Animal Density Research Articles

Occurrence of Aujeszky’s disease in wild boar (Sus scrofa) in Slovakia

Along with the rising population of wild boars (Sus scrofa scrofa Linnaeus, 1758) in Slovakia, a higher rate of exposition to Aujeszky’s disease virus (ADV) was noted. The high density of animals is one of the main influencing factors of ADV persistence. Wild boar tissue samples were obtained by local hunters from different locations of Central and Eastern Slovakia. In total, muscle tissue samples from 139 individual wild boars were collected. Muscle fluid was obtained from these samples and subjected to serological analysis; a commercial ADV Ab-ELISA kit was used. In total, 53 samples were proved to be seropositive; out of these 19 samples of piglets, 13 samples of juveniles and 21 samples of adults. Out of 139 samples tested by ELISA, 53 were seropositive, which represents 38.12 % of positive samples. No significant difference was found between the two sexes; however, piglets have shown to have a significantly higher occurrence compared to adults. Our study confirmed the presence of ADV antibodies in the wild boar population in central and eastern Slovakia.

Comparing NH3 emissions under different cattle housing conditions in cold regions in China with an inverse dispersion technique

Accurately assessing ammonia (NH3) emissions from animal farms is necessary for determining the effectiveness of various mitigation practices to minimize related environmental risks and maximize the potential of recycling nitrogen from manure. This study attempted to validate a hypothesis formulated using a mass-flow inventory model, which suggested that "Barn only" housing facilities without open lots might have a lower NH3 loss potential than "Barn+Lot" facilities with both dairy barns and open lots. NH3 emissions from two "Barn+Lot" dairy farms and one "Barn only" dairy farm were measured using a combination of an inverse dispersion modeling technique and an open-path laser in summer and winter. It was found that the uncertainty of emission estimates owing to the spatial variation of animal densities in the three dairy farms was 8–12%, and the total uncertainty of the NH3 emission estimates owing to spatial variation in animal densities, distortion of wind flow by animal buildings, and the inverse dispersion calculation was estimated to be less than 30%. The NH3 emission rates obtained from the "Barn only" farm (28–43 g head−1d − 1) were lower than the rates from the conventional "Barn+Lot" farms (93–184 g head−1d − 1), indicating emission mitigation of 71–76%. In comparison with the conventional dairy farms, the "Barn only" dairy farm had a lower NH3 loss potential, most likely due to the greater animal density, frequent manure removal, and lower crude protein feed. However, more field measurements of such comparisons are necessary to provide robust suggestions for mitigating environmental risks.

Ecological correlates of chimpanzee (Pan troglodytes schweinfurthii) density in Mahale Mountains National Park, Tanzania.

Understanding the ecological factors that drive animal density patterns in time and space is key to devising effective conservation strategies. In Tanzania, most chimpanzees (~75%) live outside national parks where human activities threaten their habitat's integrity and connectivity. Mahale Mountains National Park (MMNP), therefore, is a critical area for chimpanzees (Pan troglodytes schweinfurthii) in the region due to its location and protective status. Yet, despite its importance and long history of chimpanzee research (>50 years), a park-wide census of the species has never been conducted. The park is categorized as a savanna-woodland mosaic, interspersed with riparian forest, wooded grassland, and bamboo thicket. This heterogeneous landscape offers an excellent opportunity to assess the ecological characteristics associated with chimpanzee density, a topic still disputed, which could improve conservation plans that protect crucial chimpanzee habitat outside the park. We examined the influence of fine-scale vegetative characteristics and topographical features on chimpanzee nest density, modeling nest counts using hierarchical distance sampling. We counted 335 nests in forest and woodland habitats across 102 transects in 13 survey sites. Nests were disproportionately found more in or near evergreen forests, on steep slopes, and in feeding tree species. We calculated chimpanzee density in MMNP to be 0.23 ind/km2, although density varied substantially among sites (0.09-3.43 ind/km2). Density was associated with factors related to the availability of food and nesting trees, with topographic heterogeneity and the total basal area of feeding tree species identified as significant positive predictors. Species-rich habitats and floristic diversity likely play a principal role in shaping chimpanzee density within a predominately open landscape with low food abundance. Our results provide valuable baseline data for future monitoring efforts in MMNP and enhance our understanding of this endangered species' density and distribution across Tanzania.

