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The wild boar is a large ungulate which may produce serious economic problems. As the wild boar is highly reproductive, a fast dispersing species and flexible in behavior, management has to be adapted to the adaptive wild boar populations. On the other hand, the wild boar lives small scaled in family-groups, which enables management concepts on regional scale. Female wild boar of all age classes should be hunted in favour by comprehensive hunting methods for wild boar population regulation.

The International Symposium on Wild Boar and Other Suids (IWBS 2022), which took place in Montseny Biosphere Reserve (Catalonia, Spain) in September 2022, provided to ENETWILD with the opportunity to meet in‐person for the first time after 2.5 years, and meet the international scientific community with expertise on wild suids and other ungulates. Twelve members of ENETWILD consortium representing 6 partners were present. Bringing together international experts, stakeholders and ENETWILD collaborators was a perfect occasion to present the European Observatory of Wildlife (EOW). Two hundred and twenty‐five wildlife experts from 25 countries were present at symposium, and at presentation of the EOW. Overall, 3 'Plenary Talks' and 118 presentations (62 oral and 56 posters) were made. The meeting has gone through all the possible topics regarding wild suids, from genetics to monitoring and management. This was the optimal context to introduce the EOW to an ideal target audience, both in terms of interest and in terms of potential new member of the Network. From our presentation, it emerged the importance of comparable data on geographical distribution and abundance of wildlife hosts in Europe, fundamental to develop the best management policies and to perform effective risk assessments for shared emergent diseases. The adoption of a common and effective protocol adopted throughout the continent would ensure such comparability. Moreover, the discussion highlighted the need of extending the network to as many European countries as possible and, when feasible, of having multiple sites within each country. A number of participants manifested their interest to join the EOW during the 2023 campaign. Such a capillary distribution of observation points would provide solid and comparable density estimates as well as effective feedback about the field protocol implemented by the EOW. A number of questions were raised by the audience during the presentation of the EOW. [ABSTRACT FROM AUTHOR]

It is essential to provide tools to wildlife professionals and researchers in order to facilitate data collection on wildlife density estimation following standardized protocols in the field. This is relevant for efficient harmonized data management systems, from the field to final reporting. Our main objective was to facilitate the collection of information in the field using established density estimation protocols. The specific objectives were (i) to evaluate and use already existing data registration IT tools for collecting and storing the data in the field; (ii) to make these data available in real time (cloud‐based solution), and (iii) being flexible enough to incorporate new protocols and species, as methods (such as camera trap‐based) and needs continuously evolves. We improved an already existing tool, Spatial Monitoring and Reporting Tool (SMART; https://smartconservationtools.org/). It is an open source software, which allows easily collect, visualize, store, analyze, report and act on a wide range of field data relevant for wildlife monitoring. The integration of SMART tools on EOW was successfully done for (i) distance sampling, (ii) hunting data and (iii) camera trap protocols. ENETWILD, therefore, made now available new IT functionalities to wildlife professionals and researchers to facilitate and harmonize wildlife data collection systems. [ABSTRACT FROM AUTHOR]

This report presents the results of field activities in relation to the generation of reliable wild boar density values by camera trapping (CT) in 19 areas in Europe, mainly in East Europe. Random Encounter Model (REM) densities ranged from 0.35±0.24 to 15.25±2.41 (SE) individuals/km2. No statistical differences in density among bioregions were found. The number of contacts was the component of the trapping rate that determined the coefficient of variation (CV) the most. The daily range (DR) significantly varied as a function of management; the higher values were detected in hunting grounds compared to protected areas, indicating that movement parameters are population specific, and confirming the potential role of hunting activities in increasing wild boar movement and contact rates among individual or groups. The results presented in this report illustrate that a harmonized approach to actual wildlife density estimation (namely for terrestrial mammals) is possible at a European scale, sharing the same protocols, collaboratively designing the study, processing, and analysing the data. This report adds reliable wild boar density values that have the potential to be used for wild boar abundance spatial modelling, both directly or to calibrate outputs of model based on abundance (such as hunting bags) or occurrence data. Future REM developments should focus on improving the precision of estimates (probably through increased survey effort). Next steps require an exhaustive and representative design of a monitoring network to estimate reliable trends of wild boar populations as a function of different factors in Europe. In this regard, the newly created European Observatory of Wildlife will be a network of observation points provided by collaborators from all European countries capable to monitor wildlife population at European level. [ABSTRACT FROM AUTHOR]

