Search Results (973)

The research analysed the space-use and habitat-preference characteristics of red deer (Cervus elaphus) in the Sopron Mountains, Hungary, utilising high-resolution Global Positioning System (GPS) telemetry data and two distinct land-cover databases. Hourly location data from 10 individuals were processed using the minimum convex polygon (MCP) and kernel home range (KHR) methods. Additionally, a relative stability index (RSI) was developed to describe seasonal shifts in area use. Significant sexual dimorphism was identified in the extent of annual home ranges: the mean space use of stags (3381 ha) significantly exceeded that of hinds (1391 ha). Geomatical analyses highlighted the seasonality of space use: the smallest extent was recorded in June, and shifts in home ranges within a single year were significant, while the winter period exhibited the least seasonal variation. Regarding habitat selection, significant seasonality was observed in hinds, reflecting temporal changes in resource availability, whereas this pattern was not observed in stags. The study concluded that the applied methods are appropriate for gathering baseline information; however, integrating high-precision databases is essential for accurate modelling of deer–forest interactions. Full article

Tit species (Paridae) are an important part of urban settlements during winter. We counted wintering tit species from 31 urban settlements along a 920 km latitudinal gradient in Finland during four winters between 1991 and 2020. We observed a total of five tit species, the Great Tit (Parus major), Eurasian Blue Tit (Cyanistes caeruleus), Coal Tit (Periparus ater), Willow Tit (Poecile montanus), and Crested Tit (Lophophanes cristatus) during the surveys. The most common and abundant species were the deciduous forest preferring Great Tit and Eurasian Blue Tit, whereas the coniferous forest preferring species exhibiting a hoarding behavior, the Coal Tit, Willow Tit, and the Crested Tit, were seldom observed, and no Siberian Tits were detected. These results indicated that food-hording coniferous preferring tit species avoided urban areas. The numbers of Great Tit and Eurasian Blue Tit were greater at the end of the study period than in the first two winters studied. The average growth rate (λ) of the Great Tit and Eurasian Blue Tit increased during the winters studied. Our data indicated a greater increase rate of the Great Tit and Eurasian Blue Tit than the Finnish winter bird monitoring work, probably because we only surveyed tits within human settlements. There was a positive correlation between the average growth rate of the Great Tit and the latitude. There was a negative correlation between the changes in average growth rate (λ) of the Eurasian Blue Tit and the changes in built-up area cover within the study areas between winters 1991/1992 and 2019/2020, and vice versa, indicating that the Eurasian Blue Tit population suffered from the increase in built-up area cover. Despite the fact that the total number of winter-feeding sites decreased during the study period, changes in their numbers were not associated with the growth rates of any tit species. The abundance of the Great Tit was negatively associated with building cover and positively associated with winter temperature. The abundance of the Eurasian Blue Tit was negatively associated with building cover and negatively associated with latitude. When controlling for the latitude, the growth rate of the Great Tit increased with the temperature in winter months, indicating that the Great Tit populations have increased in colder study sites. Our results indicated that population trends of tit species may differ regionally, and that changes in urban settlements may modify the abundance of tit species during winter. We did not detect any correlation in population growth rates between species. We recommend conducting more long-term tit research both during the winter and breeding seasons to understand the population dynamics and population trends of tit species across diverse types of habitats in more detail. Full article