Analysing intensification, autonomy and efficiencies of livestock production through nitrogen flows: A case study of an emblematic Amazonian territory

CONTEXT: Livestock farming is a major factor in the balance or disruption of bio-geochemical cycles, climate and biodiversity. The Brazilian Amazon is emblematic of these tensions between livestock production and environment. Extensive cattle production has spearheaded the territorial conquest of this region for more than 50 years, and is the main cause of deforestation. The intensification of animal production is presented as a success factor for long-term maintenance of low deforestation and a good level of production. Yet in reality there is no guarantee of this outcome, and very few studies focus on quantifying the effective intensification of the Amazonian livestock sector, and its impact on deforestation.OBJECTIVE: The objective of our article is to characterize and discuss the evolution of livestock farming in Paragominas (Brazil). This municipality is presented as an example of sustainable agrarian transition in the Amazon. After several decades with one of the highest rates of Amazon deforestation, Paragominas reduced its annual deforestation rate tenfold between 2005 and 2012.METRHODS: We analyse the livestock sector, using the method of territorial metabolism. The first step consisted in making an inventory of all material flows and all areas used either directly or indirectly by livestock farming. We calculate productive and environmental indicators' trends from 1990 to 2012 (intensity, production, efficiency, self-sufficiency, deforestation and N surplus).RESULTS AND CONCLUSIONS: We observe an extensive farming system with low density (between 0.47 and 0.83 LU/ha), low production (between 0.97 and 1.48 kg N/ha/year), low efficiency, but a large degree of self-sufficiency (exceeding 95%), and very low N surplus per hectare (between 14 and 16 kg N/ha/year). Ruminants account for 98% of all Livestock Units (LU) and over 95% of animal production. The selected indicators to characterize the intensity of farming systems are divergent: indicators expressed per unit area show extensification, with a decrease in animal density, inputs per ha and a stabilization of production per ha. However, production per animal unit and livestock efficiency increase across the study period.SIGNIFICANCE: The increase in animal production and efficiency was not related to the decrease in deforestation. The increased oversight of land use, along with strict policies, enabled the cessation of deforestation, but this did not result in the intensification of livestock farming for the moment. Our study shows that there is significant potential to increase livestock production and efficiency.

Use of Network Analysis and Spread Models to Target Control Actions for Bovine Tuberculosis in a State from Brazil.

Livestock movements create complex dynamic interactions among premises that can be represented, interpreted, and used for epidemiological purposes. These movements are a very important part of the production chain but may also contribute to the spread of infectious diseases through the transfer of infected animals over large distances. Social network analysis (SNA) can be used to characterize cattle trade patterns and to identify highly connected premises that may act as hubs in the movement network, which could be subjected to targeted control measures in order to reduce the transmission of communicable diseases such as bovine tuberculosis (TB). Here, we analyzed data on cattle movement and slaughterhouse surveillance for detection of TB-like lesions (TLL) over the 2016–2018 period in the state of Rio Grande do Sul (RS) in Brazil with the following aims: (i) to characterize cattle trade describing the static full, yearly, and monthly snapshots of the network contact trade, (ii) to identify clusters in the space and contact networks of premises from which animals with TLL originated, and (iii) to evaluate the potential of targeted control actions to decrease TB spread in the cattle population of RS using a stochastic metapopulation disease transmission model that simulated within-farm and between-farm disease spread. We found heterogeneous densities of premises and animals in the study area. The analysis of the contact network revealed a highly connected (~94%) trade network, with strong temporal trends, especially for May and November. The TLL cases were significantly clustered in space and in the contact network, suggesting the potential for both local (e.g., fence-to-fence) and movement-mediated TB transmission. According to the disease spread model, removing the top 7% connected farms based on degree and betweenness could reduce the total number of infected farms over three years by >50%. In conclusion, the characterization of the cattle network suggests that highly connected farms may play a role in TB dissemination, although being close to infected farms was also identified as a risk factor for having animals with TLL. Surveillance and control actions based on degree and betweenness could be useful to break the transmission cycle between premises in RS.

Soil invertebrate abundance, diversity, and community composition across steep high elevation snowmelt gradients in the European Alps

ABSTRACT We studied abundance, diversity, and composition of soil invertebrates along snowmelt gradients to generally understand how soil animal communities are responding to life conditions across snowbeds along a west–east transect of the European Alps and to create a reference inventory for future investigations of climate change effects on snowbed habitats. We extracted microarthropods (collembolans, oribatid mites) and macroinvertebrates (spiders, beetles, insect larvae) from soil cores taken from three sections along the snowmelt gradient: high (early snowmelt), middle, and low (late snowmelt) sections. Linear models showed no correlations between either soil conditions or time of snowmelt and densities of soil animals. A small, though statistically significant, variation in the generally high soil organic matter and sand contents and high porosity of snowbed soils seems to have no effect on soil invertebrates. Species found along the snowmelt gradient were in similar shares generalist and specialist species. Microarthropod community composition in general was driven by soil porosity and soil organic matter content; for macroinvertebrate community composition we found no specific driver. We conclude that invertebrate species assemblages in snowbeds are rather similar in the European Alps.

