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The alternative prey hypothesis describes the mechanism for apparent competition whereby the mortality of the secondary prey species increases (and population size decreases decreases) by the increased predation by the shared predator if the population size of the primary prey decreases. Apparent competition is a process where the abundance of two co-existing prey species are negatively associated because they share a mutual predator, which negatively affects the abundance of both prey Here, we examined whether alternative prey and/or apparent competition hypothesis can explain the population dynamics and reproductive output of the secondary prey, wild forest reindeer (Rangifer tarandus fennicus) in Finland, in a predator-prey community in which moose (Alces alces) is the primary prey and the wolf (Canis lupus) is the generalist predator. We examined a 22-year time series (1996-2017) to determine how the population size and the calf/female ratio of wild forest reindeer in Eastern Finland were related to the abundances of wolf and moose. Only moose population size was regulated by hunting. Summer predation of wolves on reindeer focuses on calves. We used least squares regression (GLS) models (for handling autocorrelated error structures and resulting pseudo-R2s) and generalized linear mixed (GLMs) models (for avoidance of negative predictions) to determine the relationships between abundances. We performed linear and general linear models for the calf/female ratio of reindeer. The trends in reindeer population size and moose abundance were almost identical: an increase during the first years and then a decrease until the last years of our study period. Wolf population size in turn did not show long-term trends. Change in reindeer population size between consecutive winters was related positively to the calf/female ratio. The calf/female ratio was negatively related to wolf population size, but the reindeer population size was related to the wolf population only when moose abundance was entered as another independent variable. The wolf population was not related to moose abundance even though it is likely to consist the majority of the prey biomass. Because reindeer and moose populations were positively associated, our results seemed to support the alternative prey hypothesis more than the apparent competition hypothesis. However, these two hypotheses are not mutually exclusive and the primary mechanism is difficult to distinguish as the system is heavily managed by moose hunting. The recovery of wild forest reindeer in eastern Finland probably requires ecosystem management involving both habitat restoration and control of species abundances.

The practice of feeding brown bears Ursus arctos for recreational purposes is common in the easternmost areas of Finland, but this may, however, result in human-habituated bears. From 1995 to 2008, 3% of all bears killed by humans (N = 1,108 bears) in Finland represented incidents where bears were either killed for reasons of human safety under a license issued by the police or as a result of actual emergency situations where bears were shot in self defence. We constructed binary logistic regression models for comparing bears shot under police license and in self defence with bears killed in regular sport hunting by using the sex of the bear, human density, bear observation density and the distance from the nearest feeding site as independent variables. High human density was the most important factor differentiating bears shot under a license issued by police from bears killed in sport hunting. The difference in human density was largest for places located far from feeding sites. Increasing distance from feeding sites differentiated bears shot under police license and in self defence from sport hunted bears. The sex of the bears and the density of bear observation were more weakly associated with the category of shooting. Our study did not provide evidence that bear feeding for recreational purposes is associated with the nuisance-bear problem in Finland. Nevertheless, some risks for human safety might be associated with artificial bear feeding for tourism purposes. If the practice of feeding bears continues to be accepted by Finnish legislation, game management should include an action plan for occasions when bears visiting feeding sites will lose their wariness of humans.

The estimation of large carnivore populations presents major logistical challenges. We examined trends in the wolf Canis lupus population in Finland using two independent methods. We compared track indices from an annual wildlife winter census based on a constant, nationwide network of transect lines (wildlife triangles) with the number of reproductions confirmed to occur in the same year during 1996 to 2009. Nationwide, and in the eastern management zone, which is the core area of Finnish wolves, the frequency of wolf tracks in wildlife triangles (% of all triangles counted in a given year having wolf tracks) predicted quite well the log transformed number of reproductions taken place in these areas (adjusted R2-values for linear regression models 0.59 and 0.68, respectively), while not for the western management zone (R2 = 0.38). However, although mean wolf densities were low (< 1 wolf/1000 km2 nationwide and <3 wolves/1000 km2 in the eastern zone), track indices could detect the major trends in Finland's wolf population. A clear reason for this was the substantial changes in population size during the study period.

