Setts Research Articles

Development of a novel immunochromatographic lateral flow assay specific for Mycobacterium bovis cells and its application in combination with immunomagnetic separation to test badger faeces

BackgroundThe European badger is an important wildlife reservoir of Mycobacterium bovis implicated in the spread of bovine tuberculosis in the United Kingdom and Ireland. Infected badgers are known to shed M. bovis in their urine and faeces, which may contaminate the environment. To aid bovine tuberculosis control efforts novel diagnostic tests for detecting infected and shedding badgers are needed. We proposed development of a novel, rapid immunochromatographic lateral flow device (LFD) as a non-invasive test to detect M. bovis cells in badger faeces. Its application in combination with immunomagnetic separation (IMS) to detect Mycobacterium bovis cells in badger faeces is reported here.ResultsA novel prototype LFD for M. bovis cells was successfully developed, with unique specificity for M. bovis and a limit of detection 50% (LOD50%) of 1.7 × 104 M. bovis cells/ml. When IMS was employed to selectively capture and concentrate M. bovis cells from badger faeces prior to LFD testing, the LOD50% of the IMS-LFD assay was 2.8 × 105 M. bovis cells/ml faecal homogenate. Faeces samples collected from latrines at badger setts in a region of endemic bovine tuberculosis infection were tested; 78 (18%) of 441 samples tested IMS-LFD assay positive, whereas 140 (32%) tested IMS-qPCR positive (Kappa agreement −0.009 ± 0.044, p = 0.838). Subsequently, when 130 faeces samples from live captured, or captive, badgers of known infection status (on the basis of StatPak, interferon-γ and/or culture results) were tested, the IMS-LFD assay had higher relative diagnostic specificity (Sp 0.926), but poorer relative diagnostic sensitivity (Se 0.081), than IMS-qPCR (Sp 0.706, Se 0.581) and IMS-culture (Sp 0.794, Se 0.436).ConclusionsThe novel IMS-LFD assay, although very specific for M. bovis, has low analytical sensitivity (indicated by the LOD50%) and would only detect badgers shedding high numbers of M. bovis (>104–5 cells/g) in their faeces. The novel LFD would, therefore, have limited value as a non-invasive test for badger TB surveillance purposes but it may have value for alternative veterinary diagnostic applications.

Abundance of badgers (Meles meles) in England and Wales

The European badger (Meles meles) is of considerable interest in the UK as it is both a protected species and the main wildlife reservoir for bovine tuberculosis infection in cattle. While there have been three national badger surveys in the 1980s, 1990s and 2011–13, using the number of badger main setts as a proxy for the abundance of badger social groups, none has combined contemporary data on social group size at landscape and national scales. We estimated social group size by genotyping hair samples collected at 120 main setts across England and Wales and employing a capture-mark-recapture method based on genotypes. The estimated mean social group size in England and Wales was 6.74 (±0.63) badgers. There was considerable variation in badger social group size among Land Class Groups (LCGs), with a low of 2.67 in LCG3 and a high of 7.92 in LCG4. Combining these results with the recent Badger Sett Survey of England and Wales, we estimate there are approximately 485,000 badgers (95% confidence intervals 391,000–581,000) in England and Wales. Although direct comparison with previous estimates is not ideal owing to methodological differences, our results are consistent with a marked increase in the badger population of England and Wales since the 1980s.

Weather influences trapping success for tuberculosis management in European badgers (Meles meles)