Introduction: As apex and mesopredators, elasmobranchs help maintain marine ecosystem balance by shaping food-web structure and habitat connectivity, yet more than one-third of species are threatened with extinction. Identifying where and when they aggregate within atoll systems is therefore a prerequisite for spatially explicit conservation planning. Lhaviyani Atoll, in the central Maldives, lies within a recognised Indian Ocean elasmobranch hotspot and hosts two Important Shark and Ray Areas (ISRAs), yet fine-scale information on aggregation sites, habitat partitioning and seasonal use remains limited. Objective: To map persistent activity hotspots, characterise habitat partitioning between sharks and batoids, quantify seasonal and inter-annual dynamics, and provide an ecological basis for habitat-focused conservation in Lhaviyani Atoll. Methodology: Using a seven-year (2017–2024) opportunistic dive-log dataset of 12,732 SCUBA surveys and 142,994 elasmobranch records across 94 dive sites, spatial kernel-density estimation was applied separately to sharks and batoids to identify activity hotspots and visualise spatial overlap. Habitat associations were examined across substrate types and reef geomorphic zones. Seasonal and inter-annual dynamics in relative abundance and diversity (Shannon, Pielou’s evenness) were quantified across monsoon phases and the 2017–2024 period. Results: Twenty-eight species (14 sharks, 14 batoids) were recorded, including 23 listed as threatened on the IUCN Red List (4 Critically Endangered, 12 Endangered, 7 Vulnerable). Four persistent activity hotspots were identified along the northern atoll rim, two overlapping with the Fushifaru Kandu and Kuredhu–Huravalhi–Komandoo ISRAs. Sharks were concentrated along more complex exposed and semi-sheltered slopes and high-flow channels, with significantly higher occurrence on reef and sheltered reef slopes and lower occurrence on rubble and sand substrates; batoids were distributed broadly within lagoonal habitats with no strong substrate or geomorphic preferences. Relative abundance and diversity peaked during the late southwest monsoon (August–September) and declined into the northeast monsoon (December–March); after 2021, diversity and evenness increased while overall abundance declined. Conclusions: Persistent hotspots, contrasting habitat use by sharks and batoids, and consistent monsoonal seasonality support the ecological relevance of existing ISRAs in Lhaviyani Atoll, while providing finer-scale information on habitat partitioning and additional priority areas for threatened elasmobranchs, including four Critically Endangered species. Full article

The proglacial lakes of the Qinghai-Xizang Plateau serve as natural laboratories for studying microbial adaptation to extreme environments. However, research on the composition and functional characteristics of microorganisms in these settings remains limited. In this study, three typical high-altitude proglacial lakes in southern Xizang (Qudengnima proglacial lake, Gangbugou proglacial lake, and Qiangyong proglacial lake) were selected as research subjects. Bacterial community structure, diversity in the water and sediment of these lakes were analyzed using 16S rRNA sequencing. The results showed that Pseudomonadota, Actinomycetota, and Bacteroidota were highly abundant across all samples. The relative abundances of Cyanobacteriota and Acidobacteriota, however, exhibited distinct habitat preferences: Cyanobacteriota was enriched in the water, whereas Acidobacteriota was predominantly found in sediment. Alpha diversity analysis showed that both species diversity and richness in Qiangyong proglacial lake were significantly higher than those in the other proglacial lakes, and within the same lake, both diversity and richness in sediment were higher than in the water. Beta diversity analysis indicated that the bacterial community structures in sediment were similar across different proglacial lakes, whereas those in water varied considerably among the lakes. LEfSe analysis identified 94 biomarkers that exhibited significant differences among the different proglacial lake environments at an LDA score threshold of 4. Redundancy analysis revealed that pH, total phosphorus, and ammonium nitrogen were the physicochemical factors significantly influencing the bacterial community structure in the water, while total carbon was the key driver for the community in sediments. This study preliminarily characterized the bacterial community structure and diversity in high-altitude proglacial lakes on the southern Qinghai-Xizang Plateau, which lays a theoretical foundation for exploiting microbial resources and understanding their ecological functions in such extreme environments. Full article

