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

Crop 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.     

Biotic and abiotic factors modulating wild boar relative abundance in Atlantic Spain

The population dynamics of wild ungulates, particularly wild boar (Sus scrofa), are modulated by biotic (e.g. predation) and abiotic (environmental) determinants. Despite the evident potential interference of predation in the environmental patterns of wild boar population abundance, studies including both predation and abiotic factors are scarce. Here, using spatially explicit predictive models, we investigated the effects of habitat features on the relative abundance of wild boar populations and how the abundance of boars is related to frequency of Iberian wolf (Canis lupus signatus; hereafter, wolf) in the area. Wild boar relative abundance was determined by hunting bag statistics, including hunting effort-related variables (in order to avoid problems derived from modeling rates) as covariates, while wolf attacks to livestock were considered as a proxy of wolf frequency in the drive. After modeling, variation partitioning procedures were used to determine the relative importance of each factor and their overlaid effects. Our results showed that wild boar and wolf relative abundances are associated. According to previous knowledge on the wild boar ecology, we found that the species abundance is positively related to the percentage of surface occupied by mature forest and heather providing high food diversity and refuge, but these environmental variables achieved a low explanatory capacity in the models in relation to wolf frequency. The holistic approach followed in this study was attended to open new perspectives for thinking on the wolf-livestock conflict and to adequate wild boar management strategies taking into account hunting interests and natural processes.     

Faecal pellet group counting as a promising method of wild boar population density estimation

The wild boar is a native animal species of the Czech Republic that has significantly increased its population density in recent years. Objective methods of population density estimation are required to inform the intensity of regulation needed for the sustainable management of the wild boar. Population estimation and regulation of the abundance of the wild boar are problematic in comparison to those of other ungulates, and the only widely used method of control is intensive hunting. The purpose of this study was to test if faecal pellet group (FPG) counting was a reliable method of wild boar population censusing in a forest environment. The density of wild boars was evaluated in an area of 22.56 km², circumscribed by both natural and man-made barriers that restrict wild boar migration. As it is essential for proper application of FPG count methods, a separate trial was carried out to determine the daily defecation rate of wild boars. The distribution of faeces in different types of habitat in a forest environment was tested. As the period of faeces accumulation fell within the intensive hunting season, the result is biased by the fact that the calculation includes FPGs produced by animals removed from the population through hunting during winter. The average daily defecation rate of adults and piglets was 4.29 and 5.82, respectively. The corrected (without shot animals) average density of wild boars in the study area estimated by the FPG count at the time of the census was 6.08 individuals (ind.)/km². We have confirmed that an FPG count conducted in winter is applicable for estimation of wild boar abundance on a forested area.     

Sex effect on habitat selection in response to hunting disturbance: the study of wild boar

Spatial variation of the ‘predation risk’ due to human activities or distribution may increase the sexual difference in habitat selection. Indeed, females with offspring are usually more risk adverse than males. Based on a long-term wild boar study, we analysed the diurnal distribution of female and male wild boar before, during and after the hunting period. Hunting, food and foliation were investigated as factors affecting patterns of forest parcel selection. As expected, dense vegetative covers were selected during resting periods, but wild boar decreased this pattern of habitat selection in response to hunting disturbance. Moreover, the habitat selection of wild boar did not fit with the variation of food availability (presence or absence of mast) and the vegetation cycle. As expected, sows responded more to the hunting disturbance than males, leading to a more pronounced sexual difference during the riskier season. The unexpected decrease of bush use may be explained either by the increased hunting effort in this habitat or by the increased movements between resting sites due to disturbance, leading to a more random habitat selection pattern. The observed difference between sexes could result from a higher response of females with offspring to hunting, leading to an increased frequentation of secondary habitats, whereas males can tolerate more risks and remain hidden in thicket plots. Our results highlight how hunting disturbance can lead game species to change their patterns of refuge habitat selection and may affect the habitat segregation between the sexes.     

