Wild Boar Habitat Research Articles

Habitat suitability and relative abundance of wild boars in the east‐central Tianshan Mountains, China

AbstractAs wild boar populations and their distribution ranges increase, human–wild boar conflicts have become increasingly prevalent in numerous regions across the globe. These conflicts have a profound impact on human livelihoods, resulting in significant economic losses. Understanding the habitat requirements and relative abundance of wild boars is crucial prior to implementing any conservation measures. However, studies on wild boar habitat and population in the central and eastern regions of the Tianshan Mountains in China are lacking. We assessed the activity patterns and relative abundance of wild boars in these areas and evaluated habitat suitability using a combination of camera trapping, line transects, species distribution modeling (maximum entropy model), and hierarchical abundance modeling (Bayesian N‐mixture model). We used 311 infrared cameras and 280 field‐based line transects to cover approximately 31,000 km² from September 2022 to May 2023 in the east‐central Tianshan Mountains. We used 240 wild boar distribution locations and 13 environmental predictors in the development of species distribution models. We also used species counts and associated environmental predictors in the N‐mixture model to estimate the relative abundance of wild boar. Wild boars were most active during crepuscular hours (1800), and relatively active in the diurnal period compared to the nocturnal period. The probability of wild boar occurrence increased with higher normalized difference vegetation index (NDVI), the minimum temperature of the coldest month, and annual temperatures below 39°C. Boars were most likely to be found in closed deciduous‐coniferous forests. The relative abundance of wild boars was positively affected by NDVI and negatively affected by the minimum temperature of the coldest month and temperature annual range. Based on our results, we suggest areas of management priority. In particular, extensive and intact habitat with substantial wild boar populations, such as the Banfanggou, the South Mountain of Urumqi, and the Hutubi, should be prioritized for long‐term wild boar population monitoring and management so the adverse impacts of increasing wild boar populations in the study region can be minimized.

Spatial and temporal analysis of African swine fever front-wave velocity in wild boar: implications for surveillance and control strategies.

The front-wave velocity of African swine fever (ASF) virus spread is depicted through a retrospective spatial and temporal analyses of wild boar outbreaks from Jan. 2014 to Jan. 2022 in Estonia, Latvia, Lithuania and Eastern Poland-regions responsible for more than 50% of all wild boar cases in the EU. The study uses empirical semivariograms in a universal kriging model to assess spatial autocorrelation in notification dates and identifies a discernable large-scale spatial trend. The critical parameter of ASF front-wave velocity was identified (Mean = 66.33 km/month, SD = 163.24) in the whole study area, and explored the variations across countries, wild boar habitat suitability, seasons, and the study period. Statistical differences in front-wave velocity values among countries and temporal clusters are explored, shedding light on potential factors influencing ASF transmission dynamics. The implications of these findings for surveillance and control strategies are discussed.

Landscape connectivity for predicting the spread of ASF in the European wild boar population

African swine fever (ASF) is an infectious and highly fatal disease affecting wild and domestic swine, which is unstoppably spreading worldwide. In Europe, wild boars are one of the main drivers of spread, transmission, and maintenance of the disease. Landscape connectivity studies are the main discipline to analyze wild-species dispersal networks, and it can be an essential tool to predict dispersal-wild boar movement routes and probabilities and therefore the associated potential ASF spread through the suitable habitat. We aimed to integrate wild boar habitat connectivity predictions with their occurrence, population abundance, and ASF notifications to calculate the impact (i.e., the capacity of a landscape feature to favor ASF spread) and the risk (i.e., the likelihood of a habitat patch becoming infected) of wild boar infection across Europe. Furthermore, we tested the accuracy of the risk of infection by comparing the results with the temporal distribution of ASF cases. Our findings identified the areas with the highest impact and risk factors within Europe's central and Eastern regions where ASF is currently distributed. Additionally, the impact factor was 31 times higher on habitat patches that were infected vs non-infected, proving the utility of the proposed approach and the key role of wild boar movements in ASF-spread. All data and resulting maps are openly accessible and usable.

