Centre for Ecological Research

Strategies of coexistence with large carnivores should integrate scientific evidence, population monitoring providing an opportunity for advancing outdated management paradigms. We estimated wolf population density and social dynamics across a 1400 km² area in a data‐poor region of the Romanian Carpathians. Across three consecutive years (2017–2018 until 2019–2020), we collected and genotyped 505 noninvasive DNA wolf samples (scat, hair and urine) to identify individuals, reconstruct pedigrees, and check for the presence of hybridization with domestic dogs. We identified 27 males, 20 females, and one F1 wolf–dog hybrid male. We delineated six wolf packs, with pack size varying between two and seven individuals, and documented yearly changes in pack composition. Using a spatial capture–recapture approach, we estimated population density at 2.35 wolves/100 km² (95% BCI = 1.68–3.03) and population abundance at 70 individuals (95% BCI = 49–89). Noninvasive DNA data collection coupled with spatial capture–recapture has the potential to inform on wolf population size and dynamics at broader spatial scales, across different sampling areas representative of the diverse Carpathian landscapes, and across different levels of human impact, supporting wildlife decision making in one of Europe's main strongholds for large carnivores.

Ecological data on the Smooth Snake ( Coronella austriaca ) remains limited. Previous studies report that it mainly consumes lizards, but also mammals and snakes. Its habitat selection remains poorly understood, especially regarding prey availability. As there is limited data on the diet of this species from Central Europe, and it was considered a potential predator of the endangered Vipera ursinii rakosiensis (Hungarian Meadow Viper), we conducted a study concerning the diet of C. austriaca in one of the largest V. ursinii habitats in Hungary. We also tested if the availability of prey species affects its occupancy. Smooth Snake individuals were captured to collect faecal samples, in which the remains were identified. In the obtained samples, we found remains of lizards (65%, namely Lacerta viridis , Podarcis tauricus and Lacerta agilis ), mammals (20%), insects (12.5%) and Smooth Snake (2.5%). We found no remains of V. ursinii in the samples. We used two-species occupancy modelling to test if the occupancy of C. austriaca is linked to the presence of prey species in the area. We found interactions between C. austriaca and its lizard prey, as occupancy of the Smooth Snake had a higher probability when these species were present. We found no interaction between the Smooth Snake and V. ursinii . Our results support that C. austriaca mainly preys on lizards and its occupancy depends on prey availability. Importantly, we found no evidence that C. austriaca consumes V. ursinii, further supported by the lack of interaction between the occupancy of C. austriaca and V. ursinii .

Flow intermittency and poor environmental conditions can occur separately or simultaneously, affecting the occurrence of trait states in stream macroinvertebrate assemblages. Within the framework of limiting similarity theory, we investigate whether environmental filtering or limiting similarity serves as the primary driver force under three environmental conditions: unstressed (perennial environment and good ecological potential), single-stressed (intermittent condition or poor ecological potential), and multi-stressed (intermittent condition and poor ecological potential) environments. Our analysis validated neutral trait states that are not influenced by different environmental stressors. In unstressed environments, limiting similarity is the primary driver force shaping the macroinvertebrate community. In stressed environments, however, the type of stress determines the influence of environmental filtering. It is not the quantity but rather the quality of stress that increases the influence of environmental filtering. Flow intermittency has a more pronounced effect on the aquatic community than poor ecological potential because it eliminates living conditions, while poor ecological conditions merely restrict them. As anticipated, we observed that certain trait states have specific responses indicating that different driver forces influence them across various environmental conditions. Our study provides valuable insights for managing freshwater habitats and developing adaptive conservation strategies considering increasing drought frequency worldwide.

