Sheep Density Research Articles

Ungulate browsing on introduced pines differs between plant communities: Implications for invasion process and management

AbstractThe effects of herbivory on plant invasions are broadly discussed, and many studies have led to widely debated theories. In particular, the effects of herbivores on pine invasion found in different studies vary; in some cases, they controlled their expansion, and in others, they promoted it. On the other hand, vulnerability to invasion by pines differs between community types. Sites with dunes and bare ground are the most heavily invaded, followed by grasslands, while shrublands and forests are least invaded. Because current evidence is mostly observational, some of the varying responses of pine invasions to herbivory should be examined further through replicated experiments. Here, we address experimentally the extent to which preference for the non‐native invasive Pinus contorta by domestic sheep (Ovis aries) depends on the vegetation type. We installed experimental enclosures within two adjacent communities, grassland and shrubland, and in each one, we planted seedlings of P. contorta Douglas and established a sheep density typically recommended for the study area. The number of browsed seedlings, the number and type of branches browsed per seedling, the reduction in height and probability of survival immediately after browsing period were recorded. The number of browsed seedlings and damage to the terminal bud were higher in grassland than in shrubland, while the number of browsed branches per seedling was higher in shrubland than grassland. The reductions in height and probability of survival immediately after browsing were similar in both communities. These results show that moderate levels of sheep herbivory could reduce 20% seedling survival in both communities; nevertheless, the damage patterns differ between them. The sheep browsed more substantial number of seedlings in grasslands than in shrublands. However, if sheep find the seedlings, they damage it more in shrublands. These results suggest that experimental studies comparing communities are important for pine invasion management.

Crop–Livestock Interaction Effect on Soil Quality and Maize Yield in Northern Ghana

Core Ideas Soil chemical and biological sub‐indices increased with sheep and goats corralling. Soil physical sub‐quality index declined with sheep and goats corralling. Sheep and goats corralling increased soil quality index of fallow arable lands. Interactions of sheep and goats corralling, plant density and nitrogen fertilizer increased maize yield in northern Ghana. Keeping livestock overnight on fallow arable lands (Corralling) is a traditional method of soil fertility amendment in West Africa. However, there is limited quantitative data on the interaction effects of stocking density of sheep and goats corralling (SDSG), maize plant density (MPD) and nitrogen fertilizer rate (NFR) on soil quality and yield of maize. A 2‐yr study was conducted to determine the interaction effects of three SDSG (0, 70, and 140 head ha−1), three MPD (66,667, 100,000, and 133,333 plants ha−1) and three NFR (0, 60, and 90 kg ha−1 N) on soil quality index (SQI) and maize yield in northern Ghana. The study was conducted using a split‐split plot experiment replicated on eight farms. An adult sheep or goat was corralled in an area of 4 m2 and 1 m2 for the 70 and 140 head ha−1 SDSG respectively for five nights during the dry seasons of 2014 and 2015 cropping seasons. Principal component and correlation matrix analysis were used to select minimum data set for SQI. The SQI for sheep and goats corralling increased by 51% compared with the control. The SDSG×MPD, SDSG×NFR and MPD×NFR interactions were significant on maize grain and biomass yields. The results suggest that, small‐scale maize‐livestock farmers could use either SDSG of 70 head ha−1 with 90 kg ha−1 NFR or SDSG of 140 head ha−1 with 60 kg ha−1 NFR and MPD at 133,333 plants ha−1 to increase grain yield on Ferric lixisols in northern Ghana and similar ecologies in West Africa.