帽儿山3种森林生态系统土壤动物与土壤呼吸及其相互关系研究

PDF HTML阅读 XML下载 导出引用 引用提醒 帽儿山3种森林生态系统土壤动物与土壤呼吸及其相互关系研究 DOI: 10.5846/stxb201911252555 作者: 作者单位: 作者简介: 通讯作者: 中图分类号: 基金项目: 国家自然科学基金项目（31670619，41101048）；黑龙江省留学归国人员科学基金（LC2018011）；哈尔滨师范大学硕士研究生创新项目（HSDSSCX2019-01） Analysis on soil animals, soil respiration and the correlation in three forest ecosystems in Maoershan Author: Affiliation: Fund Project: Project of National Natural Science Foundation of China (31670619,41101048); Science Foundation of returned students of Heilongjiang Province (LC2018011); Innovation Project of postgraduates of Harbin normal University (HSDSSCX2019-01) 摘要 | 图/表 | 访问统计 | 参考文献 | 相似文献 | 引证文献 | 资源附件 | 文章评论 摘要:土壤呼吸是森林生态系统碳循环的关键过程，土壤动物可通过自身代谢及影响微生物活动调控土壤呼吸，因此研究土壤动物与土壤呼吸的相互关系对进一步揭示生态系统碳循环的规律和机理具有重要意义。通过野外定点，以帽儿山3种森林生态系统的土壤呼吸及土壤动物为研究对象，探讨不同森林生态系统的土壤呼吸、土壤动物个体密度和生物量的时间变化规律及二者相互关系。结果表明：（1）3种森林生态系统土壤总呼吸速率与土壤异养呼吸速率均呈现先增强后减弱的时间动态变化（P<0.05），且不同森林生态系统土壤异养呼吸速率差异显著（P<0.05），表现为硬阔叶林最高，红松人工林最低；（2）3种森林生态系统土壤动物生物量也具有显著的时间动态变化（P<0.05），均在9月份达到最大，且不同森林生态系统土壤动物个体密度显著不同（P<0.05），蒙古栎林土壤动物个体密度显著小于红松人工林与硬阔叶林；（3）通过回归分析可得，土壤动物数量及生物量的增加抑制了土壤呼吸速率，尤其在生长季初期、末期。研究表明土壤动物可通过抑制微生物生命活动和降低根系呼吸从而对土壤总呼吸及异养呼吸产生负反馈作用，三者是不可分割的整体，与土壤温度、水分等环境因子共同调控着土壤呼吸。 Abstract:Forest ecosystem is the largest organic carbon pool in terrestrial ecosystem, and its slight changes may cause significant variations in global climate. Soil respiration is the key ecological process of carbon cycle in forest ecosystem, which has a great influence on global climate change. Soil animals, as the important consumers of material cycle in the ecosystem, can regulate soil respiration the help of their own metabolism and affecting microbial activities. Therefore, study of the correlation of soil animals and soil respiration is of great significance to further reveal the law and mechanism of carbon cycle in ecosystem. Based on field experiment and indoor analysis, we chose soil respiration and soil animals in three forest ecosystems of Korean pine plantation forest (HS), Mongolian oak forest (MGL), and Hard-wood forest (YK) in Maoershan as the research object, and discuss the temporal variation and correlation between soil respiration as well as individual density or biomass of soil animals in different forest ecosystems. The results showed that: (1) the total soil respiration rate of the three forest ecosystems increased at first and then decreased (P<0.05), with the lowest value appearing in October. The soil heterotrophic respiration rate also showed significantly temporal dynamic change (P<0.05). The difference of soil heterotrophic respiration rate among different forest ecosystems was significant (P<0.05), which was the highest in Hard-wood forest and the lowest in Korean pine plantation forest. (2) The soil animal biomass and individual density of the three forest ecosystems also had notable temporal dynamic changes (P<0.05). The change trends of soil animal biomass and individual density were different, but they all had the maximum values in September. The individual density of soil animals in Mongolian oak forest was much lower than that in Korean pine plantation forest and Hard-wood forest. (3) Through regression analysis, the increase of the number and biomass of soil animals inhibited the soil respiration rate, especially at the beginning and end of the growing season. And the correlation between soil respiration and soil animals in Korean pine plantation forest was different from that in Mongolian oak forest and Hard-wood forest. It could be concluded that soil animals could produce negative feedback on total soil respiration and heterotrophic respiration by inhibiting microbial life activities and reducing root respiration. Soil animals, soil microorganisms and plant roots are an inseparable whole, which together with soil temperature, water and other environmental factors regulate soil respiration. 参考文献 相似文献 引证文献

Risk factors related to bacterial contamination by &lt;i&gt;Enterobacteriaceae&lt;/i&gt; and fecal coliforms and the prevalence of &lt;i&gt;Salmonella spp.&lt;/i&gt; in Algerian farms, slaughterhouses and butcheries: a two-year follow-up study