Wild boar hunting and socioeconomic trends in Northern Greece, 1993–2002

Wild boar (Sus scrofa) populations increased worldwide in the last decade, but boar hunters have decreased. To maintain and increase hunters and to clarify the problems for sustainable hunting, we investigated their activities, attitudes, and socioeconomic trends. Drama and Kavala, Northern Greece have the best wild boar habitat in the country. We estimated the percentage of hunters hunting wild boar in Drama and Kavala and studied their profile to determine how the recent socioeconomic changes in the region affected numbers, activities, attitudes, and socioeconomic trend, from 1993 to 2002. In 1993, data were gathered through a questionnaire distributed randomly to 411 and 480 hunters in Drama and Kavala, respectively. In 2002, 320 and 400 questionnaires were collected in Drama and Kavala, respectively. In Drama, 13.6% of the hunters hunted wild boar in 1993 and 12.3% in 2002. In Kavala, 10.0% hunted wild boar in 1993 and 9.3% in 2002. The average age of hunters in Drama in 1993 was 37.9 years and 39.4 in 2002. In Kavala, the average age per hunter was reduced from 42.3 to 37.4 years. The average hunting experience had increased by 4.8% and 0.6%, respectively. In 2002, there was an increase in the distance traveled for hunting, the level of education of the hunters, the number of people working in the private sector, and in the public service. Wild boar hunters are mainly married, middle income class, earning 4,000–7,500 Euros/year. The above data will allow managers to better understand the socioeconomics of the hunters of wild boar and may be able to use the data to encourage increased hunting.     

Efficiency of spreading maize in the garrigues to reduce wild boar (<Emphasis Type="Italic">Sus scrofa</Emphasis>) damage to Mediterranean vineyards

The aim of this work was to assess the efficiency of dissuasive spreading of maize to reduce the level of wild boar damage to vines in a Mediterranean area (Puéchabon, southern France). The 50 wine growers of Puéchabon were all questioned about the annual losses caused by the wild boar in each vineyard of the study area between 1990 and 1992. We also studied the distribution of the damage on a smaller scale, by mapping the damaged vines within two vineyards. In summer 1993, we distributed 4.7 tons of maize in the woods , and then questioned the wine growers about the losses in each vineyard for 1993. During 1990–1992, on both large and small scales, the damage had a patchy distribution, with more patches of damage occurring close to the woods. Moreover, the later the vines ripened, the less frequent the damage. The severity of the damage was only affected by the distance of the vineyard from woods. In total, the wild boar consumed 20,049 kg of grapes each year between 1990–1992 (193 kg/ha), and 63% of the vineyards were damaged. In 1993, both the density and the compensation paid in the département increased threefold. However, in our study area, both the proportion of damaged vineyards (36%) and the level of damage in the vineyards (151 kg/ha) were reduced, saving more than 60% in compensation. The dissuasive spreading of maize is therefore an efficient tool to reduce the level of damage to vineyards.     

Factors affecting wild boar abundance across an environmental gradient in Spain

The recent Europe-wide increase in wild boarSus scrofa, Linnaeus, 1758 abundance is undoubtedly due to many different factors, the relative importance of which differs from region to region. In Aragón (northeastern Spain), wild boar enlarged its distribution area eight times in the 1990s as compared with the century before, occupying the whole region. We studied wild boar abundance along an environmental gradient in Aragón to determine which factors are most responsible for its variation. Relative abundance of wild boars was estimated by catch-effort methods in 134 hunting estates (sampling units) for 5 consecutive hunting seasons. To characterise the environmental conditions, we quantified landscape composition and structure, topographical factors and climatic factors. Hunting pressure indices were also calculated for our sampling units. The average wild boar catch per hunting activity and per 100 km² ranged from 0.72 to 16.31. Our results suggest thatwild boar abundances are affected by landscape structure, mainly by landscape diversity. In addition, lowland arid agrosystems (characterized by high temperatures and open juniper woodlands with little food availability) constrain the abundance of wild boar populations in spite of their wide plasticity to colonize new habitats.     

Modern Hunting Practices and Wild Meat Trade in the Oil Palm Plantation-Dominated Landscapes of Sumatra,Indonesia

The ongoing expansion of plantation agriculture has changed the ecological, demographic, and social conditions of Southeast Asia’s forested areas, yet little is known about hunting practices in these novel landscapes. Using information from 73 in-depth interviews with hunters, agricultural workers and wild meat dealers in the Jambi province of Sumatra, Indonesia, we describe contemporary hunting practices, including how hunting methods, wildlife harvest and consumption rates vary between different indigenous and immigrant ethnic groups. Hunting is now primarily a commercial endeavor for harvesting wild boar (Sus scrofa) meat; over 7500 wild boars were sold in Jambi City alone in 2011. The Muslim majority avoids wild boar for religious reasons, but there is substantial local and export demand driven by Chinese and Christian Batak. We conclude that hunting within oil palm plantations may reduce crop damage from wild boar and also yield large amounts of wild meat with relatively little by-catch of threatened animals.     