European badgers (Meles meles) in Ireland and the UK are a reservoir for Mycobacterium bovis, the causative agent of bovine tuberculosis (TB). A number of interventions have been evaluated in attempts to control bovine TB within badger populations, and many of which rely on the capture of badgers. One strategy being implemented within Ireland is intramuscular vaccination using Bacillus Calmette-Guerin (BCG), as an alternative to badger culling. The success of vaccination as a disease control strategy depends on the ability to capture badgers and administer vaccines; thus, trapping success is crucial to effectively vaccinate the population (maximize vaccine coverage). A field vaccine trial was conducted in County Kilkenny, Ireland, from 2010–2013. We used data from this trial to evaluate the association between weather (precipitation and temperature data), badger sett characteristics, and badger trapping success. Approximately 10% of capture efforts resulted in a badger capture. Our results indicate that badger captures were the highest in drizzle, rain, and heavy rain weather conditions, and when minimum temperatures ranged from 3–8 °C. Badger captures were the highest at main setts (large burrow systems), and when sett activity scores were high (qualitative classes 4 or 5). Using local precipitation and temperature data in conjunction with observed sett characteristics provides wildlife managers with guidelines to optimize trapping success. Implementing capture operations under optimal conditions should increase the trapping success of badgers and allow for increased delivery of vaccines to manage bovine TB.

Behaviour of European badgers and non-target species towards candidate baits for oral delivery of a tuberculosis vaccine

In the UK and the Republic of Ireland, the European badger (Meles meles) is a maintenance host for Mycobacterium bovis, and may transmit the infection to cattle causing bovine tuberculosis (TB). Vaccination of badgers using an injectable Bacillus Calmette-Guerin (BCG) vaccine is undertaken in some areas of the UK with the intention of interrupting this transmission, and vaccination research is underway in Ireland. An oral badger TB vaccine is also under development. We investigated the behaviour of badgers and non-target wildlife species towards three candidate baits being considered for delivering BCG to badgers orally. Bait preference was investigated by recording removal rates of baits and through the use of video surveillance at 16 badger setts. We found high variation in rates of bait removal by badgers among setts but no significant differences in removal rates among bait types or in preference behaviour from video footage. Variation in bait removal among setts correlated with the number of nights on which badgers were seen at the sett, with most baits being removed where badgers were seen on >50% of nights during the ten-day study period. Relatively few baits were removed at setts with low levels of recorded badger activity. Monitoring badger activity prior to bait deployment may therefore be useful in increasing bait uptake and vaccine coverage. Bait removal by badgers increased over the ten-day study period, suggesting initial neophobic behaviour at some setts and that a period of ‘pre-feeding’ may be required prior to vaccine deployment. Our results indicate that all three candidate baits are attractive to badgers. Removal of baits by non-target wildlife species was generally low, but varied among bait types, with smaller baits in packaging less likely to be removed. Enclosing baits in packaging is likely to deter non-target species, although in some cases non-target species did remove up to 13% of packaged baits.

How well do farmers know their badgers? Relating farmer knowledge to ecological survey data

Knowledge of badger distribution is important for the management of bovine tuberculosis. At the farm level, typically the only information on badger activity available is from the farmers themselves. This...

3D topography and structure analysis of three badger setts from Western Switzerland

Within the framework of urban planning and spate management, three badger setts had to be destroyed in Geneva, Switzerland. We took advantage of this situation to perform a systematic excavation of these burrows in order to study their three dimensional organisation. A surveyor’s office developed the 3D-models to help visualize these complexes. The number of entrances did not match the underground complexity of the setts, and for two of them all entrances were not linked to a unique tunnel network. The smallest sett, considering the amount of earth excavated by badgers, was about 3 decades old (5 m3 excavated, 94 m of tunnels) and the largest was about 5 decades old (13 m3 excavated, 300 m of tunnels). Several screen views are presented in the manuscript and a link is proposed to have access to the 3D-models.