Density-dependent dinner: Wild boar overuse agricultural land at high densities

The Swedish wild boar (Sus scrofa) population has increased rapidly over the last decades, resulting in conflicts with human activities. Particularly, the increase has been challenging for agriculture as wild boar cause damage on crops and grasslands. To predict under what conditions to expect damage and where to prioritize management actions, basic knowledge about wild boar habitat and space use is needed. In this study, we used data from 99 wild boar equipped with GPS-collars, collected over a large temporal scale and throughout their distributional range in southern Sweden. We investigated wild boar home range size and habitat use across gradients of habitat availability and population density. Functional response in habitat use was assessed by estimating the use and availability of agricultural land on individual level and then, on population-level evaluating how use changed with changing availability. Finally, a potential response in habitat use was evaluated in relation to population density, i.e., the interaction between availability and population density. Home range size was negatively related to population density for both male and female wild boar. Wild boar used agricultural land more intensively with increasing population density and when other habitat types were less available. Our findings show that wild boar spatial behavior is highly context dependent and may vary considerably due to landscape characteristics and local conditions. Wild boars tend to overuse agricultural land at high densities which has strong implications for wildlife management. It is therefore important to consider local conditions when predicting space and habitat use by wild boar. Overall, this study provided a better understanding of the drivers of wild boar distribution and space use in agro-forested mosaic landscapes and how this knowledge can improve management practices.

Habitat suitability and crop damage risk caused by wild boar in Guizhou Plateau, China

AbstractCrop damage caused by wild boar (Sus scrofa) in many agroforestry regions of the world has affected agricultural development and farmers' livelihoods. Understanding the patterns of wild boar crop damage is important for properly managing these conflicts, and can improve the effectiveness of existing prevention strategies. We collected a comprehensive dataset from Guizhou Province, China, from 2017 to 2020, obtained from motion‐sensitive camera monitoring, transect surveys, interview surveys, and wildlife management administrations. These data include 3,156 records of wild boar activity in natural areas and 576 records of crop damage. We applied a multi‐scale MaxEnt model to map the regional distribution of wild boar habitat suitability and crop damage risk in Guizhou Province and focused on the role of habitat suitability in wild boar crop damage from a regional perspective. Wild boar habitat suitability exhibits a divergent pattern, expanding from the central area of Guizhou Province to the eastern, northern, southern, and northwestern regions, with a gradually increasing trend. Suitability of habitat for wild boar was associated with composite topographic index, mean coldest season temperature, isothermality, Shannon diversity index, edge density, and distance to village roads. Similarly, crop damage caused by wild boars in agroforestry areas is mainly concentrated in the northeast, with the risk increasing from west to east. The risk of damage was associated with temperature seasonality, roughness, distance to village roads, precipitation in the warmest quarter, edge density, and contagion index. Furthermore, in agroforestry areas, there is a positive correlation between wild boar habitat suitability and crop damage risk, with Spearman rank correlation coefficients ranging from 0.5759 to 0.5932. This correlation is not perfectly synchronized on a regional scale. This study indicates that the relationship between habitat suitability and crop damage caused by wild boar in Guizhou Province is primarily influenced by changes in population size rather than the habitat. Consequently, we emphasize the importance of controlling wild boar populations through hunting as a way to effectively reduce the risk of crop damage in agroforestry areas, without neglecting the need for proper habitat management.

Potential effect of managing connectivity to contain disease spread among free‐ranging wild boar (Sus scrofa) in disparate landscapes