The 2nd ENETWILD Annual General Meeting took place on 5‐6th October 2021, bringing together experts, stakeholders and ENETWILD collaborators in online workshop discussions. First, workshop discussions contributed to the analysis and proposal of approaches for a harmonized European‐wide wildlife monitoring framework able of sustaining coordinated decision‐making. Secondly, participants identified the key challenges that managers face in making decisions for wildlife in Europe and data needs for policies. Finally, we illustrated these challenges with the case of wild boar as a model species widely distributed across Europe. Inputs from the participants were collated into a plan of proposed steps and objectives for the mid‐term (5‐year time frame) to achieve progress on harmonised, coordinated, and integrated wildlife monitoring at the European level, which requires the contribution of experts from the early stages.. Specific proposed actions include the creation of a trans‐disciplinary authority at the European level, effective points of reference for data collection and sharing at different administrative levels and countries, a standing committee to coordinate and exchange experience and capacities on data collection between countries, and expert groups for problem solving, with proper EU financial support, establishing regular policy meetings.. To provide useful results, wildlife monitoring must ensure proper design and data analysis for subsequent science‐based management and best allocation of management resources. The 'Observatory' approach (a representative network of intensively monitored sites) can provide long‐term systematic and representative insights, normally more feasible for comparative studies, providing less biases and support for decision‐making. For international decision‐making by wildlife managers and politicians based on scientific knowledge and interdisciplinary research, experts should define the foundations of a common European wildlife decision‐making framework (inter‐institutional and inter‐sectorial). The development of a European legislation on wildlife management may represent an opportunity for addressing the abovementioned steps, identifying data priorities matching the needs of the various European Directorates, Agencies, and monitoring frameworks. [ABSTRACT FROM AUTHOR]

The ENETWILD consortium (www.enetwild.com) aims at progressively defining the spatial interface between wild ungulates and livestock in Europe, which is essential to evaluate the risk for shared diseases. This is to provide preliminary risk maps of possible wild‐domestic interfaces at European scale using relatively similar sized regions by compiling, for the first time, comprehensive data for both groups, wild and domestic ungulates in the continent. We spatially represented (i) the richness of species (livestock and wild ungulates), (ii) their specific occupancy and abundance (the latter for livestock), and finally, (iii) their spatial overlapping over Europe. Species richness in animal communities, including wildlife and domestic hosts, may moderate pathogen transmission and disease outcome.. As a first step, we should characterize the diverse assemblages of animal communities at large scale to better understand possible scenarios for further assessment of shared infection dynamics. About 90% of Europe land area hosts from one to five species of wild native ungulates. Therefore, the interface between livestock and wildlife is wide spread over the European continent. Native wild boar, roe deer and reed deer are widely distributed species, present in most possible assemblages of wild/domestic communities over Europe. The richness of ungulate species is high in Central Europe, from West to East, from the Alps (where the presence of mountain ungulates adds richness), extending to countries with important big game tradition and presence of introduced species, and finally, to Eastern Europe (where also typically northern species such as bisons appear)... To sum, we described by pair of species a wide diversity of potential interfaces, which had variable distribution areas.. While the analysis presented herein is purely spatial and at administrative level, the interface between wild and domestic ungulates is influenced by livestock husbandry (e.g., enclosed, herded or free‐ranging, level of biosecurity), landscape and land uses, and wildlife management practices, among other factors, operating locally. Therefore, there is need for a more detailed picture of the interface at European scale. [ABSTRACT FROM AUTHOR]

