Martin E. Smith

Translocation of carnivores as a method for managing problem animals: a review

Translocation of individual carnivores has been a standard management tool for decades in North America and southern Africa in response to livestock depredation and other conflict behaviours. As carnivore populations across Europe begin to increase it is expected that management problems will also increase. Before translocation becomes established as a management tool in Europe its success needs to be reviewed. In general, there has been very little follow-up of translocated animals. Almost no data exist on the subsequent levels of damage after translocation. Large carnivores have shown a consistent ability to return to the site of capture over distances of up to 400 km. Even those individuals that do not succeed in returning home roam over very large distances, best measured in units of hundreds of kilometres. Very few individuals remain at the release sites. Survival of translocated animals has occasionally been shown to be poor, often as a result of the large movements. In general, there needs to be a large area (hundreds or thousands of square kilometres) without conflict potential where the individuals can be released for the strategy to work. When such areas are not available, management efforts should concentrate on reducing conflict potential, or, where this is not practical, lethal control.

Review of Methods to Reduce Livestock Depredation II. Aversive conditioning, deterrents and repellents

The use of aversive conditioning, repellents and deterrents in the management of predator-livestock problems is evaluated based on a comprehensive literature review, contact with leading authorities and visits to areas with similar predation problems. The status of these management tools is reported and their applicability under Scandinavian conditions evaluated. Aversive conditioning usually involves treating baits with an emetic compound (usually lithium chloride), and has shown inconsistent and inconclusive results. Repellents and deterrents include physical, chemical and acoustic stimuli or devices that cause predators to stop an unwanted behaviour or to retreat from an area. Chemical repellents are not particularly effective against coyotes but have been effective for wolverines and bears under some conditions (e.g. with the availability of untreated, alternative prey). Projectile repellents give an immediate, positive result with bears, but their use is limited. Visual and acoustic devices work well, but only for a limited time, as predators quickly habituate to these devices. To summarize, these methods generally show little promise in reducing livestock depredation on a large-scale or long-term basis, especially under the conditions prevailing in Scandinavia.

Reproductive effort in relation to maternal social rank in reindeer (Rangifer tarandus)

In polygynous mammals, high-quality females may increase their fitness by providing superior care to their offspring. Based on the agonistic interactions of female reindeer in an experimental herd during two consecutive years (1997 and 1998), we tested whether maternal social rank influenced: (1) winter body-mass change of females, (2) preparturition reproductive effort (measured as fecundity, the birth mass and the birth date of their calves), (3) preweaning maternal effort (measured as calves’ preweaning mortality, early preweaning and late preweaning growth rate and September body mass of calves), and (4) postweaning maternal effort (measured as calves’ body-mass change during their first winter). In the models, we included September females’ body mass as a covariate to separate the effects of maternal rank and body mass. We also tested whether the effect of social rank on maternal efforts was dependent on offspring sex. High-ranked females gained body mass whereas low-ranked females lost weight during the winter. Fecundity was higher and date of birth was earlier in high-ranked females than in subordinates, whereas no effect of females’ rank on birth mass of calves was found. Early preweaning growth rate and September body mass of calves increased with increasing females’ social rank, whereas late preweaning daily growth rate of calves was not influenced by females’ rank. Calves’ preweaning mortality was only influenced by year, which also explained most of the variance in the winter body-mass change of calves. The effects of females’ rank on the reproductive-efforts parameters studied were not specific to offspring sex. These findings suggest that females’ rank influences reproductive effort during the preparturition, as well as the preweaning, period, the effect being sex independent.

Review of methods to reduce livestock depredation, 1: Guardian animals

The use of domestic animals to protect livestock was reviewed through visits to actual users, discussions with experts and a thorough literature search. Costs and benefits were analysed in terms of reduced livestock losses. The most common guardian animals are dogs, which have been shown to reduce predation (documented mostly for coyote) by 11?100%. Livestock guardian dogs have also been used effectively against bear, wolf and cheetah. Donkeys are also used as guardian animals, and their effectiveness lies in their natural herding behaviour and aggression, especially against canids. The effectiveness of donkeys varies considerably dependent upon the predator species and the temperament of the individual donkey. Llamas are also used as a guardian animal, with approximately the same characteristics as the donkeys, and will defend themselves against most predators. The use of guardian animals appears to be an effective tool for reducing livestock depredation and should be evaluated in areas with high predation losses against the cost of changing production systems.

Limited gene flow among brown bear populations in far Northern Europe? Genetic analysis of the east–west border population in the Pasvik Valley

Noninvasively collected genetic data can be used to analyse large‐scale connectivity patterns among populations of large predators without disturbing them, which may contribute to unravel the species’ roles in natural ecosystems and their requirements for long‐term survival. The demographic history of brown bears (Ursus arctos) in Northern Europe indicates several extinction and recolonization events, but little is known about present gene flow between populations of the east and west. We used 12 validated microsatellite markers to analyse 1580 hair and faecal samples collected during six consecutive years (2005–2010) in the Pasvik Valley at 70°N on the border of Norway, Finland and Russia. Our results showed an overall high correlation between the annual estimates of population size (Nc), density (D), effective size (Ne) and Ne/Nc ratio. Furthermore, we observed a genetic heterogeneity of ∼0.8 and high Ne/Nc ratios of ∼0.6, which suggests gene flow from the east. Thus, we expanded the population genetic study to include Karelia (Russia, Finland), Västerbotten (Sweden) and Troms (Norway) (477 individuals in total) and detected four distinct genetic clusters with low migration rates among the regions. More specifically, we found that differentiation was relatively low from the Pasvik Valley towards the south and east, whereas, in contrast, moderately high pairwise FST values (0.91–0.12) were detected between the east and the west. Our results indicate ongoing limits to gene flow towards the west, and the existence of barriers to migration between eastern and western brown bear populations in Northern Europe.

A Modification of the Hair-Trapping Method for Surveillance of Problematic Bear Activity Close to a Farm — a Case Study from the Pasvik Valley in Norway

Human—bear conflicts occur frequently in the Pasvik Valley, Norway. We used a variant of the hair-trapping method with higher densities of traps (2.5 × 2.5 km grid) to detect brown bears moving near human settlements and livestock. We distributed 20 hair traps for one month close to a farm with frequent observations of grazing bears. The study area consisted of one area close to the farm, and one adjacent area without settlements. We collected 85 hair samples and identified 13 different individuals by STR analysis. In the farm area, we detected 4 different males once, and a female that was detected in both areas. In comparison, nine bears (2 males and 7 females) were detected for more than one week in the area without settlements, suggesting lower roaming activity. Conclusively, hair trapping has the potential to survey bears at specific locations of importance to the wildlife management.