H9N2 avian influenza viruses inherently carry cross-species transmission potential, making continuous surveillance critical for pandemic prevention. This study focused on monitoring the 2024 H9N2 epidemic in Jiangsu Province’s external environment, analyzing its molecular evolution and receptor binding properties, assessing cross-species transmission and pandemic risks, and investigating serological antibody levels across different human populations. Environmental samples were collected from live poultry markets, farms, slaughterhouses, and bird habitats across Jiangsu, screened via quantitative PCR (qPCR), with positive samples used for virus isolation and whole-genome sequencing. Receptor binding properties were tested by hemagglutination assay, and H9N2 antibody levels were measured in 370 occupationally exposed individuals and 240 non-exposed individuals using hemagglutination inhibition (HI) assays. Among the 5779 collected samples, 6.89% tested H9N2-positive, and 12 strains belonging to the Eurasian lineage Y280-like clade G57 genotype were successfully isolated. All strains carried the HA-Q226L mutation, with 11 showing preferential binding to human α-2,6 receptors and one strain possessing dual receptor binding capability. Internal genes harbored mammalian adaptation mutations, and M2 proteins contained mutations conferring complete resistance to amantadine-class antiviral drugs. Serological tests revealed antibody positive rates of 4.05% in exposed populations and 2.5% in non-exposed populations, with no statistically significant difference between groups. These findings confirm that Jiangsu’s circulating H9N2 viruses have acquired human receptor preference and mammalian adaptation, posing silent infection and pandemic risks. Enhanced surveillance and the development of candidate vaccine stockpiles are strongly recommended. Full article

Mediterranean rivers experience various pressures that cause native fish populations to decline. This is the case of Achondrostoma asturicense, a threatened endemic species recently classified as "endangered" (EN) by the Portuguese Red Book. In northeastern Portugal, the main populations occur in the Carvalhais (Tua basin), Maçãs, and Angueira (Sabor basin) rivers. This study aimed to evaluate the effect of small weirs on the distribution, abundance, and habitat use of A. asturicense populations along the longitudinal gradient of River Angueira. Three river zones (Z1 to Z3) affected by small weirs were selected along the watercourse. In each zone, four sampling sites were distributed relative to the weir, as follows: A1—200 m downstream; A2—immediately downstream; A3—under the influence of the reservoir; and A4—200 m upstream (reference). Sampling was carried out in three seasons: winter, spring, and summer 2025. Physical–chemical (water), hydromorphological (habitats), and biological (fish) elements were assessed in accordance with the protocols of the Water Framework Directive. The results revealed the worst water quality in the summer season due to flow reduction, dissolved oxygen depletion, elevated conductivity, and high nutrient (N, P) concentrations, leading to eutrophication phenomena. The distribution and abundance of A. asturicense were negatively influenced by the presence of small weirs, which were dominated by the non-native species Lepomis gibbosus. PERMANOVA analysis (two-way, p < 0.05) identified significant differences (Pseudo-F = 28.349, p < 0.05) between sampling sites and river zones, and paired similarity analysis tests (ANOSIM; one-way, p < 0.05) confirmed that these differences occur only between the weir reservoir (A3) and the remaining sampling sites. A. asturicense showed a maximum length (Lmax) of 135 mm, isometric growth only in the upstream zone (Z1), and significant differences in body condition (0.75 < K < 0.84). This species showed a preference for rheophilic habitats, with coarse substrate and diversity of currents and distinct cover mainly guaranteed by submerged aquatic macrophytes. A. asturicense populations are severely affected in the River Angueira by habitat fragmentation, riparian degradation, pollution, invasive alien species (e.g., L. gibbosus, P. clarkii, N. vison), and climate change, justifying the development of mitigation and restoration measures for the conservation of natural habitats and native threatened species. Full article

