Explore the vast range of titles available.

Knowledge of factors influencing the timing of reproduction is important for animal conservation and management. Brown bears (Ursus arctos) are able to vary the birth date of their cubs in response to their fat stores, but little information is available about the timing of implantation and parturition in free-ranging brown bears. Body temperature and activity of pregnant brown bears is higher during the gestation period than during the rest of hibernation and drops at parturition. We compared mean daily body temperature and activity levels of pregnant and nonpregnant females during preimplantation, gestation, and lactation. Additionally we tested whether age, litter size, primiparity, environmental conditions, and the start of hibernation influence the timing of parturition. The mean date of implantation was 1 December (SD = 12), the mean date of parturition was 26 January (SD = 12), and the mean duration of the gestation period was 56 days (SD = 2). The body temperature of pregnant females was higher during the gestation and lactation periods than that of nonpregnant bears. The body temperature of pregnant females decreased during the gestation period. Activity recordings were also used to determine the date of parturition. The parturition dates calculated with activity and body temperature data did not differ significantly and were the same in 50% of the females. Older females started hibernation earlier. The start of hibernation was earlier during years with favorable environmental conditions. Dates of parturition were later during years with good environmental conditions which was unexpected. We suggest that free-ranging pregnant brown bears in areas with high levels of human activities at the beginning of the denning period, as in our study area, might prioritize investing energy in early denning than in early parturition during years with favorable environmental conditions, as a strategy to prevent disturbances caused by human.

As an important extrinsic source of mortality, harvest should select for fast reproduction and accelerated life histories. However, if vulnerability to harvest depends upon female reproductive status, patterns of selectivity could diverge and favor alternative reproductive behaviors. Here, using more than 20 years of detailed data on survival and reproduction in a hunted large carnivore population, we show that protecting females with dependent young, a widespread hunting regulation, provides a survival benefit to females providing longer maternal care. This survival gain compensates for the females’ reduced reproductive output, especially at high hunting pressure, where the fitness benefit of prolonged periods of maternal care outweighs that of shorter maternal care. Our study shows that hunting regulation can indirectly promote slower life histories by modulating the fitness benefit of maternal care tactics. We provide empirical evidence that harvest regulation can induce artificial selection on female life history traits and affect demographic processes.

Recreation is a crucial contribution of nature to people, relevant for forest ecosystems. Large carnivores (LCs) are important components of forests, however, their contribution to forest recreational value has not yet been evaluated. Given the current expansion of LC populations, the ongoing forest conservation debate, and the increasing use of nature for recreational purposes, this is a timely study. We used discrete choice experiments and willingness-to-travel to determine people’ preferences for both forest structural characteristics and presence of four LC species in Poland (N = 1097 respondents) and Norway (N = 1005). In both countries, two-thirds of the respondents (termed ‘wildness-positive’) perceived LCs as contributing positively to forest recreational value and preferred to visit old forests with trees of different species and ages and presence of dead wood (i.e. natural forests). Respondents with negative preferences towards LCs preferred more intensively managed forest (‘wildness-negative’); their preferences were stronger than in wildness-positive respondents and in Norway. Preferences towards wild nature were highly polarized and there were hardly neutral people. Our results showed a strong link between preferences for LC presence and forest structure, and reflected the dualism of human-nature relationships. This study highlights the need to consider the contribution of forests and LCs to human recreation services in ecosystem management policies.

The ecological requirements of brown bears are poorly known in the Himalaya region, which complicates conservation efforts. We documented the diet of the Himalayan brown bear (Ursus arctos isabellinus) by combining classical scat analysis and a newly developed molecular genetic technique (the trnL approach), in Deosai National Park, Pakistan. Brown bears consumed over 50 plant species, invertebrates, ungulates, and several rodents. Eight plant families; Poaceae, Polygonaceae, Cyperaceae, Apiaceae, Asteraceae, Caryophyllaceae, Lamiaceae, and Rubiaceae were commonly eaten with graminoids comprising the bulk of the diet. Golden marmots comprised the major mammalian biomass in the park, and were also the main meat source for bears. Animal matter, making 36% of dietary content, contributed half of the digestible energy, due to its higher nutritious value. We did not find a significant temporal pattern in diet, perhaps because the availability of the major diet (graminoids) did not change over the foraging period. Male brown bears were more carnivorous than females, probably because of their larger size, which requires higher energy and also makes them more efficient in capturing marmots. Frequencies of three plant species were also significantly higher in male brown bears; Bistorta affinis, Carex diluta, and Carex sp. Diet of the brown bear differed significantly between the park and surrounding valleys. In valleys, diet consisted predominantly of graminoids and crops, whereas the park provided more nutritious and diverse foodThe estimated digestible energy available to brown bears in Deosai was the lowest documented among brown bear populations, due to the lack of fruits and a relatively lower meat content. The low nutritious diet and high cost of metabolism in a high-altitude environment, probably explains the very low reproductive potential of this population.

