Forest composition and structural diversity play a key role in shaping habitat availability and biodiversity, particularly influencing the occurrence of saproxylic species associated with tree-related microhabitats (TreMs). TreMs and deadwood are essential features of forest ecosystems, offering critical habitats for saproxylic arthropods that contribute to decomposition, nutrient cycling, and overall forest resilience. Understanding the complex interactions between forest structures, TreMs, and arthropod communities is crucial for biodiversity conservation and sustainable forest management. This study explores how forest composition, deadwood, and TreMs together influence arthropod diversity and community composition in temperate forests, using a large-scale eDNA metabarcoding approach. We assessed arthropod communities across 135 forest plots in the Black Forest, Germany with varying degrees of retention. Our findings reveal that specific TreMs, such as cavities, mosses, and insect galleries, significantly contribute to arthropod richness, particularly for Collembola, Coleoptera, and Arachnida. Canopy closure, deadwood volume, and snag availability emerged as key determinants of community composition, while low degrees of retention negatively impacted terrestrial arthropods biodiversity by reducing habitat complexity. These findings reveal that species richness and community composition are driven by different ecological factors, highlighting the complexity of forest ecosystems. They underscore the need for forest management strategies that preserve deadwood and TreMs, enhance structural heterogeneity, and consider broader indicators of forest naturalness to effectively support arthropod biodiversity.

Caragana, a dominant leguminous plant in the barren semi-fixed deserts of northern China, forms critical symbiotic nitrogen-fixing associations with Mesorhizobium, which are vital for ecosystem functioning globally. However, the genetic adaptation of Caragana-associated Mesorhizobium symbionts driven by membrane transporters and nucleotide repair genes remained poorly illustrated. Recognizing the pivotal roles of membrane transporters (cysW, exoY, idhA) and nucleotide repair genes (mutS, uvrC) in microbial environmental resilience, this study investigated the adaptive dynamics of 68 representative Mesorhizobium strains isolated from Caragana across five geographically distant areas (A–E) in this desert belt. Phylogenetic analyses based on the five target genes revealed that strains clustered primarily by genospecies rather than geographic origin, with high topological congruence between membrane transporter, nucleotide repair and core gene trees. Genetic differentiation and frequent interspecific gene flow were predominantly driven by recombination (over mutation), indicative of active horizontal gene transfer (HGT) as a key evolutionary force. Notably, despite geographic separation, strains from the same genospecies exhibited extensive sequence homology in both gene sets, suggesting shared adaptive traits disseminated through HGT. Collectively, our results demonstrated that Caragana-associated Mesorhizobium have evolved primarily through adaptive processes shaped by homogeneous harsh desert environments, rather than geographic isolation. The membrane transporters likely facilitated rapid acquisition of nutrient uptake and stress-tolerance traits via recombination, while nucleotide repair genes maintained genomic integrity under extreme conditions. This dual genetic strategy underscores how HGT and purifying selection synergistically drive ecological adaptation in desert microbiomes.

As the wild progenitor population of cultivated apricots, Xinjiang wild apricots hold irreplaceable significance in maintaining ecosystem functions and conserving germplasm resources. This study employed a combined approach utilising chloroplast DNA fragments (rpl32-trnL and ndhC-trnV) and a single-copy nuclear gene (DXH) to conduct a systematic phylogeographic analysis of wild apricot resources within the Ili wild fruit forests of Xinjiang. Results indicate significant divergence between genetic structures revealed by chloroplast DNA and nuclear genes, reflecting complex evolutionary processes driven by natural selection, genetic drift, and gene flow across distinct genetic systems. Genetic variation predominantly resided within populations, with weak differentiation between them. Neutrality tests and mismatch analysis indicated that wild apricot maternal lineages had not undergone significant historical expansions, suggesting a possible shared population contraction (bottleneck effect). Conversely, nuclear gene data supported recent expansion, with the Yining County population exhibiting the most pronounced expansion signal, indicating effective recording of this event by the nuclear genome. Niche modelling using the MaxEnt approach indicates that key environmental factors influencing wild apricot distribution include precipitation during the wettest season (100~135 mm), precipitation during the warmest season (90~120 mm), and soil sand content (6%~38%). The current suitable habitat is primarily concentrated in the Ili Kazakh Autonomous Prefecture, while projections under future climate scenarios indicate an expansion trend in its suitable range. This study systematically elucidates the genetic diversity characteristics and phylogeographic patterns of Xinjiang wild apricot, clarifying its population history dynamics and future distribution potential. It provides theoretical foundations and practical guidance for the scientific conservation and sustainable utilisation of germplasm resources for this species.