The methods for estimating relative abundance and density in wild ruminant species are reviewed and insights on how to obtain reliable estimations by using those methods are provided. Eighteenmethods used in nineteenwild ruminant species widely distributed across Europe are reviewed. In accordance with the ENETWILD consortium objectives, we evaluate if different types of data can be used to generate harmonisedand comparable database at large scale and for calibration of hunting data into abundanceindices or population density. In addition, recommendations to select the methods to estimate the abundance or density and its implementations for ungulate populations are provided. How to increase the output quality provided by certain methods recognised as reliable (good accuracy and precision)and with the potential to be used for the validation and calibration ofother direct (i.e. based on observation of animals) or indirect (i.e. based on signs of animal activity) methods was recommended. Largely, the "counting" of large herbivores on a regional scale is often unfeasible, it can only be possible to accurately assess population status at local scale. We show that the habitat type plays a key role in the selection of the best method to determine density or relative abundance and that this is partially irrespective to species characteristics. A method that gives a density estimate rather than relative abundance, if possible, should be used. High‐quality hunting data statistics (collected at fine spatial resolution) have the highest availability and comparability potential across Europe, to give long‐term and large‐scale trends and should be used in predictive spatial modelling of wild ruminant relative abundance and density. Therefore, their standardized and harmonised collection is strongly recommended. On a local scale (e.g. management units), camera trapping is a method that can be conducted in different environmental conditions and at any time to collect robust data. In open areas, where camera trappingmay require an excessive effort, we suggest using methods involving the direct detection of animals (vantage points, linear transects, block counts, random points). This should be carried outby correctly defining the study areas (for instance by means of distance sampling) and by estimating the repeatability of the results. [ABSTRACT FROM AUTHOR]

The consumption of raw or undercooked meat products poses a serious risk for human hepatitis E virus (HEV) infections. In many high-income countries, domestic pigs and wild boars represent the main animal reservoirs for HEV and are usually identified by reverse transcription-PCR and antibody enzyme-linked immunosorbent assay (ELISA). In order to characterize the humoral immune response in more detail, a cell culture-based serum neutralization assay using a culture-adapted HEV strain was established here. Measurement of neutralizing antibodies was only possible after removing the viral quasi-envelope by detergent treatment. Serum samples of 343 wild boars from Northern Germany were first analyzed for anti-HEV IgG using an in-house ELISA, resulting in 19% positive samples. Subsequently, a subset of 41 representative samples was tested with the neutralization assay, and the results correlated well with those obtained by ELISA. Not only the human HEV strain 47832c but also two porcine HEV strains were shown to be neutralized by porcine serum antibodies. Neutralizing activity was also found in samples containing both HEV-specific antibodies and HEV RNA. Testing of serum samples derived from two experimentally infected domestic pigs showed a steep increase in neutralizing activity at 24 or 51 days post infection, dependent on the used infectious dose. The developed assay can be useful for characterization of the humoral immune response after HEV infection and for assessing the efficiency of HEV vaccine candidates., Competing Interests: The authors declare no conflict of interest.

As one of the most abundant game species in Europe, European wild boar ( Sus scrofa ) populations prove highly adaptable to cultivated landscapes. The ongoing process of climate change and the high agricultural yields seem to further optimize the living conditions for this species. In long-term reproduction monitoring, we collected data on the body weight of wild boar females. Over an 18-year period, the body weight of wild boar females increased continuously, then stopped and decreased. It was possible to detect differences between the body weights of animals from forest and agricultural areas. For these areas, differences in body weight development also led to a significant distinction in the onset of puberty. We conclude that, even in a highly cultivated landscape, forested areas provide habitat characteristics that may strongly influence reproduction. Second, with dominant agricultural areas in Germany, wild boar reproduction has been favored in recent decades.

As a zoonotic pathogen, the hepatitis E virus (HEV) leads to numerous infections in humans with different clinical manifestations. Especially genotype 3, as causative agent of a foodborne zoonosis, is transmitted to humans by ingestion of undercooked or raw meat containing liver from HEV-infected animals. Although the virus' prevalence and dissemination in hosts like wild boar and pig have been well characterized, HEV is greatly understudied on a molecular level and reliable cell culture models are lacking. For this reason, the present study concentrated on the isolation and subsequent characterization of porcine HEV from tissue samples derived from wild boar and domestic pigs: 222 wild boars hunted in Northern Germany were investigated for the presence of HEV RNA with a detection rate of 5.9%. Three additional HEV-positive wild boar liver samples as well as an HEV-positive spleen and a positive kidney from domestic pigs were included. After inoculation of positive samples onto the human hepatoma cell line PLC/PRF/5, cells were grown for several weeks. Successful isolation was confirmed by RT-qPCR, virus passage, immunofluorescence staining and titration. Overall, 15 strains from a total of 18 RNA-positive organ samples could be obtained and viral loads >10 9  RNA copies/ml were measured in cell culture supernatants. Accordingly, 83.3% of the HEV RNA-positive samples contained infectious hepatitis E viral particles and therefore must be considered as a potential source for human infections. Phylogenetic analyses revealed that all isolated strains belong to genotype 3. Further genetic characterization showed a high degree of sequence variability, but no sequence insertions, in the hypervariable region within the open reading frame 1., (© 2022 The Authors. Transboundary and Emerging Diseases published by Wiley-VCH GmbH.)