Obligate herbivores dominate studies of the effects of climate change on mammals, however there is limited empirical evidence for how changes in the abundance or quality of plant food affect mammalian omnivores. Omnivores can exploit a range of different food resources over the course of a year, but they often rely on seasonally restricted highly nutritious fruiting bodies during critical life stages. Brown bears Ursus arctos in Sweden are dependent on berries for fattening before entering hibernation. We used a ten-year time series to evaluate the effect of temperature and snow on annual variation in berry abundance and how this variation affected bears. We found marked interannual variation in berry production of bilberry Vaccinium myrtillus and lingonberry V. vitis-idaea, that we could attribute in part to temperature during plant dormancy and flowering and precipitation during fruit ripening. Both, autumn weights of female bears and spring weights of yearling bears increased linearly with bilberry abundance. When bilberry abundance was low, lightweight female bears had a lower reproductive success than females in better condition. This effect vanished when food abundance was above average, indicating that lightweight females could compensate for their initial weight during good bilberry years. Our study highlights the importance of considering individuals’ dynamic responses to variation in food availability, which leave some more vulnerable to food shortage than others. Individual life-history heterogeneity in response to resource variation likely affects long-term population recruitment. Our findings emphasize that Scandinavian bears can be dependent on a single food resource during a critical period of the year and are therefore less resilient to environmental change than expected for an omnivore. Future climate scenarios predict ambiguous trends for weather covariates that affected crucial stages of berry phenology, preventing a clear prognosis of how climate change may affect long-term bilberry production.

There is increasing evidence of indirect effects of hunting on populations. In species with sexually selected infanticide (SSI), hunting may decrease juvenile survival by increasing male turnover.We aimed to evaluate the relative importance of direct and indirect effects of hunting via SSI on the population dynamics of the Scandinavian brown bear (Ursus arctos). We performed prospective and retrospective demographic perturbation analyses for periods with low and high hunting pressures. All demographic rates, except yearling survival, were lower under high hunting pressure, which led to a decline in population growth under high hunting pressure (l ¼ 0.975; 95% CI ¼ 0.914– 1.011). Hunting had negative indirect effects on the population through an increase in SSI, which lowered cub survival and possibly also fecundity rates. Our study suggests that SSI could explain 13.6% of the variation in population growth.Hunting also affected the relative importance of survival and fecundity of adult females for population growth, with fecundity being more important under low hunting pressure and survival more important under high hunting pressure. Our study sheds light on the importance of direct and indirect effects of hunting on population dynamics, and supports the contention that hunting can have indirect negative effects on populations through SSI. population dynamics, harvesting, brown bear, sexually selected infanticide, behaviour, carnivore, ecology, behaviour

Prey usually adjust anti-predator behavior to subtle variations in perceived risk. However, it is not clear whether adult large carnivores that are virtually free of natural predation adjust their behavior to subtle variations in human-derived risk, even when living in human-dominated landscapes. As a model, we studied resting-site selection by a large carnivore, the brown bear (Ursus arctos), under different spatial and temporal levels of human activity. We quantified horizontal and canopy cover at 440 bear beds and 439 random sites at different distances from human settlements, seasons, and times of the day. We hypothesized that beds would be more concealed than random sites and that beds would be more concealed in relation to human-derived risk. Although human densities in Scandinavia are the lowest within bear ranges in Western Europe, we found an effect of human activity; bears chose beds with higher horizontal and canopy cover during the day (0700–1900 hours), especially when resting closer to human settlements, than at night (2200–0600 hours). In summer/fall (the berry season), with more intensive and dispersed human activity, including hunting, bears rested further from human settlements during the day than in spring (pre-berry season). Additionally, day beds in the summer/fall were the most concealed. Large carnivores often avoid humans at a landscape scale, but total avoidance in human-dominated areas is not possible. Apparently, bears adjust their behavior to avoid human encounters, which resembles the way prey avoid their predators. Bears responded to fine-scale variations in human-derived risk, both on a seasonal and a daily basis.