Semi-arid mallee landscapes are shaped by wildfires. Due to climate change, wildfires are expected to become more frequent and intense, making their management a conservation priority. Ants are often used as bioindicators in land management studies, as their composition and diversity respond to disturbances, including wildfires, both directly and indirectly through habitat modification. In the semi-arid zone of western New South Wales, Australia, we examined how time-since-fire influences ant species richness, abundance, and community composition, and assessed whether fire-induced changes in vegetation composition explain the observed patterns in ant community structure. We sampled ants at five sites that last burned 3, 5, 9, 26, and 34 years ago, respectively. We identified 59 ant species from 20 genera in a total of 16,360 sampled ants. We found that post-fire ant communities exhibited higher abundance immediately after fire, while species richness increased with time-since-fire. Early successional stages with greater shrub density favoured dominant and opportunistic ant species, whereas later stages with increased tree and grass cover supported more diverse ant communities. These results demonstrate that fire drives successional specialization in ant communities through niche filtering. Maintaining heterogeneous fire-age vegetation mosaics is therefore critical for conserving landscape-level biodiversity in fire-regulated mallee ecosystems.

Hunting and wildlife trade in Lao PDR (also known as Laos) has left species of larger wild fauna existing at low densities, almost exclusively in remote areas of rugged forest, and wary of human presence. This makes surveying of larger fauna in the country difficult as observation of individuals is remarkably rare. Due to the critical nature of faunal conservation in Lao PDR (many globally threatened species facing the immediate risk of extirpation) the difficulty of conducting faunal surveys does not supersede the need to do so. Occupancy estimation and modeling, using repeated sampling of presence/non-detection of a site, offers a potential solution to this challenge. We conducted presence/non-detection sampling of 80 sites spread across the potentially suitable habitat for the Critically Endangered northern white-cheeked gibbon in Nam Et-Phou Louey National Park in the northeast of Lao PDR. We used maximum likelihood models to test the significance of several natural and anthropogenic covariates on the population’s detection and occupancy probability to assess the drivers of the population’s distribution. Detection was found to be a function of cloud cover, the proportion of bamboo forest, and topographic roughness of the site. Occupancy was found to be a function of human usage of the site, distance from the nearest road, and the uninterruptedness of forest cover. These results suggest that the viability of this species in Nam Et-Phou Louey National Park relies on preventing the expansion of all forms of roads into the park, maintaining continuous forest cover, and mitigating human presence in the habitat.

Cetaceans are negatively affected by anthropogenic activities, including acoustic and physical disturbance from boat traffic. Behavioural responses to such disturbances are context-dependent, and site-specific insights are needed for effective local management plans. In this study, the impact of speed and proximity of recreational boats on the swimming speed and surfacing interval of one of the most common coastal cetacean species, the harbour porpoise (Phocoena phocoena), is investigated using data collected by unmanned aerial vehicles (UAVs) within a key habitat for the vulnerable Belt Sea population. In August 2024, two UAVs were flown simultaneously on predefined routes within the area. One UAV searched for and followed detected porpoises, while the other monitored recreational boats. All data was captured as UAV video and used to determine surfacing intervals of individual porpoises, measure speed of porpoises and boats, and calculate the closest distance between porpoises and boats for each simultaneous sighting. A total of 91 synchronous flights were conducted, resulting in 28 porpoise observational events. GLM analyses showed that an interaction between mean boat speed and distance to the boat influenced the mean speed of the porpoises. At close range, a higher mean speed of the boat reduced the swimming speed of the porpoises, but over greater distances, it increased the mean swimming speed. Also, porpoise surfacing intervals decreased with decreasing distance to boats. No effect of maximum boat speed on porpoise behaviour was observed. This study demonstrates that recreational boats influence the behaviour of porpoises, with potential negative individual- and population-level effects.

Species boundaries are not always straightforward, especially during early stages of divergence, when gene flow may still take place. Nipponocypris koreanus, a widely distributed freshwater fish species endemic to Korea, was recently classified as a separate species from its relative Nipponocypris temminckii. However, morphological differences between the two species are ambiguous and genetic differences between and within species remain largely unexplored. In this study, using mitochondrial DNA cytochrome oxidase I (COI), control region (CR) and our developed 9 microsatellite loci, we determined phylogenetic relationships and population genetic structure of N. koreanus among geographically separated six river basins in comparison with N. temminckii. We found that N. koreanus evolved relatively well-separated clades in each basin, and that some morphologically N. koreanus individuals were genetically N. temminckii, suggesting the possibility of natural hybridization between the two species. Nipponocypris koreanus individuals from the Nakdong and Seomjin Rivers are the most closely related to N. temminckii, and they probably represent cryptic species complex as they showed a genetic distance of 2.2~2.9%, although N. koreanus had a distinct genetic structure. Comparisons of the whole mitogenomes from different rivers further support the notion that the Nakdong and Seomjin River populations constitute cryptic species in N. koreanus rather than a single species. The results of this study will shed an intriguing insight into understanding how Korean freshwater fishes have evolved in response to geographically isolated major river/stream environments. The evolutionary mechanisms underpinning the cryptic species diversity in freshwater systems are worth to be further studied.

