The European badger (Meles meles) is Ireland's largest terrestrial carnivore. Since first being identified as a wildlife reservoir of bovine tuberculosis in 1974 there has been an increased research focus into the behaviour of these ecologically important mammals in the Republic of Ireland (ROI). However, to date there has never been an assessment of the helminth parasite community of Irish badgers. This study of 289 badgers found helminth infection to be endemic within the sample population and we report for the first time the prevalence, abundance, intensity and aggregation of helminth infection in ROI. Eight distinct helminth taxa were recorded: Aelurostrongylus falciformis, Crenosoma melesi, Eucoleus aerophilus, Species A, Strongyloides spp., Uncinaria criniformis, and two unidentifiable but morphologically distinct nematodes. All helminths belong to the taxon Nematoda, and this is the first report of an exclusively nematode community across the badger's Eurasian distribution. Infection was not significantly influenced by the host sex, region of origin or season of sampling.

Neospora caninum is a protozoan parasite, primarily associated with bovine abortion. The only definitive hosts discovered to date are carnivores. This study aimed to identify the role of mammalian carnivores in the epidemiology of bovine neosporosis. A sample bank of serum, fecal and brain samples was established: American mink (Mustela vison), red foxes (Vulpes vulpes), pine martens (Martes martes), badgers (Meles meles), stoats (Mustela erminea), otters (Lutra lutra) and feral ferrets (Mustela putorius). Approximately 1% of mink and 1% of fox samples were positive by IFAT. According to PCR analysis of DNA extracted from brain tissue, 3% of the mink, 4% of the otters and 6% of the foxes examined were infected with N. caninum. All fecal samples tested negative for N. caninum DNA (n = 311), suggesting that the species that tested positive were intermediate not definitive hosts. This is the first time that tissues from mustelids have tested positive for N. caninum. The need to test 2 relatively large (∼200 mg) targeted parts of the brain to avoid false negatives was also identified. The relatively low prevalence of N. caninum in Irish carnivores suggests that the local ecology of a species has an important influence on its epidemiological role.

The honey badger, or ratel, Mellivora capensis has not been well studied and data on life-history variables have previously been incomplete and contradictory. Here we present data on life-history variables that were collected from visual observations as part of the first intensive study of free-living honey badgers (25 radio-marked individuals) and we make comparisons with other similarly sized mustelids (5–25 kg). The honey badger is a non-social species and only the mother rears the young. The data do not support delayed implantation as gestation was a maximum of 50–70 days with the unusually small litter size of one cub. The long time to independence of both male and female cubs (12–16 months) resulted in birth intervals longer than 12 months with no distinct breeding season. Overall the honey badger appears to have a more K-selected life history compared to other species within the Mustelidae.

The honey badger, or ratel, Mellivora capensis has not been well studied despite its extensive distribution. As part of the first detailed study, visual observations of nine habituated free-living individuals (five females, four males) were used to investigate seasonal, annual and sexual differences in diet and foraging behaviour. Theory predicts that generalist predators ‘switch’ between alternative prey species depending on which prey species are currently most abundant, and diet breadth expands in response to decreased availability of preferred food types. There were significant seasonal differences in the consumption of eight prey categories related to changes in prey availability but no seasonal differences in food intake per kg of body mass. As predicted, the cold-dry season diet was characterized by low species richness and low foraging yield but high dietary diversity, while the reverse was true in the hot-dry and hot-wet seasons. In accordance with these predictions, results suggest that the honey badger maintains its intake level by food switching and by varying dietary breadth. Despite marked sexual size dimorphism, male and female honey badgers showed no intersexual differences in prey size, digging success, daily food intake per unit body weight or foraging behaviour. Results do not support the hypothesis that size dimorphism is primarily an adaptation to reduce intersexual competition for food.