Sulfadimethoxine and rhodamine B as oral biomarkers for European badgers (Meles meles)

A field study was carried out on Little Island (County Waterford, Ireland) in June 2000 to evaluate the potential of a bait-marking system for use in European badgers (Meles meles). Two oral biomarkers, sulfadimethoxine (SDM) and rhodamine B, were incorporated into fishmeal baits and distributed by hand at main sets in five test territories for 3 consecutive days. In parallel, non-biomarked baits were distributed at a single control territory. The objectives of the study were to: (1) assess the effects of SDM and rhodamine B on palatability and thus bait acceptance, and (2) investigate the marking capacity of SDM and rhodamine B in serum and hair samples taken from badgers. Trapping was carried out in each territory for 5 consecutive days immediately after bait distribution. Analysis of data revealed that 90-100% of baits were removed in four of the test territories and from the control territory. In the fifth test territory, 61% of baits were removed. Of the badgers (n = 26) trapped in the test territories, 18 (69%) were positive when tested for both biomarkers. In contrast, the remaining eight animals and those captured in the control territory (n = 6 badgers) were negative. In the marked animals, the highest levels of SDM were recorded in serum samples taken soon after bait distribution. Thereafter, the levels declined in each badger over the course of the study. In contrast, rhodamine B was readily detectable by fluorescence microscopy of hair samples throughout the period of study. The results indicate that SDM and rhodamine B act as systemic markers in badgers and have potential future applications for monitoring of oral vaccine uptake.     

Local feeding specialization by badgers (Meles meles) in a mediterranean environment

A case of local feeding specialization in the European badger (Meles meles), a carnivore species with morphological, physiological and behavioural traits proper to a trophic generalist, is described. For the first time, we report a mammalian species, the European rabbit (Oryctolagus cuniculus), as the preferred prey of badgers. Secondary prey are consumed according to their availability, compensating for temporal fluctuations in the abundance of rabbit kittens. We discuss how both predator (little ability to hunt) and prey (profitability and predictability) features, may favour the observed specialization, as predicted by foraging theory. Badgers show a trend to specialize on different prey in different areas throughout the species range. It is suggested that changes in prey features can reverse the badger feeding strategy at the population level. Such dynamic behavioural responses make difficult to label badgers as generalists or specialists at the species level.     

Genetic structure of Eurasian badgers Meles meles (Carnivora: Mustelidae) and the colonization history of Ireland

The present study examined the contemporary genetic composition of the Eurasian badger, Meles meles, in Ireland, Britain and Western Europe, using six nuclear microsatellite loci and a 215‐bp fragment of the mitochondrial DNA control region. Significant population structure was evident within Europe (global multilocus microsatellite F_ST = 0.205, P < 0.001; global mitochondrial control region Φ_ST = 0.399, P < 0.001). Microsatellite‐based cluster analyses detected one population in Ireland, whereas badgers from Britain could be subdivided into several populations. Excluding the island populations of Ireland and Britain, badgers from Western Europe showed further structuring, with evidence of discrete Scandinavian, Central European, and Spanish populations. Mitochondrial DNA cluster analysis grouped the Irish population with Scandinavia and Spain, whereas the majority of British haplotypes grouped with those from Central Europe. The findings of the present study suggest that British and Irish badger populations colonized from different refugial areas, or that there were different waves of colonization from the source population. There are indications for the presence of an Atlantic fringe element, which has been seen in other Irish species. We discuss the results in light of the controversy about natural versus human‐mediated introductions. © 2012 The Linnean Society of London, Biological Journal of the Linnean Society, 2012, ?? , ??–??.     

Camera trap records of leucistic Eurasian badgers (Meles meles) in central Norway

Coat coloration plays an important role in communication, camouflage, and sexual selection in animals. Genetic mutations can lead to anomalous colorations such as melanism and leucism, where animals appear, respectively, darker or lighter than normal. Reporting abnormal coloration in wild animals is an important first step to understand the distribution, prevalence, and potential fitness consequences of these rare events. Here, we report several records of suspected leucism in the Eurasian badger (Meles meles) in a population in central Norway. Several camera traps recorded at least two leucistic individuals between 2017 and 2020. It took considerable effort, almost 400,000 camera trap nights over a period of 10 years all over Norway, to obtain a total of eleven records of leucistic badgers, indicating the rarity of this phenotype. It is unclear what has caused the presence of multiple leucistic badgers in a single population, but recent colonization and lack of predators might have played a role. Due to our observations, future studies can now be developed to study the underlying mechanisms and potential consequences of leucism in this badger population. The increasing use of networks of camera traps in wildlife research will provide new opportunities to record rare coloration in wild animals.     