Cyclic thermal stresses produced by rf pulsed heating can be the limiting factor on the attainable reliable gradients for room temperature linear accelerators. This is especially true for structures that have complicated features for wakefield damping. These limits could be pushed higher by using special types of copper, copper alloys, or other conducting metals in constructing partial or complete accelerator structures. Here we present an experimental study aimed at determining the potential of these materials for tolerating cyclic thermal fatigue due to rf magnetic fields. A special cavity that has no electric field on the surface was employed in these studies. The cavity shape concentrates the magnetic field on one flat surface where the test material is placed. The materials tested in this study have included oxygen free electronic grade copper, copper zirconium, copper chromium, hot isostatically pressed copper, single crystal copper, electroplated copper, Glidcop®, copper silver, and silver plated copper. The samples were exposed to different machining and heat treatment processes prior to rf processing. Each sample was tested to a peak pulsed heating temperature of approximately 110°C and remained at this temperature for approximately 10×106 rf pulses. In general, the results showed the possibility of pushing the gradient limits due to pulsed heating fatigue by the use of copper zirconium and copper chromium alloys.

Background Limited information exists on the active role of females during mate searching. Theory primarily focuses on male reproductive behaviours, suggesting male distribution follows that of females, while female distribution is influenced by food resources and habitat. This approach might underestimate the females’ role in shaping mating strategies. Incorporating a female perspective into mating studies can enhance our understanding of evolutionary factors. Methods Using GPS data from brown bears Ursus arctos across Finland, Romania and Slovakia, we explored female movement behaviour during the mating period. First, we estimated movement speed, total distance and net distance at a daily scale. Then, we quantitatively described when the movement peaks occur by estimating two critical points of the functions described by each of the aforementioned movement parameters: (1) the point in time when the rate of change in brown bear movement behaviour is the highest; and (2) the point in time when each aspect of brown bear movement is most pronounced. We quantified temporal variations in male and female movements throughout the year using generalized additive mixed models, while we used linear mixed models to assess the relationship between peak movement parameters, bear sex and population. Results Our findings identified two overlooked behaviours: (1) male and female movement parameters showed the highest rate of change during the mating season, challenging the notion of male roaming as the primary mating strategy; and (2) females travelled the longest distances during the mating season, potentially seeking high-quality mates. This behaviour aligns with the strategy of engaging in copulations with multiple males to avoid infanticide. Conclusions Our study reveals novel insights into the active role of female brown bears in mating strategies, challenging traditional male-centric views. These results support the need for detailed investigations into female behaviours across mammalian taxa, which offer potential to advance our understanding of mammalian social and mating systems. Local differences also underscore the importance of social and ecological conditions to explain variation in the female role in mating strategies.

Dispersal influences distribution and genetic structure of animal populations. Dispersal in expanding wolf (Canis lupus) populations is not well documented, especially in Europe, where no studies of dispersal based on marked wolves are available. We studied the dispersal of wolves in Finland, where a peripheral wolf population (160–180 animals) increased and expanded during 1998–2004. We equipped 60 wolves from 8 neighboring wolf pack territories with radio or GPS transmitters in east-central Finland during 1998–2004, and at least 30 wolves (50%) dispersed from the home territory. Additional information was collected by detecting the natal pack of captured wolves with multilocus microsatellite genotyping and paternity analysis. In the study area, the directions formed a sun-ray pattern. Wolves usually departed their home territory as pups and yearlings, and in unimodal seasonal fashion. The dispersal distance (median 98.5, range 35–445 km) did not differ by sex (P = 0.342). Long-distance travelers (>200 km) were found only among wolves that departed at the age of 10–12 months. Survival was linked to the direction of dispersal. All marked wolves that dispersed to reindeer management areas in the north were shot before being able to reproduce, whereas elsewhere, the majority of dispersers (10 of 16) reproduced.

Gray wolf Canis lupus predation on domestic dogs Canis familiaris is a considerable wolf–human conflict issue in several regions of Europe and North America but it has not been well documented in the scientific literature. Livestock depredations by wolves may be related to the abundance of wild prey. Regardless of the presumed motivations of wolves for attacking dogs (likely due to interference competition and predation), the abundance of wild prey populations may also influence the risk of wolf attacks on dogs. We examined whether the annual number of fatal attacks by wolves on dogs was related to the abundance of primary prey, including wild boar Sus scrofa and roe deer Capreolus capreolus in Estonia, as well as the abundance of moose Alces alces in Finland. Statistical models resulted in significant negative relationships, thus providing evidence that the risk of attacks in both house yards (Estonia) and hunting situations (Finland) was highest when the density of wild prey was low. Wild ungulates cause damage to agriculture and forestry, but they seem to mitigate conflicts between wolves and humans; therefore, it is necessary to develop a holistic, multispecies management approach in which the importance of wild ungulates for large carnivore conservation is addressed.