Brown trout (Salmo trutta L.) is a bioindicator species of ecological integrity in mountain rivers of northern Portugal. Habitat loss and recreational fishing justify sustainable management to balance the conservation and exploitation of these fish populations. In fact, salmonid streams in NE Portugal are low productive watercourses and fish stocking has been continuously demanded by fishermen. However, this most common management action must be analyzed carefully and determined the effective increase for local fisheries, taking into consideration the potential dispersal of stocked fish. The objective of the present study, developed in River Sabor, was to determine short- and medium-term movement and dispersal patterns and habitat preferences of wild and stocked Brown trout, using radio telemetry, during a weekly monitoring 4-month period (October to February 2026; n = 18). Fish was sampled by electrofishing at beginning and the end of the experiment. Twenty-four adult Brown trout, equally distributed by two salmonid sections, and three groups, (1) wild resident (River Sabor) (213–270 mm TL); (2) wild non-resident (from contiguous basin, River Baceiro) (200–375 mm TL) and (3) rear-captivity (Castrelos Fishfarms, ICNF) (227–365 mm TL) fish, were surgically implanted with radio transmitters. Significant differences (KW-H (2;24) = 4.67; p = 0.09) were observed for the dispersal distances, considering fish detected at least in five sampling events, ranging from 120–1437 m for the wild resident stationary group to 192–14,150 m for the stocked mobile group. Moreover, wild non-resident fish displayed higher movement in the upstream direction, in opposition to the downstream movement of stocked individuals. Wild resident and non-resident trout tended to display increased movements during November and December, probably related to spawning activity, showing preferences by riffle and run habitats. Stocked fish were detected in pool habitats (mainly weir reservoirs), exhibiting significantly lower growth rates, and increased movement during January and February, particularly during flood events. These findings are valuable information for managers related to movement patterns, habitat use and stocking management. Full article

This study evaluates the multi-year taxonomic diversity and functional structure of beetle assemblages (Coleoptera) within Sub Arini Park, a historic urban green space in Sibiu, Romania. Following a preliminary baseline and methodological calibration phase in 2023, systematic monitoring was conducted during the 2024 and 2025 seasonal cycles utilizing standardized pitfall trapping across diverse park zones. We explicitly tested two hypotheses: (H1) that long-standing historic park management preserves a resilient and functional insect community structure, and (H2) that local spatial heterogeneity and microhabitat variations significantly drive species distribution. A total of 14,843 individuals belonging to 39 species were analyzed. While total abundance exhibited a slight decrease from 2024 (N = 7112) to 2025 (N = 6551), true diversity metrics (Hill numbers) revealed a significant increase in raw species richness (q = 0) from 30 to 39 species, alongside an enhanced equity of frequent species (Shannon diversity, q = 1, increased from 4.26 to 5.12). Functional guild analysis and multivariate PCA demonstrated a highly structured biocenotic distribution; specialist and hygrophilous species (e.g., Carabus variolosus Fabricius, 1787) were strictly constrained to high-humidity riparian corridors, whereas thermophilous generalists dominated open lawns under high anthropogenic stress. Our spatial analysis identified critical degradation within these heavily managed zones, specifically driven by intensive mowing, soil compaction, and organic debris removal. These findings confirm both hypotheses, revealing that the park operates as a heterogeneous mosaic of ecological refugia rather than a uniform habitat block. Crucially, this study provides a concrete, quantitative basis—derived from empirical thresholds of species richness, abundance shifts, and mapped microhabitat preferences—for implementing nature-based management strategies (such as establishing buffer zones with reduced mowing frequencies, limiting trampling, and retaining coarse woody debris) aimed at mitigating urban biodiversity loss and maintaining vital biological pest control services in Central–Eastern Europe. Full article

Introduction: Understanding the movement ecology of invasive species such as the European catfish Silurus glanis, with documented strong impacts on freshwater fish communities, is essential to improve the effectiveness of management and containment actions, as detailed knowledge of species spatio-temporal habitat use strongly influences the success of control strategies. Objective: This study aimed to investigate the spatial and temporal behaviour of the S. glanis in a river–reservoir system in Portugal, including the Ponsul River and part of the Tagus River within the Cedillo reservoir, and to provide ecologically relevant insights to support targeted management strategies. Methodology: Acoustic telemetry was used to monitor 27 tagged individuals equipped with depth sensors. Fish movements were tracked using an array of 17 acoustic receivers over one and a half years. Results: Three behavioural profiles were identified: a resident group in the lower Ponsul (n = 4), a group moving between the Tagus River and the lower Ponsul (n = 6), and a larger group primarily migrating within the Ponsul River (n = 12). The remaining five individuals were considered dead, due to illegal fishing in this protected area. Migratory individuals showed a clear seasonal pattern, moving downstream to deeper waters during early winter and returning upstream to shallower areas as temperatures increased in early spring, likely in response to thermal gradients. Distance-based analyses confirmed this trend, with minimum inter-individual distances occurring in winter and early summer. Vertical behaviour supported this pattern, with individuals occupying shallow waters (≤7 m) for most of the year and reaching depths of up to 30 m in winter. Conclusions: The observed preference for shallow habitats during warmer periods and downstream migration in winter indicates that eradication efforts should be spatially and temporally targeted. Control actions should prioritize upstream sections during warm seasons and downstream areas of the Ponsul during winter migration, focusing efforts on traditional methods such as large-mesh multimesh gillnets or new longline techniques. Overall, this study highlights the value of telemetry in supporting targeted, evidence-based management of invasive species. Full article

