Managing wild boar - Considerations for wild boar management based on game biology data: Grouping patterns, space use, dispersal, hunting impact, and hunting efficiency

Objectives To prevent economic problems by high wild boar populations, an effective and biologically based wild boar management has to be established. A lot of wild boar research has been done in the last decades. However, game managers were not able to incorporate this knowledge into the development of effective management strategies. Thus, furthermore studies have to be accomplished to expand wild boar science and management. This thesis, based on a radiotelemetric study in southwestern Mecklenburg–Western Pomerania, presents research results on wild boar space use patterns, dispersal, grouping patterns and divisions. For all these measures I examined the influence of age classes and environmental factors affecting behavioural patterns (e.g. hunting, seasonal resources, seasonal requirements). Finally, I discussed efficiency and amount of hunting pressure of different hunting methods. Results The wild boar groups divided temporarily in 12.3 % of all observed localisations. We defined four types of divisions: short-term local, short-term extensive, long-term extensive and final division. The small home range sizes did not differ between age classes or group types with a slight tendency for larger home ranges of yearlings, especially in summer. The shift of summer home ranges was stronger in yearlings than in adults. Three space use patterns occurred in summer: field sows, commuters and forest sows. Only 15 % of all shot animals were shot outside their mothers’ home range, only one fourth of these “dispersed” animals were females. Males were shot at larger distances than females. Diurnal activity was positively influenced by daytime length, nutritional needs and fewer disturbances. Due to this reasons an impact of hunting was not clearly detectable. Hunting did influence activity and space use only in moderate intensities. Single hunt from hides is the dominating and an efficient hunting method. The sustainable harvest rate was not exhausted. Conclusions The small home ranges and low, male biased, dispersal rates denote strong site fidelity in all age and reproductive classes within female wild boar. The short distances and low dispersal rates, even within males, might be affected by all year round equably distributed high abundance of resources. Changed space use patterns in summer are mainly influenced by changed food availability. Although hunting was often presumed to be responsible for behavioural changes, little direct influences were observed in this study. The results reflect an interaction between habitat types, season, and nutritional needs on most behavioural patterns. Sound nutritional conditions and year-round low hunting pressure might be responsible for similar seasonal home ranges. Group fluctuations, occurrence of sub-groups as well as temporary and final divisions seem to be common behavioural patterns within wild boar groups, depending on age classes, reproduction, and seasonal nutritional supplies. Wild boar groups react flexible on several seasonal internal and extrinsic factors. The omnivore wild boar is enabled easily to adapt to various environments. Its wide eco-ethological plasticity enables the species to colonize new habitats and enlarge its distribution. All over Europe hunting rates seem to be lower than reproduction of wild boar. To reduce populations and thus, damages, supplemental feeding should be reduced and hunting rates have to be increased especially for females, as all age classes of females are highly reproductive. Hunting management is the most important tool for disease and damage control. As all hunting methods caused similar and negligible disturbances in this study, efficiency should get top priority. The combination of different hunting methods is necessary for reduction on comprehensive areas.Ziele Um ökonomische Probleme durch Schwarzwild zu vermeiden, muss eine effektive und biologisch fundierte Schwarzwildbewirtschaftung etabliert werden. Die Schwarzwildforschung hat sich in den letzten Jahrzehnten stark entwickelt. Trotzdem konnten viele Erkenntnisse nicht in eine effektive Bewirtschaftung umgesetzt werden. Daher sind Untersuchungen zur Erweiterung des Wissens um das Schwarzwild weiterhin wichtig. Diese These, basierend auf einer radiotelemetrischen Studie im südwestlichen Mecklenburg-Vorpommern, präsentiert Ergebnisse zu Raumnutzung, Ausbreitung, Rottenverhalten und –teilungen. Für all diese Verhaltensmuster wurden Einflüsse der Altersklassen und anderer Faktoren wie Bejagung, saisonale Ressourcen und Bedürfnisse untersucht. Abschließend werden Effektivität und Störungseinfluss verschiedener Bejagungsmethoden diskutiert. Ergebnisse In 12,3 % der Lokalisationen waren die Rotten vorübergehend getrennt. Wir haben vier Trennungstypen definiert: kurzzeitig-lokal, kurzzeitig-extensiv, langzeitig-extensiv und final. Die kleinen Streifgebietsgrößen unterschieden sich kaum zwischen Altersklassen und Rottentypen. Überläuferbachen zeigten eine leichte Tendenz zu größeren Sommerstreifgebieten und verlagerten die Sommerstreifgebiete stärker als Familienrotten. Drei Raumnutzungsmuster waren im Sommer offensichtlich: Feldsauen, Pendler und Waldsauen. Lediglich 15 % aller erlegten Tiere wurden außerhalb ihres Mutterstreifgebietes geschossen, nur ein Viertel dieser „abgewanderten“ Tiere waren weiblich. Keiler wurden in größeren Distanzen als Bachen erlegt. Tagaktivität wurde positiv von der Tageslichtlänge, Nahrungsbedarf und geringer Störung beeinflusst. Aufgrund dieser Faktoren war ein Einfluss durch Bejagung nicht klar erkennbar. Bejagung beeinflusste Aktivität und Raumnutzung nur moderat. Die dominierende Jagdart „Einzeljagd auf dem Ansitz“ war durchaus effektiv, dennoch wurde die nachhaltige Zuwachsrate nicht abgeschöpft. Schlüsse Die kleinen Streifgebiete und niedrigen, keilerdominierten Abwanderungsraten deuten eine starke Standorttreue weiblichen Schwarzwildes in allen Altersklassen an. Die niedrige Abwanderung mit gleichzeitig geringen Distanzen, auch bei Keilern, dürfte durch ganzjährig gleichmäßig verteilte besonders günstige Ernährungsbedingungen beeinflusst sein. Unterschiedliche geänderte Raumnutzungsmuster werden vor allem durch unterschiedliche Nahrungsverfügbarkeiten beeinflusst. Obwohl oft Jagddruck als Hauptursache für Verhaltensänderungen angesehen wird, konnten in dieser Untersuchung nur ein geringer Einfluss der Jagd nachgewiesen werden. Die Ergebnisse reflektieren eine Interaktion zwischen Habitattypen, Jahreszeiten und Nahrungsbedarf auf die meisten Verhaltensmuster. Günstige Ernährungsbedingungen und ganzjährig gleichmäßig niedriger Jagddruck könnten für gleich bleibende saisonale Streifgebiete verantwortlich sein. Änderungen in der Rottenstruktur, Auftreten von Teilrotten sowie temporäre und finale Teilungen scheinen normale Verhaltensmuster beim Schwarzwild zu sein, abhängig von Altersklassen, Reproduktion und saisonalem Nahrungsangebot. Schwarzwildrotten reagieren flexibel auf diverse saisonale interne und externe Faktoren. Das omnivoren Schwarzwild ist befähigt, sich schnell an verschiedenste Umwelten anzupassen. Die große öko-ethologische Plastizität ermöglicht es dieser Art neue Lebensräume zu erschließen und sein Verbreitungsgebiet auszudehnen. In ganz Europa scheinen die Jagdstrecken unter der Zuwachsrate des Schwarzwildes zu liegen. Um die Populationen, und damit die Schäden zu reduzieren, müssen Fütterungen reduziert und die Bejagung intensiviert werden. Dieses gilt insbesondere für die Bejagung von weiblichem Schwarzwild, da alle Altersklassen hohe Reproduktionsraten aufweisen. Jagdliche Bewirtschaftung ist das wichtigste Werkzeug zur Bekämpfung von Krankheiten und Wildschäden. Da alle Jagdmethoden in der vorliegenden Studie ähnlich geringe Störungen hervorrufen, sollte die Effektivität in den Vordergrund treten. Die Kombination verschiedener Jagdmethoden und Zusammenarbeit der Jäger ist zwingend erforderlich zur Reduktion der Schwarzwildpopulationen