The quality of indigenous sheep milk and its paneer and cheese

Indian sheep produce small quantity of milk to meet their offspring requirement and contribute little to human nutrition. Major portion of sheep milk is consumed as fluid milk and in certain areas convert into ghee and dahi. The present study was undertaken to evaluate the quality of sheep milk and cheese and paneer prepared from it. Sheep milk was collected from experimental animals of Animal Nutrition Division. The pH, titratable acidity and specific density of sheep was 6.13, 0.20 and 1.01 respectively. Sheep milk contained 16.70 % total solids, 5.22% proteins, 7.26% fat, 3.09% lactose and 1.12 % total ash. Effect of two acidulants: acetic and citric acid was evaluated in paneer. The yield of paneer was significantly higher (P<0.05) in paneer made by acetic acid (0.048%) than citric acid (2.00%). The moisture and fat content of T1 paneer (2% citric acid) was 46.17 and 17.86 and that of T2 paneer (0.048% acetic acid) was 45.08 and 18.11 % respectively. The yield of paneer was 23.25 and 28.25% for T1 and T2. The sensory attributes of the paneer were numerically higher for T2. Texture profile indicated that, hardness, gumminess and chewiness were significantly lower in T2 samples. Mozzarella cheese was prepared from sheep milk and evaluated. The yield of mozzarella cheese was 10%. The moisture and dry matter content of mozzarella cheese was 55.90 and 44.10%. The sensory attributes were acceptable. The findings of the study indicated that, sheep milk is nutrient dense and could be processed into value added products. The paneer made by using acetic acid, gave higher yields and desirable soft texture.

Unpacking multi-trophic herbivore-grass-endophyte interactions: feedbacks across different scales in vegetation responses to Soay sheep herbivory

Grazing can induce changes in both plant productivity and nutritional quality, which may subsequently influence herbivore carrying capacity. While research on Soay sheep (Ovis aries L.) dynamics on Hirta Island in the St. Kilda archipelago has elucidated the complexity of population drivers, including parasites, the role of herbivore-generated feedbacks as an intrinsic regulating factor remains unclear. The sheep lack large predators and every 3–9 years undergo population crashes (overcompensatory mortality). We investigated the effects of grazing on (1) sward productivity and (2) quality (toxicity) of the primary forage species, red fescue (Festuca rubra L.), which is highly infected by an alkaloid-synthesizing fungal endophyte. Grazing had a negative impact on both forage quantity and quality. At higher sheep densities, impacts on sward growth were magnified, resulting in a nonlinear relationship with plant productivity. Simultaneously, endophyte hyphal load (and by inference, toxicity) peaked close to the time of a crash. A greenhouse experiment showed that alkaloid concentration in F. rubra increased in response to artificial defoliation. We conclude that at high sheep densities, grazing-mediated reductions in productivity, together with sustained alkaloid production, are likely to influence sheep dynamics. Future research should consider the interactive effects of forage toxicity, quantity, and nutritional content.

Global distribution data for cattle, buffaloes, horses, sheep, goats, pigs, chickens and ducks in 2010

Global data sets on the geographic distribution of livestock are essential for diverse applications in agricultural socio-economics, food security, environmental impact assessment and epidemiology. We present a new version of the Gridded Livestock of the World (GLW 3) database, reflecting the most recently compiled and harmonized subnational livestock distribution data for 2010. GLW 3 provides global population densities of cattle, buffaloes, horses, sheep, goats, pigs, chickens and ducks in each land pixel at a spatial resolution of 0.083333 decimal degrees (approximately 10 km at the equator). They are accompanied by detailed metadata on the year, spatial resolution and source of the input census data. Two versions of each species distribution are produced. In the first version, livestock numbers are disaggregated within census polygons according to weights established by statistical models using high resolution spatial covariates (dasymetric weighting). In the second version, animal numbers are distributed homogeneously with equal densities within their census polygons (areal weighting) to provide spatial data layers free of any assumptions linking them to other spatial variables.

A Systematic Review of Heat Load in Australian Livestock Transported by Sea.