<abstract> This study was conducted to investigate first the bacterial contamination by <italic>Enterobacteriaceae,</italic> fecal coliforms and the prevalence of <italic>Salmonella spp.</italic> and second to identify the main associated risk factors in Algerian farms, slaughterhouses and butcheries during a two-years period. Thus, a cross-sectional study was performed using a simple random sampling method to target 20 farms, 10 slaughterhouses and 5 butcheries. A structured questionnaire was further used to assess hygienic status of the farms and slaughterhouses. A total of 265 samples were collected from wall, floor, litter, food, water and animals' samples composed mainly of meat, neck skin and liver. Samples from walls and floors, from different sites were analyzed to evaluate the overall contamination and the hygiene of sites for Total viable bacteria, <italic>Enterobacteriaceae</italic> counts and Fecal coliforms counts. Furthermore, <italic>E.coli</italic> and <italic>salmonella spp</italic>. were identified in all samples. The overall contamination by sampling sites expressed as log_{10 CFU/g} (mean ± SD) for Total Aerobic Microbial Count, Enterobacteriaceae count and fecal coliforms counts were around 4.71 ± 1.1, 4.73 ± 1.3 and 4.68 ± 1.2 respectively. The findings evidenced that the prevalence of <italic>E.coli</italic> and <italic>Salmonella spp.</italic> were 63.40% and 18.49% respectively. The highest rate of <italic>E.coli</italic> contamination was for poultry farms (70%), beef farms (64%) and butcheries (74.54%) followed by poultry meat slaughterhouses (60%) and sheep farms (48%) while beef slaughterhouses have the lowest rate of contamination (33.84%). For <italic>salmonella spp.</italic> the contamination was found to be mainly in poultry meat slaughterhouses (31.11%), butcheries (25.45%), followed by poultry farms (22%), beef farms (20%) and sheep farms (12%) while beef slaughterhouses have the lowest rate of contamination (4.61%). This study evidenced multifactor effects of microbial contamination in farms such as animal density, litter hygiene and scraping, manure storage, water and pest control, contact with other animals and decontamination process. Overall, this trial indicated a high rate of microbial contamination for which further studies are needed to determine all the potential risk factors in order to evaluate the corrective effects. </abstract>

Factors influencing survival of tiger and leopard in the high-altitude ecosystem of the Nilgiris, India

Tiger conservation is a global initiative, and data on distribution, prey dynamics, competition, and range extension are critical factors in sustaining its fragile populations. We concentrated on evaluating the data pertaining to these variables in order to designate the high-altitude Nilgiri forest division as a tiger conservation unit. We gathered secondary data on animal density, mortality, and conflicts. We also conducted a people perception survey, a systematic grid-based prey species survey, and a tiger and leopard scat survey to assess the prey-predator relationship and understand human attitudes toward carnivore conservation. According to the findings, the Nilgiri forest division has a healthy prey base with positive or random prey-predator associations and a significant correlation between mammalian assemblages. Because the niche overlap between the tiger and the leopard is high, the latter broadens its niche and relies on wild prey in the shola fringes and tea estates. The tiger avoids human-dominated areas and prefers to stay in the shola, rarely venturing into tea estates. In contrast to previous considerations, we believe the Nilgiri forest division is an ideal tiger habitat. We specify that instead of being considered a connective corridor, the Nilgiri forest division may be merged with Mukkurthi National Park to form a high-altitude tiger reserve.