Badger (Meles meles) Sett Site Selection in Darwin Reserve, Northwestern Russia

Badger (Meles meles) sett site selection was studied in non-optimal habitats of the Darwin Reserve in northwestern Russia. Peat bog areas constitute the greater part of the reserve territory. Because subterranean waters lie close to the surface, soil conditions are unfavorable for sett construction and badgers dig their burrows in old charcoal pits – ring-shaped elevated grounds, which are remains of the charcoal trade of the 19th century. From 1963 to 1998, 599 coal-bunkers were surveyed in the reserve for species using burrows (European Badger Meles meles; Red Fox Vulpes vulpes; and Raccoon Dog Nyctereutes procyonoides). Badgers used only 14% of the charcoal pits for sett construction; 38 of them were mapped in 20012006. They were divided in three groups: 1) charcoal pits with main setts, 2) charcoal pits with outliers, and 3) charcoal pits not used by badgers. For each charcoal pit, we recorded a number of variables related to food and shelter for badgers: size and height of coal pits, abundance of undergrowth on coal pits, areas of different forest types, and length of ecotones in the vicinity of coal pits. Biotope composition of charcoal pit surroundings was similar for all groups of charcoal pits. Badgers preferred mosaics of habitats, as suggested by the extent of forest-swamp borders near setts where badgers find their main food, i.e., frogs. The size and height of the charcoal pits was also important. Big charcoal pits can hold large shelters with a few tunnel systems used by animals to move among chambers and possibly escape accumulation of ectoparasites. Badgers also use large charcoal pits to overwinter.

Ecology of European Badger Meles Meles in the Western Capathian Mountains: A Review

European badgers inhabiting Western Carpathians use excavated setts (53%), caves and rock crevices (43%), and burrows under human-made constructions (4%) as permanent shelters. Excavated setts are located up to 640 m a.s.l., but shelters in caves and crevices until 1,050 m a.s.l. Badger setts are mostly located in forests on slopes with southern, eastern and western exposure. Within their territories, ranging from 3.35 to 8.45 km2 (MCP100%), badgers possess 1-12 setts. Family groups are small (mean 2.3 individuals), as is population density (2.2 ind./10 km2) and reproduction (0.57 young/year/10 km2). Hunting by humans is the most important mortality factor (0.37 ind./year/10 km2). Regardless the altitude at which their main sett is located, badgers forage mostly in foothills, as this climatic zone offers the richest food sources. Badgers eat mainly fruits (54%) and earthworms (38%), but seasonal and altitudinal differences in diet were observed.

A big-data spatial, temporal and network analysis of bovine tuberculosis between wildlife (badgers) and cattle

Bovine tuberculosis (TB) poses a serious threat for agricultural industry in several countries, it involves potential interactions between wildlife and cattle and creates societal problems in terms of human-wildlife conflict. This study addresses connectedness network analysis, the spatial, and temporal dynamics of TB between cattle in farms and the European badger (Meles meles) using a large dataset generated by a calibrated agent based model. Results showed that infected network connectedness was lower in badgers than in cattle. The contribution of an infected individual to the mean distance of disease spread over time was considerably lower for badger than cattle; badgers mainly spread the disease locally while cattle infected both locally and across longer distances. The majority of badger-induced infections occurred when individual badgers leave their home sett, and this was positively correlated with badger population growth rates. Point pattern analysis indicated aggregation in the spatial pattern of TB prevalence in badger setts across all scales. The spatial distribution of farms that were not TB free was aggregated at different scales than the spatial distribution of infected badgers and became random at larger scales. The spatial cross correlation between infected badger setts and infected farms revealed that generally infected setts and farms do not coexist except at few scales. Temporal autocorrelation detected a two year infection cycle for badgers, while there was both within the year and longer cycles for infected cattle. Temporal cross correlation indicated that infection cycles in badgers and cattle are negatively correlated. The implications of these results for understanding the dynamics of the disease are discussed.

Badger Meles meles setts and bryophyte diversity: A newly found role for the game animal in European temperate forests

