Electric wire enclosures to protect livestock represent one intervention to mitigate negative impacts of large carnivores. However, appropriate fence construction and voltage level in the live wires are crucial to deter carnivores. To ensure that the voltage level remains sufficiently high, maintenances and clearing the wires from tall or growing vegetation is regularly needed. In this study, we investigate the performance of a fence wire coated with conductive rubber, claimed by the supplier not to short circuit and drop in voltage due to contact with e.g. ground and vegetation. We examine the voltage of the rubber‐coated wire during contact with soil, ground, and wet vegetation and observed a voltage loss comparable to that of the standard metal fence wire. Our results imply that the rubber‐coated wire does not perform better than a conventional metal fence wire when in contact with growing grass and other elements that usually short circuit an electric fence.

Large carnivore feeding ecology plays a crucial role for management and conservation for predators and their prey. One of the keys to this kind of research is to identify the species composition in the predator diet, for example, prey determination from scat content. DNA-based methods applied to detect prey in predators' scats are viable alternatives to traditional macroscopic approaches, showing an increased reliability and higher prey detection rate. Here, we developed a molecular method for prey species identification in wolf (Canis lupus) scats using multiple species-specific marker loci on the cytochrome b gene for 18 target species. The final panel consisted of 80 assays, with a minimum of four markers per target species, and that amplified specifically when using a high-throughput Nanofluidic array technology (Fluidigm Inc.). As a practical example, we applied the method to identify target prey species DNA in 80 wolf scats collected in Sweden. Depending on the number of amplifying markers required to obtain a positive species call in a scat, the success in determining at least one prey species from the scats ranged from 44% to 92%. Although we highlight the need to evaluate the optimal number of markers for sensitive target species detection, the developed method is a fast and cost-efficient tool for prey identification in wolf scats and it also has the potential to be further developed and applied to other areas and large carnivores as well.

Monitoring goals and methods: Wolves in Sweden and Norway are members of a joint cross-boundary Scandinavian wolf population. In both countries, the wolf population is being monitored each winter. The Swedish Environmental Protection Agency and the Norwegian Environment Agency have joint Scandinavian guidelines and instructions for monitoring of wolves; these guidelines have been used since winter 2014-2015. Numbers, distribution and trends in the wolf population in Scandinavia are primarily determined through a survey of family groups, scent-marking pairs and reproductions during 1 October - 31 March. The survey of wolves is done mainly through snow-tracking and DNA-analyses of scats, urine and hair. Information from GPS-collars, other research data and dead wolves are used when available. The County Administrative Boards in Sweden and the Norwegian Nature Inspectorate (SNO) together with Inland Norway University of Applied Sciences in Norway are responsible for collecting field data. They also confirm reports of tracks and other observations by the public. For the wolf monitoring, contributions from the public are very important. Number of family groups and scent-marking pairs: During winter 2018-2019, 40 family groups were documented in Scandinavia; 28 within Sweden, six across the Norwegian-Swedish border and six within Norway. 28 territorial pairs were confirmed; 18 within Sweden, five across the border and five within Norway. Population size: Using the same method as last winter and based on the number of reproductions, Scandinavian wolf numbers were estimated to 380 (95% CI = 300-494). The Swedish sub-population was estimated to 300 wolves (95% CI = 237-390), including half of the cross-boundry wolves. The calculation includes both alive and dead wolves during the monitoring period. The smaller Norwegian population was counted directly in the field. Including half of the 40-41 cross-boundary wolves, a total of 84-87 wolves were counted in Norway. Genetics: One previously known Finnish-Russian female wolf was still resident within the populations breeding range (Orebro County), where she raised a F1-litter of pups born in 2018. Three new Finnish-Russian immigrant wolves were confirmed in Scandinavia, all outside the breeding range. Two during autumn 2018 in Northern Norway (Finnmark County) and one during spring 2019 in Northern Sweden (Norrbotten County). In addition, 12 older F1 offspring from five known FinnishRussian immigrants were confirmed in Scandinavia, including five F1 as scent-marking adults in family groups or pairs. The estimated average inbreeding coefficient in family groups was 0.25 this winter, a slight increase compared to last years monitoring season.

Knowledge of the wolverine Gulo gulo mating system is limited. In this study, we use 20 microsatellite loci for paternity testing in 145 wolverine offspring with known mothers. Samples were collected during > 10 years in two Scandinavian populations, mainly in connection with radio-telemetry studies and as part of long-term population monitoring. In total, 51% of the offspring were assigned a father. Our results demonstrate that the wolverine exhibits a polygamous mating system as some males were shown to produce offspring with more than one female in a single year. Females often reproduced with the same male in subsequent breeding years, but sometimes changed their partner, potentially as a consequence of a change in the territory-holding male in the area. In the majority of litters, siblings were unambiguously assigned the same father, indicating that multiple paternity is rare. Of 23 breeding pairs, for which telemetry data were available, 20 had overlapping home ranges, suggesting that pair formation generally is consistent with the territories held by wolverine males and females.

