Meles Meles Research Articles

Towards an automated protocol for wildlife density estimation using camera‐traps

Abstract Camera‐traps are valuable tools for estimating wildlife population density, and recently developed models enable density estimation without the need for individual recognition. Still, processing and analysis of camera‐trap data are extremely time‐consuming. While algorithms for automated species classification are becoming more common, they have only served as supporting tools, limiting their true potential in being implemented in ecological analyses without human supervision. Here, we assessed the capability of two camera‐trap based models to provide robust density estimates when image classification is carried out by machine learning algorithms. We simulated density estimation with Camera‐Trap Distance Sampling (CT‐DS) and Random Encounter Model (REM) under different scenarios of automated image classification. We then applied the two models to obtain density estimates of three focal species (roe deer Capreolus capreolus, red fox Vulpes vulpes and Eurasian badger Meles meles) in a reserve in central Italy. Species detection and classification was carried out both by the user and machine learning algorithms (respectively, MegaDetector and Wildlife Insights), and all outputs were used to estimate density and ultimately compared. Simulation results suggested that the CT‐DS model could provide robust density estimates even at poor algorithm performances (down to 50% of correctly classified images), while the REM model is more unpredictable and depends on multiple factors. Density estimates obtained from the MegaDetector output were highly consistent for both models with the manually labelled images. While Wildlife Insights' performance differed greatly between species (recall: badger = 0.15; roe deer = 0.56; fox = 0.75), CT‐DS estimates did not vary significantly; on the contrary, REM systematically overestimated density, with little overlap in standard errors. We conclude that CT‐DS and REM models can be robust to the loss of images when machine learning algorithms are used to identify animals, with the CT‐DS being an ideal candidate for applications in a fully unsupervised framework. We propose guidelines to evaluate when and how to integrate machine learning in the analysis of camera‐trap data for density estimation, further strengthening the applicability of camera‐traps as a cost‐effective method for density estimation in (spatially and temporally) extensive multi‐species monitoring programmes.

Temporal relationships between the red fox and the European badger in a Mediterranean protected area

AbstractNiche partitioning according to time, space, or resources is the key to interspecific coexistence. Interactions among carnivore species are complex: interference is common, although positive relationships may develop through trophic facilitation. In turn, different behavioral responses to coexistence may be reported, ranging from avoidance to attraction, the outcome of which is highly dependent on the local environmental context. Here, we evaluated the temporal partitioning by analyzing spatiotemporal relationships between the red fox Vulpes vulpes and the European badger Meles meles in a Mediterranean?protected area for three full years, using intensive camera trapping. The two species showed similar temporal activity patterns, with a nocturnal activity and peaks at dawn and dusk. We found a substantial temporal overlap between red fox and badger (Δ > 0.78, on a 0‐1 scale). However, we detected some differences in temporal activity patterns across these species and no evidence of interspecific spatiotemporal avoidance. Previous work provided no evidence supporting spatial avoidance among the study species. Our results suggest a role of temporal partitioning at a finer scale during the night to facilitate interspecific coexistence.

Molecular analysis of vector-borne pathogens in Eurasian badgers (Meles meles) from continental Europe