Abstract Landscape connectivity is a major factor shaping the spread of pathogens in wildlife populations. By managing connectivity, transmission pathways can be broken and disease spread be contained, particularly in the early phases of an outbreak. Having witnessed recent outbreaks of African Swine Fever in free‐ranging wild boar (Sus scrofa) in Belgium, Germany and Italy, offices for disease control are on the alert also in other western European countries. This study investigates the potential effect of managing landscape connectivity to contain disease spread among free‐ranging wild boar in disparate landscapes. It involves research into (1) the ease with which wildlife corridors can be blocked for wild boar, (2) the connectivity of wild boar habitat and (3) the impact of landscape fragmentation on connectivity management. This is addressed by carrying out GIS analyses and performing graph operations on the wild boar networks in different biogeographical regions of Switzerland. The results of doing research into the three above‐mentioned objects show that, regarding the first, most wildlife corridors are hard to block for wild boar, because their features or location make fencing difficult. Regarding the second, the wild boar habitat is connected. Opening wildlife passages that are currently under construction may allow wild boar to disperse to hitherto uncolonized areas. Regarding the third, all wild boar networks could be partially decomposed by blocking the easy to block corridors and closing the passages. Network decomposition would be easiest to achieve in the region where the built infrastructure is most abundant. All over Switzerland, the potential epidemic size could be reduced by 25% when blocking the minimal set of corridors and passages that cut the networks to non‐decomposable components. This study suggests that (a) combining connectivity analysis with fragmentation analysis is key to explaining why a specific measure of disease containment is more effective in one landscape than in the other, (b) complementing the permeability model with a species distribution model is essential to identify connected habitat patches for the species of concern and (c) connectivity metrics should consider also the surface area of occupied habitat patches and relative abundance of the species of concern.

The importance of fine-scale predictors of wild boar habitat use in an isolated population.

Predicting the likelihood of wildlife presence at potential wildlife–livestock interfaces is challenging. These interfaces are usually relatively small geographical areas where landscapes show large variation over small distances. Models of wildlife distribution based on coarse data over wide geographical ranges may not be representative of these interfaces. High‐resolution data can help identify fine‐scale predictors of wildlife habitat use at a local scale and provide more accurate predictions of species habitat use. These data may be used to inform knowledge of interface risks, such as disease transmission between wildlife and livestock, or human–wildlife conflict.This study uses fine‐scale habitat use data from wild boar (Sus scrofa) based on activity signs and direct field observations in and around the Forest of Dean in Gloucestershire, England. Spatial logistic regression models fitted using a variant of penalized quasi‐likelihood were used to identify habitat‐based and anthropogenic predictors of wild boar signs.Our models showed that within the Forest of Dean, wild boar signs were more likely to be seen in spring, in forest‐type habitats, closer to the center of the forest and near litter bins. In the area surrounding the Forest of Dean, wild boar signs were more likely to be seen in forest‐type habitats and near recreational parks and less likely to be seen near livestock.This approach shows that wild boar habitat use can be predicted using fine‐scale data over comparatively small areas and in human‐dominated landscapes, while taking account of the spatial correlation from other nearby fine‐scale data‐points. The methods we use could be applied to map habitat use of other wildlife species in similar landscapes, or of movement‐restricted, isolated, or fragmented wildlife populations.

Habitat model for wild boar (Sus scrofa) in Bukhansan National Park, Seoul

Abstract Since the first known sighting in 2004, wild boar have frequently appeared in Seoul causing increased human–wildlife conflicts. Although South Korea designated wild boar as a ‘pest’ species, limited ecological information exists concerning habitat preference and use of the largest wild mammal in the country. Based on 213 presence points, we modeled wild boar habitat preference in Bukhansan National Park, Seoul and validated the model. We analyzed boar presence with 25 raster datasets using MaxEnt, software for species distribution model using maximum entropy modeling algorithm. Slope (23.4%) was the greatest contributing factor for the habitat model, followed by Temperature seasonality (20.4%) and forest type (16.9%), while Precipitation of driest quarter (37.6%) was the most important factor (normalized contribution) of the model, followed by Temperature seasonality (18.9%) and slope (15.4%). Field verification of the model confirmed that the density of boar signs and rooting are twice as high in the area with high MaxEnt values (over 0.7). The habitat model of wild boar will assist habitat management and further our understanding of how to mitigate human–wild boar conflict.