Badgers (Meles meles) inhabiting Central European forests may be a leading factor driving changes in plant species community and diversity. The digging activity of badgers may shape plant species communities in important ways, especially in managed forests where natural events on the forest floor (e.g. soil disturbance due to tree uprooting) are largely eliminated by silviculture. We tested the following hypotheses in our study: that badger burrows act as focal sites which allow many bryophyte species to occur and complete their reproductive cycle; that the effect of burrows as focal sites of bryophyte diversity is more pronounced in mesotrophic forests than in fertile forests; and that the bryophyte communities of badger burrows differ quantitatively and qualitatively from those of their near vicinity. The study was done in 2013 in the Kampinos Forest, one of the largest (ca. 385km2) lowland forest complexes in central Poland. We distinguished two types of research sites: badger burrows (main setts) and paired reference plots. The pairs of plots were divided into two groups depending on habitat fertility (C/N ratio): lower-fertility plots (N=20) and higher-fertility plots (N=20). All data were collected from circular plots (5.64m radius); the burrow plots were centered on the badger burrows and were paired with same-size reference plots. We recorded 55 bryophyte species in the survey, 26 of them exclusively on burrows. The beta diversity of the bryophyte assemblages, expressed as total dissimilarity, turnover and nestedness, was similar for the burrows and the reference plots. The mean number of bryophyte species and their Shannon H′ diversity index were significantly higher for burrow plots than for undisturbed reference plots. Neither the number of species nor the species diversity of bryophytes were affected by the interaction of habitat fertility. We observed no relation between the profile of bryophyte groups on the burrows and specific substrate, acidity or life history. Only epiphytic bryophytes were overrepresented in burrow plots. The spatial scale and range of disturbance caused by badger digging suggest that badger setts contribute to the diversity of bryophyte species in managed and protected forests in Central Europe. The burrowing activity of badgers seems to be an important factor boosting the diversity of bryophyte species in managed forests, especially where natural topsoil disturbances are limited by silviculture practices. In forest ecosystems, badger activity creates a patch distribution of microhabitats for vascular plants – and also for bryophytes, as shown here.

Herd-level risk factors for bovine tuberculosis and adoption of related biosecurity measures in Northern Ireland: A case-control study

Bovine tuberculosis (bTB) is a zoonotic disease which is endemic in Northern Ireland. As it has proven difficult to eradicate this disease, partly due to a wildlife reservoir being present in the European badger (Meles meles), a case-control study was conducted in a high incidence area in 2010–2011. The aim was to identify risk factors for bTB breakdown relating to cattle and badgers, and to assess the adoption of bTB related biosecurity measures on farms. Face-to-face questionnaires with farmers and surveys of badger setts and farm boundaries were conducted on 117 farms with a recent bTB breakdown (cases) and 75 farms without a recent breakdown (controls). On logistic regression at univariable and multivariable levels, significant risk factors associated with being a case herd included having an accessible badger sett within the farm boundaries in a field grazed in the last year (odds ratio, OR, 4.14; 95% confidence interval, CI, 1.79, 9.55), observation of live badgers (OR 4.14; 95% CI 1.79, 9.55), purchase of beef cattle (OR 4.60; 95% CI 1.61, 13.13), use of contractors to spread slurry (OR 2.83; 95% CI 1.24, 6.49), feeding meal on top of silage (OR 3.55; 95% CI 1.53, 8.23) and feeding magnesium supplement (OR = 3.77; 95% CI 1.39, 10.17). The majority of setts within the farm boundary were stated to be accessible by cattle (77.1%; 95% CI 71.2, 83.0%) and 66.8% (95% CI 63.8, 69.7%) of farm boundaries provided opportunities for nose-to-nose contact between cattle. Adoption of bTB related biosecurity measures, especially with regards to purchasing cattle and badger-related measures, was lower than measures related to disinfection and washing.

First molecular detection of Mycobacterium bovis in environmental samples from a French region with endemic bovine tuberculosis.

The aim of the study was to determine the prevalence of Mycobacterium bovis (the causative agent of bovine tuberculosis, bTB) in environmental matrices within a French region (Côte d'Or) affected by this zoonotic disease. We report here the development and the use of molecular detection assays based on qPCR (double fluorescent dye-labelled probe) to monitor the occurrence of Mycobacterium tuberculosis complex (MTBC) or Myco. bovis in environmental samples collected in pastures where infected cattle and wildlife had been reported. Three qPCR assays targeting members of the MTBC (IS1561' and Rv3866 loci) or Myco. bovis (RD4 locus) were developed or refined from existing assays. These tools were validated using Myco. bovis spiked soil, water and faeces samples. Environmental samples were detected positive for the presence of MTBC strains and Myco. bovis in the environment of bTB-infected farms in the Côte d'Or region. The development of molecular assays permitted testing of several types of environmental samples including spring water, sediment samples and soils from badger setts entrance located in the vicinity of these farms, which were repeatedly contaminated with Myco. bovis (up to 8·7 × 10(3) gene copies per gram of badger sett soil). For the first time, direct spoligotyping of soil DNA enabled identification of Myco. bovis genotypes from environmental matrices. All together, these results suggest that Myco. bovis occurs at low levels in environmental matrices in Côte d'Or within the bTB-infected area. Drinking contaminated water or inhaling contaminated bioaerosols might explain cattle infection in some cases.