BackgroundVector-borne pathogens (VBPs) are increasing in significance in veterinary medicine and public health settings, with wildlife playing a potentially crucial role in their transmission. Eurasian badgers (Meles meles) are widely distributed across Europe. However, information currently available on the prevalence of VBPs in badgers is limited. The objective of the current study was to investigate the occurrence of Anaplasmataceae, Bartonella spp., Mycoplasma spp., Rickettsia spp., Piroplasmida, Trypanosomatida and Filarioidea in badgers and subsequently, based on the results, assess the potential risk to domestic animals, other wildlife and humans.MethodsBetween 2017 and 2021, blood or spleen samples from 220 badgers were collected in nine continental European countries: Austria (n = 7), Bosnia and Herzegovina (n = 2), Croatia (n = 22), France (n = 44), Germany (n = 16), Hungary (n = 7), Italy (n = 16), Romania (n = 80) and Serbia (n = 26). VBPs were identified by performing PCR analysis on the samples, followed by Sanger sequencing. Additionally, to distinguish between different Babesia lineages we performed restriction fragment length polymorphism (RFLP) analysis on piroplasm-positive samples, using HinfI as restriction enzyme. A phylogenetic analysis was performed on Mycoplasma spp.ResultsThe pathogens identified were Babesia sp. badger type A (54%), B (23%), and C (37%); Trypanosoma pestanai (56%); Mycoplasma sp. (34%); Candidatus Mycoplasma haematomelis (8%); Candidatus Mycoplasma haematominutum (0.5%); and Ehrlichia spp. (2%). Rickettsia spp., Bartonella spp. and filarioid nematodes were not detected among the tested samples.ConclusionsThe large sample size and diverse study populations in this study provide valuable insights into the distribution and epidemiology of the analyzed pathogens. Some of the VBPs identified in our study show high similarity to those found in domestic animals, such as dogs. This finding suggests that badgers, as potential reservoirs for these pathogens, may pose a threat not only to other wildlife but also to domestic animals in close vicinity. Continuous surveillance is essential to monitor VBPs in wildlife as a means to enable the assessment of their impact on other wildlife species, domestic animals and human health.Graphical

A histopathological study in road-killed European badgers (Meles meles) from the English midlands with isolation of novel non-tuberculous atypical mycobacteria

European badgers (Meles meles) play an important role in the epidemiology of bovine tuberculosis (caused by Mycobacterium bovis) in England, but little is known about the prevalence of atypical mycobacteriosis. Badgers are also known to be infected by other infectious agents, and the relationship between mycobacteriosis and concomitant infections needs further investigation. Overall, 88 badger carcasses from the Midlands of England collected between July 2016-August 2017 were selected for histopathological examination based on the degree of autolysis (mild), mycobacterial culture results and a balanced sex ratio. Mycobacteria were cultured from 44 badgers, of which 31 were mycobacteria belonging to the M. tuberculosis complex (MTBC) (based on IS6110 PCR and Hsp64 and/or rRNA PCR and sequencing) and 13 were non-tuberculous atypical mycobacteria (NTM). Mycobacteria were not cultured from the remaining 44 animals. Histologically, the most common findings were silica-laden macrophages (85%), granulomas (53%), sarcocystosis (47%), nephritis (31%), portal/periportal hepatitis (26%), ulcerative dermatitis (18%). Culturable mycobacteriosis was associated with higher prevalence of granulomas (p < 0.001) and lower prevalence of hepatitis (p = 0.003). NTM (M. nonchromogenicum, M. avium complex, M. hassiacum, M. malmoense, M. vaccae.) infections were associated with granulomatous pneumonia, and M. malmoense was associated with pyogranulomatous and ulcerative dermatitis. In conclusion, this study describes, for the first time, histological lesions associated with NTM in badgers, the histomorphology of which was similar to those caused by MTBC. In addition, the negative relationship between mycobacteriosis and periportal hepatitis may indicate a complex relationship between mycobacteriosis and other diseases, as previously observed with tuberculosis.

The contingent impact of wind farms on game mammal density demonstrated in a large-scale analysis of hunting bag data in Poland

Wind farms are still developing dynamically worldwide, with promising prospects for further growth. Therefore, the assessment of their impact on animals has been carried out. So far, few studies have been conducted on game mammals, and their results are divergent. Previous studies on the impact of wind farms on game species were typically based on regional research covering one or, at most, several wind farms. In this study, we aimed to verify the effect of wind farms on the density of game mammals through a large-scale analysis at the country level, using lowland Poland as an example. The study was based on hunting bag data from open-field hunting districts. It covered seven game species: roe deer (Capreolus capreolus), wild boar (Sus scrofa), red fox (Vulpes vulpes), raccoon dog (Nyctereutes procyonoides), European badger (Meles meles), European polecat (Mustela putorius), and European hare (Lepus europaeus). We used Corine Land Cover to account for differences in land cover and the area covered by wind farms in generalized linear mixed models. The study showed that in agricultural landscapes, mainly herbivorous species of game mammals were related to land cover types. These species tend to exhibit higher densities in agricultural areas containing more natural landscape features. Conversely, mesocarnivores are primarily driven by the abundance of prey with little to no observable effects from land cover types. Only roe deer and wild boar presented lower densities with an increase in the area covered by wind farms (for roe deer: estimate: − 0.05, 95% CI: − 0.1–0.0; for wild boar: estimate: − 0.03, 95% CI: − 0.11–0.05), while no effect was observed for mesocarnivores or European hare. The underlying reasons for these relationships remain unclear and require more specific studies. The uncertainty regarding the cause of the observed effects did not allow for a large-scale assessment of the impact of further wind energy development on the studied game mammals.

