ABSTRACTAimMountainous regions are rich in reptile biodiversity but face threats from climate and land use changes. Understanding how these factors affect reptile diversity in these regions can highlight key conservation hotspots that require effective conservation actions. Here, we explored reptile taxonomic and functional diversity patterns along the Sierra Madre del Sur region in southeast Mexico, and potential changes in future years caused by different climate and land use change scenarios.LocationSierra Madre del Sur, México.TaxonReptiles.MethodsWe used species distribution models and information on species traits to estimate taxonomic and functional diversity throughout the Sierra Madre del Sur (SMS) region under current and future climate and land use change scenarios.ResultsGreater taxonomic and functional diversity was observed in both temperate and tropical forests. Taxonomic diversity was higher in more drier areas at high elevations while higher functional diversity was observed in wetter areas at intermediate‐to‐high elevations. Lower diversity for both dimensions was associated with anthropic land uses. In future scenarios, both dimensions of diversity are expected to increase in temperate forest in highlands of central Oaxaca and decrease in the southcentral portion of the SMS, particularly for the worst scenarios due to increased deforestation rates.Main ConclusionsHigher taxonomic diversity in more drier areas at high elevations could be due to historical and evolutionary factors, while higher functional diversity in wetter areas at intermediate‐to‐high elevations may be explained by a higher environmental heterogeneity in forests within these conditions. Larger diversity losses in the southcentral portion of the SMS are probably due to larger predicted deforestation rates in those areas. Our results are valuable not just for informing conservation actions, such as the creation of protected natural areas but also to understand the underlying processes behind the patterns of reptile diversity.

ABSTRACTAimThe Amazon rainforest is one of the most biodiverse regions on earth, but our understanding of the processes that have shaped its patterns of diversity remains incomplete. One hypothesis for Amazonian speciation is the river‐refuge hypothesis, which suggests that retraction of forests away from the periphery of Amazonia, where rivers are narrow, facilitated divergence of populations separated by wide rivers. Later re‐expansion of forests would have allowed secondary contact between these populations, and co‐occurring hybrid zones may reveal the location where expanding forests first reconnected. Here, we test whether a widespread Amazonian songbird species shows evidence of population contact zones in the eastern headwaters of the Tapajós river, hypothesised to be an area of secondary contact under the river‐refuge hypothesis.LocationAmazon and Atlantic forests of South America.TaxonCeratopipra rubrocapilla (Pipridae, Passeriformes).MethodsWe sampled 147 C. rubrocapilla (Red‐headed Manakin) across its vast range, with 70 samples sequenced using reduced‐representation genomic sequencing and 139 sequenced at the mitochondrial gene cytochrome b. We use population genetic and phylogenetic analyses to investigate patterns of gene flow and population structure across the range, with a particular focus on samples from the headwaters of the Tapajós River to evaluate the potential role of the river‐refuge hypothesis.ResultsWe observe shallow population structure and evidence for widespread gene flow across the range of C. rubrocapilla. Patterns in the Tapajós headwaters match predictions of the river‐refuge hypothesis, with eastern headwater samples most similar to samples farther west on the opposite bank of the Tapajós River.Main ConclusionsThe close co‐occurrence between population contact zones within C. rubrocapilla and other previously studied hybrid zones reinforces the hypothesis that the eastern Tapajós headwaters is where rainforest populations reconnected in the past, following predictions of the river‐refuge hypothesis of Amazonian speciation.

ABSTRACTAimChanging biodiversity and environmental conditions may allow multi‐host pathogens to spread among host species and affect prevalence. There are several widely acknowledged theories about mechanisms that may influence variation in pathogen prevalence, including the controversially debated dilution effect and abundance‐occupancy relationship hypotheses. Here, we explore such abundance‐occupancy relationships for unique lineages of three vector‐borne avian blood parasite genera (the avian malaria parasite Plasmodium and the related haemosporidian parasites Parahaemoproteus and Leucocytozoon) across biogeographical regions.LocationNearctic‐Neotropical and Palearctic‐Afrotropical regions.MethodsWe compiled a cross‐continental dataset of 17,116 bird individuals surveyed from 46 bird assemblages across the Nearctic‐Neotropical and Palearctic‐Afrotropical regions and explored relationships between local parasite lineage prevalence and host assemblage metrics in a Bayesian random regression framework.ResultsMost lineages from these three genera infected ≥ 5 host species and exhibited clear phylogenetic or functional host specificity. Lineage prevalence from all three genera increased with host range, but also with higher degrees of specialisation to phylogenetically or functionally related host species. Local avian community features were also found to be important drivers of prevalence. For example, bird species richness was positively correlated with lineage prevalence for Plasmodium and Leucocytozoon, whereas higher relative abundances of the main host species were associated with lower prevalence for Plasmodium and Parahaemoproteus but higher prevalence for Leucocytozoon.ConclusionsOur results broadly support several of the leading hypotheses about mechanisms that influence pathogen prevalence, including the niche breadth hypothesis in that higher avian host species diversity and broader host range amplify prevalence through increasing ecological opportunities and the trade‐off hypotheses in that specialisation among subsets of available host species may increase prevalence. Furthermore, the three studied avian haemosporidian genera exhibited different abundance‐occupancy relationships across the major global climate gradients and in relation to host availability, emphasising that these relationships do not strictly follow common rules for vector‐borne parasites with different life histories.