Protecting badger setts – Where law and science clash

This article examines the definition of a badger sett under the Protection of Badgers Act 1992 which is: ‘any structure or place which displays signs indicating current use by a badger’. In McLintock v Harris 2015 SLT (Sh Ct) 26 the Sheriff held that ‘current use’ required the sett to be ‘in use at the present time’. This narrow interpretation is analysed against other case law and the Parliamentary intention taken from Hansard during the passage of the Badgers Act 1991. It concludes that the Sheriff’s interpretation accords with Parliament’s intention. A review of the scientific literature on how badgers ( Meles meles) use their main and secondary setts shows that setts which are not in ‘current use’ under the statutory definition, are used in rotation as an important part of badgers’ behaviour throughout the year. It is concluded that the statutory definition does not provide adequate protection for setts which has implications for badger welfare. The Nature Conservation bodies’ former licensing guidance used a wider interpretation of ‘current use’ in line with scientific literature; however, a more cautious approach is now being taken. The authors examine the scope for judicial review of the Nature Conservation bodies’ approach to the statutory definition. They recommend a definition that would protect badgers’ welfare but conclude that with the present controversy about the bovine tuberculosis cull, strong lobbying will be required to get the Westminster or Scottish Parliaments or the Welsh Assembly to amend the definition.

Spatial organisation of European badger (Meles meles) in northern Italy as assessed by camera-trapping

Italy is amongst the European countries for which data on badger Meles meles numbers and variation in population size are still too few to assess its conservation status. With the aim of estimating badger density in northern Italy, between February 2013 and March 2014, we extensively surveyed an isolated hilly area for badger setts and assessed group size by monitoring a sample of setts by two sessions of camera-trapping. The size and shape of each home range were assessed from main sett coordinates using the Dirichlet tessellation method. Then, assuming that badger home ranges tend to be delimited by hard boundaries or geographical features, the polygon shapes were successively modified by hand to draw more realistic home ranges. The overall trapping effort was 754 camera trap-days. The number of badger individuals sharing the same sett/entrances was recorded, distinguishing individuals based on the time and hole of emergence and, possibly, tail patterns. Groups consisted of two to four adult individuals, averaging 2.75 badgers/group. Camera-trapping proved to be a cost-effective and time-saving method. Depending on the method used to draw home ranges, in the study area, sett density was 0.34–0.51 sett/km2, whilst badger density was 0.93–1.4 adult individuals/km2. Both sett and badger densities were rather high with respect to most available data for continental Europe. As badger mean group size seems to be rather constant throughout both hilly and plain areas of the River Po basin, sett density may be used as an accurate estimator of badger density throughout this wide area.

Effects of agro-forestry activities, cattle-raising practices and food-related factors in badger sett location and use in Portugal

Mediterranean landscapes in Europe are characterized by a mixed matrix of agriculture, agro-forestry or cattle-farming areas, which have influenced native communities for centuries. Recently, new changes were imposed on these agro-forestry landscapes due to novel management options that provide new challenges for wildlife. From a conservation perspective, there is an urgent need to assess what are the impacts and ecological responses of local wildlife populations to those changes. In the present study, we assessed the influence of human-caused disturbances (e.g. agroforestry practices, cattle-breeding activities and game management), together with food/water and landscape-related factors, on sett site selection by European badgers. We also tested the role of these factors, together with climatic variability, on sett use. We detected that areas further away from water sources, but close to game species feeding structures, have a higher probability of hosting a European badger sett. Moreover, sett use was promoted by low disturbance: setts with lower cattle presence and without understory removal activities were more often in use. Thus, our study shows that, in our study area, agro-forestry and cattle breeding activities constrain badger sett use, while food and water availability influence their distribution. Although badgers have been adapting to anthropogenic activities for centuries, they respond differently depending on the type and intensity of management. Thus, to ensure biodiversity persistence and sustainable human exploitation of the landscape, we need to identify trade-offs between wildlife ecological adaptations and anthropogenic agriculture, forestry and cattle production.