Interactions in single-host–parasite systems provide a tractable framework for understanding the ecological mechanisms that maintain community stability. Here, we integrated network topology, multidimensional niche analysis, and functional group delineation to investigate the adaptive strategies and assembly rules of a 12-species flea community on Mongolian gerbils (Meriones unguiculatus). The host–flea network was characterized by a stable, nested structure and exhibited strong seasonal dynamics, with connectivity peaking in summer and modularity increasing in autumn. To understand the niche mechanisms driving these patterns, we identified four key ecological gradients (Seasonal Climate, Host Physiology, Weather Exposure, Host Behavior) and quantified the niche breadth of each species along these axes. Our analysis revealed that the community was organized along a steep hierarchy of generalization. Two ”hyper-generalist” species (Nosopsyllus laeviceps kuzenkoui and Xenopsylla conformis conformis) dominated the community, exhibiting near-maximal niche breadth across all four dimensions and occupying the core of the co-occurrence network. A broad niche was a major determinant of a species’ role, correlating strongly with a wider range of exploited hosts (p < 0.05). In contrast, specialist species, such as the ”extreme specialist” (Ophthalmopsylla jettmari), were confined to the network’s periphery and a narrow subset of ecological conditions. Clustering based on the multidimensional niche profiles identified four distinct functional groups, reflecting a clear hierarchy of ecological strategies from dominant hyper-generalists to highly restricted specialists. Overall, by integrating a multidimensional niche framework with network analysis, this study demonstrates that a hierarchical niche structure, rather than complex trade-offs, is the primary organizing principle in this seasonally dynamic community, providing a more nuanced understanding of stability in parasitic systems.

Studies of Taiwanese mammals reveal varied patterns of population divergence. Low-mobility species such as mole-shrews and Formosan wood mice exhibit strong north–south splits. Surprisingly, similar patterns also occur in mobile taxa like Formosan serow and sambar deer. In contrast, other mobile species, including flying squirrels, and Reeves’s muntjac, show weak or no population structure. This recurring north–south divergence across taxa with diverse ecologies suggests that shared environmental and geographic gradients, in addition to historical isolation, may underlie these patterns. If so, species occupying similar habitats may exhibit comparable genetic breaks regardless of life history traits. Prior studies based solely on mitochondrial DNA may have missed fine-scale structure in species like muntjac; high-resolution SNP data now offer improved resolution. Here, we analyzed genome-wide SNPs from 71 Taiwanese Reeves’s muntjac and comparative Chinese samples. We detected deep divergence from Chinese muntjac (~0.24 MYA), and further north–south subdivision within Taiwan (~0.06 MYA). Demographic modeling revealed a complex history involving glacial isolation and asymmetric gene flow, mainly from north to south. Within Taiwan, genetic differentiation was shaped by both geography and climate, especially temperature annual range (Bio7), with niche models showing environmental separation. Selection scans identified PLA2-associated genes, potentially linked to thermal adaptation. This is the first study to demonstrate that both geographic and environmental heterogeneity jointly contribute to mammalian divergence in Taiwan. The repeated north–south split across ecologically diverse species highlights shared climatic and topographic factors driving parallel population structure in Taiwan’s montane ecosystems.

Protist biogeography, speciation, and systematics continue to generate debate and inquiry because protist distributions and dispersal remain poorly resolved. Identifying potential vectors and basibionts for epibiont protists would contribute to our limited understanding of their ecology. Migratory animals seasonally link disparate landscapes, incidentally transporting other organisms in the process. Waterbirds are known microbe dispersers, but evidence for other avian groups is limited—such as taxa that often migrate longer distances. We asked whether terrestrial songbirds (Passeriformes) host diatoms (Bacillariophyta) by sampling tail plumage of four thrush species (Hermit Thrush Catharus guttatus, Swainson’s Thrush C. ustulatus, Wood Thrush Hylocichla mustelina, American Robin Turdus migratorius) spanning multiple migration strategies. Unexpectedly, we found diatoms in all seven samples, yielding 224 individuals of 25 genera and 9 orders: primarily benthic, freshwater, raphe-bearing genera (e.g., Encyonopsis, Navicula, Nitzschia). Several diatoms contained chloroplasts prior to digestion and slide mounting, consistent with potential viability. These natural history observations suggest that songbirds are overlooked carriers of hitchhiking diatoms, implying an undescribed but potentially important avian-algal relationship.