Use of European badger setts by invasive raccoons and other mesocarnivores in western Poland

AbstractWe describe a cases of main setts of European badger Meles meles being used by non-native raccoons Procyon lotor and raccoon dogs Nyctereutes procyonoides and native red foxes Vulpes vulpes in western Poland. From April to June 2022 and from November 2022 to mid-April 2023, we monitored the main badger setts (27 in spring and 14 in winter) using camera traps. We recorded the presence of red foxes in 63.0%, raccoon dogs in 48.1% and raccoons in 22.2% of the setts. These species were more likely to occupy badger setts in winter. The raccoon is the second invasive species after the raccoon dog to use badger setts for shelter in Poland. In four setts, we observed that two native (badger and red fox) and two non-native (raccoon and raccoon dog) mesocarnivores cohabited the same sett.

Above‐ground nest locations support key life stages and group behaviours in Eurasian badger territories

Although the Eurasian badger Meles meles is well known for occupying underground setts, badgers also use nests above ground. There is limited research as to how these above‐ground nests function within a badger territory and which behaviours and life stages they provide for social groups. This project investigated the use of above‐ground nests within known badger territories, taking into consideration when and how they are used by the group, as well as identifying where nests are located and where they are likely to be found in relation to other territory features. We found that nests were located closer to habitat boundaries than main sett or satellite locations, and latrines. The probability of a badger using a nest was greater at night, with nests supporting important behaviours such as mating and social interactions during the hours of darkness. Mating and grooming were found to decrease the further nests were from main sett locations, whereas territorial behaviours in nests were found to decrease the further nests were from habitat edges. This study provides new understanding of above‐ground badger behaviour and use of nests and their function within badger territories, which may have implications for current badger legislation and best‐practice survey guidelines.

Contact zone of European (Meles meles Linnaeus, 1758) and Asian (M. leucurus Hodgson, 1847) badgers (Mustelidae, Mammalia) in the rightand left-bank districts of the Saratov region

DNA studies of badgers (Meles sp.) from the right-bank and left-bank areas of the Volga river in the Saratov region are described. Asian badgers (Meles leucurus Hodgson, 1847) inhabit the Left Volga Bank of the Saratov region, while European badgers (M. meles Linnaeus, 1758) inhabit the Right Volga Bank districts of the region, but Asian badgers were found in Khvalynsky district of the Saratov region, besides the European badger. Despite a sufficient number of publications devoted to the Asiatic badger distribution in the Vyatka–Kama region and the Volga region, and studies devoted to the development of systematics of the genus Meles in Russia, the question of the boundaries of the ranges of European and Asiatic badgers and the zones of their sympatry (parapatry) in the Volga–Kama region has not been fully investigated to date. Our work is devoted to the study of this question. As a result of analyzing the biological material collected by us, it was found that all five studied individuals of badgers from the Saratov Volga region phenotypically looked like Asian badgers, but our DNA analysis showed that only two of them were M. leucurus, whilst three ones were heterozygous individuals carrying genes from both species and were identified as hybrids. The remaining 29 individuals were captured in the right-bank areas of the region. Badgers were sampled from individuals from the northern to southern borders of the region in areas located along the Volga river on the Volga upland and in the Oka–Don plain. Of these, one individual from Khvalynsky district turned out to be an Asian badger, one individual from Krasnoarmeysky district was a hybrid of the two named species, and three individuals, one from Tatishchevsky, the second from Volsky and the third from Khvalynsky districts showed introgression of Asian badger genes into the genotype of the European badger. Thus, we have managed to find out that at this stage of development of the phase of the climatic cycle in the Lower Volga region, characterized by warming winters, the Volga river, with its two reservoirs within the Saratov region, is not an absolute zoogeographical boundary, and badgers, whose species are characterized by winter sleep, can in certain conditions overcome, most likely on ice, both the river itself and the lake parts of the Volgograd and Saratov reservoirs. According to the revealed introgression in some individuals from different areas on the Volga upland of the right bank of the Saratov region, it can be assumed that such traveling across the Volga river took place earlier, possibly before its flow was regulated by dams.