Genetic Differentiation of Wild Boar Populations in a Region Endangered by African Swine Fever

For areas at risk for African swine fever (ASF) introduction from neighboring regions, it is important for epidemic control to know how wild boar (Sus scrofa) dispersion dynamics could be used to combat the spread of ASF. In this regard, long-term information based on population genetic data makes an important contribution. We selected our study area as Rhineland-Palatinate, Germany, because it had a high density of wild boars and was threatened by ASF via infected wild boars from neighboring Belgium. On an area of around 20,000 km², we collected almost 1,200 blood samples from 22 wild boar hunting grounds. The study area included a network of potential barriers to movement, including roads and rivers. We assessed genetic differentiation based on microsatellite data. We used 2 spatial (Bayesian Analysis of Population Structure [BAPS] and TESS) and 1 non-spatial (STRUCTURE) Bayesian model-based approaches to analyze the data. Each of the algorithms detected 4 clusters with different cluster compositions in different areas and identified the highest degrees of differentiation between hunting grounds east and west of the Rhine River, between Pfalz and Eifel-Hunsrück, and to a lesser degree between Westerwald and Taunus and between Eifel and Hunsrück. Thus, genetic evidence suggests barriers of different strength that might be helpful in a setup of complex and expensive measures against the spread of animal diseases such as ASF. The described approach could also provide valuable information for other threatened regions to contain ASF. © 2021 The Authors. The Journal of Wildlife Management published by Wiley Periodicals LLC on behalf of The Wildlife Society.     

Does wild boar rooting affect livestock grazing areas in alpine grasslands?

Interactions between traditional livestock management practices and wildlife activities are important in the conservation of many mountain ecosystems including the summer rangelands in the Spanish Central Pyrenees, where rooting by wild boar (Sus scrofa) is a large disturbance that can reduce the amount of area available to grazing livestock. This study explored the likely impact of wild boar rooting on Pyrenean grasslands. It quantified the extent of wild boar rooting in livestock grazing areas and determined whether wild boars selected or avoided areas depending on the type of livestock and stocking rates. Wild boar rooting affected 16% of livestock grazing area and occurred in sites that were grazed by cattle, rather than by sheep. In addition, a preference for areas that had intermediate stocking rates was found. The relationship between the increase in the number of wild boars and trends in livestock management suggests that the extent of wild boar rooting will increase especially in cattle grazing areas, and therefore, the area available for cattle grazing in Pyrenean mountain rangelands would decrease significantly.     

Combined evaluation of bovine tuberculosis in wild boar (<Emphasis Type="Italic">Sus scrofa</Emphasis>) and red deer (<Emphasis Type="Italic">Cervus elaphus</Emphasis>) from Central-East Portugal

Bovine tuberculosis (bTB), widely considered a disease of livestock, can also affect large game species despite their poorly understood role in the epidemiology of the endemic state of the disease. The Idanha-a-Nova County, situated in the eastern region of central Portugal, is one of the most important regions for large game hunting activity. In order to investigate the role of large game and the presence of bTB in Idanha-a-Nova, 132 wild boar (Sus scrofa) and 339 red deer (Cervus elaphus) were inspected for bTB-compatible lesions (bTBCL) during the 2008–2009 hunting season. Tissue samples with bTBCL were collected and processed for bacteriological confirmation and spoligotyping of Mycobacterium bovis isolates. In wild boar, bTB lesions were single, mostly calcified (21/29, 72.4%) and situated in the mandibular lymph nodes. Lesions were more severe and largely non-calcified (36/40, 90%) in red deer. Wild boar presented a consistently higher bTB infection rate than the red deer; however, the difference was only significant in the southern B area. This area was significantly affected by bTB for both animal species (up to 72.7% in wild boar and 34.8% in red deer) and requires the urgent implementation of intervention measures to contain the disease. Wild boar may assume an important role in the emergence of new disease foci in distant areas that infected red deer cannot reach. Spoligotyping of M. bovis isolates grouped the strains into three clusters, revealing patterns common to wild boar, red deer, and also to local cattle, indicating possible transmission among different animal species.     