Spatial Targeting for Bovine Tuberculosis Control: Can the Locations of Infected Cattle Be Used to Find Infected Badgers?

Bovine tuberculosis is a disease of historical importance to human health in the UK that remains a major animal health and economic issue. Control of the disease in cattle is complicated by the presence of a reservoir species, the Eurasian badger. In spite of uncertainty in the degree to which cattle disease results from transmission from badgers, and opposition from environmental groups, culling of badgers has been licenced in two large areas in England. Methods to limit culls to smaller areas that target badgers infected with TB whilst minimising the number of uninfected badgers culled is therefore of considerable interest. Here, we use historical data from a large-scale field trial of badger culling to assess two alternative hypothetical methods of targeting TB-infected badgers based on the distribution of cattle TB incidents: (i) a simple circular ‘ring cull’; and (ii) geographic profiling, a novel technique for spatial targeting of infectious disease control that predicts the locations of sources of infection based on the distribution of linked cases. Our results showed that both methods required coverage of very large areas to ensure a substantial proportion of infected badgers were removed, and would result in many uninfected badgers being culled. Geographic profiling, which accounts for clustering of infections in badger and cattle populations, produced a small but non-significant increase in the proportion of setts with TB-infected compared to uninfected badgers included in a cull. It also provided no overall improvement at targeting setts with infected badgers compared to the ring cull. Cattle TB incidents in this study were therefore insufficiently clustered around TB-infected badger setts to design an efficient spatially targeted cull; and this analysis provided no evidence to support a move towards spatially targeted badger culling policies for bovine TB control.

Role of badger setts in life of other carnivores

A study of interspecific interactions of European (Meles meles) and Asian (M. leucurus) badgers with other carnivores at badger setts was carried out in Darwin Reserve (European part of Russia) and in Ussuriisk Reserve (Russian Far East) in 2006-2011. We used camera traps for the registration of visits of carnivore mammals to the badger setts. Overall, 11 species were recorded. In both reserves, badger setts attract carnivore species during the whole year. Some predators visit badger setts regularly. The visitors can be divided into two groups: species searching shelter, or searching prey. The first group includes raccoon dog Nyctereutes procyonoides and red fox Vulpes vulpes. Raccoon dog was the most frequent visitor in both study areas (34 visits in Darwin reserve and 73 in Ussuriisk reserve). The second group includes lynx Lynx lynx and wolf Canis lupus in Darwin reserve and Asiatic black bear Ursus thibetanus, brown bear U. arctos, yellow-throated marten Martes flavigula aterrima and lynx Lynx lynx in Ussuriisk reserve. Smaller predators are also included into the second group because they can find prey at badger setts too: leopard cat Prionailurus bengalensis euptilura, sable Martes zibellina and Siberian weasel Mustela sibirica in Ussuriisk reserve and European pine marten Martes martes in Darwin reserve. No cases of aggressive interactions between the badgers and the visitors were recorded. But we noted two cases of change of sett owners and one case when raccoon dog removed dead badger cubs from the sett.

A new Magneto‐Inductive tracking technique to uncover subterranean activity: what do animals do underground?

