Ecology and Evolution最新文献

[This corrects the article DOI: 10.1002/ece3.53.].

Feral horses (Equus ferus caballus) have established large populations in west-central British Columbia (BC), Canada, where they overlap with native ungulates, including a declining woodland caribou (Rangifer tarandus caribou) herd. In addition, feral horses co-occur with large carnivore species including wolf (Canis lupus) and cougar (Puma concolor). Feral horses may act as a resource subsidy for predators, potentially altering predator-prey dynamics, yet empirical observations of predator interactions with feral horses are scarce in Canada. Between 2019 and 2025, we documented 21 instances of wolf predation or scavenging of feral horses, including one direct observation of wolves actively hunting feral horses. We also documented 58 instances of confirmed feral horse predation by GPS-collared cougars. To the best of our knowledge, these are the first published observations of wolves hunting feral horses, and the first records of cougar predation of feral horses in British Columbia. Our findings suggest that feral horses may increase food availability for these two large carnivore species, potentially facilitating elevated predation pressure on native ungulate populations via apparent competition. These novel interactions underscore the complex and far-reaching ecological consequences of feral species. Further, they highlight the importance of incorporating non-native prey subsidies into predator-prey management frameworks.

Interactions between co-occurring pathogens can have complex and significant impacts on host survival, fitness, and population dynamics. While common in wildlife, coinfections are often overlooked, and research may create biased management perspectives when individual pathogens are assessed in isolation. Recent work has found that wild turkeys (Meleagris gallopavo) are affected by various pathogens, but it is unknown how infections and coinfections are spatially structured or interact with each other. Here, we determined the associations and risk factors of infection by lymphoproliferative disease virus (LPDV), reticuloendotheliosis virus (REV), three avian Mycoplasma species, and internal parasites in Pennsylvania wild turkeys. Our results indicate varying prevalences: LPDV (70%), REV (1%), Mycoplasma gallisepticum (0%), Mycoplasma meleagridis (4%), Mycoplasma synoviae (2%), and internal parasites (63%). The prevalence of LPDV was greater in adults than juveniles but did not vary with year, sex, study area, or landscape type. Parasite species richness was greater in juveniles than adults, greater in males than females, varied by year and study area, but did not vary with landscape type. Coinfections with LPDV and parasites were more common (41%) than infections with only LPDV (26%) or only parasites (22%). All other coinfection prevalences involving viruses, Mycoplasma species, and parasites were low (0%-3%). Finally, infection with LPDV did not differ with overall parasite species richness but was negatively associated with infection with parasitic nematodes. These results reveal high rates of coinfections with LPDV and parasites in turkeys but suggest that parasite infections are independent of LPDV infections. Ongoing work is currently investigating the sublethal effects of these coinfections on wild turkey populations.

Formalin, ethanol, and RNAlater are the most commonly used fixatives for morphological and molecular studies. Formalin is preferred for preserving tissue morphology, whereas ethanol and RNAlater are used to obtain high-quality nucleic acids for molecular analyses, including emerging -omics techniques. Over the past few years, the study of non-model organisms has gained attention, but the lack of laboratory cultures for many species requires collecting and fixing the animals directly in the field. Very often, just a few specimens are secured, limiting the possibility of using multiple fixatives for parallel analyses. A single fixative that preserves both morphology and molecules while being easy to handle in the field would therefore be highly valuable. KINFix, a non-toxic alcohol-based fixative, was developed to preserve histology, proteins, and nucleic acids simultaneously, enabling both morphological and molecular analyses with the same sample. Here, we evaluate the suitability of KINFix for electron microscopy, RNA preservation, and cell dissociation for single-cell RNA sequencing (scRNA-seq) experiments, using four invertebrate species from different spiralian phyla. Our results demonstrate that KINFix maintains RNA integrity for over 3 months, similarly to other standard fixatives, but also preserves morphology and cellular integrity even after cell dissociation, suggesting its suitability for scRNA-seq applications. While fixation conditions may require optimization for different species and tissues, our findings highlight KINFix as a cost-effective, versatile, and valuable fixative that enables a wide range of morphological and molecular studies in non-model invertebrates. KINFix is particularly useful for field-based research where sample availability and preservation logistics are especially challenging.