Leishmania infantum infection in European badgers (Meles meles) from northeastern Spain: a histopathological and immunohistochemical investigation

The European badger (Meles meles) is a common mustelid species known as a significant reservoir for various human and animal diseases. Studies investigating Leishmania infection in European badgers across Mediterranean regions have yielded inconsistent findings. In Spain, results are particularly controversial: some studies confirm the presence of Leishmania in badgers, while others do not. Our study aimed to conduct a retrospective histopathological and immunohistochemical analysis to detect Leishmania in tissues of nine European badgers from northeastern Spain, a region previously unevaluated for Leishmania infection in this species. Microscopic examination revealed lesions indicative of leishmaniosis in the lymph nodes and spleens of six badgers. In one of them, Leishmania-like structures were identified in multiple organs and confirmed via immunohistochemistry. Parasites were detected in the lymph nodes, spleen, adrenal glands, and pancreas. The parasite load was high in the adrenal glands, moderate in the lymph nodes and spleen, and low in the pancreas. No parasites were found in other examined organs. This finding represents a frequency of 11.11% (1/9) of Leishmania infection among the badgers we studied. Further investigation of wildlife and atypical reservoirs can enhance our understanding of the pathogenesis of this significant zoonotic disease.

Ecological Adjustments and Behavioural Patterns of the European Badger in North-Western Italy

The European badger is a highly adaptable species, inhabiting a range of environments across Europe, from woodlands to urban areas, with its behaviour influenced by environmental conditions and human activities. This study examines the badger feeding habits, patterns of diel activity, and sett site choice in north-western Italy, assessing how landscape composition affects these behaviours. We conducted our research across seven study areas in northern Italy from December 2020 to November 2022, utilising camera trapping, faeces analysis, and sett surveys. Our findings revealed significant dietary variation, with earthworms being the primary food source in natural landscapes, while fleshy fruits being consumed especially in mixed and heavily modified landscapes, up to constitute the staple of the diet in one agricultural area. Badgers were found to be nocturnal, primarily active between sunset and sunrise. Setts varied considerably in structure and location, with a preference for natural grounds over human-made structures; key factors influencing sett site choice included slope, exposure, and vegetation cover. This study underscores the European badger’s remarkable adaptability, illustrating how its diet, activity patterns, and sett site preferences are shaped by a complex interplay of factors, allowing the species to thrive in both pristine and modified environments across northern Italy.

Dead-reckoning facilitates determination of activity and habitat use: a case study with European badgers (Meles meles)