付疃河流域中下游大型底栖动物群落结构与水质生物学评价

2018年12月-2019年10月对山东省日照市付疃河流域中下游大型底栖动物及相应水环境因子进行分季节的监测，并对底栖动物群落组成、多样性特征及与水质因子的相关性进行分析。结果表明，调查共采集底栖动物42种（环节动物14种、节肢动物20种、软体动物8种），广泛分布物种为霍甫水丝蚓（Limnodrilus hoffmeisteri）、水丝蚓属（Limnodrilus sp.）及摇蚊属（Chironomus sp.）；底栖动物总密度呈春季 > 冬季 > 秋季 > 夏季；CCA （Canonical Correspondence Analysis）分析表明环节动物与COD、TP有显著正相关性，各门类与NH₃-N相关性差异较大；底栖动物多样性分布特征与河流水源结构有关。采用生物多样性指标、指示物种水质生物学指标进行水质评价，Shannon-Wiener指数、Margalef指数评级偏差，Pielou指数评级偏优，而指示物种水质生物学评价（Goodnight-Whitley指数、相对重要性指数及Wright指数）基本一致，整体平均处于中污染，评价过程仍须考虑河流及物种客观属性特征，得到更具适用性的评价管理方法。;This study investigates macrobenthos and corresponding water environmental factors seasonally in middle and lower reaches of Futuan River in Rizhao City, Shandong Province from December 2018 to October 2019, to analyze the composition and biodiversity characteristics of benthic communities and the correlation with water quality factors. The results show that 42 species of benthic animals (14 species of link animals, 20 species of arthropods, and 8 species of molluscs) are identified. The widely distributed species are Limnodrilus hoffmeisteri, Limnodrilus sp. and Chironomus sp. The relationship between total density of benthic animals is spring > winter > autumn > summer. Canonical Correspondence Analysis (CCA) shows a significantly positive correlation between link animals and COD and TP, as well as different correlations between each category and NH₃-N. Biodiversity distribution of benthic animals is related to the structure of river water sources. Water quality is evaluated using biodiversity indicators and water quality biological indicators of indicator species. The results show that Shannon-Wiener index and Margalef index are worse and Pielou index is better, while water quality biological indicators (Goodnight-Whitley index, Bio-pollution index and Wright index) are almost the same with the level of moderately pollution. The evaluation process should consider the objective attributes of rivers and species to obtain a more applicable evaluation management method.

Outbreak of Endoparasitosis in Free-Range Chickens (Gallus gallus domesticus) in Bahia, Brazil

Background: Free-range chickens are quite common in Brazil. In this alternative rearing system, the animals are rustic and raised in an extensive system. Free access to “bare soil” results in the increased occurrence of intestinal parasites since larvae and / or eggs of helminths and protozoa oocysts find favorable conditions for their survival and dissemination in the soil. Although the occurrence and importance of parasitic infections in free-range chickens is well known, the objective of this study is to report an outbreak of endoparasites in free-range chickens in the municipality of Barra - BA, in view of bird susceptibility associated with scarcity of studies in western Bahia.Cases: The chickens were kept free, in a bare soil yard in a household at the urban perimeter of the municipality of Barra - BA. Feeding consisted of whole corn grains, thrown directly in the soil. The drinking fountains were dirty and the animals had no history of vaccination or deworming. Symptoms Anorexia, difficulty in eating and in locomotion, presence of seromucous secretion in the oral cavity, emaciation and diarrhea were all observed symptoms. One of the birds presented excessive vocalization, drowsiness and flaccid paralysis of the neck. Necropsy was performed on 3 chickens: 2 females (cases 1 and 2) and 1 male (case 3). Macroscopic analysis revealed the presence of seromucous secretion in the upper respiratory tract of all animals. Specimens of Ascaridia galli were observed in cases 1 and 2, Heterakis gallinarum in cases 2 and 3, Raillietina sp. in cases 2 and 3 and Davainea proglottina in case 1. Microscopically, the animals had an inflammatory infiltrate in the liver and intestines. Some animals presented necrosis of the tracheal epithelial cells, as well as of the epithelial cells present at the apex of the villi. No significant results were found in the coproparasitological exam.Discussion: The diagnosis of endoparasitosis in this outbreak was based on epidemiological, clinical and pathological findings. The prevalence of intestinal parasitosis in free-range chickens is linked to factors such as age, high animal density, absence of sanitary hygienic measures, as well as environmental temperature and humidity. The appearance of injuries in the intestinal mucosa is influenced by characteristics such as parasitic load, concomitant infections, age and the host's immune status. During necropsy of the birds were found 2 helminths of the Nematoda class (Ascaridia galli and Heterakis gallinarum) and 2 of the Cestoda class (Davainea proglottina and Raillietina sp.). A. galli, seen in 2 cases, is considered low pathogenicity for adult chickens, however young birds are susceptible and can die due to intestinal obstruction and hemorrhages. H. gallinarum is responsible for causing typhlitis, with diarrhea and weight loss, this helminth was found in 2 animals in the present study, however only 1 had changes in the digestive tract. Davainea proglotina and Raillietina spp. might cause, respectively, severe hemorrhagic enteritis and nodule formation in the small intestine mucosa. In Brazil, even though it is notable that intestinal parasitism is one of the key problems in alternative poultry farming, there are few studies that evaluate the presence of endoparasites in chickens raised in alternative production systems, with animals being more frequently exposed to nematodes and cestodes. The multiparasitism observed in this study probably stems from flaws in the rearing system, mainly related to sanitary hygiene management. Therefore, the reduction in the occurrence of these helminths is closely related to the performance of basic prophylactic measures, such as offering good quality food and water in clean containers, separating lots by age, performing sanitary emptiness and deworming.Keywords: livelihood creation, nematode, cestode, multiparasitism, avian pathology.Surto de endoparasitose em galinhas caipiras (Gallus gallus domesticus) na Bahia, BrasilDescritores: criação de subsistência, nematoide, cestoide, multiparasitismo, patologia aviária.