Reproductive and demographic parameters in two Iberian wild boarSus scrofa populations

From 1990 to 2006, we studied the demographic, reproductive, and biometric characteristics of two Iberian wild boarSus scrofa (Linnaeus, 1758) populations in contrasting environments. In the Pyrenees (studied in 1990–1993), forest cover is high, hunting pressure is low, and the density of wild boar is high. In the Ebro Valley (studied in 1994–2006), there are few shelter areas for boars, hunting pressure is high, and density is very low. In the second semester of life and after two years of age, the sows in Ebro Valley were heavier than were those in the Pyrenees. Pregnancy during the first year of life was frequent in the Ebro Valley and rare in the Pyrenees. Litter sizes, ovulation rates, and intrauterine mortalities did not differ significantly between the two populations, but the foetal sex ratio in the Ebro Valley was skewed significantly towards males. Life expectancy was lower in the Ebro Valley (6 yr) than it was in the Pyrenees (10 yr). In the Ebro Valley 75% of the wild boar were >24 months old, whereas in the Pyrenees, the proportion was 59%. We suggest that shelter availability influenced the growth, productivity, hunting pressure, and life expectancy in the two Iberian populations of wild boar.     

Do intensive drive hunts affect wild boar (Sus scrofa) spatial behaviour in Italy? Some evidences and management implications

Wild boar have been increasing in numbers all over Western Europe in the last 30 years. The species is a major pest for agriculture, but it has a high value as a game species, and in Italy, as in several other countries, it is traditionally hunted in drive hunts by hunting teams with several dogs. This hunting method can have disruptive effects on the demography and spatial behaviour of wild boar, especially family groups. We conducted a 2-year study (2003 and 2004) to determine the effects of drive hunt disturbance on the spatial behaviour of wild boar family groups in the Northern Apennines (central Italy). Twenty wild boar belonging to ten family groups were ear tagged with a radio device. We located resting sites daily and used intensive tracking sessions during drive hunts. Three seasons were determined: pre-hunting, hunting and post-hunting. A general pattern of increased spatial instability during the hunting season was shown. Resting ranges were larger, and resting sites were more interspersed. Distances between consecutive resting sites were greater during the hunting season and, especially, on hunting days. The displacement of family groups caused by drive hunts was generally short lived except for those groups that were repeatedly hunted and so abandoned their pre-hunt (native) range. During drive hunts, wild boar showed a moderate tolerance to hunting disturbance, and only family groups which were directly chased by dogs escaped or altered their behaviour. The response of wild boar to hunting disturbance seemed to be highly related to the degree of hunting pressure combined with individual variability. The impact on wild boar behaviour should be reduced, above all by avoiding repeated hunts in the same areas within a short period and by employing well-trained hounds.     

Influence of habitat features and hunter behavior on white-tailed deer harvest

Sport hunting may help in controlling cervid populations over large areas. As with natural predators, several environmental factors can influence sport harvest. A better understanding of the environmental variables that limit the efficiency of sport hunting could provide guidelines for more efficient wildlife management using hunting. We studied white-tailed deer (Odocoileus virginianus) hunting on a high deer density island where hunting was the sole form of predation. Our objective was to study the behavior of sport hunters and determine the habitat characteristics (e.g., abundance of deer forage, visibility of the deer from the hunter's point of view, and accessibility of the territory to hunters) that are associated with a successful harvest. We collected movements and harvest site location data from 477 hunters equipped with handheld Global Positioning System (GPS) units. Harvest sites were visited and characterized, along with a paired random site, to determine the environmental conditions associated with a successful hunt. We also developed a model to predict the daily number of deer seen by hunters considering weather conditions, hunter characteristics (e.g., age, experience), and date of hunting. We used the mean number of deer seen per hunter per day as a relative index of local density in each hunted territory. At both the site and landscape scales, the combination of visibility and access had a positive effect on the distribution of harvested deer. Habitat types with less visual obstruction from vegetation enabled hunters to see more deer in a given day. At the site scale, harvested deer were located in areas with a lower density of access routes compared to areas where hunters travelled throughout the day. Using an innovative approach of studying hunter behavior with GPS technology, digital maps, and questionnaires, we highlighted the factors associated with hunter success. Our study suggests that habitat characteristics could be modified to increase harvest by improving accessibility and visibility near roads. Creating openings in mature and regenerating forest near access roads could make sport hunting a more efficient management tool, but the potential impact of increased forage availability in forest openings should not be overlooked. © 2012 The Wildlife Society.     