BackgroundStudies describing the movement of free-ranging animals often use remotely collected global positioning system (GPS) data. However, such data typically only include intermittent positional information, with a sampling frequency that is constrained by battery life, producing sub-sampling effects that have the potential to bias interpretation. GPS-enhanced ‘dead-reckoning’ of animal movements is an alternative approach that utilises combined information from GPS devices, tri-axial accelerometers, and tri-axial magnetometers. Continuous detailed information of animal movement, activity and habitat selection can then be inferred from finer-scale GPS-enhanced dead-reckoning. It is also a useful technique to reveal the minutiae of an animal’s movements such as path tortuosity. However, examples of studies using these approaches on terrestrial species are limited.MethodsCollars equipped with GPS, tri-axial accelerometer, and tri-axial magnetometer loggers were deployed on European badgers, Meles meles, to collect data on geo-position, acceleration and magnetic compass heading, respectively. This enabled us to compare GPS data with calculated GPS-enhanced dead-reckoned data. We also examined space use, distances travelled, speed of travel, and path tortuosity in relation to habitat type.ResultsNightly distances travelled were 2.2 times greater when calculated using GPS-enhanced dead-reckoned data than when calculated using GPS data alone. The use of dead-reckoned data reduced Kernel Density Estimates (KDE) of animal ranges to approximately half the size (0.21 km2) estimated using GPS data (0.46 km2). In contrast, Minimum Convex Polygon (MCP) methods showed that use of dead reckoned data yielded larger estimates of animal ranges than use of GPS-only data (0.35 and 0.27 km2, respectively).Analyses indicated that longer periods of activity were associated with greater travel distances and increased activity-related energy expenditure. Badgers also moved greater distances when they travelled at faster speeds and when the routes that they took were less tortuous. Nightly activity-related energy expenditure was not related to average travel speed or average ambient temperature but was positively related to the length of time individuals spent outside the sett (burrow). Badger activity varied with habitat type, with greater distance, speed, track tortuosity, and activity undertaken within woodland areas. Analyses of the effects of varying GPS sampling rate indicate that assessments of distance travelled depend on the sampling interval and the tortuosity of the animal’s track. Where animal paths change direction rapidly, it becomes more important to use dead-reckoned data rather than GPS data alone to determine space use and distances.ConclusionsThis study demonstrates the efficacy of GPS-enhanced dead-reckoning to collect high-resolution data on animal movements, activity, and locations and thereby identify subtle differences amongst individuals. This work also shows how the temporal resolution of position fixes plays a key role in the estimation of various movement metrics, such as travel speed and track tortuosity.

Investigations on the Potential Role of Free-Ranging Wildlife as a Reservoir of SARS-CoV-2 in Switzerland.

Amid the SARS-CoV-2 pandemic, concerns surfaced regarding the spread of the virus to wildlife. Switzerland lacked data concerning the exposure of free-ranging animals to SARS-CoV-2 during this period. This study aimed to investigate the potential exposure of Swiss free-ranging wildlife to SARS-CoV-2. From 2020 to 2023, opportunistically collected samples from 712 shot or found dead wild mustelids (64 European stone and pine martens, 13 European badgers, 10 European polecats), canids (449 red foxes, 41 gray wolves, one golden jackal) and felids (56 Eurasian lynx, 18 European wildcats), as well as from 45 captured animals (39 Eurasian lynx, 6 European wildcats) were tested. A multi-step serological approach detecting antibodies to the spike protein receptor binding domain (RBD) and N-terminal S1 subunit followed by surrogate virus neutralization (sVNT) and pseudotype-based virus neutralization assays against different SARS-CoV-2 variants was performed. Additionally, viral RNA loads were quantified in lung tissues and in oronasal, oropharyngeal, and rectal swabs by reverse transcription polymerase chain reactions (RT-qPCRs). Serologically, SARS-CoV-2 exposure was confirmed in 14 free-ranging Swiss red foxes (prevalence 3.1%, 95% CI: 1.9-5.2%), two Eurasian lynx (2.2%, 95% CI: 0.6-7.7%), and one European wildcat (4.2%, 95% CI: 0.2-20.2%). Two positive foxes exhibited neutralization activity against the BA.2 and BA.1 Omicron variants. No active infection (viral RNA) was detected in any animal tested. This is the first report of SARS-CoV-2 antibodies in free-ranging red foxes, Eurasian lynx, and European wildcats worldwide. It confirms the spread of SARS-CoV-2 to free-ranging wildlife in Switzerland but does not provide evidence of reservoir formation. Our results underscore the susceptibility of wildlife populations to SARS-CoV-2 and the importance of understanding diseases in a One Health Concept.

