Patterns of crop damage by wild boar (Sus scrofa)in Luxembourg over a 10-year period

In many European countries, the wild boar (Sus scrofa) is often associated with crop damage. In this study, we analyse data relating to 13,276 cases of wild boar damage to agricultural crops over a 10-year period in Luxembourg (an area of 2,586 km² in Western Europe). Results show that (1) damage is more severe in this area than in others; (2) damage to permanent grassland is far more frequent and more severe than damage to annual crops; (3) trichomatous crops such as barley are avoided; (4) damage is seasonally distributed according to type of crop; (5) damage is distributed spatially in a non-uniform manner; (6) damage intensity is significantly correlated with wild boar hunting bags, both over time and space. We suggest that wild boar management strategy should always take into account the issue of damage to agricultural crops. Our results imply that measures for preventing or reducing damage should be more targeted in time and space and that adjustments to cropping patterns should contribute towards a reduction of wild boar damage.     

保护区及周边居民对野猪容忍性的影响因素——以黑龙江凤凰山国家级自然保护区为例

以黑龙江凤凰山国家级自然保护区为例,于2010年9、10月份,采用问卷调查法和实地考察法相结合的形式,调查该保护区及周边地区野猪危害农田的情况,以及居民对野猪的容忍性和认知度。结合Mann-Whitey U检验和Kruskal-Wallis H检验方法比较各个因素对保护区及周边居民野猪容忍性的影响差异,用主成分分析法对主要影响因素进行辨析。结果表明:农田收入比例、文化程度、人均农田面积以及野猪毁田面积是影响居民对野猪容忍性的主要因素。被访问的居民中,66.19%的居民希望野猪种群减少或消失;63.38%的居民赞同或者完全赞同保护措施;毁田事件发生后,46.48%的居民赞同或完全赞同捕杀野猪;在村外遇见野猪时,66.20%的居民不赞同或者完全不赞同捕杀野猪;在山野遇见野猪时,65.59%的居民不赞同或者完全不赞同捕杀野猪,说明遇到野猪的地点对居民所持捕杀态度基本没有影响。     

Diet of wild boar Sus scrofa L. and crop damage in an intensive agroecosystem

The Middle Ebro Valley (MEV) is a semiarid area in northeast Iberia where the original riparian ecosystems are almost extinct and were replaced by intensive irrigated agricultural lands. To minimize crop damages and to understand the impact of wild boar on relict riparian ecosystems, a culling program was undertaken from 1994 until 2004. To assess the impact of wild boars, we analyzed stomach contents and surveyed crop damage. In the MEV, wild boars feed mainly on crops, particularly, maize. Other elements of the diet that are of agricultural origin include wheat, barley, and alfalfa, which are the alternatives to maize in the period between harvest and seeding, which is the basis of seasonal changes in diet. Results indicate that wild boar actively selected maize crops and consumed wheat in proportion to its abundance; barley and alfalfa fields were damaged less than expected based on their abundance. In the MEV, the wild boar population is limited by the availability of shelter areas found in the scarce riparian ecosystems, which do not provide important food items for this population. We conclude that in the region of this study, wild boars are not a significant threat to the flora and fauna of riparian ecosystems, although as these habitats are restored and areas are protected, the carrying capacity for wild boars might increase.     

张广才岭南部东北虎猎物种群冬季营养容纳量研究

猎物匮乏是影响东北虎（Panthera tigris altaica）种群恢复的关键因素之一。容纳量研究是开展东北虎猎物恢复工作的必要前提。通过Maxent模型、聚类分析和训练随机树分类等方法,结合调查数据,预测了吉林省张广才岭南部黄泥河林业局东北虎主要猎物的适宜栖息地空间分布,解译了植被类型,在此基础上基于不同植被类型动物可采食部分代谢能、不同生境等级食物可利用率、马鹿（Cervus elaphus）和狍（Capreolus capreolus）生境等级重叠情况以及动物冬季能量需求,分析了东北虎猎物的冬季营养容纳量。结果表明：黄泥河林业局狍、野猪（Sus scrofa）和马鹿的适宜栖息地分别占研究区域总面积的52.8%、40.7%和25.4%;从猎物获取能量来看,以山杨（Populus davidiana）、桦树（Betula）、核桃楸（Juglans mandshurica）为主的植被类型是马鹿、狍可获得能量较多的生境,以蒙古栎（Quercus mongolica）、核桃楸为主的植被类型是野猪可获得能量较多的生境。东北虎猎物种群的综合冬季营养容纳量为574只马鹿（0.29只/km²）,7016只狍（3.54只/km²）,4785只野猪（2.38只/km²）。     

Habitat use and spatial patterns of wild boar <Emphasis Type="Italic">Sus scrofa</Emphasis> (L.): agricultural fields and edges

Rapidly increasing populations of wild boar in Sweden and Europe cause much damage to crops, and there is a critical need for more knowledge about their habitat utilization, especially of agricultural fields. In our study, we first assess the spatial pattern of damage in relation to the edges of agricultural fields. Next, with the aid of global positioning system collars, we studied the pattern of movement of wild boar on agricultural fields. Finally, in order to understand the role of agricultural fields, we studied how habitat selection may vary throughout the year. We found edge effects on damage patterns in agricultural fields. During winter and spring, we found wild boar not only to follow edges, but also to move along narrow landscape elements within agricultural fields. In our habitat analysis, we found strong avoidance of exposed agricultural fields throughout the year, but significantly less when crops are ripe.     

