Sett density as an estimator of population density in the European badger Meles meles

• 1 Estimations of European badger population density in the UK are usually based on surveys of numbers of main setts. However, this approach cannot be used in low‐density areas, such as the Mediterranean region, where no main setts can be defined. Therefore, an alternative method is needed to estimate badger density over large areas.
• 2 We reviewed the existing published information to evaluate whether badger density is correlated to the density of all setts in an area (not only the main setts) and to ask whether badger density can be predicted from total sett number throughout the geographical range of the species.
• 3 In multiple regression analysis, badger density and the size of the study area explained 73% of the variance in sett density. Badger density had a significant positive effect on sett density, while the effect of study area size was not significant. Therefore, total sett density can be used to obtain an estimation of relative badger density in all habitats and regions throughout the badger's geographical range, allowing comparative research.

     

Birds in the diet of the Eurasian badger Meles meles: a review and meta-analysis

1. We reviewed 110 published studies of badger diet or badger predation of birds. The studies covered most of the Eurasian badger's range, from Ireland east to Japan and from Sweden south to southern Spain. 2. Bird remains were recorded in 2038 cases out of a total 36699 samples of badger faeces and stomachs. The overall percentage frequency of occurrence of bird remains in badger faeces and stomachs was 5.55% for all studies combined, and 7.97% for UK studies. The remains of 45 bird species from 11 orders were recorded. 3. The percentage frequency of occurrence of birds in badger diet increased significantly with latitude. There was no significant relationship between the occurrence of birds in badger diet and season. 4. While the prevalence of birds in the diet of badgers is generally low, the studies reviewed here provide insufficient evidence to assess whether badger predation has an impact on bird populations at a national scale, and experimental approaches to this problem are required.     

Intraspecific morphological variation of the middle ear in the European badger,Meles meles (Carnivora: Mustelidae)

Many studies have been conducted about the information contained in the anatomy of the mammalian middle ear. Most of these only use a few specimens. Thus we aim to provide a quantitative analysis of the intraspecific and interspecific variations of the middle ear, focusing on the auditory bulla. For that purpose, we focused on the mustelids, as a quite generalist taxon and, more specifically, on the European badger, Meles meles. Our study includes two types of statistical methods. We first compared the mean of a subjectively chosen measure between individuals of the same species and between individuals of different species. We then used a multidimensional scaling procedure to cluster individuals according to different measures. We conclude that the middle ear varies effectively less intraspecifically than interspecifically. However, we think that the few anatomical parameters to measure in the auditory bulla involve using more specimens or focusing on geometric morphometrics in studies focusing on middle ear.     

Female receptivity, embryonic diapause, and superfetation in the European badger (Meles meles): implications for the reproductive tactics of males and females

The European badger Meles meles is thought to mate throughout the year with two mating peaks occurring in late winter/spring and summer/autumn. After mating, fertilized ova enter embryonic diapause (delayed implantation) at the blastocyst stage, which lasts up to eleven months. Even if mating is successful, however, the estrous cycle may continue during embryonic diapause, which suggests that female badgers are capable of superfetation (conception during pregnancy). This may increase female fitness by facilitating polyandry, and reduce the risk of infanticide by resident males through paternity confusion. Detailed understanding of female receptivity, specifically the association of superfetation with embryonic diapause, may explain field observations of seemingly inconsistent reproductive tactics of male badgers with regard to, for instance, whether or not they guard mates or defend territories. The combination of embryonic diapause and superfetation may occur in other mustelids; if so, the sociobiology of mustelids will need reevaluating, and the Mustelidae may prove to be a good model taxon for studies of sexual conflict in the reproduction of eutherian mammals.     

Age, sex, and condition as predictors of moult and the efficacy of a novel fur-clip technique for individual marking of the European badger (Meles meles)

The European badger ( Meles meles ) moults once a year. In our study site in lowland England, pelage replacement of the guard hairs and a protracted period of fur growth (follicular anagen) occur between May and early November, with a peak in July. The precise timing of the moult depends on the age and condition of the badger. Yearling badgers undergo moult significantly earlier than adults. Adult females that have lactated, moult significantly later than other classes of adult, delaying the moult until autumn which corresponds to an annual period of food abundance. Lactation was significantly associated with poor condition in these badgers. It was not possible to determine whether delayed moult was due to poor condition per se , or due to some other physiological consequence of lactation, e.g. hormonal changes. We hypothesize that delay of moult in laclating/poor condition individuals has the adaptive consequence of delaying the metabolic costs of pelage replacement from a time of energy deficit until a time of relative plenty.
These findings are of practical importance to a novel solution to the problem of individually marking badgers during observational studies. The technique involves clipping the dark band near the tips of the badger's guard hairs to reveal the white under-fur and produce patterning of the coat. The highly contrasting marks were well suited to visual identification during observations under low light and infra-red illumination, and they allowed a large number of individuals (over 80 in our study) to be distinctively marked. The mark persists until the badger undergoes its single annual moult, or until three months of the active phase of fur growth have passed. Clip marks on adults made in late August had the greatest longevity, with 80% still visible after nine months. Though clipping had no significant effect on body condition in our study site, it should be cautiously applied with individuals in poor condition or in cold climates.     