Eight years of African swine fever in Poland

African swine fever (ASF) was detected in Poland on February 17, 2014. Epidemiological studies from other European countries and the results of epidemiological investigations in different regions of Poland in which the disease was detected indicate that the African swine fever virus (ASFV) must have been present in Poland for at least a few months before the first ASF outbreak was detected. The ASFV virus was introduced into the territory of the Republic of Poland from the Republic of Belarus. During the 8 years of the ASF epizootic in Poland, multidisciplinary measures were taken to eradicate the disease from the wild boar population and limit the possibility of virus transmission from the wild boar habitat to pig farms. Despite the various attempts to stop the expansion of ASF, we have not been successful in eradicating the disease in Poland. By the end of March, 2022, a total of 14016 ASF outbreaks were found in the wild boar population and 488 in the pig population. Throughout the 8-year ASF epidemic in Poland and other countries of Central and Eastern Europe, the course of the disease in the wild boar population, and consequently in pigs, differed significantly from that observed in the 1960s, 70s, 80s, and 90s in Portugal and Spain. First of all, according to predictions by experts from countries previously affected by ASF, the emergence of the disease in the wild boar population in Eastern Europe was supposed to result in the disease becoming spontaneously extinct in the wild boar population because of its mortality rate amounting to almost 100% and the high virulence of ASFV. However, these predictions have not materialized. The possible development of the epizootic situation in Eastern Europe was similarly underestimated. Experts expected a course of ASF similar to that of classical swine fever (CSF) in the wild boar population in Europe in the 1990s and at the beginning of the 21st century. Unfortunately, observations made so far in Poland, the Baltic countries, and southern Europe show that most assumptions regarding the dynamics of ASF spread were inaccurate. Actions aimed at limiting the circulation and spread of ASFV in the wild boar population in Poland proved to be insufficient. The regulations, and above all their implementation and enforcement, were ineffective. Consequently, during the period analyzed (February 2014 – end of March 2022), the disease spread to 11 out of 16 voivodeships in the case of pigs and to 11 voivodeships, though not exactly the same, in the case of wild boar. In principle, the number of ASF outbreaks in the pig and wild boar populations increased year by year. It can be concluded that since the appearance of the first case of ASF the chances of eradicating the disease in Poland have been continuously diminishing. It seems that the situation may improve only if there is a fundamental change in the approach to controlling ASF. This should include radical measures against producers who do not comply with the established principles of biosecurity and a significant change in the strategy of controlling ASF in the wild boar population with a more active involvement on the part of hunters, foresters, veterinary inspectors, police, and farmers themselves.

The golden jackal (Canis aureus) and the African swine fever pandemic: Its role is controversial but not negligible (a diet analysis study).

BackgroundIn Europe, the African swine fever (ASF) pandemic mostly affects the environmental domain of health, which is a strongly human‐impacted ecosystem. However, the current control strategies focus solely on the wild boar and tend to disregard other epidemiologically relevant elements of the ecosystem.ObjectivesThis study investigated the potential impact of the golden jackal on the surveillance effort and disease transmission.MethodsFor this reason, the authors analysed the content of 277 stomachs of this canid species within its westernmost inhabitant population, in order to determine the amount of suid remains, disposed.ResultsThe findings confirmed that in a densely populated wild boar habitat, the main diet component of jackals was wild boar all the year round. The jackals disposed of 0.3–0.6 kg/km2/day offals that potentially contained suid remains. On the other hand, the scavenging activity removed the most important target objects on which the passive surveillance of ASF should be based.ConclusionsThis study cannot determine whether canid scavengers positively or negatively influence the control efforts; however, the impact of the jackal should not be disregarded. The results warn the necessity of a multidisciplinary approach to complex epidemiological situations within different ecosystems.