The mirid bug Apolygus lucorum (Meyer-Dür), a major pest affecting tea, also poses significant threats to a wide range of other crops across China. Identifying the dominant predatory spiders of the mirid bug and their pest control functions can provide a scientific basis for developing biological control technologies for this pest in tea plantations. In this study, we calculated the dominant presence of these spider species and evaluated the phenological overlap with the population of A. lucorum. Additionally, DNA from field-collected specimens of spider species was analyzed by A. lucorum-specific primers to detect the presence of residual DNA from the mirid bug. Using the predator-prey functional response model, the predation efficiency of various adult spider species on A. lucorum was assessed in laboratory conditions by testing different prey densities. The results showed that the greatest temporal niche overlap was observed between Xysticus ephippiatus and A. lucorum. Molecular detection results showed that X. ephippiatus and Misumenops tricuspidatus had significantly higher detection rates of the mirid bug than other spiders. The functional response of lab predation indicates that the predation ability of different spider species on A. lucorum increases with the density of prey. The predation functions of both adult X. ephippiatus and M. tricuspidatus conform to the Holling-II model. At a high prey density, the predation quantity of adult X. ephippiatus is significantly higher than that of adult M. tricuspidatus. In conclusion, the spider X. ephippiatus demonstrates the greatest potential as a biological control agent against A. lucorum within an integrated pest management framework. This research offers valuable scientific insights for leveraging predator species to effectively manage A. lucorum populations in tea plantations.

Solar eclipses rapidly alter abiotic conditions and thus represent natural experiments for understanding how animals respond to ephemeral environmental change. Using a large acoustic dataset (181 species, 873 locations) from participatory science, we quantified how birds changed their vocalizations in response to the 2023 annular and 2024 total eclipses in North America. During the total eclipse, most species vocalized less, but nocturnal and large-eyed species vocalized more. The generalized quieting was restricted to locations with > 94% solar obscuration; most bird species vocalized more in locations with 70%-93% solar obscuration, which experienced only modest dimming. During the annular eclipse (which occurred during the nonbreeding season and reached a maximum of 90% obscuration), most birds did not change their vocalization behavior. Thus, changing photic conditions during solar eclipses are reflected in the composition of species vocalizing, leading to ephemeral shifts in ecological soundscapes.

Climate change poses a serious threat to global species distributions and has significantly altered the distribution patterns of invasive species. Coreopsis spp. are widely distributed invasive plants with strong adaptability and reproductive capacity, whose invasion has become a major ecological concern in China. Using three climate change scenarios (SSP-126, SSP-245, SSP-585), combined with the Maximum Entropy (MaxEnt) model and Geographic Information System (ArcGIS), this study delineated the potential distribution areas and distribution centroids of invasive Coreopsis plants in China. The results indicated that temperature (especially isothermality BIO3 and mean temperature of the warmest quarter BIO10) and moisture are the primary climatic factors influencing the distribution of Coreopsis spp., while human activity (HA) also plays a key role in shaping their distribution. Coreopsis drummondii exhibited the largest suitable habitat area (4.138 × 10⁶ km²), whereas Coreopsis verticillata had the smallest (9.53 × 10⁵ km²). Under current climatic conditions, the six Coreopsis species are mainly distributed in southern China. In future climate scenarios, their distributions are projected to shift northward and toward plateau regions. Moreover, high niche and range overlap was observed among Coreopsis grandiflora, Coreopsis lanceolata, and Coreopsis tinctoria, suggesting potential intensified interspecific competition. This study systematically reveals the invasion potential and spatial dynamics of Coreopsis spp. under climate change, providing a scientific basis for early warning, regional management, and ecological control. It also offers perspectives for future research on the interaction mechanisms between invasive and native species.