Summary Despite the importance of the subterranean ecotope, knowledge of underground movement and behaviour has been extremely limited. Previous technologies have relied upon techniques with very low spatial or temporal resolution, such as VHF telemetry. Rather incongruously, therefore, relatively simple underground activity regimes have often been assumed, with insufficient attention to the ecological importance of burrow use. We test the capability of Magneto‐Inductive (MI) tracking, recording underground movement within a European badger sett over a 2 week period in February. These data allowed us to: quantify subterranean movement; extrapolate the three‐dimensional burrow architecture; simultaneously track multiple individuals; and establish the function of specific movement patterns; demonstrating the technique's utility. Contrasting data generated using MI tracking, against the resolution achievable with VHF tracking, we establish how sampling frequency can influence the perception of movement. Taking 20 locational fixes per minute, MI collars operated for 1 year before on‐board batteries failed, resulting in an average five billion data points per collar deployment. Socio‐ecologically we found that rather than foraging continuously throughout the night, badgers returned to the sett an average of 2·2 times, approximately every 3–4 h. From burrow mapping, badgers tended to use peripheral chambers for c. 45 min on these return visits. These outlying chambers were used less by day, when badgers selected deeper chambers, suggesting each chamber type fulfils a different function. This technology also exposed that badgers exhibited a far greater extent of underground movement than revealed by former technologies, which by comparison captured <0·5% of subterranean activity. Importantly, these high‐resolution data showed that individuals left, returned to, and moved about the sett independently, with no tendency for synchronous subterranean activity. In overview, Magneto‐Inductive tracking proved relatively simple and cost‐effective to deploy, it provided very detailed and accurate subterranean fixes, and was robust enough for long‐term field deployment. Furthermore, the capabilities of MI are highly transferable, enabling a better understanding of underground activity and the ecological importance of subterranean burrows for the conservation and management of a wide range of species.

Exposure of nontarget wildlife to candidate TB vaccine baits deployed for European badgers

In the UK and Republic of Ireland, the European badger Meles meles is considered a maintenance host for bTB and is involved in transmission of infection to cattle. A badger vaccine delivered in an oral bait is currently under development as part of an ongoing effort to reduce levels of disease in the badger population. An oral vaccine would likely be deployed in close vicinity to badger burrows (setts), such that bait will most likely be taken by the target species. However, a range of nontarget species may also occur close to badger setts, and some may potentially interfere with or consume baits. In this study, we used surveillance cameras to record the presence of nontarget species at 16 badger setts involved in a bait deployment study in southwest England. We recorded significant levels of nontarget species activity close to badger setts. The most commonly observed species were small rodents, which were observed at all setts, and in some cases accounted for >90 % of nontarget species observations. A total of 11 other nontarget species were also observed, indicating that a broad range of species may potentially come into contact with vaccine baits deployed at badger setts. Although the majority of these species were not observed interacting directly with baits, small rodents and squirrels were observed eating baits in a number of instances. In addition, monitoring of bait disappearance at 24 setts indicated that small rodents may take >30 % of bait deployed at some setts. The implications for the deployment of an oral vaccine for badgers are discussed.

Eurasian badger (meles meles) habitat and sett site selection in the northern Apennines

The principal aim of this research was to study coarsescale habitat selection and distribution of main setts of the Eurasian badger (<em>Meles</em> <em>meles</em> L., 1758). The study area extends for 161 Km2 in the hilly territory of southern Lombardy (Italy). The positions of 23 main setts (SP) and 28 random points (RP) were mapped into a GIS. For each point, several environmental characteristics were measured in the field or taken from thematic digital maps. A statistical comparison of the distribution of these characteristics in a circular area (radius 300 m) around each point was carried out. Eurasian badger setts were primarily dug in sheltered places, with high tree cover. The Manly selection index pointed to a strong selection for deciduous woods. Southern slope orientation and the presence of chestnut trees, a potentially important resource for badgers in this area, were also preferred. Similar to other studies, geological and lithological characters and the distance from water did not appear to influence den use. However, the substratum of the study area was mainly formed with sedimentary rocks, loam rocks and sandstones, with also easy-to-dig alluvial soils. Water is a resource easily available over the whole territory, with a well-branched network of rivers and streams. The road network and the presence of urban or industrial infrastructures seem to be a real factor of danger and disturbance, as one of the leading causes of mortality for badgers are road casualties. Our results suggest that badgers of this region are more selective for the sett site than for food resources.