Epidemiological analysis of classical swine fever in wild boars in Japan

BackgroundClassical swine fever (CSF) is a contagious disease of pigs and wild boars that is transmitted through direct/indirect contact between animals or CSF virus-contaminated fomites. When the disease re-emerged in 2018 in Japan, a CSF-infected wild boar was reported shortly after the initial pig farm outbreak; subsequently, the disease spread widely. To control the disease spread among wild boars, intensive capturing, fencing, and oral bait vaccination were implemented with concomitant virological and serological surveillance. This study aimed to describe the disease spread in the wild boar population in Japan from September 2018, when the first case was reported, to March 2020, based on the surveillance data. We conducted statistical analyses using a generalized linear mixed model to identify factors associated with CSF infection among wild boars. Moreover, we descriptively assessed the effect of oral bait vaccination, which started in March 2019 in some municipalities in the affected areas.ResultsWe observed a faster CSF infection spread in the wild boar population in Japan compared with the CSF epidemics in European countries. The infection probability was significantly higher in dead and adult animals. The influence of the multiple rounds of oral bait vaccination was not elucidated by the statistical modeling analyses. There was a decrease and increase in the proportion of infected and immune animals, respectively; however, the immunization in piglets remained insufficient after vaccination for 1 year.ConclusionsConditions regarding the wild boar habitat, including forest continuity, higher wild boar population density, and a larger proportion of susceptible piglets, were addressed to increase the infection risk in the wild boar population. These findings could improve the national control strategy against the CSF epidemic among wild boars.

Semi-quantitative risk assessment by expert elicitation of potential introduction routes of African swine fever from wild reservoir to domestic pig industry and subsequent spread during the Belgian outbreak (2018-2019).

Since the introduction in Georgia in 2007 of an African swine fever (ASF) genotype 2 virus strain, the virus has rapidly spread to both Western European and Asian countries. It now constitutes a major threat for the global swine industry. The ongoing European transmission cycle has been related to the 'wild boar habitat' with closed transmission events between wild boar populations and incidental spillovers to commercial and non-commercial (backyard) pig holdings. During the epidemic in Belgium, only wild boar were infected and although the introduction route has not yet been elucidated, the 'human factor' is highly suspected. While ASF was successfully contained in a small region in the Southern part of Belgium without affecting domestic pigs, the risk of spillover at the wild/domestic interface remains poorly assessed. In this study, we used a semi-quantitative method, involving national and international experts, to assess the risk associated with different transmission routes for ASF introduction from wild boar to domestic pig holdings and subsequent dissemination between holdings in the Belgian epidemiological context. Qualitative responses obtained by our questionnaire were numerically transformed and statistically processed to provide a semi-quantitative assessment of the occurrence of the hazard and a ranking of all transmission routes. 'Farmer', 'bedding material', 'veterinarian' and 'professionals from the pig sector' were considered as the most important transmission routes for ASF introduction from the wild reservoir to pig holdings. 'Animal movements', 'farmer', 'veterinarian', 'iatrogenic', 'animal transport truck' and 'animal care equipment' were considered as the most important transmission routes posing a risk of ASF spread between pig holdings. Combined with specific biosecurity checks in the holdings, this assessment helps in prioritizing risk mitigation measures against ASF introduction and further spread in the domestic pig industry, particularly while the ASF situation in Western Europe is worsening.

Detection of African swine fever virus in free-ranging wild boar in Southeast Asia.

African Swine Fever (ASF) is a highly contagious and fatal viral disease affecting both domestic and wild suids. The virus was introduced to Southeast Asia in early 2019 and has since spread rapidly throughout the region. Although significant efforts have been made to track and diagnose the disease in domestic pigs, very little is known about ASF in free‐ranging wild boar and their potential role in maintaining the disease within Southeast Asia. Through a collaboration between government and non‐government actors in Laos, Viet Nam, and Cambodia, investigations were conducted to (a) characterize the interface between domestic pigs and wild boar, (b) document risk factors for likely ASF spillover into wild boar populations by way of this interface, and (c) determine whether ASF in wild boar could be detected in each country. An extensive overlap between wild boar habitat and domestic pig ranging areas was found around villages bordering forests in all three countries, creating a high‐risk interface for viral spillover between domestic pig and wild boar populations. Fifteen and three wild boar carcasses were detected through passive reporting in Laos and Viet Nam, respectively, in 2019 and early 2020. Four of five carcasses screened in Laos and two of three in Viet Nam were confirmed positive for African swine fever virus using real‐time PCR. There were no confirmed reports of wild boar carcasses in Cambodia. This is the first confirmation of ASF in wild boar in Southeast Asia, the result of a probable viral spillover from domestic pigs, which highlights the importance of early reporting and monitoring of ASF in wild boar to enable the implementation of appropriate biosecurity measures.