Background Mosquitoes, as vectors of various pathogens, have been a public health risk for centuries. Human activities such as international travel and trade, along with climate change, have facilitated the spread of invasive mosquitoes and novel pathogens across Europe, increasing the risk of mosquito-borne disease introduction and their spread. Despite this threat, mosquito control in Hungary still relies predominantly on chemical treatments, which poses the risk of developing insecticide resistance in local populations. While pyrethroid resistance has been documented in several countries, there is no information on this issue from Hungary. This study aims to investigate the presence of resistance in Hungarian mosquito populations by analyzing a native, already known disease vector and a recently established invasive species with public health significance. Methods We assessed the presence of knockdown resistance (kdr) mutations L1014F in Culex pipiens and V1016G and F1534C in Aedes albopictus mosquitoes, which are responsible for pyrethroid resistance. Mosquito specimens were investigated retrospectively, collected from previous years within the framework of local monitoring programs run in urban areas representing five regions of Hungary. The mutations in mosquitoes were detected individually by allele-specific polymerase chain reaction (PCR) and gel electrophoresis, following generally used protocols. Results In Cx. pipiens, the kdr mutation was detected across all five collection sites, with resistance allele frequencies ranging from 18.1% to 36.3%. Resistance alleles were identified in homozygosity and heterozygosity with the susceptible allele, resulting in 53% of the investigated mosquitoes showing resistance to pyrethroids in the Hungarian populations. In contrast, for Ae. albopictus, the analyzed individuals were found to carry only the susceptible alleles, indicating a homozygous susceptible genotype across the investigated populations on the basis of V1016G and F1534C genes. Conclusions Our work highlights the consequences of the unilateral and long-term use of chemical treatments on mosquitoes. This indicates an urgent need for a change of concept in mosquito control strategy in Hungary, as well as in countries where mosquito control still relies dominantly on insecticides. The restricted use of chemical treatment is highly recommended to prevent the development of pyrethroid resistance in recently established populations of the invasive Ae. albopictus, and to decrease the public health risk of vector-borne diseases. Graphical Abstract

Saline lakes are hypersensitive to changes in their water balance and therefore show amplified responses to climatic and land-use changes in their catchment. However, despite the resulting, often dramatic ecological consequences, saline lakes rank low on policy agendas as they are assumed to support few ecosystem services and low levels of biodiversity. Here, we challenge this view and evaluate ecosystem services and threatened species in 84 saline lakes distributed across the globe. We found that saline lakes harbour not only threatened aquatic biota but also a diverse range of red-listed terrestrial species that critically rely on the lakes’ existence. Further, our results highlight that saline lakes support, irrespective of their salinity, a number of culturally and economically important ecosystem services. We conclude our analysis with best-practice recommendations for sustainable management of saline lakes. Their local adaptation and implementation will be key for safeguarding biodiversity and ecosystem services of these valuable but highly sensitive ecosystems.

Land use change threatens global biodiversity and compromises ecosystem functions, including pollination and food production. Reduced taxonomic α‐diversity is often reported under land use change, yet the impacts could be different at larger spatial scales (i.e., γ‐diversity), either due to reduced β‐diversity amplifying diversity loss or increased β‐diversity dampening diversity loss. Additionally, studies often focus on taxonomic diversity, while other important biodiversity components, including phylogenetic diversity, can exhibit differential responses. Here, we evaluated how agricultural and urban land use alters the taxonomic and phylogenetic α‐, β‐, and γ‐diversity of an important pollinator taxon—bees. Using a multicontinental dataset of 3117 bee assemblages from 157 studies, we found that taxonomic α‐diversity was reduced by 16%–18% in both agricultural and urban habitats relative to natural habitats. Phylogenetic α‐diversity was decreased by 11%–12% in agricultural and urban habitats. Compared with natural habitats, taxonomic and phylogenetic β‐diversity increased by 11% and 6% in urban habitats, respectively, but exhibited no systematic change in agricultural habitats. We detected a 22% decline in taxonomic γ‐diversity and a 17% decline in phylogenetic γ‐diversity in agricultural habitats, but γ‐diversity of urban habitats was not significantly different from natural habitats. These findings highlight the threat of agricultural expansions to large‐scale bee diversity due to systematic γ‐diversity decline. In addition, while both urbanization and agriculture lead to consistent declines in α‐diversity, their impacts on β‐ or γ‐diversity vary, highlighting the need to study the effects of land use change at multiple scales.

The objective to study the influence of microbiome on host fitness is frequently constrained by spatial and temporal variability of microbial communities. In particular, the environment serves as a dynamic reservoir of microbes that provides potential colonizers for animal microbiomes. In this study, we analyzed the microbiome of Hydra oligactis and corresponding water samples from 15 Hungarian lakes to reveal the contribution of environmental microbiota on host microbiome. Correlation analyses and neutral modeling revealed that differences in Hydra microbiota are associated with differences in environmental microbiota. To further investigate the influence of environmental bacterial community on the host microbiome, field-collected Hydra polyps from three populations were cultured in native water or foreign water. Our results show that lake water bacteria significantly contribute to Hydra microbial communities, but the compositional profile remained stable when cultured in different water sources. Longitudinal analysis of the in vitro experiment revealed a site-specific change in microbiome that correlated with the source water quality. Taken together, our findings demonstrate that while freshwater serves as a critical microbial reservoir, Hydra microbial communities exhibit remarkable resilience to environmental changes maintaining stability despite potential invasion. This dual approach highlights the complex interplay between environmental reservoirs and host microbiome integrity.