The anatomical structure of the stellate ganglion in the European badger (Meles meles)

Abstract The stellate ganglion belongs to the sympathetic part of the autonomic nervous system. It responds to signals from the brain to the organs in the chest, including the heart, whose function it regulates. In this study, an analysis of the normal anatomy of the stellate ganglion in the European badger was presented. The research involved 6 male specimens, 3 female specimens, and 1 specimen with undetermined sex. Dissection was performed to remove the skin and muscles of the thorax, as well as parts of the ribs and lungs. The shape, topographical location, dimensions, and the ganglia constituting the structure of interest were analyzed. The results were compared with studies conducted on other animal species. However, these studies are preliminary and require further expansion with a larger group of specimens. They provide a basis for further development of the normal and comparative anatomy of the European badger.

Ethological and ecological adaptations of Eurasian badger (&lt;i&gt;Meles meles&lt;/i&gt;) in the exclusion and resettle zone of the Polesie State Radiation-Ecological Reserve

Ethological and ecological adaptations of Eurasian badger (&lt;i&gt;Meles meles&lt;/i&gt;) in the exclusion and resettle zone of the Polesie State Radiation-Ecological Reserve

An integrated assessment of niche partitioning reveals mechanisms of coexistence between mesocarnivores

Species diversity depends on the capacity of species to coexist, and when these share similar ecological requirements some degree of partitioning of the ecological niche is expected. Within the order Carnivora, direct and indirect interspecific interactions shape community structure and composition. Although strong negative interactions (e.g., interspecific killing) are expected between large carnivores and subordinate species, mesocarnivores that dominate most human disturbed landscapes can still strongly compete for resources given their similar body size and energy requirements. To identify the mechanisms of coexistence between mesocarnivore species in a Mediterranean landscape we assessed the ecological niche overlap between five species (Vulpes vulpes, Meles meles, Martes foina, Herpestes ichneumon, Genetta genetta), by simultaneously measuring the space, time, and trophic resource use. The multi-species occupancy model fit to camera-trapping data revealed spatial co-occurrence between most species’ pairs and an avoidance pattern between only stone marten and Eurasian badger (78 % probability of a negative effect). Using genetically identified scats, we assessed trophic niche breadth and overlap. Niche breadth was narrow for red fox, Eurasian badger, and stone marten, given these species consumed almost exclusively fruits and arthropods, and so trophic niche overlap was high. For the genet and the mongoose, the consumption of different food resources (e.g., mammals, birds, and reptiles) increased niche breadth and decreased the niche overlap with the other sympatric species. Finally, niche segregation was more significant along the temporal axis, since the mongoose has a diurnal activity pattern and the remaining carnivore species, although mostly nocturnal, had small asynchronies in the activity peaks which could decrease the chance of direct encounters. Therefore, our results suggest that similar habitat preferences and ecological requirements rather than interspecific competition shape the mesocarnivores’ resource use in this landscape. Nonetheless, fine-scale temporal segregation seems the main mechanism to facilitate coexistence, together with small differences in trophic resource use, especially for species with high spatial and temporal overlap.

Farm management practices and host species richness associated with higher likelihood of tuberculosis positive farms in Western Spain

Despite enormous efforts, complete animal tuberculosis (TB) eradication has only been achieved in few regions. Epidemiological analyses are key to identify TB risk factors and set up targeted biosecurity measures. Here, we conducted an in-depth characterization of 84 extensive beef cattle farms from a high TB prevalence region in Western Spain, and assessed how farm management and wildlife presence on farms contribute to cattle TB risk. Twenty-six out of 84 variables were associated with cattle farm TB positivity. Farm management variables associated with TB positivity included older cattle, larger herd size, highly fragmented farm structure and greater connectivity between farms. TB-positive farms provided supplemental feed over a higher number of months, used calf feeders, and had higher number of waterholes. Detecting Eurasian wild boar (Sus scrofa), red fox (Vulpes vulpes), European badger (Meles meles), roe deer (Capreolus capreolus), or Egyptian mongoose (Herpestes ichneumon) on cattle farms was also associated with farm TB positivity. The best ordinal regression model indicated that in farms with a large herd size (> 167 animals) the odds of being positive or recurrently positive (versus negative) was 7.34 (95% CI = 2.43–23.51) times higher that of farms with small herd size. Further, for every additional host species detected in the farm premises, the odds of being TB-positive increased 56%. We conclude that both cattle management and wildlife need to be targeted for successful TB control in grazing-based farming systems.