The South American silver croaker, Plagioscion squamosissimus, holds significant importance for the artisanal fisheries operating in the sub-middle and lower courses of the São Francisco River, located in northeastern Brazil. Its complex horizontal movement patterns and habitat-use preferences are not fully understood in the waters of hydroelectric dam reservoirs, raising important questions for the rational and sustainable management of this species. This study aimed to identify the habitat use of P. squamosissimus individuals captured in three fishers’ associations (Olho D’água do Casado, Petrolândia and Rodelas). Individuals were collected between September 2023 and March 2024. A selection of 25 individuals per location from the same age group (+2 years) was used, following annual age estimation based on existing growth curves. Element-to-calcium (element/Ca) ratios in the otolith cores and edges were determined using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). The data were analyzed using univariate and multivariate statistics to assess the degree of separation between individuals in relation to natal origin (otolith cores) and time of capture (otolith edges) from the three sampling sites. Significant differences in element/Ca ratios between core and edges of the otolith were observed for Ba/Ca, Mg/Ca, Mn/Ca and Sr/Ca ratios. These results indicate an ontogenetic change in the habitat use, in which similarity in core signatures suggests a common natal origin, likely influenced by shared environmental conditions of the individuals investigated in this study. Full article

The ecological consequences of hydraulic engineering on riverine environments have intensified the need for scientifically grounded ecological flow regimes. To ensure habitat suitability during critical fish spawning periods, this study developed habitat preference curves by correlating physiological parameters with key hydro-environmental drivers. A habitat suitability index (HSI) model was established using fuzzy logic, integrated with a genetic algorithm (GA) to simultaneously optimize fuzzy membership functions and inference rules. This model was applied to simulate the relationship between the weighted usable area (WUA) and discharge for various fish egg types in the reach downstream of the Fengman Dam, ultimately facilitating the determination of an optimized ecological pulse flow hydrograph. The results reveal distinct hydro-environmental preference variations among species. Specifically, drifting eggs require specific hatching cycles supported by higher flow magnitudes and velocities. Conversely, adhesive eggs experience a significant reduction in suitable habitat area under high-flow and high-velocity conditions. These findings suggest that reservoir water resource allocation must be tailored to the life-history requirements of target species to maximize spawning success. This study provides a robust scientific framework for eco-friendly reservoir scheduling and the conservation of regulated river ecosystems. Full article

Balancing of macronutrient intake assumes that animals change their food preferences to increase consumption of the deficient nutrients and/or decrease consumption of nutrients in excess. Harvestmen are generalist predators that consume mostly soft-bodied insects, but they supplement this with plant-derived food such as berries (omnivory). In spite of this, they are often carbohydrate-limited in their natural habitats. As aphids have higher sugar content than most other insect prey, they are a potential source of sugar. We hypothesized that sugar-deficient harvestmen have increased preference for aphids relative to other insect prey (fruit flies) and consume more aphids than sugar-satiated harvestmen. Likewise, we hypothesized that protein-deficient harvestmen would show increased consumption of aphids relative to a pure sugar source (dried grape pulp). The former hypothesis was confirmed but the latter was not. Carbohydrate-deprived harvestmen (Leiobunum gracile) consumed 1.9 times more aphids than nutritionally balanced ones (p = 0.0004). Consumption of dried grape was increased in carbohydrate-deficient harvestmen, while protein deficiency did not increase consumption of aphids. These results indicate that aphids may be used as a carbohydrate source if no better alternative is available, but they are unable to relieve a deficiency in protein. We suggest that carbohydrate deprivation in predators may enhance aphid control. Full article