Does Hunting Affect the Behavior of Wild Pigs?

Wild boar and feral swine (Sus scrofa) numbers are growing worldwide. In parallel, their severe ecological and economic impacts are also increasing and include vehicle collisions, damage to crops and amenities, reduction in plant and animal abundance and richness, and transmission of diseases, the latter causing billions of U.S. dollars in losses to the livestock industry each year. Recreational hunters are the main cause of mortality for this species, and hunting has traditionally been the main method to contain populations of wild pigs. Hunting might affect the behavior of the species, which potentially can lead to these animals moving to new areas or to an increase in disease transmission. This review summarized the evidence that recreational hunting influences the behavior of wild pigs. Twenty-nine studies reported the effect of recreational hunting on social, spatial, and temporal behavior. Although most found that recreational hunting caused changes in home range size, home range shifting, habitat use, and activity patterns, there was little agreement between studies on the size, direction, and duration of these effects. Several studies suggested that other factors, such as season and food availability, equally affect the behavior of this species. Very few studies provided details about the type and frequency of hunting, the number of hunters and dogs (Canis lupus familiaris), the number of animals harvested, or the presence of reserve areas where hunting was forbidden on neighboring sites. As wild pigs adapt to human disturbance, these factors should be investigated to minimize the effects of recreational hunting on the behavior of the species, particularly in the context of disease transmission

Human–wildlife coexistence in a changing world

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

Validation and inference of high‐resolution information (downscaling) of ENETwild abundance model for wild boar

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Analysis of wild boar-domestic pig interface in Europe: spatial overlapping and fine resolution approach in several countries