The wolverine is an endangered carnivore that in northwestern Europe is restricted to the mountain range along the border between Sweden and Norway. The Scandinavian wolverine population experienced a severe decline in numbers due to human persecution during the 20th century, although with legislative protection the population has recently implied that the population slowly has started to recover (current population size estimate of 800 individuals). In the mid 1990s, wolverines appeared in two new and isolated areas east of the mountain range, in the forest landscape close to the Gulf of Bothnia. Using non-invasive, DNA-based monitoring, we show here that these new subpopulations were likely founded by as few as 2 and 2–4 individuals, respectively, and that little, if any, genetic contact with the main population since colonisation has been established. A high degree of genetic similarity among individuals in the two areas indicates inbreeding. We estimate the minimum number of wolverines known to be alive in these areas during the period of 2001–2005 to 5 and 17, respectively, with one subpopulation showing decreasing (currently 2) numbers and the other increasing (10). For the somewhat larger population, we infer a tentative pedigree from relatedness values and parentage tests, which indicates the occurrence of brother–sister matings. This study illustrates the usefulness of non-invasive monitoring in the management of endangered carnivore populations.

Recently, a two-step PCR approach, referred to as multiplex pre-amplification, was proposed to improve microsatellite amplification from non-invasive samples such as faecal DNA. Here, we compare this new approach to standard PCR with respect to amplification success and genotyping error rates in microsatellite analysis (18 markers) of wolverine faecal DNA (48 extracts initially shown to contain amplifiable DNA). The multiplex pre-amplification approach was clearly advantageous both in terms of successful PCR amplifications (91% vs. 80%) and allelic dropout rate (2.4% vs. 12.5%). However, dropouts were to a high extent repeated in all second-step amplifications following multiplex pre-amplification, indicative of being generated during the initial PCR. Analysing more than one PCR from the initial multiplex PCR product may thus be of limited value. We instead suggest to perform two initial multiplex PCRs and to analyse a single second-step PCR from each of them. This was tested for 22 extracts at 18 loci and proved to be an effective way to obtaining a correct genotype.

Tanned hides, a common form of preservation of mammalian specimens, are usually resistant to DNA analysis. However, we show that DNA isolated from the pulp of claws of tanned hides amplifies well for microsatellite markers. For eight wolverine and eight lynx hides tanned 5-20 years ago, 93-98% of replicate amplifications gave distinct PCR products. Genotypes obtained in analysis of tissue samples of the same individuals were in all cases in agreement with those obtained by analysis of claws. We thus conclude that the use of claws from tanned hides offers new possibilities to genetic studies of preserved mammalian specimens, for instance, in the monitoring of illegal trade.

Non-invasive genetic analyses are important for studies of species that are rare, sensitive or at risk of extinction. This study investigates the possibility of using faeces and urine to obtain microsatellite genotypes for individual identification of wolverines (Gulo gulo). The reliability of the employed method was assessed by analysing independent amplifications of non-invasive samples (a multiple-tube approach) and by comparing genotypes obtained from faeces to genotypes obtained from blood or tissue of the same individual. Ten microsatellite markers were successfully amplified in 65% of the faecal samples (n = 32) and 40% of the urine samples (n = 22). Allelic dropout was found in 12 and 14% of the amplifications from extracts of faeces and urine, respectively. Nevertheless, all multi-locus genotypes were correct, as judged from comparison to data from tissue or blood samples, after three replicates. These results suggest that a non-invasive approach based on DNA-analysis of faeces can be a powerful tool in population monitoring of wolverines, potentially providing reliable estimates of population size and immigration rate. A second objective of the study was to develop markers for DNA-based sex identification in wolverines using non-invasive samples. We developed two Y-linked markers, one that was specific to wolverine and one that also successfully identified sex in another mustelid. Importantly, none of the markers amplified potential prey species such as reindeer or rodents.

The southern Norwegian wolverine (Gulo gulo) population was considered functionally extinct in the 1960s but has partly recovered in recent years. Proper management of this population is highly dependent on reliable estimates of critical population parameters such as population size, sex ratio, immigration rate, and reproductive contribution from immigrants. We report on a large-scale population monitoring project assessing these parameters through genetic tagging of individuals, with feces as the source of DNA. Sixty-eight different individuals were detected among 147 successfully genotyped samples collected in 2000 and 2001. Sixty of these individuals were represented in the 2001 sample, which may be considered a minimum estimate of the population size. Almost 50% of these animals were sampled only once, however, indicating that the true population size may be markedly higher. Accordingly, a capture-recapture estimate based on the observed resampling rates suggested a population size of 89 wolverines (95% confidence interval [CI] = 74-104), which is approximately 35% higher than an estimate of 64 obtained from the number of active natal dens (95% CI = 46-95; p = 0.08). Indirect estimates of dispersal distances inferred from mother-offspring relationships suggested that wolverine males have the ability to disperse up to 500 km, a distance exceeding anything previously reported in the literature. Dispersal distances of more than 100 km were detected for females. Bayesian clustering analysis and subsequent assessment of individual relationships suggest that immigrants from northern Scandinavia have contributed and still contribute to the southern Norwegian gene pool, counteracting genetic erosion and reducing the risk of inbreeding depression. Additional sampling efforts will be undertaken during the coming years to allow for observations of population trends, immigration rate, and reproductive variance among individuals. Such data will provide an important basis for the design of an appropriate conservation plan for this small and vulnerable population.