Differences in ungulate population use in different hunting ground units in Lithuania

Abundant ungulate populations are considered ecosystem drivers that affect forestry and agriculture. Their management is ecologically and economically based on game density regulations, considering the balance between density and carrying capacity of the territory, population status and dynamics, as well as hunting needs.&#x0D; Although the population status and dynamics are not new questions, it is still unclear how to manage populations properly depending on the hunting intensity. We aimed to analyse and compare the ungulate population status like moose, red deer, roe deer and wild boar in the Punia pine forest, where the commercial hunting is conducted, and in the hunting grounds managed by hunter clubs in Prienai forest. We performed the study during four hunting seasons of 2009-2010, 2010-2011, 2011-2012, and 2012-2013. The data on harvesting and abundance were obtained from the field works and using the official statistics of the Ministry of Environment.&#x0D; The moose local populations are not abundant, or animals occur occasionally, and their density does not reach the minimum permissible rate. At the same time within the study area, moose hunting is remained to be insufficient. The red deer population is rather stable in the hunting grounds used by hunter clubs while hardly reaches the minimum density rate. On the commercial hunting area, the population density 2-3 times exceeds the permissible density rate. The red deer population should be harvested more intensively. The wild boar is used intensively in the grounds of hunter clubs, while animal density is close to the permissible rate. Unfortunately, on the areas of commercial hunting, wild boar is not actively managed that is why their density exceeds permissible rate even four times.&#x0D; The main harvested species are red deer and wild boar in both hunting grounds. Their abundant populations stay close to permissible density rate. However, gamekeepers keep the larger animal numbers on the areas of commercial hunting. As the main aim is the trophy hunting, the stags and boars are most used when compared to females and young. Therefore, on the areas of commercial hunting, use of wild boar and red deer is unreasonable and their density exceeds permissible rate several times. Keywords: commercial hunting, hunting clubs, population, status, ungulate

Differences in ungulate population use in different hunting grounds in Lithuania

Abundant ungulate populations are considered ecosystem drivers that affect forestry and agriculture. Their management is ecologically and economically based on game density regulations, considering the balance between density and carrying capacity of the territory, population status and dynamics, and hunting needs.&#x0D; Although the population status and dynamics are not a new question, it is still unclear how to manage populations properly depending on the hunting intensity. We aimed to analyse and compare the ungulate population status like moose, red deer, roe deer and wild boar in the Punia pine forest, where the commercial hunting is conducted, and in the hunting grounds managed by hunter clubs in Prienai forest. We performed the study during four hunting seasons 2009 - 2013. The data on harvesting and abundance were obtained from the field works and using the official statistics of the Ministry of Environment.&#x0D; The moose local populations are not abundant, or animals occur occasionally, and their density does not reach the minimum permissible level. The control of moose is non-purposeful and insufficient on both of study territories. The red deer population is rather stable on areas of hunting clubs while hardly reaches the minimum density level. On the commercial hunting area, the population density 2-3 times exceeds the permissible density level. Red deer population should be used more intensively. Wild boar is used intensively on the areas of hunter clubs, and animal density is close to the permissible level. Unfortunately, on the areas of commercial hunting, wild boar is used passively that is why their density exceeds permissible level even four times.&#x0D; The main harvested species are red deer and wild boar in both hunting grounds. Their numerous populations stay close to permissible density level. However, gamekeepers keep the larger animal numbers on the areas of commercial hunting. As the main aim is the trophy hunting, the stags and boars are most used when compared to females and young. Therefore, on the areas of commercial hunting, use of wild boar and red deer is unreasonable and their density exceeds permissible level several times.&#x0D; Keywords: commercial hunting, hunting clubs, population, status, ungulate

First expert elicitation of knowledge on drivers of emergence of influenza D in Europe.

The influenza D virus (IDV) was first identified and characterized in 2011. Considering the virus' zoonotic potential, its genome nature (segmented RNA virus), its worldwide circulation in livestock and its role in bovine respiratory disease, an increased interest is given to IDV. However, few data are available on drivers of emergence of IDV. We first listed fifty possible drivers of emergence of IDV in ruminants and swine. As recently carried out for COVID-19 in pets (Transboundary and Emerging Diseases, 2020), a scoring system was developed per driver and scientific experts (N=28) were elicited to (a) allocate a score to each driver, (b) weight the drivers' scores within each domain and (c) weight the different domains among themselves. An overall weighted score was calculated per driver, and drivers were ranked in decreasing order. Drivers with comparable likelihoods to play a role in the emergence of IDV in ruminants and swine in Europe were grouped using a regression tree analysis. Finally, the robustness of the expert elicitation was verified. Eight drivers were ranked with the highest probability to play a key role in the emergence of IDV: current species specificity of the causing agent of the disease; influence of (il)legal movements of live animals (ruminants, swine) from neighbouring/European Union member states and from third countries for the disease to (re-)emerge in a given country; detection of emergence; current knowledge of the pathogen; vaccine availability; animal density; and transport vehicles of live animals. As there is still limited scientific knowledge on the topic, expert elicitation of knowledge and multi-criteria decision analysis, in addition to clustering and sensitivity analyses, are very important to prioritize future studies, starting from the top eight drivers. The present methodology could be applied to other emerging animal diseases.