ABSTRACTBackground and AimColour polymorphic populations constitute excellent model systems for testing ecological and evolutionary hypotheses, as alternate colourations are associated with differences in various biological, behavioural and life‐history traits. Melanism is the most common and most obvious form of polymorphism. In reptiles in general (and snakes in particular), thermal melanism has been a popular hypothesis used to explain the appearance of black individuals. It suggests that a trade‐off exists between superior thermoregulation and reduced protection through the loss of crypsis. Surprisingly, despite the growing body of literature available, to date, there are only two qualitative reviews on the evolutionary significance of melanism in reptiles and no quantitative synthesis. We conducted the first systematic review and meta‐analysis summarising the current knowledge on melanism in polymorphic terrestrial snakes and synthesised the evidence for an adaptive advantage of the melanistic morph.LocationNorthern Hemisphere.TaxonPolymorphic terrestrial snakes.ResultsMean prevalence of melanism is 31% with no significant differences between species. Annual precipitation was a significant moderator of melanism prevalence. Our results revealed no significant differences in odds ratios of melanism between sexes or in mean body size.Main ConclusionsEnvironmental plasticity can be considered the primary cause of melanism, possibly as a result of seasonal climatic variations, a result corroborated by the formal meta‐analysis conducted. Conclusions from the meta‐analysis are that melanism in snakes follows Gloger's rule, as is the case in birds and mammals, and as opposed to the thermal melanism hypothesis. Further, our findings do not lend support for other predictions from the thermal melanism hypothesis, such as skewed frequency of melanistics in favour of males or females, or larger body sizes in black individuals. Our results hold implications for the future diversity of animal populations, as climate change is predicted to decrease the degree of colour variation.

ABSTRACTAimWe aimed to enhance our understanding of the distribution of mesopelagic mesozooplankton (MM) using species distribution models, assess the performance of various modelling techniques, identify key environmental predictors for MM distribution and compute their habitat suitability indices.LocationOur study focused on the mesopelagic zone globally, with data analysed from different oceans.TaxonOur focus was primarily on mesopelagic mesozooplankton, gathering data on 861 different species from the Mesopelagic Mesozooplankton and Micronekton (MMM) Database.MethodsWe used an ensemble of species distribution models, applying 10 different modelling algorithms and three multi‐model ensemble approaches. We explored two important factors that can affect model performance: subsampling and the choice of background points. We also estimated the relative importance of various environmental conditions such as mixed layer depth, temperature, salinity, net primary productivity, euphotic zone depth and dissolved nitrate concentration on the distribution of these species.ResultsEuphotic zone depth, salinity and dissolved nitrate concentration were identified as the most important variables for explaining the distribution of mesopelagic mesozooplankton. The ensemble modelling results were robust in areas with abundant observational records, but high uncertainty was observed in data‐limited regions. We found a patchy habitat suitability map for zooplankton when modelled within their native range, largely due to uneven sampling. Unrestricted range models yielded smoother patterns but could inaccurately project species in areas where they do not occur.Main ConclusionsOur study highlights the need for increased sampling effort in data‐limited regions to improve the accuracy of mesopelagic species distribution models. Despite some inaccuracies, unrestricted range models, assuming ecological equivalence (where different species occupying a similar ecological niche in different geographical regions or different ecosystems exhibit similar adaptations and behaviours), provide a reasonable comparison for habitat suitability maps and model performance. It also confirms the significant impact of certain environmental conditions on mesozooplankton distribution.