The Iranian Ground Jay (Podoces pleskei) is the endemic bird species inhabiting the deserts and steppes of Iran, a region experiencing severe ecological disturbances like habitat loss and fragmentation of preferred habitat. Despite its remarkable adaptation to arid environments, Iranian Ground Jay exhibits strong habitat specialization, making it both ecologically resilient and vulnerable—an intriguing case for evaluating how the species responds to climate-driven habitat shifts. The present study aims to assess the current and future distribution of Iranian Ground Jay under climatic change using MaxEnt incorporating presence records and bioclimatic variables. We modeled the species’ potential distribution under two climate models (HadGEM3-GC31-LL and MIROC6) for 2070. Then, using the predicted habitats, we estimated the coverage of protected areas in Iran. Among climatic variables, we predicted that the annual precipitation (bio12), precipitation of driest quarter (bio17), and temperature seasonality (bio4) significantly influenced the distribution of Iranian Ground Jays. The highly suitable distributions of the species are concentrated in Eastern, Southeastern, and Central Iran. Our results indicated that a vast range of potential distribution is located outside protected areas, emphasizing the importance of conservation efforts. Our investigation shed lighted the consequences of global warming, where the highly suitable habitat is expected to shift under predicted climatic changes, resulting in a reduction in suitable habitat extent projected for the future. Based on these insights, it becomes imperative to reassess current conservation policy and devise an action plan specifically tailored for the Iranian Ground Jay, particularly emphasizing the protection of its core habitats within anthropogenically altered landscapes and non-protected regions. Full article

The Biological Monitoring Working Party (BMWP) and Average Score Per Taxon (ASPT) indices, which rely on family-level environmental sensitivity values (FESVs), are widely used in freshwater bioassessment. However, regional differences in taxonomic composition often render existing FESV systems incomplete or incompatible, and the influence of rare families remains poorly understood. Using a historical dataset from the temperate Taizi River basin in Northeast China, we developed a regional FESV system for benthic macroinvertebrates. A total of 67 FESVs were established, including 10 families not previously scored in the UK system. These values followed a normal distribution and were ecologically validated using canonical correspondence analysis (CCA). Both BMWP and ASPT indices showed significant correlations with water quality parameters, the Water Quality Index (WQI), and the Habitat Quality Index (HQI). Notably, excluding rare families (occurrence frequency < 1%) did not reduce but slightly enhanced the responsiveness of both indices. CCA identified HQI, conductivity, and ammonia nitrogen as the primary drivers of community composition, and the inferred ecological preferences aligned well with the assigned FESVs. This study provides a robust, regionally adapted framework for family-level bioassessment in temperate East Asian rivers and supports the exclusion of rare taxa to improve cost-effectiveness and index sensitivity. Full article

Improving peri-urban accessibility involves enhancing infrastructure and connectivity for diverse populations. This study proposes a design-led framework for a multiscalar landscape approach to improve peri-urban accessibility using GIS to assess corridor impacts on (i) pedestrian access to green areas, and (ii) cycling access to semi-natural areas, enhancing daily use and socioecological connectivity. It examines how a continuous, safe network of routes can reduce barriers between urban cores, peri-urban belts, and natural spaces, facilitating recreational access. The network improves accessibility to Madrid’s natural and peri-urban landscapes, intersecting with existing networks and reinforcing city structure. New corridors significantly alter 15 min walk and cycling accessibility to green spaces. Findings suggest that Madrid’s peri-urban landscape access can be improved via a corridor network, linking the green belt to the city at walkable and cyclable distances. This strategy promotes sustainable land use by focusing recreation on resilient routes, buffering habitats, and aligning public preferences for beauty with ecological health. Full article