Simple SummaryThe transport of livestock by sea (‘live export’) is an important contemporary animal welfare issue in Australia. There is particular concern for the effects of heat load on the welfare of sheep being shipped live from Australia to the Middle East during the Northern Hemisphere summer. To reduce bias in a contentious context, we performed a systematic review of the literature relevant to Australian sea transport, heat load, and livestock. We discuss the factors contributing to harmful heat load, pathways for mitigating risks and existing knowledge gaps. We identified several areas requiring research to address these knowledge gaps.The transport of animals by sea (‘live export’) is one of the most important current animal welfare issues in Australian society. Recent media attention has highlighted concerns regarding the effects of high environmental temperature and humidity on the welfare and mortality of sheep being shipped live from Australia to the Middle East, especially during the Northern Hemisphere summer. To improve understanding of how and why harmful heat load occurs, we systematically reviewed Australian research into heat load and sea transport. High thermal load occurs during the sea transport of sheep and cattle from Australia when animals are subject to hot and humid environmental conditions and cannot remove heat generated by metabolic processes in the body, potentially also gaining heat from the environment. Several approaches have been proposed to mitigate these risks, including avoidance of voyages in hot seasons, selection of heat-resistant livestock breeds, reducing stocking density, and improved ventilation. We identified a lack of scientific literature relating to heat load in animals transported by sea and considerable potential for bias in the literature that was found. We identified the following priority research areas: (i) experimental manipulation of variables thought to influence the incidence and severity of harmful heat load, including sheep density; (ii) further assessment of the Heat Stress Risk Assessment (HSRA) model used to predict heat load events, and (iii) development of a suite of animal welfare indicators that may allow identification of ‘at risk’ sheep before they reach debilitating heat load condition. Addressing these knowledge gaps will assist efforts to reduce the frequency and intensity of harmful heat load events.

Corralling, planting density, and N fertilizer rate effect on soil properties, weed diversity, and maize yield

ABSTRACTThe interaction effect of stocking density of sheep and goat corralling (SDSG), maize planting density (MPD), and N fertilizer rate (NFR) on soil properties, weed diversity, and maize yield were evaluated on-farm in a smallholder maize-livestock farming system of Northern Ghana during the 2014 and 2015 cropping seasons. A split-split plot design replicated on eight farms was used to study the effect of three SDSG (0, 70, and 140 head ha−1), three MPD (66 667, 100 000, and 133 333 plants ha−1), and three NFR (0–40-40, 60–40-40, and 90–40-40 NPK kg ha−1). The SDSG at 70 and 140 head ha−1 increased (P < 0.01) soil chemical and biological properties and weed diversity compared with the control in both cropping seasons. Maize growth, yield and yield components, and weed biomass were affected (P < 0.05) by the SDSG, MPD, and NFR interactions. Maize-livestock farmers with smaller flock size could use SDSG at 70 head ha−1 with NFR at 90 kg ha−1, whilst those with large flock size could stock at 140 head ha−1 with NFR at 60 kg ha−1 and MPD at 133 333 plants ha−1 for increased maize yield and weed management.

A spatial and temporal analysis of risk factors associated with sporadic Shiga toxin-producing Escherichia coli O157 infection in England between 2009 and 2015.

Infection with STEC O157 is relatively rare but has potentially serious sequelae, particularly for children. Large outbreaks have prompted considerable efforts designed to reduce transmission primarily from food and direct animal contact. Despite these interventions, numbers of infections have remained constant for many years and the mechanisms leading to many sporadic infections remain unclear.Here, we show that two-thirds of all cases reported in England between 2009 and 2015 were sporadic. Crude rates of infection differed geographically and were highest in rural areas during the summer months. Living in rural areas with high densities of cattle, sheep or pigs and those served by private water supplies were associated with increased risk. Living in an area of lower deprivation contributed to increased risk but this appeared to be associated with reported travel abroad. Fresh water coverage and residential proximity to the coast were not risk factors.To reduce the overall burden of infection in England, interventions designed to reduce the number of sporadic infections with STEC should focus on the residents of rural areas with high densities of livestock and the effective management of non-municipal water supplies. The role of sheep as a reservoir and potential source of infection in humans should not be overlooked.