The hepatitis C virus (HCV)-related bovine hepacivirus (BovHepV) can cause acute as well as persistent infections in cattle. The true clinical relevance of the virus is not yet known. As reliable antibody detection methods are lacking and prevalence studies have only been conducted in cattle and few countries to date, the true distribution, genetic diversity, and host range is probably greatly underestimated. In this study, we applied several RT-PCR methods and a nano-luciferase-based immunoprecipitation system (LIPS) assay to analyze bovine serum samples from Bulgaria as well as wild ruminant sera from Germany and the Czech Republic. Using these methods, BovHepV infections were confirmed in Bulgarian cattle, with viral genomes detected in 6.9% and serological reactions against the BovHepV NS3 helicase domain in 10% of bovine serum samples. Genetic analysis demonstrated co-circulation of highly diverse BovHepV strains in Bulgarian cattle, and three novel BovHepV subtypes within the genotype 1 could be defined. Furthermore, application of a nested RT-PCR led to the first description of a BovHepV variant (genotype 2) in a wild ruminant species. The results of this study significantly enhance our knowledge of BovHepV distribution, genetic diversity, and host range.

Understanding the spatio-temporal distribution of ungulates is important for effective wildlife management, particularly for economically and ecologically important species such as wild boar ( Sus scrofa ). Wild boars are generally considered to exhibit substantial behavioral flexibility, but it is unclear how their behavior varies across different conservation management regimes and levels of human pressure. To analyze if and how wild boars adjust their space use or their temporal niche, we surveyed wild boars across the core and buffer zones (collectively referred to as the conservation zone) and the transition zone of a biosphere reserve. These zones represent low and high levels of human pressure, respectively. Specifically, we employed a network of 53 camera traps distributed in the Schaalsee UNESCO Biosphere Reserve over a 14-month period (19,062 trap nights) and estimated circadian activity patterns, diel activity levels, and occupancy of wild boars in both zones. To account for differences in environmental conditions and day length, we estimated these parameters separately for seven 2-month periods. Our results showed that the wild boars were primarily nocturnal, with diurnal activity occurring dominantly during the summer months. The diel activity patterns in the two zones were very similar overall, although the wild boars were slightly less active in the transition zone than in the conservation zone. Diel activity levels also varied seasonally, ranging from 7.5 to 11.0 h day -1 , and scaled positively with the length of the night ( R 2  = 0.66-0.67). Seasonal occupancy estimates were exceptionally high (point estimates ranged from 0.65 to 0.99) and similar across zones, suggesting that the wild boars used most of the biosphere reserve. Overall, this result suggests that different conservation management regimes (in this case, the zoning of a biosphere reserve) have little impact on wild boar behavior. This finding is relevant for wildlife management in protected areas where possibly high wild boar densities could interfere with conservation goals within these areas and those of agricultural land use in their vicinity., Competing Interests: None declared., (© 2021 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

The ubiquitous wild boar is causing diverse and growing conflicts of socio-ecological and economic relevance worldwide. For that reason, knowledge of its spatial ecology is crucial to designing effective management programmes. But this knowledge is scarce in Mediterranean areas with mixed land uses. We describe the spatial ecology and habitat selection of 41 adult wild boar monitored using GPS collars and analyse the effects of sex and the period (food shortage period, hunting season and food abundance period) under different land uses (protected areas, mixed farms and fenced hunting estates). The spatial ecology of wild boar was characterised by marked temporality, mediated by sex and the land uses in the area. The activity (ACT), daily range (DR) and home range (HR) were higher for males than females, and in mixed farms versus fenced hunting estates, while the lowest values were obtained in protected areas. These effects were more marked for ACT and DR (movement) than HR. The selection of scrublands and avoidance of woodlands was observed where drive hunt events occur (mixed farms and fenced estates), but not in the protected areas. The differences in the requirements, reproductive behaviour and, interestingly, response to disturbance according to sex may explain this dissimilar behaviour. Disturbance originated higher movement rates and the selection of sheltering land cover as a refuge during the hunting season. This information is useful for designing species monitoring and management programmes; including both preventive and reactive actions in response to events such as outbreaks of African swine fever and agricultural damage produced by wild boar in Europe., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2021. Published by Elsevier B.V.)