Background Chironomidae, with over 7,300 described species, are amongst the most diverse and abundant insect families in freshwater ecosystems worldwide. Chironomids are known for their widespread distribution from various water types. The level of documentation of chironomid fauna varies considerably amongst European countries, with more comprehensive knowledge for Western Europe compared to other regions. Despite the recent extensive sampling effort and the increasing number of available data, the chironomid fauna of Central European countries still remains poorly known. New information This study contributes to the knowledge of chironomid fauna in three river catchments in Croatia, Hungary and Czechia. A combination of morphological and molecular techniques was employed, with a focus on larvae, although pupae and exuviae were also examined. We found 207 taxa, amongst which 170 were identified to species level. In Croatia, 14 species were recorded for the first time and two species were newly recorded in Czechia. DNA barcoding of 31 specimens resulted in 23 BINs, including eight new ones to BOLD. We provided detailed notes on taxa with taxonomic problems and/or morphological peculiarities. Our results highlight that extensive studies conducted in relatively small areas and a limited range of habitats (only streams in hilly regions) can remarkably contribute to the local and global knowledge on Chironomidae fauna, especially when the taxonomically difficult and often problematic larvae are investigated.

To address a gap in our understanding of viral infections in epidemiologically important rat species, we aimed to detect DNA viruses from the tissues of free-ranging rat populations in Hungary. DNA viruses were identified from the parenchymal organs of 230 Rattus norvegicus and Rattus rattus, using family-specific pan-PCR assays followed by sequencing of the PCR products. Adeno-, herpes-, circo-, and polyomaviruses were detected, while irido-, pox-, and dependoparvoviruses were not. Adenovirus DNA was present in 6.5% of the samples, herpesvirus and polyomavirus DNA in 12.2%, and circovirus DNA in 1.7%. All detected herpesviruses belonged to the β and γ subfamilies, with a majority being β herpesviruses. Some adenovirus and herpesvirus sequences were novel, while only the known Rattus norvegicus polyomavirus 1 was detected for polyomaviruses. The rare circovirus-positive samples revealed the presence of both rodent and bird circoviruses, indicating the ability of circoviruses to cross species barriers. Our findings show that rats host a variety of DNA viruses, many of which were previously uncharacterized, highlighting the need for further diagnostic studies.

Purpose of review We are amid a historical momentum encouraging forest restoration, yet the translation of ambitious targets into reality is hindered by poor documentation and understanding of the success and failure of past restoration efforts. This review aims to evaluate the ecological, social, political and economic characteristics of forest restoration across Europe, their development over time and key lessons learned to guide future restoration initiatives. The analysis is based on the synthesis of expert assessments from 18 European countries. Recent findings Early restoration initiatives in central and southern Europe were largely reactive to natural disasters or timber shortages, and while effective in erosion control and timber production, their ecological benefits were often limited due to monoculture plantations and short-rotation systems. Geopolitical crises intensified timber production, with nationalized and centrally managed forests in several countries, but often at the cost of biodiversity. Since the 1990s, a shift toward multifunctionality has emerged driven by the convergence of environmental, social, political and economic events. Summary Forest restoration in Europe has transitioned from disaster reduction and production-driven efforts to a more multifunctional approach that promotes biodiversity. Changes have been driven by a combination of environmental (e.g., catastrophic consequences following natural disasters), political (e.g., wars, forest nationalization and management centralization), legal (e.g., strict and ambitious national and international policies), social (e.g., rural abandonment and changes in societal values) and economic (e.g., new funding mechanisms or market fluctuations) events. Despite the development, conflicting goals, insufficient funding, climate change and short-term thinking persist as key barriers.