Depredación del borrego Ovis canadensis (Artiodactila: Bovidae) y el venado bura Odocoileus hemionus (Artiodactila: Cervidae) por Puma concolor (Carnivora: Felidae) en Coahuila, México

Small and isolated populations of bighorn sheep (subject to special protection according to NOM-059-SEMARNAT-2010) are vulnerable to predation by mountain lion in habitat sympatric with mule deer. Understanding the specific causes of death and survival is important for the development of conservation strategies for bighorn sheep and other ungulates that share the same habitat, such as mule deer.We evaluated and compared the rate of predation by puma in 12 bighorn sheep (10 females, two males) and 10 adult females of mule deer with radio collars through measure risk program (micromorts). The impact of predation in both populations of herbivores is evaluated through the estimation of densities of sheep and mule deer. 88 % (8/9) deaths by puma in bighorn sheep with an average monthly survival rate of 0.79 and predation rates due to puma range from 0.17 to 0.30. In mule deer predation due to puma was 83 % (5/6) with an average monthly survival rate of 0.86 and predation rates due to puma range from 0.10 to 0.25, however when comparing the mountain lion depredation rate we found a significant difference between species (Z = 1.826, df = 6, P = 0.05). The density in mule deer was 9x more that bighorn. The bighorn sheep being the prey most selected and the one most affected as the population with the lowest density.

Spatiotemporal patterns and agroecological risk factors for cutaneous and renal glomerular vasculopathy (Alabama Rot) in dogs in the UK

The annual outbreaks of cutaneous and renal glomerular vasculopathy (CRGV) reported in UK dogs display a distinct seasonal pattern (November to May) suggesting possible climatic drivers of the disease. The...

Sheep and Goat Corralling Density Effect on Soil Properties and Weed Species Diversity of Arable Lands

The hypothesis that livestock corralling improves soil properties and weed species richness was investigated in a 2-year on-farm trial conducted in Sudan savanna agro-ecology of Ghana. The effect of three stocking densities of sheep and goats corralling (0, 70 and 140 head ha−1) on soil properties and weed species diversity was evaluated in a randomized complete block design with eight replicates. Sheep and goats weighing 27 ± 2.0 and 24 ± 1.5 kg, respectively, were corralled on fallow arable lands from 19: 00 to 06: 00 GMT hours daily for 178 nights during 2014 and 2015 cropping seasons. Soil parameters measured include pH, organic carbon (OC), total nitrogen, available phosphorus, exchangeable potassium, microbial biomass carbon, microbial biomass nitrogen, soil microbial quotient, earthworm cast, bulk density, porosity, and moisture. Soil properties and weed species diversity increased (P < 0.01) with sheep and goats corralling relative to the control. Broadleaf and sedge species were positively correlated with soil OC while the grass was positively correlated with soil OC, microbial biomass carbon, bulk density, and porosity. The results suggest that crop-livestock farmers could corral 70 head ha−1 sheep and goats for soil fertility amendment on Ferric Lixisol in Sudan savanna agro-ecology of West Africa and similar agro-ecologies.

Spatial modeling of oestrosis in sheep in Guantánamo province, Cuba

Oestrosis is a myiasis caused by larvae of the fly Oestrus ovis (Linné 1761, Diptera: Oestridae) that occurs worldwide. Oestrosis was first reported in Cuba in the middle of the 1990s in the municipality of Imías, Guantánamo province. Determining the spatial pattern and risk factors for the disease might be useful to help explain the disease occurrence and select options for disease surveillance and control. In the present study, the number and distribution of affected premises was shown to have been similar throughout the period studied (2006–2010). The disease was found to occur mostly in the southern and western parts of the province with high dispersion in an east-west direction over the period of study. Three “hotspots” (Getis-Ord Gi*) were identified in the province in which there was an increased risk of disease occurrence. Geographically Weighted Logistic Regression was used to test associations between environmental variables and disease occurrence. Results demonstrated that areas with lower mean annual rainfall, higher mean temperature, and higher sheep density had the highest risk of disease occurrence. High risk areas are mostly located in the western zone (El Salvador, Niceto Pérez and Guantánamo municipalities) and also in the central zone (coast of San Antonio del Sur and Imías). The associations between oestrosis cases and local environmental characteristics varied geographically within the study area. These results might be useful to improve disease surveillance and control. Treatment of animals in these “hotspots”, as well as in other places where the risk is higher should be prioritized to more efficiently reduce the harmful impact of this disease.