Landscape effects on wild boar home range size under contrasting harvest regimes in a human-dominated agro-ecosystem

Agro-ecosystems can experience elevated human-wildlife conflicts, especially crop damage. While game management often aims at reducing number to mitigate conflicts, there is on-going debate about the role of hunting disturbance in promoting game to range over wider areas, thereby potentially exacerbating conflicts. Herein, we hypothesised that landscape configuration and non-lethal disturbance modulate the response to harvest disturbance. We used an information theoretic approach to test the effects of landscape and anthropogenic variables on wild boar ranging patterns across contrasting harvest regimes. We used 164 seasonal home ranges from 95 wild boar (Sus scrofa) radio-tracked over 6 years in the Geneva Basin where two main harvest regimes coexist (day hunt and night cull). Mean seasonal 95% kernel home range size was 4.01 ± 0.20 km² (SE) and 50% core range size 0.79 ± 0.04 km², among the smallest recorded in Europe. Range sizes were larger in the day hunt area than in the night cull area, with no seasonal effect. However, when accounting for landscape variables, we demonstrate that these patterns were likely confounded by the underlying landscape configuration, and that landscape variables remain the primary drivers of wild boar ranging patterns in this human-dominated agro-ecosystem with range size best explained by a model including landscape variables only. Therefore, we recommend accounting for landscape configuration and sources of non-lethal disturbance in the design of harvest strategies when the aim is to limit wide-ranging behaviour of wild boar in order to mitigate conflicts.     

How does hunting influence activity and spatial usage in wild boar <Emphasis Type="Italic">Sus scrofa</Emphasis> L.?

Increasing wild boar (Sus scrofa L.) population densities all over Europe cause severe economic problems. In popular belief, the wild boar is a more or less diurnal species, causing only minor problems when undisturbed, but is assumed to become nocturnal and wide-ranging when opposed to hunting pressure. In our study, we investigated the impact of hunting and several environmental factors on movements, spatial utilisation and activity patterns by radiotelemetry. Activity pattern revealed a mean proportion of diurnal activity of 12% of all localisations with a monthly change. The wild boar showed increased diurnal activity on undisturbed feeding habitats, especially in early summer. Different hunting methods did influence activity and spatial utilisation in terms of activity and smaller home ranges in areas with only single hunt, although this might be biased by seasonal effects. Flight distances increased significantly after single hunt and capture incidents, but still ranged inside the annual home ranges. Battues did not influence the spatial utilisation before and after hunt significantly. In only 14% of the observed cases did wild boar show small scaled escape movements after battues. The overlaps of home ranges did not change after battues.     

