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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.
More info: Hertel A., Steyaert S.M.J.G., Zedrosser A., Mysterud A., Lodberg-Holm H., Wathne-Gelink H., Kindberg J., Swenson J.E. 2016. Bears and berries: species-specific selective foraging on a patchily distributed food resource in a human-altered landscape. Behavioral Ecology and Sociobiology 03/2016; DOI: 10.1007/s00265-016-2106-2
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.
More info: Ziolkowska E., Ostapowicz K., Radeloff V., Kuemmerle T., Sergiel A., Zwijacz-Kozica T., Zięba F., Śmietana W., Selva N. 2016. Assessing differences in connectivity based on habitat versus movement models for brown bears in the Carpathians. Landscape Ecology 03/2016; DOI: 10.1007/s10980-016-0368-8
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.
More information: Evans, A. L., N. J. Singh, A. Friebe, J. M. Arnemo, T. G. Laske, O. Fröbert, J. E. Swenson, and S. Blanc. 2016. Drivers of hibernation in the brown bear. Frontiers in Zoology 13:7, DOI: 10.1186/s12983-016-0140-6.
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.
More information: Stenset, N. E., P. N. Lutnæs, V. Bjarnadóttir, B. Dahle, K. H. Fossum, P. Jigsved, T. Johansen, W. Neumann, O. Opseth, O. Rønning, S. M. J. G. Steyaert, A. Zedrosser, S. Brunberg, and J. E. Swenson. 2016. Seasonal and annual variation in the diet of brown bears (Ursus arctos) in the boreal forest of southcentral Sweden. Wildlife Biology 22(3):107-1122(3):107-116.
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.
For more information:
Støen O.-E., Ordiz A., Evans A.L., Laske T.G., Kindberg J., Fröbert O., Swenson J.E., Arnemo J.M. 2015. Physiological evidence for a human-induced landscape of fear in brown bears (Ursus arctos). Physiology and Behavior 152 (2015) 244-248.
Dr. Marc Cattet is a research associate with the Canadian Wildlife Health Cooperative (CWHC) and an adjunct professor in the Department of Veterinary Pathology at the Western College of Veterinary Medicine in Saskatoon, Canada. He is currently engaged in major studies of environmental health assessment in grizzly bear landscape ecology, of new measures of long-term stress in vertebrates in the context of environmental monitoring, health and impact assessment, and on chemical immobilization and handling of wild animals (https://www.usask.ca/wcvm/wcvm_people/profiles/Cattet_Marc.php). We cooperate within GLOBE project on disentangling brown bear stress ecology within work package 3: “Climate and human-mediated effects on brown bear stress ecology“. He paid us a weeklong visit, during which he gave a lecture on wildlife health issues and worked on our ongoing studies of bear stress
We recommend to all interested in the research on the brown bears a movie from the series "Dancing with Nature" realised by the TVP http://www.tanczacyznatura.tvp.pl/21488540/odcinek-5-wsluchani-w-niedzwiedzia. Nuria Selva, Tomasz Zwijacz-Kozica and Filip Zieba talk about what and how we study in, among others, the GLOBE project.
"This time "Dancing with Nature" are looking for signs of bears. When hiking in the Tatra you need to keep your eyes wide open. What matters are the scratches on the tree, bones scattered among pines, large animal droppings on a wild meadow, hair left on husky trunk, but also all traces around Zakopane garbage dams and surrounded shelters. At all these diligently look Assoc. prof. Nuria Selva, a bear researcher and Filip Zieba, an employee of the Tatra National Park. They trace Tatra bears with aerial telemetry. When "Dancing with Nature" move into the forest, they find out that bears are often just around the corner, even in the middle of the day, though it can not be seen and heard."
We highly recommend it!
Big game hunting is providing scavengers with large amounts of carrion every year and, thus, affecting ecosystems and animal communities. In Europe, hunters discard about 100 million tonnes of carcasses and remains each year. This paper reviews the vertebrate species consuming carrion derived from this activity across different ecosystems in the world. As much as 79 species use this human-provided food; 19% of which are globally threatened. Fifteen apex predators, including the brown bear, were recorded scavenging on hunting remains. Their consumption is dominated by generalists, like bears, particularly in areas where vultures and specialist apex predators are rare or absent. By feeding on carrion, scavengers support key ecosystem services, such as accelerating nutrient recycling or limiting disease spreading. However, in degraded ecosystems with low diversity of scavenger, these services can be at risk.
For more information:
Mateo-Tomas P., Olea P.P., Moleon M., Vicente J., Botella F., Selva N., Vinuela J., Sanchez-Zapata J.A. 2015. From regional to global patterns in vertebrate scavenger communities subsidized by big game hunting. Diversity and Distribution, 21 (8): 913–924.