High wild boar population densities lead to demands for a population reduction to avoid crop damages or epidemic diseases. Along with biological studies, a better understanding of the human influence on wildlife and on wildlife management is important. We conducted inquiries on hunting methods and on hunters' attitudes in the Federal State of Lower Saxony, Germany, to better understand hunting strategies and the influence on increasing wild boar population, as well as to underpin game management concepts. Single hunt, especially at bait, is still the most widely used method for hunting wild boar. The proportion of drive hunts within the hunting bag is increasing. The proportions of hunting methods vary regionally due to wild boar densities, geographical features (vegetation, terrain, etc.) and hunters' practices. Hunters increased the proportion of conjoint hunts on wild boar. Baiting remains an important hunting method in wild boar management and the proportion of drive hunts should be fostered. Private hunting is important for wild boar management, although it is just insufficient. Additionally, administrative wildlife managers are recommended for the near future as coordinators of wild boar management, and as such, could manage hunting, the incorporation of regional conditions and investigating hunters' attitudes and abilities.

Hunting can easily be linked to stress in wildlife. Drive hunts performed two to three times in one area during the respective hunting period, are thought to decrease the pressure hunting places on wildlife. Nevertheless, the expression of cortisol-one of the main mammalian stress hormones-is considered to have negative impacts on animals' well-being if expressed excessively, which may occur during some (especially repeated) hunting events. We explored the effect of drive hunts on cortisol levels in wild boar in Lower Saxony, Germany, compared these cortisol levels to reference values given by a similar study, and investigated the effect of age, sex, and pregnancy. Blood collected from wild boar shot on drive hunts was analysed using a radioimmunoassay. As expected, we observed elevated cortisol levels in all samples, however, we still found significant differences between age groups and sexes, as well as an influence of pregnancy on cortisol levels. The effect of drive hunts on cortisol levels appears to be weaker than predicted, while the effects of other variables, such as sex, are distinct. Only half of the evaluated samples showed explicitly increased cortisol levels and no significant differences were found between sampling months and locations. Group living animals and pregnant females showed significantly higher cortisol levels. The impact of hunting is measurable but is masked by natural effects such as pregnancy. Thus, we need more information on stress levels in game species., (© 2021. The Author(s).)

Background: The wild boar population in Europe is steadily growing, one of the reasons for this increase probably being the high reproductive potential of this large mammal. Population management is important to stabilise wild boar numbers and a great deal of attention is focusing on the reasons, which might contribute to the high reproductive rates. Understanding the timing of puberty attainment provides information required for proper management practices. Knowledge of the earliest expected time of sexual maturation in male wild boars is limited, research being mostly focused on females. Previous hunting references indicate that sexual maturity in males occurs in the second year after birth. In contrast, male domestic pigs become sexually mature from about seven months of age. Thus, aims of this study were to investigate (1) whether there is a physiological ability for reproduction also in male wild boars of a younger age and (2) whether the body weight of wild boar males has a more important role than age in driving the maturation of the testis., Methods: Male wild boar individuals were sampled during hunting drives in the eastern part of Lower Saxony in Germany. Testes with epididymides from 74 males were collected and prepared for histological examination and immunohistochemistry. The reproductive status could be ascertained based on development/occurrence of different germ cell populations using histology and based on the immunohistochemical detection of the anti-Müllerian hormone and androgen receptor., Results: In this study, male wild boars aged nine to ten months already passed puberty and were able to reproduce if they had reached the appropriate body condition of about 29 kg dressed weight. Immunopositivity to the anti-Müllerian hormone in Sertoli cells was evident only in prepubertal animals and decreased with the onset of puberty. No immunoreaction was evident at postpuberty. The androgen receptor was detected in Sertoli cells, peritubular cells and Leydig cells, surprisingly already in Sertoli cells of prepubertal wild boars as well depending on body weight. Moreover, two-thirds of young males aged about ten months were precociously reproductively mature, showing histologically the presence of spermatozoa in testes and epididymides., Conclusions: As piglets are mostly born in spring, also these young male individuals could target the heat of female wild boars in the winter months, resulting in the observed population increase. Therefore, a reduction in wild boar numbers should also focus on piglets of both sexes., Competing Interests: The authors declare there are no competing interests., (©2021 Maistrelli et al.)