黑龙江凤凰山国家级自然保护区野猪冬季容纳量及最适种群密度

近年黑龙江省凤凰山国家级自然保护区野猪数量不断增长,人猪冲突加剧,保护区资源保护管理工作面临较大管理压力.为确定野猪种群的实际数量,同时评估该保护区的野猪的容纳量水平,以便为保护区管理局针对野猪的管理提供相关指导意见.2009-2010年冬季,在保护区采用样带调查、雪地足迹链跟踪和观察食痕的方法,并结合已有野猪生态研究确定野猪食性.野猪主要食物种类包括:木贼(Equisetum hiemale)、红松(Pinus koraiensis)果实松籽、胡桃楸(Juglans mandshurica)果实核桃、蒙古栎(Quecusmongolica)果实橡子、稠李(Padus racemosa)、榛子(Corylus heterophlla)、苔草(Carex spp.)、辽东葱木(Aralia elata).研究期间共布设长3-5km、单侧宽度50m、总长134 km的样带30条.调查中,每隔200 m布设10 m×10 m的大样方,并在每个大样方中央及四角布设1 m×1 m的小样方,共布设大样方350个,小样方1 750个.通过样方调查,统计野猪栖息生境当年可食植物枝条及其食物种类,然后计算其食物的总供给量,再结合食物营养成分,通过粗蛋白、粗纤维、粗脂肪的能量转换,按照每克粗蛋白和粗纤维的能量转换系数为16.74kJ、每克粗脂肪的能量转换系数为37.66 kJ,确定野外生境食物总能量供给.结合野猪冬季日营养需求,以能量为基础估算保护区野猪的营养容纳量.在种群密度调查过程中,通过足迹链判断个体方法为:单一清晰足迹链确定为一个体所留,30m内多条足迹穿越同一样带被认为是一个野猪群所留,调查中根据个体分开时的足迹链数确定野猪个体数,同时将粪便、卧迹、啃食痕迹作为个体判断的辅助信息.研究结果表明:凤凰山保护区内能够提供的总能量为7.375 ×107MJ,冬季平均每头野猪生存所需能量为(14 677.698±409.92) MJ,野猪营养容纳量为(1 006±28)头,种群密度为(3.79±0.11)头/km2.此外,调查中发现30余个野猪套及2头野猪被猎杀现场,反应出当地的人猪冲突较为严重.结合调查中发现的野猪套数量及野猪被猎杀概率,对野猪种群数量引入20％的死亡风险系数.最终确定凤凰山野猪种群的最适数量在(603±17)头左右,最适密度为(2.27±0.06)头/km2.通过样带法调查得出凤凰山自然保护区实际野猪种群数量为(596±155)头,密度(2.24±0.58)头/km2,已趋近营养容纳量.因此,野猪并未过量,不能采取狩猎等降低种群数量的措施,同时保护区也应对野猪种群进行持续监控,防止野猪种群过度繁殖以至成灾.     

Detection and genetic characterization of porcine circovirus 2 isolates from the first cases of postweaning multisystemic and wasting syndrome in wild boars in Greece

In 2002, postweaning multisystemic wasting syndrome (PMWS) was diagnosed in a European female wild boar (Sus scrofa), based on the detection of porcine circovirus 2 (PCV2) DNA in various organs, including the uterus, and on histopathologic lesions. This is the first detection of PCV2 DNA in the uterus of a wild boar. Three years later (2005), a wild boar < 6-8 mo of age was found moribund. It presented wasting and dyspnea and finally died. PCV2 DNA was detected in tissue samples, and histopathologic lesions consistent with PMWS were observed. Both wild boars were from neighboring hunting areas in central Greece. Two PCV2 strains from the wild boars were genetically characterized and compared to other reported PCV2 sequences from wild boars and domestic pigs. The PCV-2 sequences from the wild boars in this study were closely related to each other and were grouped with two isolates from wild boars from Hungary. The phylogenetic analysis revealed that the virus might be transmitted between hunting areas. In addition, PCV2 may spread from domestic pigs to wild boars and vice versa.     

Disentangling Natural From Hunting Mortality in an Intensively Hunted Wild Boar Population

Abstract We assessed age-specific natural mortality (i.e., excluding hunting mortality) and hunting mortality of 1,175 male and 1,076 female wild boar (Sus scrofa) from Chǎteauvillain-Arc en Barrois (eastern France), using a 22-year dataset (1982–2004) and mark-recapture-recovery methods. Overall yearly mortality was >50% for all sex and age-classes. Low survival was mostly due to high hunting mortality; a wild boar had a >40% of chance of being harvested annually, and this risk was as high as 70% for adult males. Natural mortality rates of wild boar were similar for males and females (approx. 0.15). These rates were comparable to rates typical of male ungulates but high for female ungulates. Wild boar survival did not vary across sex and age-classes. Despite high hunting mortality, we did not detect evidence of compensatory mortality. Whereas natural mortality for males was constant over time, female mortality varied annually, independent of fluctuations in mast availability. Female wild boar survival patterns differed from those reported in other ungulates, with high and variable natural mortality. In other ungulates, natural mortality is typically low and stable across a wide range of environmental conditions. These differences may partly reflect high litter sizes for wild boar, which carries high energetic costs. High hunting mortality may induce a high investment of females in reproduction early in life, at the detriment to survival. Despite high hunting mortality, the study population increased. Effective population control of wild boar should target a high harvest rate of piglets and reproductive females.