The effects of human disturbance spread over virtually all ecosystems and ecological communities on Earth. In this review, we focus on the effects of human disturbance on terrestrial apex predators. We summarize their ecological role in nature and how they respond to different sources of human disturbance. Apex predators control their prey and smaller predators numerically and via behavioral changes to avoid predation risk, which in turn can affect lower trophic levels. Crucially, reducing population numbers and triggering behavioral responses are also the effects that human disturbance causes to apex predators, which may in turn influence their ecological role. Some populations continue to be at the brink of extinction, but others are partially recovering former ranges, via natural recolonization and through reintroductions. Carnivore recovery is both good news for conservation and a challenge for management, particularly when recovery occurs in human-dominated landscapes. Therefore, we conclude by discussing several management considerations that, adapted to local contexts, may favor the recovery of apex predator populations and their ecological functions in nature.

Human persecution and habitat loss have endangered large carnivore populations worldwide, but some are recovering, exacerbating old conflicts. Carnivores can injure and kill people; the most dramatic form of wildlife-human conflict. In Scandinavia, the brown bear (Ursus arctos) population increased from ~500 bears in 1977 to ~3300 in 2008, with an increase in injuries, fatalities, and public fear of bear attacks. We reviewed media coverage and interviewed victims to explore how bear population trends, hunter education, and other factors may have influenced the number of injuries and fatalities in Scandinavia from 1977 to 2016. We found 42 incidents with 42 injuries and 2 fatalities; 42 were adult men, one was an adult woman conducting forestry work, and one was a boy skiing off-piste. Thirty-three adult men were hunting bears, moose, or small game, often with a hunting dog, and 26 had shot at the bear at 8±11 m before injury. Eleven nonhunters were conducting forestry work, inspecting a hunting area, picking berries, tending livestock, hiking, harassing a denned bear, and one person was killed outside his house at night. Eight of the 11 incidents of nonhunters involved female bears with cubs; three of these family groups were in dens and two were on carcasses. The annual number of hunters injured/killed was mostly influenced by the increase in the bear population size. The pattern was similar regarding injuries/fatalities to other outdoor users, but the relation with the bear population size was weaker than for hunters, and the null model was equally supported. Bear physiology at denning may make encounters with bears more risky in the fall, when bears show prehibernation behavior. Awareness and education efforts, especially among hunters, seem important to ensure human safety. Recreationists and forestry workers should avoid dense vegetation or make noise to warn bears of their presence.

One of the classic approaches in environmental economics is the environmental Kuznets curve, which predicts that when a national economy grows from low to medium levels, threats to biodiversity conservation increase, but they decrease when the economy moves from medium to high. We evaluated this approach by examining how population densities of the brown bear (Ursus arctos), gray wolf (Canis lupus), and Eurasian lynx (Lynx lynx) were related to the national economy in 24 European countries. We used forest proportions, the existence of a compensation system, and country group (former socialist countries, Nordic countries, other countries) as covariates in a linear model with the first- and the second-order polynomial terms of per capita gross domestic product (GDP). Country group was treated as a random factor, but remained insignificant and was ignored. All models concerning brown bear and wolf provided evidence that population densities decreased with increasing GDP, but densities of lynx were virtually independent of GDP. Models for the wolf explained >80% of the variation in densities, without a difference between the models with all independent variables and the model with only GDP. For the bear, the model with GDP alone accounted for 10%, and all three variables 33%, of the variation in densities. Wolves exhibit a higher capacity for dispersal and reproduction than bear or lynx, but still exists at the lowest densities in wealthy European countries. We are aware that several other factors, not available for our models, influenced large carnivore densities. Based on the pronounced differences among large carnivore species in their countrywide relationships between densities and GDP, and a strikingly high relationship for the gray wolf, we suggest that our results reflected differences in political history and public acceptance of these species among countries. The compensation paid for the damages caused by the carnivores is not a key to higher carnivore densities, but might be necessity for the presence of large carnivores to be accepted in countries with high GDP.