While there is abundant theoretical work on the evolution of phenotype plasticity, empirical support has lagged. One model for the evolution of phenotype plasticity is by genetic accommodation. Under this model of evolution when a population encounters a new environment there are widely variable responses amongst different genotypes, which are then pruned by selection into a single adaptive response. Because of the requirement to replicate genotypes, testing this prediction requires inbred lines as well as populations that are both adapted and not adapted to a resource. We previously demonstrated that D. melanogaster adapted to ethanol through genetic accommodation using D. simulans as an ancestral proxy lineage. However, we wondered how generalizable these results were. Using a new population of D. melanogaster from France and an ancestral range population from Zambia we demonstrated here that the Zambian population is not adapted to ethanol and that the French population has evolved ethanol resistance through genetic accommodation. We also investigated alternative splicing in response to ethanol and find that gene expression and splicing appear to evolve independently of one another, and that the splicing response to ethanol is largely distinct between populations. Thus, we have independently replicated evidence for evolution by genetic accommodation in D. melanogaster, suggesting that the evolution of plasticity may be an important contributor to the ability to exploit novel resources.

1. The interactions between phytophagous insects and their host plants show a strong trend towards specialization. However, the reasons behind this trend remain largely unclear, at both the evolutionary and mechanistic level. 2. One possible explanation is an increased energy expenditure for digesting and metabolizing more challenging hosts included in a broader host repertoire, which may reduce the energy available for other processes such as growth and development (“metabolic load hypothesis”). Differences in the performance across various hosts could reflect such costs. 3. Using the polyphagous Polygonia c-album (comma butterfly), we tested whether observed performance differences can be linked to variation in the energetic requirements. For this, we measured the metabolic rate of larvae feeding on three different host plants and converted it into the amount of CO2 produced per gram of mass gain (“growth cost”) to assess how much energy is allocated to growth vs digestion and assimilation. 4. The metabolic rate of larvae feeding on a chemically more challenging plant (Ribes uva-crispa) was similar to that of individuals on the host supporting the highest growth rate (Urtica dioica). 5. However, larvae on Ribes uva-crispa exhibited a higher energy demand per unit of growth and a lower growth rate, indicating a different energy allocation in growing larvae than when they were reared on a chemically less challenging plant. 6. Our findings suggest that energy expenditure for digesting different hosts varies and can have direct consequences for the larval performance. This indicates that the trend towards ecological specialization may, at least partly, be driven by selection to reduce the energetic costs for detoxification and digestion, in support of the metabolic load hypothesis.

Population genetic studies have traditionally relied on data from short tandem repeat (STR) markers, known as microsatellites, to produce individual genotypes used in population genetics research. However, size fragment analysis from traditional capillary electrophoresis presents scoring challenges and limits data comparisons among labs. Here, we present a new, cost-effective universal microsatellite genotype-by-sequencing assay for Canis species that allows for unambiguous allele calls, flags homoplasy for more accurate assignment tests and estimates of diversity and improves genotyping output from low-template DNA. We note size homoplasy in 18 of 26 loci with the number of alleles being 32% higher in the dataset that included sequence mutations (Namut=334) compared to the dataset based on size alone (Nalen=253). Assignment tests with Bayesian cluster analysis were similar for both datasets, although 64 of 84 samples had higher assignment values to their primary cluster when mutations were considered. We document and code a list of sequence mutations associated with each locus and propose a framework for building an accessible, universal STR dataset for wolves, coyotes, and dogs that improves cluster assignments and admixture estimates in a system with complex demography and hybridization patterns. Overall, the assay provides an improved microsatellite method of genetic monitoring to aid conservation of wolf populations.