Risk factors for cutaneous myiasis (blowfly strike) in pet rabbits in Great Britain based on text-mining veterinary electronic health records

Blowfly strike is a devastating and often rapidly fatal disease in rabbits. In Great Britain (GB), Lucilia sericata is the primary causative species. Despite its severity, there has been minimal investigatory work into the disease in rabbits. Here we used text mining to screen electronic health records (EHRs) from a large sentinel network of 389 veterinary practices in GB between March 2014 and April 2017 for confirmed cases of blowfly strike in rabbits.Blowfly strike was identified in 243 of 42,226 rabbit consultations (0.6%), affecting 205 individual rabbits. The anatomical site of recorded blowfly strike lesions was overwhelmingly the perineal area (n = 109, 52.4%). Less commonly lesions were observed affecting other areas of the body (n = 9, 4.3%) and head (n = 8, 3.8%); in 83 consultations (39.9%), the affected area was not specified. Of the rabbits presenting with blowfly strike, 44.7% were recorded as being euthanized or died.A case control study was used to identify risk factors for blowfly strike in this population. Whilst sex and neuter status in isolation were not significantly associated with blowfly strike, entire female rabbits showed a 3.3 times greater odds of being a case than neutered female rabbits. Rabbits five years of age and over were more than 3.8 times likely to present for blowfly strike. For every 1 °C rise in environmental temperature between 4.67 °C and 17.68 °C, there was a 33% increase risk of blowfly strike, with cases peaking in July or August. Overall blowfly strike cases started earlier and peaked higher in the south of Great Britain. The most northerly latitude studied was at lower risk of blowfly strike than the most southerly (OR = 0.50, p < 0.001). There appeared to be no significant relationship between blowfly strike in rabbits and either the sheep density or rural and urban land coverage types.The results presented here can be used for targeted health messaging to reduce the impact of this deadly disease for rabbits. We propose that real-time temporal and spatial surveillance of the rabbit disease may also help inform sheep control, where the seasonal profile is very similar, and where routine surveillance data is also not available. Our results highlight the value of sentinel databases based on EHRs for research and surveillance.

The prevalence and distribution of sheep scab in Wales: a farmer questionnaire survey.

Outbreaks of ovine psoroptic mange in the U.K. have increased 100-fold since its deregulation in 1992, with the highest prevalence in Wales, a region of high sheep density. A cross-sectional, retrospective, questionnaire-based survey of 7500 members of the association of Welsh lamb and beef farmers [Welsh Lamb and Beef Producers Ltd (WLBP)] was used to investigate the prevalence and distribution of sheep scab in this region in 2015. The survey was completed by 14.0% (n = 972) of potential respondents. Scab outbreaks were reported on 15.8% (n = 154) of farms in 2015. However, 29.0% (n = 282) of farms reported at least one scab outbreak and 2.4% (n = 23) of farms had experienced between six and 10 outbreaks in the previous 10 years. Most outbreaks occurred during September-January (83.0%, n = 150), and were clustered around Brecon (mid-Wales) and Bangor (North Wales). Farmers who used common grazing were significantly more likely to report scab outbreaks in the previous 10 years than farmers who did not. No quarantine procedures for sheep bought in were used by 29.0% (n = 262) of farmers. Future research should be directed towards the development of localized management programmes, with a particular focus on areas of common grazing.

Establishing baseline estimates of blue sheep (Pseudois nayaur) abundance and density to sustain populations of the vulnerable snow leopard (Panthera uncia) in Western Bhutan