Absence of effects of widespread badger culling on tuberculosis in cattle

Government policy in England aims for the elimination of bovine tuberculosis (bTB). This policy includes culling of European badger (Meles meles) to reduce cattle TB incidence. The rationale is based on a field trial, the Randomised Badger Culling Trial (RBCT) 1998–2005, which reported a substantial decrease in bTB herd incidence where badger culling had been implemented, in comparison to untreated control areas. The RBCT was undertaken because previous studies of reductions in badgers by culling, reported a possible association between bTB in badger and cattle, but none could directly show causation. The effect of intensive widespread (proactive) culling in the RBCT was reported in 2006 in the journal Nature. Analysis of an extensive badger removal programme in England since 2013 has raised concerns that culling has not reduced bTB herd incidence. The present study re-examined RBCT data using a range of statistical models. Most analytical options showed no evidence to support an effect of badger culling on bTB herd incidence ‘confirmed’ by visible lesions and/or bacterial culture post mortem following a comparative intradermal skin test (SICCT). However, the statistical model chosen by the RBCT study was one of the few models that showed an effect. Various criteria suggest that this was not an optimal model, compared to other analytical options available. The most likely explanation is that the RBCT proactive cull analysis over-fitted the data with a non-standard method to control for exposure giving it a poor predictive value. Fresh appraisal shows that there was insufficient evidence to conclude RBCT proactive badger culling affected bTB breakdown incidence. The RBCT found no evidence of an effect of culling on ‘total’ herd incidence rates. Total herd incidences include those confirmed as bTB at necropsy and those herds where there was at least one animal animal positive to the comparative intradermal skin test, the standard diagnostic test used for routine surveillance, but not confirmed at necropsy. This was also the case using the more suitable statistical models. Use only of ‘confirmed’ herd incidence data, together with a more recent (2013) published perception that RBCT data presented ‘a strong evidence base….with appropriate detailed statistical or other quantitative analysis’ should be reconsidered. The results of the present report are consistent with other analyses that were unable to detect any disease control benefits from badger culling in England (2013–2019). This study demonstrates one form of potential driver to the reproducibility crisis, in this case with disease control management in an increasingly intensified livestock industry.

Are Eurasian badgers responsible for lamb predation? An investigation using farmer interviews, post‐mortem examination and molecular tools

Abstract This study investigates farmers' reports of lamb predation by badgers on Scottish sheep farms. Differentiating between predation and scavenging, and identifying the species responsible, is essential for livestock managers to effectively mitigate risk. Questionnaire‐style interviews established farmer perceptions of lamb predation by badgers and incidents of suspected predation were investigated on farms in 2022 and 2023 using post‐mortem examination and molecular tools. Farmers submitted 29 carcasses for post‐mortem. Of these, evidence of predation was present on 14 lambs (48%) and predation could not be ruled out for six further lambs (21%). No evidence of predation, but wounds consistent with scavenging after death, were present on nine lambs (31%). Nine (64%) of the 14 predated lambs also showed evidence of scavenging after death. Swabs were taken from 39 dead or injured lambs for potential predator/scavenger DNA recovery, and from 20 live control lambs. Badger DNA was obtained from the partial remains of two (5%) lambs. Badger DNA was not present on any of the carcasses submitted for post‐mortem or from any living, wounded lambs. Fox DNA was obtained from 34 (87%) dead or injured lambs, including all lambs that exhibited evidence consistent with predation at post‐mortem. Dog DNA was present on 12 (31%) lambs. While the results of this study cannot fully rule out the occurrence of lamb predation by badgers, no direct evidence was found to suggest that it does occur. The overall contribution of wildlife predation to lamb losses is considered to be low, but the results strongly suggest that foxes are likely to be responsible for lamb predation where it does occur. For livestock managers, a review of predator management strategies should be a key response to prevent future predation incidents. Practical implications. This study highlights the value of using post‐mortem examination and molecular evidence to accurately confirm predation events and to identify predator species, informing appropriate management interventions.

