Selecting the right habitat in a risky landscape is crucial for an individual's survival and reproduction. In predator–prey systems, prey often can anticipate the habitat use of their main predator and may use protective associates (i.e. typically an apex predator) as shields against predation. Authors assessed the relationship between offspring survival and habitat selection, as well as the use of protective associates, in a system in which sexually selected infanticide, rather than interspecific predation, affects offspring survival. Researchers used the Scandinavian brown bear population living in a human-dominated landscape as a model system. Bears, especially adult males, generally avoid humans in our study system. Authors analyzed data gathered between 2005 and 2012 from GPS-collared brown bear mothers which cubs survived and not survived during the mating seasons. Habitat selection was a predictor of litter survival. Successful mothers were more likely to use humans as protective associates, whereas unsuccessful mothers avoided humans.
Scandinavian Brown Bear Research Project team published a new paper based on their long term studies, partially realized also within the GLOBE project. Authors underline that quantifying temporal changes in harvested populations is critical for applied and fundamental research. Because of the difficulty of collecting detailed individual data from wild populations, data from hunting records are often used. Yet, the hunting records not always represent a random sample of a population, so the authors aimed to detect and quantify potential bias in hunting records. They compared data gathered between 1996 and 2013 in a long-term monitoring project with the hunting records of brown bears (Ursus arctos) in Sweden. They checked the ratio of yearlings to adult females, yearling mass and adult female mass and concluded that the data from hunting records underestimated the decline in yearling and adult female mass over time, most likely owing to the legal protection of family groups from hunting, but reflected changes in the ratio of yearlings to adult females more reliably. Authors claim that although hunting data can be reliable to approximate population abundance, but they should be used with caution in management and conservation decisions, as they can represent a biased sample of a population.
Wildlife damage to human properties is an important component of human-wildlife conflicts worldwide. Which populations are more “conflictive” and why are unresolved questions that need to be dealt at broad scales. The article authored by Carlos Bautista with a team of 23 European brown bear researchers “Patterns and correlates of claims for brown bear damage on a continental scale”, published in the Journal of Applied Ecology (http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12708/full), is the first study that tries to disentangle these questions on a continental scale by comparing different management units. Authors analyzed 18,300 compensated claims for damage caused by brown bears across 18 European regions with different socio-ecological conditions. On average, over 3200 claims of bear damage were annually compensated; 70% of them in 4 of the 18 studied regions, and 59% due to livestock losses. Authors found that compensation schemes, management practices like supplementary feeding, and agricultural cover, influenced the number of claims for bear damage,while bear abundance did not.
Link to the article: http://onlinelibrary.wiley.com/doi/10.1111/1365-2664.12708/full
Fig. 1. Bear track stamped on the frame of beeswax from the damaged hive of apiaries in Slovenia (photo by Miha Krofel)
Iwo, the bear who last spring became famous for an extraordinary journey from the Tatra to Hungary and then through the Polish Bieszczady Mountains further into the Ukrainian Eastern Carpathians, happily survived the winter in the Gorgany range. His telemetry collar completed its two-year mission and automatically opened.
When animals are faced with extraordinary energy consuming events, like hibernation, finding abundant, energy-rich food resources becomes particularly important. The profitability of food resources can vary spatially, depending on occurrence, quality, and local abundance. Authors used the brown bear as a model species to quantify selective foraging on berries in different habitats during hyperphagia in autumn prior to hibernation. In their research they stated that compared to random locations, bears selected locations with a higher probability of occurrence and higher abundance of bilberries (Vaccinium myrtillus) and a higher probability of occurrence, but not abundance, of lingonberries (Vaccinium vitis-idaea). Brown bears in Sweden inhabit a landscape shaped by forestry practices. As forestry practices had a large effect on berry occurrence and abundance, brown bears responded by foraging most selectively in mature forests and on clearcuts. Authors conclude that bears successfully navigated in this heavily human-shaped landscape by selectively foraging in high-return habitats for bilberries, but did not compensate for the decline in bilberries by eating more lingonberries.
Connectivity assessments typically rely on resistance surfaces derived from habitat models, assuming that higher-quality habitat facilitates movement. This assumption remains largely untested though, and it is unlikely that the same environmental factors determine both animal movements and habitat selection, potentially biasing connectivity assessments. Our findings highlighted that connectivity assessments should be based on movement information if available, rather than generic habitat models. However, the parameterization of movement models is important, because the type of movement events considered and the sampling method of environmental covariates, can greatly affect connectivity assessments, and hence the predicted corridors.
Hibernation has been a key area of research for several decades, essentially in small mammals in the laboratory, yet we know very little about what triggers or ends it in the wild. Do climatic factors, an internal biological clock, or physiological processes dominate? Using state-of-the-art tracking and monitoring technology on fourteen free-ranging brown bears over three winters, researchers recorded movement, heart rate, heart rate variability, body temperature, physical activity, ambient temperature, and snow depth to identify the drivers of the start and end of hibernation. Studies revealed that brown bear hibernation was initiated primarily by environmental cues, but terminated by physiological cues.
Authors analysed 527 fecal samples of the brown bears inhabiting boreal forest of southcentral Sweden, collected in 1994-1996 and 2000-2001. They described seasonal and annual variation in the diet of brown bears, they also studied berry availability by inventorying 308 random plots. Authors suggest that the effects of predicted future climatic change might have severe effects on the availability of the berries, which is the only important food available for fat acquisition prior to hibernation.
The GLOBE project team met again for the the fourth working meeting, this time in Zakopane (Poland) on 8-10 December. We had the opportunity to meet in the hospitable Center for Research and Conservation of Mountain Plants with Mountain Botanical Garden in Zakopane, where for three full days researchers and collaborators had another opportunity to meet and discuss next steps of the project, the results achived by the time on the issues related to the stress, diet analyses based on stable isotopes, as well as modelling of climate and human-bear relations. The meeting in Zakopane was attended by both researchers responsible for implementing specific research tasks and all the young researchers recruited for a post-doc in the GLOBE project. And again, we had a productive and inspiring time.
photo: GLOBE project
Authors present a study on the human-induced landscape of fear in brown bears, which is an extremely important issue as human persecution is a major cause of mortality for large carnivores. Large carnivores avoid humans, but may use human-dominated landscapes by being nocturnal and elusive. Behavioral studies indicate that certain ecological systems are “landscapes of fear”. Because behavior and physiology are closely interrelated, physiological assessments may provide insight into the behavioral response of large carnivores to human activity.