Context Advances have been made in the development of reliable methods for estimating the abundance and density of large threatened mammalian predators, but there is little progress on developing population estimates for their principal prey. No standardised protocol for estimating prey populations exists, therefore different researchers use different methods. As such, there is little information on key prey species of the vulnerable snow leopard and this has hindered the preparation of effective snow leopard conservation plans. Aims This study aimed to establish an estimated seasonal baseline population abundance and density of blue sheep in the Lingzhi Park Range (LPR) of Bhutan’s Jigme Dorji National Park over winter (December to February) and summer (May to July). It also aimed to assess the number of snow leopard individuals that the current blue sheep population can sustain in the study area. Methods A refined double-observer survey method was used and involved walking transect lengths of 414 km in winter and 450 km in summer to estimate blue sheep abundance with the aid of 8 × 30 binoculars and 15 × 45 spotting scopes. Key results In total, 1762 (s.e. ± 199) blue sheep individuals were recorded in winter at a density of 8.51 individuals per km2 and 2097 (s.e. ± 172) individuals in summer at a density of 9.32 individuals per km2. Mean group size of blue sheep was 38.12 individuals (s.e. ± 6) in winter and 52.36 individuals (s.e. ± 4) in summer. LPR was estimated to sustain 11–17 snow leopards in winter and 15–21 in summer. Key conclusions LPR can be a hotspot for snow leopard conservation in western Bhutan and regionally in the eastern Himalayas, because the comparatively higher estimated blue sheep abundance and density supports possibly the highest density of snow leopards in Bhutan. The modified double-observer method used to assess blue sheep population estimates is inexpensive, robust and practical for the mountainous terrain of the Himalayas. Implications On the basis of this study, it is recommended that a refined double-observer method is adopted as a standard technique for estimating blue sheep populations in the snow leopard range countries of the Himalayas. Snow leopard conservation plans should, additionally, include efforts to minimise threats to blue sheep populations. This refined method is also highly applicable for future surveys of gregarious mammalian taxa, such as ungulates and primates, in difficult mountainous terrain elsewhere in the world.

Assessing the social context of wildfire-affected areas. The case of mainland Portugal

Wildfires cause different impacts, depending on the conditions and resilience level of the exposed communities. Wildfire occurrence in mainland Portugal was assessed with regard to socioeconomic and demographic parameters, to identify the most distinctive conditions of fire-affected areas, without implying the existence of causal relationships. The latest population and agriculture census data were used to retrieve conditions at the civil parish level, regarding demographic patterns, social and labor conditions, physical structures and agricultural activities. To identify differences between parishes, two groups were created with the communities that showed the highest and lowest 20% of wildfire incidence between 2007 and 2014, separately for density of fire events and for burned area. A stepwise approach based on classification trees and random Forest methods was applied to identify the best discriminant variables between the groups. First, irrelevant variables were removed by an interactive process based on misclassification rates. The second step used random Forest analysis to the remaining variables to evaluate their importance in distinguishing the groups. In the final step, cluster analysis was applied to test the correspondence between the clusters created with the selected variables and the initial groups. Results showed that parishes with higher fire density have higher population density, higher proportion of young and educated people, larger families and more overcrowded buildings. On the contrary, parishes with larger burned area are less populated, less attractive to foreigners, have a higher proportion of elderly people, more degraded housing conditions and agricultural activities, visible in the density of sheep and goat and pastures, are still relevant. The cluster analysis demonstrated a better performance of the model for wildfire density, revealing a strong association with socioeconomic dynamics with an agreement above 0.85, much higher than for burned areas which is 0.29. Overall, the spatial distribution of wildfire impacts is framed by societal settings and particular conditions must be further understood to improve the coping capacity of affected communities.

Characterization and typology of sheep and goat production systems in the State of Paraíba, a semi-arid region of northeastern Brazil

Breeding of goats and sheep is an important activity in northeast Brazil, contributing to economic and social development of this region. Thus, the objective of this study was to characterize goat and sheep rearing and breeding in the central-western region of the State of Paraíba, northeast Brazil. The study area included Borborema and mesoregions of the backlands of the state, represented by 127 municipalities in an area of 38.293 km2, with density of goats and sheep at 12.9 and 8.27 head/km2, respectively. A total of 62 farms belonging to five municipalities of the Borborema mesoregion and four municipalities of the Sertão mesoregion were surveyed. Epidemiological surveys were conducted in the farms, and questionnaires sought information on the economic, productive, and social aspects of the farm owners and the farms. The results allowed the classification of goat and sheep production systems in the semi-arid Paraíba as a family system and of subsistence, for farmers’ own consumption and for local trade, with low technology use and herds with up to 100 animals. The farmers’ level of education was low, and the investments and technical assistance for the development of breeding activity in the region were insufficient and/or inadequate. Thus, it was essential to conduct an economic study on the farms to assess the actual economic and financial status of breeding activity and the subsequent returns. It is suggested that these aspects be taken into account when planning livestock development policies, especially in terms of finance and technical assistance, as well as in the implementation of strategies to control commonly occurring diseases in the region, aimed at combating agents, environmental control, and protection of susceptible livestock.