Food habits and habitat selection of suburban badgers (Meles meles) in Japan

A study of the Japanese badger Meles meles anakuma was undertaken in Hinode, a suburb of Tokyo, between 1992 and 1998. Faecal analysis, based on 82 samples, revealed that during spring and summer, earthworms ( Megaseolocidae spp.) occurred at high frequency in the diet, with berries ( Rubus spp.), beetles and persimmon Dymopyrus kaki also eaten during summer months. Scavenged food was eaten in early spring when earthworm availability was low, and badgers switched from worms when persimmon became abundant in autumn. Twenty-one Japanese badgers (14 males and seven females) were radio-tracked. Adult badger home ranges were stable, and those of males [40±19 ( sd ) ha, n =7] were larger than those of females [11±6 ( sd ) ha, n =4]. Badger resting sites in each home range were located within 630 m of each other and categorized as setts or couches. Setts were sited within core areas (30% adaptive kernel method) of home ranges. Most setts were on a sub-ridge and avoided west-facing slopes. Couches, mainly in deciduous forest and forest edge, were generally sited towards the periphery of home ranges. Most badger foods were distributed along ecotones between forestry plantations and farmland; earthworms, their main food from late spring to summer, and berry thickets were both concentrated at the edge of conifer plantations. Persimmon trees, the main food source for badgers in autumn, were also found in agricultural land bordering forest edge. Badger home range size was related to forest edge density.     

Body weight as an indication of density-dependent population regulation in badgers (Meles meles) at Woodchester Park, Gloucestershire

The body weights of badgers were examined to look for density-dependent effects of the increase in group size at Woodchester Park, Gloucestershire. The weight of badgers in 21 groups were studied from 1978–1993. A significant negative relationship was found between weight and group size in breeding adult females in autumn and winter, and adult males in summer, such that increase in group size caused a decrease in weight. However, these relationships were affected by year-to-year changes and random variation, and overall there was no downward trend in body weight. The existence of density-dependent effects on badger populations at high density was consistent with previous findings     

狗獾粪便DNA提取方法的初步探讨

在京杭大运河扬州段堤坝上采集狗獾的新鲜粪便,采用预处理-酚/氯仿抽提法、NaCl改良法、异硫氰酸胍裂解法、淀粉吸附法及QIAamp试剂盒法5种方法对粪便样品中狗獾DNA进行提取,探讨狗獾粪便样品中DNA提取方法和优化条件。结果表明,在5种提取方法中,淀粉吸附法的效果明显优于其它4种方法。采用粪便裂解液快速裂解细胞后,加入淀粉去除其中的大量PCR抑制物,然后用蛋白酶K裂解、酚/氯仿/异戊醇抽提,最后使用UNIQ-10柱纯化粪便DNA,对线粒体控制区和微卫星位点的PCR扩增反应及测序结果证实该方法的可行性。以上结果表明,通过该方法获得的粪便DNA能够用于更深入的分子遗传学等学科的研究。     

Movement of badgers (Meles meles) in a high-density population: individual,population and disease effects.

The movement of 1763 badgers trapped between 36 social groups in Woodchester Park, Gloucestershire, over 18 years was analysed to determine the frequency and duration of moves, the factors associated with a predisposition to move and the spatial pattern of movements. Of those badgers whose capture history could be categorized, nearly half had moved. Of these, 73.1% were classified as ''occasional movers'', 22.1% as ''permanent movers'' and 4.8% as ''frequent movers''. Most adult badgers that moved made occasional moves (78.8%, n = 67). Cubs made all types of move including permanent moves (29%, n = 10). Seventy per cent of females were non-movers compared with 37% of males. Badgers were significantly more likely to move to smaller groups, whereas male badgers were significantly more likely to move to groups with a greater proportion of females. The spatial pattern of movement differed from the distribution of groups with bovine tuberculosis in the study area. However, temporal changes in movement were significantly related to the incidence of Mycobacterium bovis infection in the following year, indicating that as the movement of badgers between groups varies so does the incidence of bovine tuberculosis in the population. This finding is of central importance in the formulation of badger control policy.     