Combining citizen science and recreational hunters to monitor exotic ungulates and native wildlife in a protected area of northeastern Argentina

Monitoring wildlife population trends is essential for resource management and invasive species control, but monitoring data are hard to acquire. Citizen science projects may monitor species occurrence patterns in time and space in a cost-effective way. A systematic management program of exotic wild boar (Sus scrofa) and axis deer (Axis axis) in a protected area of northeastern Argentina (El Palmar National Park) provided a framework for implementing a wildlife monitoring system based on park-affiliated hunters. We assessed the level of agreement between three indices of relative abundance: hunter sightings and camera trapping for wild boar, axis deer, capybaras (Hydrochoerus hydrochaeris), brown brocket deer (Mazama guazoubira), and crab-eating and pampas foxes combined (Cerdocyon thous and (Lycalopex gymnocercus), and catch per unit effort (CPUE) for both exotic ungulates only. Most (74%) hunting parties participated in the monitoring program and contributed to its sustainability. Bland-Altman plots displayed large levels of agreement between methods across species, with larger systematic differences between sighting and camera-trapping indices for native species. Restricting camera-trapping to the same time window as hunter sightings substantially increased the agreement between methods across species. Sighting and CPUE indices revealed similar temporal trends and large variations in spatial patterns between species. Comparison of the number of sighted and killed exotic ungulates indicated that, on average, 17% of wild boar and 75% of axis deer escaped hunters. The three indices were appropriate metrics for management purposes and corroborated the sustained, high-level abundance of axis deer and low numbers of wild boar in recent years.

     

Diet of wild boar Sus scrofa in Western Europe, with particular reference to consumption of agricultural crops

1. The diet of wild boar Sus scrofa in Western Europe is reviewed, paying particular attention to the consumption of agricultural crops and the implications of this from the point of view of crop damage. Data were taken mainly from 11 studies that provide quantitative information about the consumption of different food types, but we also list all the foods reported as being eaten by wild boar in a total of 21 studies. 2. Vegetable foods occurred more frequently in the diet than animal foods, and also constituted the bulk of the food ingested. Overall, there were four major vegetable food categories: mast, roots, green plant matter and agricultural crops. Depending on the study area, wild boar always consumed at least one energy‐rich plant food such as acorns, beechnuts, chestnuts, pine seeds, olives, cereal grains or other crops. The number and types of agricultural crops consumed varied between study areas but crops represent an important component of wild boar diet throughout its Western European range. Among animal foods, insects, earthworms, birds and mammals were eaten most consistently but the diet also included amphibians, reptiles, gastropods and myriapods. 3. Seasonal, interannual and regional differences in the diet, together with its striking overall breadth, indicate that wild boar are opportunistic omnivores whose diet, in any particular instance, is largely determined by the relative availability of different food types. Dependence on energy‐rich plant material as a major component of the diet, coupled with large body size and a propensity to trample crops as well as consume them, means that wild boar cause significant agricultural damage.     

Comparison of larval performance and oviposition preference of Spodoptera frugiperda among three host plants: Potential risks to potato and tobacco crops

Fall armyworm (FAW), Spodoptera frugiperda (J.E. Smith), is a major polyphagous pest with the potential to seriously damage various crops. A better understanding of FAW's performance on different hosts may help to predict which plants will be attacked when the preferred host is absent, and facilitate the development of effective pest management practices. We compared the larval performance of FAW fed on maize with that of FAW fed on potato and tobacco, which are important crops in China, using an age-stage two-sex life table and adult female oviposition preference experiments. In cage experiments with potato, tobacco, or maize as the host, FAW reared on maize exhibited the strongest performance with shorter developmental time in the larval stage, longer longevity, and a higher reproductive rate in adults. Females oviposited on maize in preference to potato or tobacco. Compared with larvae fed on maize, those fed on potato and tobacco exhibited significantly lower survival, with only 31.61% and 8.13% developing to the adult stage, respectively. Several life table parameters, including the mean generation time (T), net reproductive rate (R₀), finite rate of increase (λ), and intrinsic rate of natural increase (r) were negatively affected in FAW fed on potato and tobacco. Our results support the preference–performance hypothesis, that is, that herbivore females maximize fitness by choosing host plants associated with strong larval performance. Although larvae and adults performed poorly on potato and tobacco, their offspring will be capable of establishing populations on them, posing a potential threat to these crops in China.     

The robust phylogeny of Korean wild boar (<Emphasis Type="Italic">Sus scrofa coreanus</Emphasis>) using partial D-loop sequence of mtDNA

In order to elucidate the precise phylogenetic relationships of Korean wild boar (Sus scrofa coreanus), a partial mtDNA D-loop region (1,274 bp, NC_000845 nucleotide positions 16576-1236) was sequenced among 56 Korean wild boars. In total, 25 haplotypes were identified and classified into four distinct subgroups (K1 to K4) based on Bayesian phylogenetic analysis using Markov chain Monte Carlo methods. An extended analysis, adding 139 wild boars sampled worldwide, confirmed that Korean wild boars clearly belong to the Asian wild boar cluster. Unexpectedly, the Myanmarese/Thai wild boar population was detected on the same branch as Korean wild boar subgroups K3 and K4. A parsimonious median-joining network analysis including all Asian wild boar haplotypes again revealed four maternal lineages of Korean wild boars, which corresponded to the four Korean wild boar subgroups identified previously. In an additional analysis, we supplemented the Asian wild boar network with 34 Korean and Chinese domestic pig haplotypes. We found only one haplotype, C31, that was shared by Chinese wild, Chinese domestic and Korean domestic pigs. In contrast to our expectation that Korean wild boars contributed to the gene pool of Korean native pigs, these data clearly suggest that Korean native pigs would be introduced from China after domestication from Chinese wild boars.     

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.