Abstract Attacks by wolves (Canis lupus) on dogs (C. familiaris) presumably are motivated both by preying and elimination of potential competitors. Regardless of these alternative motivations in wolves, the risk of attacks might be higher when the density of primary prey is low. We examined how many dogs do territorial wolves in Finland kill in relation to the population density of the most abundant ungulates, moose (Alces alces), white-tailed deer (Odocoileus virginianus), and roe deer (Capreolus capreolus). Most attacks by wolves on dogs take place in hunting with dogs. The number of wolf-killed dogs was in highly significant negative relationship to the population density of white-tailed deer and to total ungulate biomass per unit area which is largely determined by the density of white-tailed deer. Our results indicate that abundant wild prey would decrease the risk at which wolves attack dogs. On the other side of the coin prevail two hard facts which wildlife managers had to take a notice. White-tailed deer, although a potential mitigator of wolf–human conflict, is an alien species and a partner in > 6000 traffic collisions annually in Finland. One factor that seemed to increase the risk of wolf attacks on dogs is the low ungulate density in regions where moose is the only remarkable ungulate prey. Higher moose densities could decrease the risk of attacks, but on the other hand, higher densities could increase the risk of serious traffic collisions and browsing damages in forests.

Background Limited information exists on the active role of females during mate searching. Theory primarily focuses,on male reproductive behaviours, suggesting male distribution follows that of females, while female distribution,is infuenced by food resources and habitat. This approach might underestimate the females’ role in shaping mating,strategies. Incorporating a female perspective into mating studies can enhance our understanding of evolutionary,factors.,Methods Using GPS data from brown bears Ursus arctos across Finland, Romania and Slovakia, we explored female,movement behaviour during the mating period. First, we estimated movement speed, total distance and net distance,at a daily scale. Then, we quantitatively described when the movement peaks occur by estimating two critical points,of the functions described by each of the aforementioned movement parameters: (1) the point in time when the rate,of change in brown bear movement behaviour is the highest; and (2) the point in time when each aspect,of brown bear movement is most pronounced. We quantifed temporal variations in male and female movements,throughout the year using generalized additive mixed models, while we used linear mixed models to assess the,relationship between peak movement parameters, bear sex and population.,Results Our fndings identifed two overlooked behaviours: (1) male and female movement parameters showed,the highest rate of change during the mating season, challenging the notion of male roaming as the primary mating,strategy; and (2) females travelled the longest distances during the mating season, potentially seeking high-quality,mates. This behaviour aligns with the strategy of engaging in copulations with multiple males to avoid infanticide.,Conclusions Our study reveals novel insights into the active role of female brown bears in mating strategies,,challenging traditional male-centric views. These results support the need for detailed investigations into female,behaviours across mammalian taxa, which ofer potential to advance our understanding of mammalian social,and mating systems. Local diferences also underscore the importance of social and ecological conditions to explain,variation in the female role in mating strategies.

The isolated gray wolf (Canis lupus) population of the Scandinavian Peninsular is suffering from inbreeding depression. We studied dispersal of 35 wolves fitted with very high frequency (20) or Global Positioning System-global system for mobile (15) radiocollars in the neighboring Finnish wolf population. The growing wolf population in Finland has high numbers of dispersing individuals that could potentially disperse into the Scandinavian population. About half (53%) of the dispersing wolves moved total distances that could have reached the Scandinavian population if they had been straight-line moves, but because of the irregular pattern of movements, we detected no wolves successfully dispersing to the Scandinavian population. Dispersal to the Scandinavian population was also limited by high mortality of wolves in reindeer (Rangifer tarandus) management areas and by dispersal to Bothnian Bay at times of the year when ice was not present. We suggest that when a small wolf population is separated from source populations by distance, barriers, and human exploitation, wildlife managers could promote the population's viability by limiting harvest in the peripheral areas or by introducing wolves from the source population.