ABSTRACTMainAnimals not only forage for abundant and nearby resources, but their diets can also be influenced by abiotic and geographic factors. This often results in non‐random interactions among species. We investigate how seed density, distance from nest, abiotic (e.g., climate stability, temperature, precipitation) and geographic factors (e.g., latitude, elevation and continental hemisphere) influence the removal of food items (i.e., seeds and dead arthropods) by Pogonomyrmex species.LocationSouth and North America, from Patagonia to the Rocky Mountains.TaxonGenus Pogonomyrmex (Formicidae: Hymenoptera).MethodsConducting standardised experiments, we performed a seed removal experiment and an assessment of the items retrieved by ant workers of 160 nests from eight Pogonomyrmex spp. at 16 sites extending the American continent.ResultsPogonomyrmex ants native to North America removed more seeds than their South American counterpart. In general, results align with optimal foraging theory, indicating a higher probability of seed removal near ant nests. High climate stability correlated with lower seed predation rates, emphasising seed consumption's significance in historically arid environments. Increased precipitation and temperature led to reduced removal of food resources, suggesting reduced water availability and lower mean temperatures increases the consumption of seeds by harvester ants.ConclusionsOverall, Pogonomyrmex ants' food resource use is influenced by a combination of factors such as region, distance from the nest and climate. This study underscores harvester ants' potential impact on plant distribution over large spatial scales consuming seeds from the immediate proximity of their nest and preventing establishment.

ABSTRACTAimPrevious local‐scale research (within plots or landscapes) has shown that invasive plants can alter the composition and diversity of soil microbial communities, with potential feedback effects on their own invasion success. However, the broader ecological patterns of these interactions across different invasion timescales and geographic regions remain poorly understood. This study investigated whether the composition and diversity of soil microbial communities associated with Solidago canadensis (Canada goldenrod) invasion vary across both population residence times and geographic locations.LocationSouth‐eastern China.TaxonSoil fungal and bacterial communities and S. canadensis.MethodsWe collected rhizospheric soil of S. canadensis, nonrhizospheric soil and adjacent uninvaded soil from each of 36 populations of S. canadensis with varying residence times (8–89 years), totalling 108 samples. We extracted DNA from these samples and sequenced the V3–V4 region of the bacterial 16S rRNA gene and the ITS2 region of the fungal rDNA. We analysed the DNA sequences to assess whether variation in α‐diversity, β‐diversity, arbuscular mycorrhizal fungi (AMF) richness and the ratio of AMF to plant pathogens in the soil microbial communities varied with S. canadensis population residence time, latitude and longitude.ResultsThe α‐diversity and β‐diversity of soil fungal and bacterial communities significantly varied with S. canadensis residence times, latitude and longitude. In locations where S. canadensis had been established for longer periods, there was an increase in AMF richness and a decrease in plant pathogens in the rhizospheric soil. Fungal diversity in rhizospheric soils was positively correlated with longitude, while bacterial diversity in rhizospheric and nonrhizospheric soils was positively correlated with both latitude and longitude.Main ConclusionsThese findings indicate that the time since invasion and geographical location can both significantly influence the composition and diversity of soil microbial communities associated with invasive plant species.

ABSTRACTAimSubalpine larch is a long‐lived conifer with a restricted distribution at treeline in the mountains of western North America. Climate change is reducing the availability of this habitat and subalpine larch is unlikely to adapt to its changing environment due to its long generation time, relatively low levels of standing genetic variation and the high degree of habitat fragmentation across the species' range. This study seeks to elucidate the genetic structure of subalpine larch to inform future conservation and management efforts.LocationWestern North America.TaxonSubalpine larch (Larix lyallii Parl.).MethodsTissue was collected from high‐elevation populations across the entire species range. Restriction site associated DNA sequencing was used to generate single nucleotide polymorphism (SNP) data. Population genetic analyses identified genetic differentiation.ResultsClustering analyses performed using 751 neutral SNPs identified three genetically differentiated regions: the Cascade Range, the southern Rocky Mountains and the northern Rocky Mountains. AMOVA confirmed significant genetic differentiation among regions. A discriminant analysis of principal components and a dendrogram of Provesti's genetic distance both supported the hypothesis that genetically distinct lineages arose after dispersal from a single Pleistocene refugium. Significant isolation by distance (IBD) supported the key role of dispersal in shaping modern patterns of genetic variation in subalpine larch.Main ConclusionsPost‐Pleistocene dispersal resulted in genetic differentiation among groups of subalpine larch in the Cascade Range, the southern Rocky Mountains and the northern Rocky Mountains. These three regions should be prioritised for future management.