Western Melanesia sits at the junction of three major tectonic plates, characterised by dynamic plate interactions and geological diversity. Tectonic activity in this region has given rise to modern New Guinea, a relatively young island with extreme topographic heterogeneity and evolutionarily complex biota. New Guinea—particularly the East Papuan Composite Terrane (EPCT)—supports exceptional frog diversity; however, evolutionary histories of many frogs of the EPCT are poorly understood. The microhylid frog genus Mantophryne currently includes five described species (M. axanthogaster, M. insignis, M. louisiadensis, M. menziesi and M. lateralis), with the first four confined to small portions of the EPCT and the last distributed across the eastern half of New Guinea. The biogeographic history of these frogs remained incompletely resolved at the time of our study. We estimate that Mantophryne diverged from other microhylid genera approximately 14.4 million years ago (MYA) and began to speciate ca. 8.5 MYA. We recover eight distinct lineages within frogs assigned to M. lateralis, which started to diverge ca. 5.5 MYA. Dispersal of Mantophryne out of the EPCT occurred in the late Pliocene, around the time the Central Highlands expanded eastward to connect with the EPCT. Six pairs of sister lineages arose during a time of significant climate reorganisation in the Late Pliocene – Early Pleistocene when it is possible that areas to the north of the Central Highlands experienced increased precipitation, while areas south of the Central Highlands experienced lower rainfall, resulting in contraction of rainforests and expansion of savannahs

We document honeybees collecting latex from breadfruit in Puerto Rico, a rare interaction that reveals how plant chemical diversity can shape bee foraging, plant-insect dynamics, and evolutionary trajectories---highlighting the role of nonnative species in driving eco-evolutionary change in tropical ecosystems.

1. Testing inter- and intraspecific competition is essential for understanding the processes that maintain diversity within communities and populations. Pairwise growth assays are well-established methods to study the outcome of competition between bacterial genotypes or species. However, distinguishing bacterial competitors in coculture remains a major challenge due to their small cell size, similar cell morphology and often large population sizes. Current approaches are either labour intensive and require prior morphological and sequence-based characterisation, or genetic modification of the bacteria. 2. We present a simple assay that tracks the relative abundances of two competing bacterial species or genotypes of the same species through transient staining of one competitor with a fluorescent dye. The use of a transient dye relieves of prior characterisation or genetic modification. Our approach uses a sample-dependent threshold evaluation for the fluorescent intensity, enabling the quantification of bacteria frequencies over generations. The method provides a high accuracy for tracking of competing genotypes and species. 3. The outcome of competition often depends on frequency-dependent fitness effects and/or environmental variables. Therefore, our method tests across different initial abundances and can also assess the role of a biotic interaction (presence/absence of a predator) on the outcome of competition. 4. Our method presents a simple and high-throughput assay for competition. Absence of genetic modifications and applicability to little characterised competitors make it particularly useful for assays involving bacterial isolates from evolving populations.

Ecological and genetic interactions among conspecific populations play an important role in population viability, but these interactions are not always fully considered in strategies to recovery endangered taxa. The Southern Resident Killer Whales are a high-profile population listed as endangered by both the U.S. and Canada. Risks to the population are well known, and include insufficient prey, inbreeding depression, disturbance, and environmental contaminants. Here, we argue that a fifth factor–interactions with other sympatric killer whale populations–plays an under-appreciated role in the population’s current and potential status. Based on studies conducted over the past two decades, we illustrate that consumption of shared prey, behavioral interactions in shared habitat, and shared DNA through potential interbreeding with other populations will strongly influence the future trajectory of the Southern Resident Killer Whales.

For road mitigation measures to prevent roadkill and conserve landscape connectivity to be effective, the measures must be located where animals are most likely to encounter roads. However, accurate identification of road encounter hotspots is difficult when presence records are sparse and collected haphazardly, often the case with small, uncommon species. Blanding’s turtle Emydoidea blandingii (BT) is a threatened species for which road-mortality contributes to population declines. Using fortuitous detections of BT along roads, we investigated whether it is possible to predict road encounter hotspots throughout an extensive road network with such data. We applied three approaches: (1) general linear modeling (GLM) to infer landscape features associated with BT road encounter records; (2) after locating spatial clusters of encounters, GLM was used to identify landscape features associated with these hotspots; and (3) BT least cost movement paths were delineated within the landscape and sites where paths crossed roads were located. Predicted hotspots based on the modeled movement trajectories were then compared with BT road encounter hotspots. BT locations were positively associated with presence of wetlands and negatively associated with grasslands and developed land use. Hotspots were located along predicted BT least cost movement paths, indicating that behavioral movement models are useful for predicting encounter locations. Each of the three modeling approaches identified valid landscape indicators of BT road encounter hotspots, and a significant fraction of road encounter records came from a small number of hotspot sites, located along the predicted movement paths. Overall, we conclude that it is possible to generate predictive models of road encounter hotspots even when data are sparse, collected unsystematically, and subject to spatial biases in reporting across a road network, and these models can be applied throughout a road network to identify road segments that are good candidates for effective road mitigation.