Human-wildlife conflict (HWC) is a key topic in conservation and agricultural research. Decision makers need evidence-based information to design sustainable management plans and policy instruments. However, providing objective decision support can be challenging because realities and perceptions of human-wildlife interactions vary widely between and within rural, urban, and peri-urban areas. Land users who incur costs through wildlife argue that wildlife-related losses should be compensated and that prevention should be subsidized. Supporters of human-wildlife coexistence policies, such as urban-dwelling people, may not face threats to their livelihoods from wildlife. Such spatial heterogeneity in the cost and benefits of living with wildlife is germane in most contemporary societies. This Special Section features contributions on wildlife-induced damages that range from human perspectives (land use, psychology, governance, local attitudes and perceptions, costs and benefits, and HWC and coexistence theory) to ecological perspectives (animal behavior). Building on current literature and articles in this section, we developed a conceptual model to help frame HWC and coexistence dimensions. The framework can be used to determine damage prevention implementation levels and approaches to HWC resolution. Our synthesis revealed that inter- and transdisciplinary approaches and multilevel governance approaches can help stakeholders and institutions implement sustainable management strategies that promote human-wildlife coexistence., (© 2020 The Authors. Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology.)

Pegiviruses belong to the family Flaviviridae and have been found in humans and other mammalian species. To date eleven different pegivirus species (Pegivirus A-K) have been described. However, little is known about the tissue tropism and replication of pegiviruses. In 2016, a so far unknown porcine pegivirus (PPgV, Pegivirus K) was described and persistent infection in the host, similar to human pegivirus, was reported. In this study, qRT-PCR, phylogenetic analyses and fluorescence in situ hybridization (FISH) were implemented to detect and quantify PPgV genome content in serum samples from domestic pigs from Europe and Asia, in tissue and peripheral blood mononuclear cell (PBMC) samples and wild boar serum samples from Germany. PPgV was detectable in 2.7% of investigated domestic pigs from Europe and China (viral genome load 2.4 × 10 2 to 2.0 × 10 6 PPgV copies/ml), while all wild boar samples were tested negative. Phylogenetic analyses revealed pairwise nucleotide identities >90% among PPgVs. Finally, PPgV was detected in liver, thymus and PBMCs by qRT-PCR and FISH, suggesting liver- and lymphotropism. Taken together, this study provides first insights into the tissue tropism of PPgV and shows its distribution and genetic variability in Europe and China.

As a part of the ongoing game survey of the German federal state of Lower Saxony (WTE), we conducted inquiries into wild boar management and distribution, as well as hunters' attitudes, in order to determine the reasons for the increase of wild boar populations and to inform our game management strategy. According to hunters' reports within the WTE, increases in distribution and population continue and a reduction of the wild boar population has been deemed necessary on a large scale. In the home region, however, it seems to be "somebody else's problem" (SEP), according to hunters' opinions. The majority of hunters are not able to regulate the population and this could be a reason that wild boar numbers continue to increase. Cooperation and comprehensive hunting with efficient hunting methods seems to be the most promising solution, as non-hunting methods are unpopular amongst hunters. The hunters seem to be aware of the problems, solutions and contributing factors; however, most hunters do not feel responsible and see the management of wild boar, again, as a SEP. Regional conditions, as well as hunters' willingness and capacity to manage wild boar will have to be incorporated into management concepts., (Copyright © 2016 Elsevier B.V. All rights reserved.)

The wild boar population has increased enormously in all of Europe over the last decades and caused problems like crop damage, transmission of diseases, and vehicle accidents. Therefore, it is necessary to investigate the underlying causes of this increase in order to be able to manage populations effectively. The purpose of this study was to analyse how environmental (food and climate) and physiological factors (maternal weight and age) as well as hunting and population density influence the litter size of wild boar populations in Northern Germany. The mean litter size in the studied population for the whole period was 6.6 (range 1–12), which is one of the highest in all of Europe. Litter size was positively influenced by maternal body weight, higher mast yield of oak as well as higher temperature in combination with higher precipitation in summer. Only higher temperature or only higher precipitation in summer however had a negative effect on litter size production. Probably,weather and food conditions act via maternal bodyweight on the litter size variation in wild boar. Hunting as well a s population density did not affect the litter size variation in this study which might indicate that wild boar population did not reach carrying capacity yet.