Wetlands, wild Bovidae species richness and sheep density delineate risk of Rift Valley fever outbreaks in the African continent and Arabian Peninsula.

Rift Valley fever (RVF) is an emerging, vector-borne viral zoonosis that has significantly impacted public health, livestock health and production, and food security over the last three decades across large regions of the African continent and the Arabian Peninsula. The potential for expansion of RVF outbreaks within and beyond the range of previous occurrence is unknown. Despite many large national and international epidemics, the landscape epidemiology of RVF remains obscure, particularly with respect to the ecological roles of wildlife reservoirs and surface water features. The current investigation modeled RVF risk throughout Africa and the Arabian Peninsula as a function of a suite of biotic and abiotic landscape features using machine learning methods. Intermittent wetland, wild Bovidae species richness and sheep density were associated with increased landscape suitability to RVF outbreaks. These results suggest the role of wildlife hosts and distinct hydrogeographic landscapes in RVF virus circulation and subsequent outbreaks may be underestimated. These results await validation by studies employing a deeper, field-based interrogation of potential wildlife hosts within high risk taxa.

Costs of Livestock Depredation by Large Carnivores in Sweden 2001 to 2013

Livestock depredation by large carnivores entails economic damage to farmers in many parts of the world. The aim of this paper is to analyse and compare the costs of livestock depredation by carnivores in Sweden across different carnivore species and counties. To this end, we estimate the government's compensation cost function using Swedish data on the county level over the period of 2001 to 2013. Compensation costs due to depredation by three large carnivores are considered: the brown bear (Ursus arctos), the wolf (Canis lupus) and the lynx (Lynx lynx). The results show that a 1% increase in the density of the carnivores leads to a 0.3–0.4% increase in compensation costs, whereas a 1% increase in the density of sheep results in a 0.8 and 1.1% increase in the compensation costs for brown bears and wolves, respectively. A larger share of unfenced pastures is associated with higher compensation costs for brown bear. The marginal cost of an additional carnivore individual varies considerably between counties, ranging between 1 and 82 EUR for lynxes, 0 and 266 EUR for brown bears, and 52 and 1067 EUR for wolves.

Assessing wild canid depredation risk using a new three steps method: the case of Grosseto province (Tuscany, Italy)

The recovery of large carnivores in human dominated landscapes can cause controversy and concern for livestock producers, especially where wild predator populations and farmland overlap. This is the case in the Grosseto province, located in the southern part of Tuscany, Italy. Anticipating where predator attacks are likely to occur can help focus mitigation efforts. We suggest a three-step method to predict wild canid depredation risk using presence only data on wild canid detections and confirmed depredation events in the study area. We obtained the probability of occurrence for canids and depredation events based on ecological variables and then performed an ensemble model following an ad-hoc procedure. We compared models’ outputs obtained from two different approaches to species distribution modeling: Maximum Entropy (Maxent) and Bayesian for Presence-only Data (BPOD) testing their ability to predict the occurrence of events. The ecological niche factor analysis (ENFA) was used to assess the importance of each environmental variable in the description of the presence points. Forested areas were identified as the most important attribute predicting wild canid occurrence. Livestock predation was most likely to occur close to farms where sheep densities were higher and more accessible. Higher depredation risk zones were characterized by proximity to forested areas and the presence of landscape features that allowed wild canids to reach pastures with minimum effort such as the network of smaller watercourses. Only 15% of the total sheep farms fall within higher risk areas, indicating that depredation was facilitated by environmental conditions (e.g. closeness to the woods) rather than the availability of prey. Overall BPOD performed better than Maxent in terms of sensitivity, suggesting that BPOD could be a promising approach to predict probability of occurrence using presence only data.