A survey of helminth infection in Eurasian badgers (Meles meles) in relation to their foraging behaviour in a Mediterranean environment in southwest Portugal

This study provides the first data on the helminth fauna of the Eurasian badger in the southwestern edge of its range (Grândola Mountain, Portugal) and interprets the results in relation to badger diet and feeding behaviour. By examination of 163 badger faecal samples, faecal developmental stages (eliminative forms) of four helminth species and one genus were identified: one cestode (Atriotaenia incisa) and four nematodes (Mastophorus muris, Molineus patens, Uncinaria criniformis and Strongyloides sp.). The overall prevalence of parasites was 62%, with limited seasonal variation. Single parasite excretions were dominant and Strongyloides sp. excretion was the most common. Diet assessment based on 450 faecal samples revealed that badgers consumed mainly insects and fruits. No correlation was detected between helminth prevalence and diet. Apparently, diet (mainly insects) and feeding behaviour (fossorial), together with the species’ social behaviour (anal scent marking of group members), facilitate the infection with helminths. The helminth fauna of Eurasian badgers in Grândola Mountain has isolationist characteristics, apparently indicating low host colonisation.     

The effects of weather conditions on the movements and activity of badgers (Meles meles) in a suburban environment

This study provides quantitative data relating short-term fluctuations in local weather conditions to various measures of badger activity. These relationships were examined on a yearly, quarterly and monthly basis using behavioural data collected from 65 animals radio-tracked for a total of 518 nights in the suburbs of north-west Bristol. The yearly pattern of badger activity was reflected in a strong positive correlation between activity and daylength; in addition, moonlight and the absence of cloud cover were shown to restrict both the speed of travel and nightly range size, and to delay emergence. Looking at the data on a quarterly basis, activity increased with increasing temperature in the spring and autumn. Heavy rain reduced above-ground activity in the autumn, and in the winter speed of travel increased with wind speed. Nutritionally stressed adult females showed an increase in activity during the shorter summer nights. However, in general, changes in badger activity could not be readily predicted on the basis of the weather variables measured. The significance of these relationships is discussed in the light of the behaviour of badgers living in suburban Bristol.     

Comparative study on the consequences of culling badgers (Meles meles) on biometrics, population dynamics and movement

1.  Capture–mark–recapture data were used to describe the process of recovery from a typical badger removal operation (BRO) at North Nibley, Gloucestershire, UK, which was carried out as part of the government's strategy to control bovine tuberculosis. Data on biometrics, demographics and movement from this low-density disturbed population were compared with those of two nearby high-density undisturbed populations (Wytham Woods and Woodchester Park, UK) in order to study fundamental principles of population dynamics and density-dependence.
2.  Badgers moved more between social groups at North Nibley than in the other study areas, particularly in the immediate aftermath of the removal operation.
3.  Recolonization of the vacated habitat occurred in the first instance by young females.
4.  Although in the first year after the BRO no cubs had been reared in any of the culled groups, and although the shortage of sexually mature boars may have limited the reproductive output of sows in the following year, the population took only 3 years to recover to its (already lowered) preremoval density.
5.  Losses from the adult (and cub) population due to mortality or emigration were smaller at North Nibley than at the other sites.
6.  There was much evidence that during 1995 and 1996 density-dependent effects constrained the reproductive output of the high-density populations, and some support for the hypothesis that badgers exhibit the non-linear 'large mammal' type of functional response to density.
7.  Badgers at North Nibley were younger, heavier and in better condition than badgers at Wytham Woods and Woodchester Park.
8.  We argue that the disease dynamics are likely to be different in disturbed compared with undisturbed badger populations, and that this could affect the effectiveness of BROs.     

狗獾秋季对生境的选择——以黑龙江省方正林业局为例

在黑龙江省方正林业局新风林场利用痕迹检验法和洞穴辨别法对狗獾秋季生境选择进行研究。通过在选定的15个林班的23条样线进行调查,共测定了106个利用样方和106个对照样方的19种生态因子。结果表明,狗獾秋季利用样方和对照样方在优势乔木、坡向、灌木密度和灌木高度4种生态因子上差异极显著(P0.001),在灌木距离上差异显著(P0.05),其余的生态因子无显著差异(P0.05),相对于对照样方而言,狗獾秋季更偏爱选择位于阳坡,优势乔木为紫椴和黄菠萝,灌木密度大、高度高、距离近的生境。在典则系数的直方图上可以看出秋季狗獾的利用样方与对照样方存在一定的重叠,但是Wilk’sλ值显示秋季狗獾的利用样方与对照样方具有较高的差异性(Wilk’sλ=0.507,χ2=141.524,df=3,P0.001),较高比例的(84.0%)正确判别率也支持了这种差异性。逐步判别分析表明在区分秋季狗獾的利用样方与对照样方方面有3个生态因子发挥作用,依照贡献值的大小依次为:郁闭度、灌木密度和植被盖度。