Habitat fragmentation is among the most important global threats to biodiversity; however, the direct effects of its components including connectivity loss are largely unknown and still mostly inferred based on indirect evidence. Our understanding of these drivers is especially limited in microbial communities. Here, by conducting a 4-month outdoor experiment with artificial pond (mesocosm) metacommunities, we studied the effects of connectivity loss on planktonic microorganisms, primarily focusing on pro- and microeukaryotes. Connectivity loss was simulated by stopping the dispersal among local habitats after an initial period with dispersal. Keeping the habitat amount constant and the abiotic environment homogeneous allowed us to track the direct effects of the process of connectivity loss. We found that connectivity loss led to higher levels of extinction and a decrease in both local and regional diversity in microeukaryotes. In contrast, diversity patterns of prokaryotes remained largely unaffected, with some indications of extinction debt. Connectivity loss also led to lower evenness in microeukaryotes, likely through changes in biotic interactions with zooplankton grazers. Our results imply that connectivity loss can directly translate into species losses in communities and highlight the importance of conserving habitat networks with sufficient dispersal among local habitats.

The mitochondrial genome of Metazoa is predominantly maternally inherited, providing a valuable genetic marker in various fields such as phylogenetics and phylogeography. However, mitochondrial heteroplasmy, where multiple copies of mitochondrial DNA (mtDNA) coexist within an individual or even cell, presents a challenge to the use of mtDNA markers. This phenomenon may arise from replication errors, mutagenic processes, or paternal leakage. In this study, we investigated mitochondrial heteroplasmy in the freshwater bug Aphelocheirus aestivalis (Fabricius, 1794) using both Sanger and Illumina sequencing approaches. Our analyses confirmed the presence of diverse mtDNA variants within individual specimens collected from various locations across Europe. Signals of mitochondrial heteroplasmy were observed in chromatograms derived from both female and male individuals, indicating a prevalent phenomenon across A. aestivalis populations in general. Further comparative analyses of COI (partial cytochrome c oxidase subunit I) haplotypes indicated their high similarity and complex phylogenetic relationships. In turn, Illumina sequencing of a single male specimen revealed 102 heteroplasmic sites across the protein-coding sequences of mitogenome. Our results suggest the widespread and heritable nature of mitochondrial heteroplasmy in A. aestivalis, highlighting its importance for future phylogenetic and phylogeographic studies.

This study aimed to examine the vertical stratification of the soil seed bank in wet grasslands, with a special emphasis on seeds in deeper soil layers that are generally not considered in seed bank studies. We studied the soil seed bank at four depths: 0–10 cm, 10–30 cm, 30–50 cm, 50–70 cm in five study sites in Central Hungary. The seedling emergence method was used to detect viable seeds. The relationship between the vertical stratification of the seed bank and species traits was studied using generalized linear mixed models. We also sampled the aboveground vegetation and applied non-metric multidimensional scaling to evaluate the species composition of the seed bank and vegetation. The species richness and the seed density of different layers were significantly different; both decreasing with increasing depth. Although most viable seeds were found in 0–10 cm depth (22,632 seeds/m ² ), an unexpected large number of seeds germinated also from the deepest soil layer (50–70 cm; 4170 seeds/m ² ). Species without morphological specializations for spatial seed dispersal (i.e., Allium dispersal type), lower water requirements, and heavier seeds occurred in great abundance in the deeper soil layers. The dominance of species without specialized spatial dispersal suggests that they invest more in temporal dispersal by the soil seed bank. Forbs and perennial species dominated both the seed bank and the aboveground vegetation; however, the dominant species in the seed bank did not correspond to the dominant species in the aboveground vegetation. Our results suggest that the seed bank of wet grasslands does not contain the full habitat-specific species pool despite its high seed density and species richness. The restoration of the studied wet grasslands cannot rely solely on the local seed banks.

Although angler’s groundbaits (GBs) can be an important food resource for fish, we do not know much about the effects of GB consumption on the growth and health of fish. To fill this knowledge gap, we conducted a controlled, six-week long feeding trial (feeding ration: 2% of body weight) with common carp at 22 °C (Cyprinus carpio, mean initial body weight: 557 g) to test the effect of two GBs composed mostly of animal-derived ingredients (AN-GBs) and two plant-based GBs (PL-GBs) relative to one aquaculture feed, as a control (five treatment altogether). Consumption of PL-GBs resulted in lower growth rate than AN-GBs, presumably due to the low protein content. However, the unit biomass increment per unit nitrogen input was higher in PL-GBs. Although PL-GBs resulted in reduction of hepatic energy reserves, hepatosomatic index, viscerosomatic index, and body condition did not differ among the treatments. We did not find differences in expression of inflammatory cytokines in the liver. In conclusion, AN-GBs more effectively increases the carrying capacity of fisheries, but fish sequester a higher portion of nitrogen content of PL-GBs –PL-GB input can be more effectively counterbalanced by fish removal. Finally, the GB consumption does not pose a health risk to fish.