Using spatial data on habitat suitability in estimation of wild boar resources in Russia

Wild boar is one of the most important hunting husbandry resources in Eurasian boreal and temperate forests. In Russia, these animals inhabit a large part of the territory; however, official bodies do not allow public access to relevant and unbiased regional statistics. In parallel with official figures, such statistics have been kept for decades by VNIIOZ (All-Russian Scientific Research Institute for Hunting and Animal Breeding): the resource is estimated using the indirect method of recalculating multiple scores from independent respondents. We compared VNIIOZ long-term datasets with the wild boar habitat suitability distribution in the Russian territory to assess the reliability of these figures and to carry out a pilot evaluation of the need for their adjustment. Our results show a good correlation between the abundance assessment by VNIIOZ and habitat suitability (about 0.7); we also identified several regions where wild boar abundance indicators are sharply dissonant with the existing environmental capacity. We discussed the impact of man-made and natural factors on the population growth rate of wild boar in Russia.

Epidemiological analyses of African swine fever in the Baltic States and Poland: (Update September 2016-September 2017).

EFSA assisted four countries in the analysis of epidemiological data on African swine fever (ASF), collected until September 2017. The temporal analysis demonstrated that the average proportions of PCR and antibody‐ELISA positive samples from the hunted wild boar remained below 3.9 and 6.6, respectively. A peak in the ASF incidence was observed 6 months after the first observed case, followed by a significant reduction of the number of cases and low levels of African swine fever virus (ASFV) circulation at the end of 38 months follow‐up period at different spatial resolutions. The spatial analysis concluded that human‐mediated spread of ASFV continues to play a critical role in the ASF epidemiology, despite all measures currently taken. ‘Wild boar density’, ‘total road length’ (as proxy for human activity) and ‘average suitable wild boar habitat availability’ were identified as predictors for the occurrence of ASF in Estonia by a Bayesian hierarchical model, whereas ‘wild boar density’ and ‘density of pig farms’ were predictors according to a generalised additive model. To evaluate the preventive strategies proposed in EFSA's Scientific Opinion (2015) to stop the spread of ASFV in the wild boar population, a simulation model, building on expert knowledge and literature was used. It was concluded that reduction of wild boar population and carcass removal to stop the spread of ASFV in the wild boar population are more effective when applied preventively in the infected area. Drastic depopulation, targeted hunting of female wild boar and carcass removal solely implemented as measures to control ASF in the wild boar population need to be implemented in a highly effective manner (at or beyond the limit of reported effectivity in wild boar management) to sustainably halt the spread of ASF.

Update on the Risk of Introduction of African Swine Fever by Wild Boar into Disease-Free European Union Countries.

Despite efforts to prevent the appearance and spread of African swine fever (ASF) in the European Union, several Member States are now affected (Lithuania, Poland, Latvia and Estonia). Disease appearance in 2014 was associated with multiple entrances linked to wild boar movement from endemic areas (EFSA Journal, 8, 2015, 1556), but the risk of new introductions remains high (Gallardo etal., Porcine Health Management, 1, and 21) as ASF continues to be active in endemic countries (Russian Federation, Belarus and Ukraine). Since 2014, the number of ASF notifications has increased substantially, particularly in wild boar (WB), in parallel with slow but constant geographical advance of the disease. This situation suggests a real risk of further disease spread into other Member States, posing a great threat to pig production in the EU. Following the principles of the risk-based veterinary surveillance, this article applies a methodology developed by De la Torre etal. (Transboundary and Emerging Diseases, 62, and 272) to assess the relative risk of new introductions of ASF by natural movements of WB according to the current epidemiological situation. This update incorporates the most recent available data and an improved version of the most important risk estimator: an optimized cartographic tool of WB distribution to analyse wild boar suitable habitat. The highest relative risk values were estimated for Slovakia (5) and Romania (5), followed by Finland (4), Czech Republic (3) and Germany (3). Relative risk for Romania and Finland is associated mainly with disease entrance from endemic areas such as the Russian Federation and Ukraine, where the disease is currently spreading; relative risk for Germany and Czech Republic is associated mainly with the potential progress of the disease through the EU, and relative risk for Slovakia is associated with both pathways. WB habitat is the most important risk estimator, whereas WB density is the least significant, suggesting that WB presence is more relevant than density. These results can provide actionable advice for dealing with risk. They can be directly used to inform risk-based national strategies and identify countries that may need to pay greater attention to surveillance or conduct additional evaluations at the subnational level.