The composition and function of animal gut microbiota are influenced by various intrinsic and extrinsic factors. Hibernation represents a significant physiological challenge for heterothermic mammals, yet the effects on gut microbiota in bats remain understudied. This study investigated seasonal variations in the gut microbiota of Rhinolophus sinicus between summer activity and winter hibernation using 16S rRNA gene sequencing (n = 12 per group). Sequencing analysis identified 907 ASVs in the hibernation group and 555 ASVs in the summer group, with only 27 ASVs shared between groups, suggesting substantial seasonal turnover in microbial community membership. At the phylum level, Pseudomonadota (formerly Proteobacteria) dominated the gut microbiota, but no significant difference was found between seasons (77.52% during hibernation vs. 57.15% during summer). Bacillota (formerly Firmicutes) decreased significantly, while Actinomycetota (formerly Actinobacteriota) increased significantly in the hibernation group compared to the summer group. Genus-level composition exhibited seasonal variation, with distinct microbial communities characterizing each period. Alpha diversity analysis revealed significant differences in Faith's phylogenetic diversity between seasons, suggesting shifts in phylogenetic composition, while Chao1, Shannon, and Simpson indices remained unchanged. Beta diversity analyses revealed significant structural divergence between seasonal groups. Functional prediction using PICRUSt2 suggested seasonal shifts in metabolism-related pathways, with putative enrichment of lipid metabolism and xenobiotic biodegradation pathways during hibernation, while carbohydrate metabolism appeared more prominent during the active period. These findings suggest that winter fasting may alter intestinal microbial metabolic functions, potentially shifting the microbiota from carbohydrate-oriented to lipid-oriented metabolism. This study enhances our understanding of host-microbiome crosstalk in hibernating mammals and highlights the potential adaptive role of gut microbes in facilitating survival under extreme physiological conditions.

Climate change alters the oceans' temperature, pH, and oxygen concentration. These changes are expected to increase globally over the coming decades, affecting a wide range of marine organisms. Coastal upwelling zones, characterized by their high environmental variability, serve as ideal natural laboratories to study the potential impacts on marine organisms and ecosystems of temperature change, acidification, and ocean deoxygenation. The estimation of survival using capture-mark-recapture (CMR) data has been commonly applied to vertebrates, and to date, very few studies have been done on marine invertebrate organisms. In this study, we combined field CMR data and laboratory measurements to assess the physiological responses (metabolic rate and heart rate) and survival probability of individuals in two populations of intertidal mollusks, Chiton granosus and Scurria zebrina, in contrasting upwelling environments (i.e., semi-permanent vs. seasonal). We found that (1) there are no differences between the two studied populations for heart rate in both species, (2) the S. zebrina population subjected to seasonal upwelling has a higher metabolism, (3) there are no differences in the calcification rate between the two studied populations of both species, and (4) survival is significantly higher in the semi-permanent upwelling location for both species. Our findings highlight species-specific responses to contrasting upwelling regimes, suggesting that phenotypic plasticity and survival differences may influence resilience under ongoing climate change.

Rickettsia is an endosymbiotic bacterium that infects various arthropods, affecting the host's biology, ecology, and evolution. Leptocybe invasa is an invasive pest that severely damages eucalyptus plants. A comprehensive investigation of Rickettsia in 313 female L. invasa individuals from 17 Chinese populations revealed a 100% infection prevalence. Sequencing of three host molecular markers-mitochondrial COI, nuclear ITS, and 28S-led to the identification of a novel L. invasa haplotype, designated Haplotype 1 × 2, which exhibits mito-nuclear discordance. Concurrently, sequencing of four Rickettsia genes (16S rRNA, gltA, atpA, rpmE) revealed two distinct strains, termed STRiA and STRiB. These strains demonstrated a specific association with the host lineages, where STRiA was exclusively associated with lineage A (comprising Haplotype 1 and Haplotype 1 × 2), and STRiB was linked to lineage B. Phylogenetic analysis of the multigene datasets from both the host and Rickettsia revealed a high degree of topological congruence between their inferred trees. Correlation analysis further demonstrated a moderate positive association (r = 0.307). The significance of this relationship was supported by a Mantel test (p < 0.005), suggesting coevolution. Low-dose tetracycline treatment effectively eliminated Rickettsia from L. invasa. L. invasa treated with tetracycline exhibited a significantly higher proportion of male offspring, reduced Rickettsia expression, and decreased body length and lifespan in female offspring. Transcriptome analysis comparing Rickettsia-free and Rickettsia-infected L. invasa following antibiotic treatment identified 178 differentially expressed genes (122 up-regulated, 56 down-regulated). These genes were enriched in GO terms related to metabolic processes, cellular processes, cellular components, binding functions, and catalytic activities. KEGG pathway analysis revealed enrichment of differentially expressed genes primarily in metabolic pathways, insect hormone biosynthesis, and thermogenesis. Additionally, enrichment was observed in key signaling pathways, including Ras, MAPK, NF-κB, TGF-β, TNF, and Apelin. These findings elucidate the coevolutionary relationship and functional roles of Rickettsia in L. invasa, providing a foundation for symbiont-mediated biological control.