A spatial capture–recapture model to estimate call rate and population density from passive acoustic surveys

Abstract Spatial capture–recapture (SCR) models are commonly used to estimate animal population density from detections and subsequent redetections of individuals across space. In particular, acoustic SCR models deal with detections of animal vocalisations across an array of acoustic detectors. Previously published acoustic SCR methods either estimate call density (calls per unit space per unit time) rather than animal density itself, require an independently estimated call rate to estimate animal density, or discard data from all but one detected call from each individual. In this manuscript, we develop a new spatial capture–recapture model that estimates both call rate and animal density from the acoustic survey alone, without requiring an independently estimated call rate. Our approach therefore alleviates the need for the additional fieldwork of physically locating and monitoring individual animals. We illustrate our method and compare it to an existing approach using a simulation study and an application to data collected on an acoustic survey of the visually cryptic Cape peninsula moss frog Arthroleptella lightfooti. In the context of our acoustic survey, our calling animal density estimator has low bias, good precision and confidence intervals with appropriate coverage, yielding results that are consistent with previous studies of the same species. Our method can obtain accurate and precise estimates of animal density while eliminating the fieldwork burden associated with separately estimating call rate. We discuss how the development of our model's likelihood reveals a clear path to further extensions, which may incorporate features such as animal movement processes and uncertain individual identification.

A first acoustic density estimate for sperm whales in Irish offshore waters

Previous studies off western Ireland have suggested that substantial numbers of, mainly male, sperm whales may be found in these habitats. Whaling vessels operating from shore stations in Ireland in the early 20th century frequently caught sperm whales in oceanic waters. It is likely that this North Atlantic region contains important foraging habitats for this species, and that mature males must also migrate through this area moving between breeding grounds to the south and other feeding areas further north. Increasingly, these offshore waters are being utilised and potentially impacted by human industrial activities. For example, as inshore resources are depleted and technology improves, both the commercial fishing and the oil and gas industry are becoming more active in deeper waters beyond the continental margin. It is important therefore to better understand the biology and ecology of sperm whales in these more remote areas. However, their offshore location and deep diving habits, together with weather constraints in the exposed Atlantic, make research difficult. New sperm whale density estimates are reported using data from six seasonal passiveacoustic surveys carried out in two successive years (2015 and 2016). These covered a corridor approximately 110km wide which bounded a major portion of Ireland’s continental shelf break. Towed hydrophone line-transect methodologies were used, which have proven to be highly effective for surveying sperm whales in offshore waters and in poor weather conditions. Target motion analysis was applied to calculate the ranges of vocalising whales from the survey tracklines and the effective strip half-width calculated across all surveys was 7,958m. The study area was surveyedin three blocks and animal densities within these blocks varied between 1 and 4.6 individuals per 1,000km2 (CV 0.34 and 0.21 respectively) with an overall mean density in waters deeper than 300m of 3.2 individuals per 1,000km2(CV 0.04). These robust density estimates are the first of their kind for Irish waters and are similar to those reported in other Atlantic areas considered significant for this species. These results emphasise the significance of this region as sperm whale habitat. The results of this study should be used to inform the future sustainable development and management of Ireland’s offshore Atlantic.

A New Method for Calculating the Population Density of Terrestrial Animals Using Camera Traps with Assessment of Roe Deer (Capreolus pygargus Pallas, 1771) (Cervidae, Mammalia) Population Density in the Khingan Nature Reserve as an Example

A new method for calculating the population density of terrestrial animals, which are not amenable to individual identification, using photos or video images obtained by automatic cameras is proposed for discussion. The method is based on the continuous registration of animals on sites formed by the detection zones of camera traps with subsequent extrapolation of the results to the entire study area. A much simpler mathematical apparatus is a significant difference between our proposed method and other methods of accounting by camera traps, which allows it to be applied by a wide range of users. Both the positional measures and the scattering measures necessary for subsequent statistical analysis are calculated quite easily. Also, one of our method’s advantages is no need to know the animal movement speed, the most difficult parameter to calculate, especially in the snowless period of the year. An example of using the bootstrap method is given for the case when the input data distribution parameters do not correspond to the normal one. Using the de Moivre–Laplace theorem, the probability that the animals resting on their beds would get into the detection zone of the camera trap matrices is estimated, which is necessary for the correct use of the proposed method. Solutions are proposed for cases when this probability is low. The problems of our proposed method and their possible solutions are described. An example of calculating the density of roe deer in the open oak forest of the Khingan Nature Reserve is given on the basis of our data obtained from four camera traps.