Confirmation of the invasive American mink (Neogale vison) as carrier of Mycobacterium bovis in southern Chile

Bovine tuberculosis (bTB) is a chronic infectious-contagious disease with worldwide distribution, caused by the zoonotic pathogen Mycobacterium bovis. It is believed that the existence of wild cycles may hamper the success of bTB control strategies worldwide, where wildlife species could be reservoirs of this bacterial agent across their native (e.g., European badgers, wild boars) or non-indigenous (e.g., brushtail possum in New Zealand) ranges. However, further studies are required to understand the potential risk posed by non-native wildlife in becoming carriers of M. bovis in other neglected latitudes, such as the Southern Cone of South America. In this study, we performed a specific M. bovis-RD4 real-time PCR (qPCR) assay to detect bacterial DNA in tissues from the invasive American mink (Neogale vison) in Los Ríos region, Chile. We detected M. bovis DNA in blood samples collected from 13 out of 186 (7 %) minks with known sex and age. We did not find any significant differences in bacterial DNA detection according to mink sex and age. We found that 92 % (12/13) of specimens were positive in lung, 39 % (5/13) in mediastinal lymph node, and 15 % (2/13) in mesenteric lymph node, which suggest that both respiratory and digestive pathways as possible routes of transmission between infected hosts and minks. Our study is the first report on M. bovis molecular detection in invasive minks in an area where the largest cattle population in the country is located. Furthermore, this area is characterized by a low within-herd prevalence of M. bovis infection in cattle, with a relatively low number of infected herds, and so far, no attempts at eradicating the disease have been successful.

Characterisation of Lagovirus europaeus GI-RHDVs (Rabbit Haemorrhagic Disease Viruses) in Terms of Their Pathogenicity and Immunogenicity.

Rabbit haemorrhagic disease viruses (RHDV) belong to the family Caliciviridae, genus Lagovirus europaeus, genogroup GI, comprising four genotypes GI.1-GI.4, of which the genotypes GI.1 and GI.2 are pathogenic RHD viruses, while the genotypes GI.3 and GI.4 are non-pathogenic RCV (Rabbit calicivirus) viruses. Among the pathogenic genotypes GI.1 and GI.2 of RHD viruses, an antigenic variant of RHDV, named RHDVa-now GI.1a-RHDVa, was distinguished in 1996; and in 2010, a variant of RHDV-named RHDVb, later RHDV2 and now GI.2-RHDV2/b-was described; and recombinants of these viruses were registered. Pathogenic viruses of the genotype GI.1 were the cause of a disease described in 1984 in China in domestic (Oryctolagus (O.) cuniculus domesticus) and wild (O. cuniculus) rabbits, characterised by a very rapid course and a mortality rate of 90-100%, which spread in countries all over the world and which has been defined since 1989 as rabbit haemorrhagic disease. It is now accepted that GI.1-RHDV, including GI.1a-RHDVa, cause the predetermined primary haemorrhagic disease in domestic and wild rabbits, while GI.2-RHDV2/b cause it not only in rabbits, including domestic rabbits' young up to 4 weeks and rabbits immunised with rabbit haemorrhagic disease vaccine, but also in five various species of wild rabbits and seven different species of hares, as well as wild ruminants: mountain muskoxen and European badger. Among these viruses, haemagglutination-positive, doubtful and harmful viruses have been recorded and described and have been shown to form phylogenogroups, immunotypes, haematotypes and pathotypes, which, together with traits that alter and expand their infectious spectrum (rabbit, hare, wild ruminant, badger and various rabbit and hare species), are the determinants of their pathogenicity (infectivity) and immunogenicity and thus shape their virulence. These relationships are the aim of our consideration in this article.