may have important thermoregulatory and protective consequences. In cool environments, ectotherms should be darker, to maximize heat gain, and larger, to minimize heat loss. Dark colours should also predominate under high UV‐B conditions because melanin offers protection. We test these predictions in ants (Hymenoptera: Formicidae) across space and through time based on a new, spatially and temporally explicit, global‐scale combination of assemblage‐level and environmental data.Location: Africa, Australia and South America.Methods: We sampled ant assemblages (n = 274) along 14 elevational transects on three continents. Individual assemblages ranged from 250 to 3000 m a.s.l. (minimum to maximum range in summer temperature of 0.5–35 °C). We used mixed‐effects models to explain variation in assemblage cuticle lightness. Explanatory variables were average assemblage body size, temperature and UV‐B irradiation. Annual temporal changes in lightness were examined for a subset of the data.Results: Assemblages with large average body sizes were darker in colour than those with small body sizes. Assemblages became lighter in colour with increasing temperature, but darkened again at the highest temperatures when there were high levels of UV‐B. Through time, temperature and body size explained variation in lightness. Both the spatial and temporal models explainedc. 50% of the variation in lightness.Main conclusions: Our results are consistent with the thermal melanism hypothesis, and demonstrate the importance of considering body size and UV‐B radiation exposure in explaining the colour of insect cuticle. Crucially, this finding is at the assemblage level. Consequently, the relative abundances and identities of ant species that are present in an assemblage can change in accordance with environmental conditions over elevation, latitude and relatively short time spans. These findings suggest that there are important constraints on how ectotherm assemblages may be able to respond to rapidly changing environmental conditions.

A checklist of 2265 spider species and subspecies, 495 genera and 71 families is provided. Data were extracted from the South African National Survey of Arachnida database and over 200 taxonomic revisions, ending December 2022. Global distributions, endemicity and conservation assessment using IUCN Criteria are provided for each species. A total of 1325 spp. are endemic to South Africa (58.5%), 126 spp. (5.6%) are of special concern and 693 spp. (30.6%) are Data Deficient (DD), while 15 species were described without exact locality data. Most species (1444 spp., 63.8%) are widely distributed with no known threats and are of Least Concern. A total of 1316 spp. (57.6%) are known from both sexes and 23 spp. (1.0%) were described from juveniles. Salticidae is the most species-rich family (354 spp.), followed by Gnaphosidae (195 spp.), Thomisidae (143 spp.) and Araneidae (100 spp.) and ten families are represented by a single species.

Roads now penetrate even the most remote parts of much of the world, but the majority of research on the effects of roads on biota has been in less remote temperate environments. The impacts of roads in semi-arid and arid areas may differ from these results in a number of ways. Here, we review the research on the impacts of roads on biodiversity patterns and ecological and evolutionary processes in semi-arid regions. The most obvious effect of roads is mortality or injury through collision. A diversity of scavengers are killed whilst feeding on roadkill, a source of easily accessed food. Noise pollution from roads and traffic interferes with vocal communication by animals, and birds and frogs living along noisy roads compensate for traffic noise by increasing the amplitude or pitch of their calls. Artificial light along roads impacts certain species’ ability to navigate, as well as attracting invertebrates. Animals are in turn attracted to invertebrates at streetlights, and vulnerable to becoming roadkill themselves. Genetics research across taxa confirms a loss of genetic diversity in small populations isolated by roads, but the long-term impact on the fitness of affected populations through a reduction in genetic diversity is not yet clear. Roads may rapidly cause genetic effects, raising conservation concerns about rare and threatened species. We assess mitigation measures and collate methods to identify the impact of roads on wildlife populations and their associated ecosystems, with a particular focus on recent advances.

Coarse-scale studies that focus on species distributions and richness neglect heterogeneity that may be present at finer scales. Studies of arthropod assemblage structure at fine (1 × 1 km) scales are rare, but important, because these are the spatial levels at which real world applications are viable. Here we investigate fine-scale variation in spider assemblages, comparing five representative vegetation types in the western Soutpansberg, Limpopo Province, South Africa. We assess these vegetation types in terms of their family and species composition, as well as levels of endemicity, relating these differences with vegetation structure. We inventoried 297 species (49 families) in an area less than 450 ha, as part of South African National Survey of Arachnida. Analysis of the results suggests that endemic taxa are associated with Tall Forest and, to a lesser extent, Woodland. The Woodland had the highest species diversity, and much of the variation observed in spider assemblage structure is explained by these two vegetation types. Based on vegetation structure variables that explained significant variation in spider assemblages, human influence through bush encroachment will result in a change of spider assemblages to that of Short Forest and Mosaic Woodland vegetation types, with implications for biodiversity maintenance and heterogeneity.

Triage in conservation biology necessitates the prioritization of species and ecosystems for conservation. Although highly diverse, ecologically important, and charismatic, spiders are rarely considered. With 2,253 known species, South Africa's spider diversity is among the highest in the world. A 22-year initiative culminating in a national assessment of all the South African species saw a 33% increase in described species and a 350% rise in specimen accessions of the national collection annually. Endemism is high, at 60% of all South African species. Levels of endemicity are particularly high in Fynbos, Succulent Karroo and Forests. Relative to its area, Forests have three times more endemics than any of the other biomes, followed by the Indian Ocean Coastal Belt. A total of 127 species (5.7%) are either rare or endangered. Threats to these species are largely linked to habitat destruction in the form of urbanization and agriculture. The bulk (62.8%) of taxa are of least concern, but many species are data deficient (27%). Predicted large-scale diversity patterns are confounded by the localised nature of distribution records. Best estimates of compositional turnover point to an east-west bias in our understanding and conservation of spiders in the country, a bias that is most acute in the north-western parts of the country because this region has seen less collecting and has fewer conservation estates. In general, rare and threatened species are mainly ground-dwelling taxa that are either relictual or have poor dispersal abilities. Complemented with long-term surveys that will provide insights into population dynamics of spiders, exploring the use of species traits in predicting extinction probability could provide additional criteria for conservation prioritization. Based on these assessments, targeted species-level interventions might provide a platform for more public awareness and institutional involvement.