Ecological Aspects of an Outbreak of Hemorrhagic Fever with Renal Syndrome in the Territory of the Saratov Region

Hemorrhagic fever with renal syndrome (HFRS) is classifed as a most widely spread natural-focal zoonotic infection in the forest and forest-steppe regions of Russia, taking a leading position by the incidence rate among the population. The Saratov region is enzootic as regards to HFRS, but it is not included in the list of constituent entities characterized by sustainably high morbidity rates. In some years, given favorable ecological conditions, explosive growth in the numbers of the red vole (the main carrier of Hantavirus) is registered, which leads to epidemic complications. In the winter 2018– 2019season, an intensive subniveal breeding of the red vole occurred, which led to an increase in the numbers of the species in the spring. The density of such animals increased, they began to spread widely across the territory. Intensive and extensive epizooties in rodent settlements developed in the natural foci of HFRS. This was especially evident in the territory of the forest park zone “Kumysnaya Polyana”, located in the vicinity of the regional center. The numbers of rodents in ravine and floodplain deciduous forests increased everywhere and amounted to 37.6% in spring and 53.7% in autumn per 100 capture gears, which was 1.6–2 times higher than the average long-term level. The index of dominance of the red vole has also doubled and amounted to 69.5%. In general, the infection rate of rodents increased by 2-3 times in the region. This indicator in the territory of the Saratov forest park was 20.6% in spring and 35.3% in autumn. Against this background, a record outbreak of HFRS was registered in 2019, namely, 109.7 cases per 100 thousand of the population, which was ten times higher than the long-term indicator (7.2). The results of this research should be taken into account when organizing and conducting epizootiological monitoring and preventive measures in the natural foci of HFRS and other zoonotic infections.

Fast, flexible alternatives to regular grid designs for spatial capture–recapture

Abstract Spatial capture–recapture (SCR) methods use the location of detectors (camera traps, hair snares and live‐capture traps) and the locations at which animals were detected (their spatial capture histories) to estimate animal density. Despite the often large expense and effort involved in placing detectors in a landscape, there has been relatively little work on how detectors should be located. A natural criterion is to place traps so as to maximize the precision of density estimators, but the lack of a closed‐form expression for precision has made optimizing this criterion computationally demanding. Recent results by Efford and Boulanger (2019) show that precision can be well approximated by a function of the expected number of detected individuals and expected number of recapture events, both of which can be evaluated at low computational cost. We use these results to develop a method for obtaining survey designs that optimize this approximate precision for SCR studies using count or binary proximity detectors, or multi‐catch traps. We show how the basic design protocol can be extended to incorporate spatially varying distributions of activity centres and animal detectability. We illustrate our approach by simulating from a camera trap study of snow leopards in Mongolia and comparing estimates from our designs to those generated by regular or optimized grid designs. Optimizing detector placement increased the number of detected individuals and recaptures, but this did not always lead to more precise density estimators due to less precise estimation of the effective sampling area. In most cases, the precision of density estimators was comparable to that obtained with grid designs, with improvement in some scenarios where approximate &lt; 20% and density varied spatially. Designs generated using our approach are transparent and statistically grounded. They can be produced for survey regions of any shape, adapt to known information about animal density and detectability, and are potentially easier and less costly to implement. We recommend their use as good, flexible candidate designs for SCR surveys when reasonable knowledge of model parameters exists. We provide software for researchers to construct their own designs, in the form of updates to design functions in the r package oSCR.

Game Animal Density, Climate, and Tick-Borne Encephalitis in Finland, 2007-2017.

Tick-borne encephalitis (TBE) is an endemic infection of public health importance in Finland. We investigated the effect of ecologic factors on 2007–2017 TBE trends. We obtained domestic TBE case data from the National Infectious Diseases Register, weather data from the US National Oceanic and Atmospheric Administration, and data from the Natural Resources Institute in Finland on mammals killed by hunters yearly in game management areas. We performed a mixed-effects time-series analysis with time lags on weather and animal parameters, adding a random effect to game management areas. During 2007–2017, a total of 395/460 (86%) domestic TBE cases were reported with known place of exposure and date of sampling. Overall, TBE incidence increased yearly by 15%. After adjusting for the density of other animals and minimum temperatures, we found thatTBE incidence was positively associated with white-tailed deer density. Variation in host animal density should be considered when assessing TBE risks and designing interventions.