Isolation of 39 polymorphic microsatellite loci and the development of a fluorescently labelled marker set for the Eurasian badger (Meles meles) (Carnivora: Mustelidae)

We have isolated 78 microsatellite loci from the Eurasian badger (Meles meles). Of the 52 loci characterized, 39 were found to be polymorphic. A fluorescently labelled primer set was developed to enable individual‐specific 17‐locus genotypes to be obtained efficiently.     

An inquiline fig wasp using seeds as a resource for small male production: a potential first step for the evolution of new feeding habits?

The processes allowing evolutionary transitions in resources used by parasitic wasps are largely unknown. Microhymenopteran communities associated with figs could provide a model system to investigate such transitions. We investigate here a species of genus Idarnes . The larvae generally develop as inquilines of the pollinating wasp larvae. However, in figs where the parasitic pressure is high, eggs are laid in developing seeds. These eggs turn into small males. This is the first report of seed consumption by a fig wasp. Using an alternative resource to produce small males could provide a pathway to select for increased ability to use this resource and hence provide an intermediate step for evolving the capacity to use new resources.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society , 2007, 92 , 9–17.     

Host range of the European,rhizome-stem feeding scale Rhizaspidiotus donacis (Hemiptera: Diaspididae), a candidate biological control agent for giant reed,Arundo donax (Poales: Poaceae) in North America

The armored scale Rhizaspidiotus donacis (Leornardi) was evaluated as a potential biological control agent of the invasive reed grass Arundo donax in North America. No-choice tests, native range field surveys and non-target host exposures were used to determine the fundamental host range of the scale collected from Caloma, Spain and Perpignan, France. Thirty-five species, including two genotypes of A. donax and seven ecotypes of Phragmites australis, along with closely related grasses, economic grasses and habitat associates were tested. In quarantine no-choice testing using releases of 200 crawlers per plant, normal development of R. donacis was observed on A. donax and A. formosana, with very limited survival to the adult stage on Spartina alterniflora and Leptochloa spp. In follow-up studies using 1000 crawlers per plant, 10 live adult females were found on Leptochloa virgata, and one adult female on Spartina alterniflora, but average adult female abundance per plant was (2580%) 26-times lower on L. virgata and over (39,090%) 100-times lower on S. alterniflora than on A. donax. Field surveys were conducted at five locations in Spain and France at which A. donax infested with R. donacis, co-occurred with two non-target species of concern and R. donacis was only found on A. donax. Six-month field host exposures in Spain using potted Leptochloa plants entwined with heavily infested A. donax confirmed that R. donacis is specific to Arundo under field conditions. Based on our results, the scale R. donacis appears to be specific to the genus Arundo and is unlikely to harm native or cultivated plants in the Americas.     

Complete H and C NMR chemical shift assignments of mono-, di-, and trisaccharides as basis for NMR chemical shift predictions of polysaccharides using the computer program casper

The computer program casper uses ¹H and ¹³C NMR chemical shift data of mono- to trisaccharides for the prediction of chemical shifts of oligo- and polysaccharides. In order to improve the quality of these predictions the ¹H and ¹³C, as well as ³¹P when applicable, NMR chemical shifts of 30 mono-, di-, and trisaccharides were assigned. The reducing sugars gave two distinct sets of NMR resonances due to the α- and β-anomeric forms. In total 35 ¹H and ¹³C NMR chemical shift data sets were obtained from the oligosaccharides. One- and two-dimensional NMR experiments were used for the chemical shift assignments and special techniques were employed in some cases such as 2D ¹H,¹³C-HSQC Hadamard Transform methodology which was acquired approximately 45 times faster than a regular t₁ incremented ¹H,¹³C-HSQC experiment and a 1D ¹H,¹H-CSSF-TOCSY experiment which was able to distinguish spin-systems in which the target protons were only 3.3 Hz apart. The ¹H NMR chemical shifts were subsequently refined using total line-shape analysis with the PERCH NMR software. The acquired NMR data were then utilized in the casper program (http://www.casper.organ.su.se/casper/) for NMR chemical shift predictions of the O-antigen polysaccharides from Klebsiella O5, Shigella flexneri serotype X, and Salmonella arizonae O62. The data were compared to experimental data of the polysaccharides from the two former strains and the lipopolysaccharide of the latter strain showing excellent agreement between predicted and experimental ¹H and ¹³C NMR chemical shifts.