Background We focus on Haldane’s familial selection in monogamous families in a diploid population, where the survival probability of each sibling is determined by altruistic food sharing with its siblings during starvation. An autosomal recessive-dominant or intermediate allele pair uniquely determines the altruistic or selfish behavior, which are coded by homozygotes. We focus on the case when additive cost and benefit functions determine the survival probability of each full sibling. Results We provide conditions for the existence of the altruistic and selfish homozygote. We show that the condition of evolutionary stability of altruism depends on the genotype-phenotype mapping. Furthermore, if the offspring size increases then the condition of evolutionary stability of altruism becomes stricter. Contrary to that, for the evolutionary stability of selfish behavior it is enough if the classical Hamilton’s rule does not hold. Moreover, when the classical Hamilton’s rule holds and the condition of evolutionary stability of altruism does not hold, then the selfish and altruistic phenotypes coexist. Conclusions In summary, the classical Hamilton’s rule is a sufficient condition for the existence of altruism, but it alone does not imply the evolutionary stability of the pure altruistic homozygote population when the altruistic siblings share the cost of altruism.

The valorization of misshapen fruits and vegetables (FV) offers a promising approach to tackling food waste by addressing deeply ingrained aesthetic preferences that influence consumer behavior. Embracing these imperfect yet nutritious products reduces food waste and also challenges the societal standards of beauty in produce, encouraging a broader shift toward sustainability and inclusivity in food consumption. This study aims to support the reduction of FV waste and valorization of misshapen FV by fulfilling two objectives: 1) To map and visualize the key research themes, trends, and relationships within the literature on consumer behavior toward misshapen FV, particularly in the context of food waste; 2) To identify the main drivers of misshapen FV waste and solutions to reduce their waste. Eighty-seven relevant papers (from Web of Science, timespan 1990–2024) were found and analyzed to meet the two objectives, following the Cochrane Rapid Reviews Methods recommendations and minimum standards for rapid reviews. The VOSviewer analysis was conducted for the first objective. It created a keyword network based on abstracts and revealed the central role of consumer awareness and visual biases in shaping purchasing decisions. For the second objective, a rapid review of the full texts was performed and it revealed drivers such as negative perceptions, disgust, and advertising of perfectly shaped products. The study suggests that by integrating sustainability goals with consumer behavior through focused education, marketing, and policies, there is substantial potential to minimize food waste and foster more sustainable consumption habits.

Expertise in biodiversity research (taxonomy, faunistics, conservation with taxonomic background) appears to decline worldwide. While the “taxonomic impediment” is discussed extensively in the literature, much fewer papers focus on the identification crisis, i.e., the decreasing number of experts who can identify species, and the decline of species-based biodiversity research. As a test case to explore the gravity of the identification crisis, we chose Hungary, a Central European country with a strong history of comprehensive taxonomic expertise and research output. We set out to answer two main questions. (1) What proportion of the Hungarian fauna could currently be identified by Hungarian experts, and what factors determine which groups are covered; and (2) what are the trends of biodiversity research in Hungary, and what are the underlying reasons for these trends? We show that Hungary lacks active biodiversity experts for almost half of the nearly 36,000 animal species recorded in the country, and more than a quarter of the fauna have only one or two active experts available. We also show that faunistic research experienced a golden era between ca. 1990 and 2010. Since then, however, there has been a strong decline, with the number of active experts and published papers decreased to a level like that of the 1970s. Multiple factors are identified causing this trend, such as increased pressure to publish in high impact journals and increasing administrative duties of professional scientists. The next generation of biodiversity experts needs to be fluent in modern techniques and publication strategies but also maintain robust morphology-based knowledge to be equipped for identification tasks of difficult taxa. Despite being disadvantaged by exclusive application of citation-based evaluation, we do need more positions and focused grants for biodiversity researchers to maintain the country’s knowledge base and to avoid being increasingly dependent on—equally declining—foreign expertise.