瀬戸内海における海を越えたイノシシの生息拡大プロセス

Habitat expansion of wild boar (Sus scrafa) cross the waters in Island See is studied based on interview research conducted in all residential islands in Matsuyama City, Ehime Pref., Japan. Wild boar has immigrated around 1999 from the direction of Kashima Island, Hiroshima Pref. in the north. In A group islands where far from original habitat, sporadic damage phase exists for 6-8 years. After damage increase phase of 3-4 years, grate damage phase starts from 2009. In B group islands where near from original habitat, sporadic damage phase relatively short. In other islands far from original habitat and with very small area, wild boar has immigrated but not colonized. Gogo Island is now in sporadic damage phase, but predicted to go into damage increase phase in the near future. It is effective solution of wildlife-human conflict to make opportunity for local people getting information and learning opportunity about wild boar, as well as to monitor wild boar habitat expansion on the edge of original habitat, resulting in effective control of wild boar habitat.

Influence of Abandoned Farmland and Protection Fence on Agglomeration and Connectivity of Wild Boar Habitat around Orchard Field

Influence of Abandoned Farmland and Protection Fence on Agglomeration and Connectivity of Wild Boar Habitat around Orchard Field

Can habitat suitability predict the presence of wild boar? Suitable land uses vs. georeferenced data in Bulgaria

The aim of this work was to use standardized digital cartography of vegetation coverage to test whether or not the predicted range of habitat suitability for wild boar in Bulgaria coincides with the georeferenced/presence records of this species. The predicted range of habitat suitability based on potential biological resources in Bulgaria encompasses 13 land uses from the CORINE program, being “Broad-leaved forests” (23432 km2) the most representative. The total potential resources for wild boar correspond to 57.54 % of the country area. A high level of correlation (0.86) was found between inverse distance of wild boars presence and habitat suitability areas. A significant level of correlation (0.71, p < 0.0001) per Bulgarian region between area of habitat suitability category 2 (resources suitable for use as both food and shelter) and number of wild boar was also found.Suitable wild boar habitat on borders appeared as the most relevant parameter for evaluating the risk of introduction of diseases by wild boar into the European Union from neighbouring countries. Despite being the longest (608 km), the Bulgaria-Romania border did not represent the most important corridor for wild boar since only 12.78 % of its surface is suitable habitat; the percentage of the importance of this border edges the passage of wild boar is 20.63 %. The Bulgaria-Macedonia (FYROM) border must be regarded as the most important passageway for wild boar (96.88 %), with 148 km of border and 12.34 % of its surface area of suitable habitat. Our findings could be highly useful for developing adequate strategies for wildlife management practices on large spatial scales, as well as for the control of wildlife and its habitats (territorial integration and spatial planning according to the casuistry of the zone), and relationships between wildlife and other human interests.

Wild boar rooting in a northern coniferous forest – minor silviculture impact

European wild boar (Sus scrofa) is expanding northwards beyond its preferred habitat of broadleaved forests. We studied wild boar habitat use in a northern coniferous forest, and noted whether their rooting damaged roots, thereby influencing timber quality and forest regeneration (n = 562 rootings). Overall, the animals selected older spruce (Picea abies L.) forest of higher soil fertility with sparse field vegetation for rooting. During winter, they rooted more in pine (Pinus sylvestris L.) forest on lower soil fertility, possibly because the lichen cover can easily be removed even on frozen ground. Average size and depth of rootings were 6 ± 0.6 m2 and 10 ± 0.2 cm, respectively. Rooting occurred on <1% of the area and caused negligible damage to roots of trees with commercial value. Because the wild boar mainly rooted in older forest, rootings will do little to improve germination of seeds by scarification of the top soil layer.