In order to define the spatial interface between wild boar and domestic pigs in Europe, the ENETWILD consortium (www.enetwild.com) described in a preliminary report the different sources of data for domestic pigs at European scale, and developed a preliminary risk map of possible spatial interaction between both groups. This modelexplored and assessed the use of pig distribution data from Gridded Livestock of the Worlddatabase (GLW), FAO. However, in some specific countries used as cases, the GLW predictions did not reliably represent the pig abundance distribution within countries. The currently available census data of livestock at the European Union level (Eurostat) is limited to the spatial resolution at NUTS2. While Eurostat ensures that data can be potentially comparable,there is still needed to resolve definition issues regarding better spatial resolution (level of aggregation of information) and the pig production systems. In this context, the objectives of this report are (i) assessing the spatial interface between pigs and wild boar over Europe using the best quality data available (Eurostat data and ENETWILD spatial models). We(ii) secondly assessed the interface at higher spatial resolution, distinguishing pig production types in countries where data was available. Based on comparisons at different scales and quality of data, we propose future steps in both data collection and modelling approach.Precisespatial resolution of pig data is not available at European level yet, and the discrimination of extensive vs. intensive farms, backyards vs. commercial; outdoor vs. indoor, is essential to quantify and perform risk analyses separatelyfor each production system and/or considering this relevant source of variation in risk at the interface. The development of a framework to collect harmonised and standardised data at European scale athigher resolution is needed.Peer reviewe

Update of model for wild boar abundance based on hunting yield and first models based on occurrence for wild ruminants at European scale

In the previous ENETWILD model, the predicted patterns of wild boar abundance based on hunting yield data reached an acceptable reliability when the model was downscaled to higher spatial resolution. This new approach, based on the modelling of hunting yield densities instead of hunting yield counts and the assessment of spatial autocorrelation, was only applied with simulated data and with data from two regions at hunting ground level, the smallest spatial resolution. In this report, (1) we evaluate whether this approach can correct the overpredictions for high-resolution predicted patterns when raw data are present at a different spatial resolution (i.e. the European region). For this purpose, hunting yield densities were incorporated as response variable (one model per bioregion) and predictions reliability at 10x10km and 2x2km spatial resolution were assessed. Internal validations and comparisons with the previous two-step model carried out at European scale were addressed, as well as an evaluation with external data at the same scale at country level. The model presented certain overprediction (much less than the previous model) of the total hunting bags reported per country, although a good correlation in terms of values and linearity between observed and predicted values was achieved. Secondly (2), a generic model framework to predict habitat suitability and likely occurrence for wildlife species using opportunistic presence data was proposed (occurrence records for wild ungulate species from the past 20 years exclusively from the Global Biodiversity Information Facility extracted on 9/12/2020). Across all wild ungulate species (elk (Alces alces), roe deer (Capreolus capreolus), red deer (Cervus elaphus), dam deer (Dama dama), muntjac (Muntiacus reevesi), wild boar (Sus scrofa)) the model framework performs well. For those species where area under the curve is below 0.7 we note lower accuracy in predicting absences, which requires further investigation to understand the root cause; whether a result of underlying assumptions regarding the testing data or due to the model performance itself.EFSA-Q-2020-00678Peer reviewe

Data generated by camera trapping in 40 areas in Europe including East and South Europe: report of the field activities (May 2022)

The new-born European Observatory of Wildlife (EOW)2 is a part of the EFSA-funded ENETWILD project, and has the aim of improving the European capacities for monitoring wildlife populations, implementing international standards for data collection, providing guidance on wildlife density estimation, and finally, to promote collaborative, open data networks to develop wildlife monitoring. As a next step, the EOW has engaged and enhanced the existing network of collaborators, and a number of participants are currently preparing field operations to estimate wild mammal density (focused on wild ungulates and other medium to big sized mammals) in certain areas from their respective countries. A field camera trap (CT) based protocol provided by the EOW is going to be applied. An online training course held in May 2022 provided specific training on camera trapping methods and protocols, specifically the random encounter method (REM) and other methods which do not require individual recognition. Here we also present the new field protocol, which is compatible with the subsequent application of artificial intelligence to process and analyze photo trappings using the online app AGOUTI. This strategy aims at promoting a network of professionals/researchers capable of designing, developing field work and analysing data, contributing also to disseminate the experience and train other colleagues in their respective countries. By now, the overall number of countries participating in the EOW is 25. Some participants from 12 countries could already estimate mammal densities during the previous seasons 2019/2020/2021, which will also apply the same methodology in different populations during 2022 in their respective countries. The number of density values finally obtained through this experience by the end of 2022 will exceed 40 different locations in a total of at least 30 countries, since some countries are on the process to confirm their participation. The EOW website is presented. This coordinated field trial activity over a range of European countries, involving different experts and professionals, follows the original plan.EFSA-Q-2022-00057Peer reviewe

Report of the 2nd Annual General Meeting of ENETWILD 5-6th October 2021

External Scientific Report.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.EFSA-Q-2020-00669.Peer reviewe

Launch of the European Wildlife Observatory platform at 13th international symposium on wild boar and other suids (IWBS 2022) - 6-9 September 2022

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.EFSA-Q-2022-00053Peer reviewe