The cost of research: Lasting effects of capture, surgery and muscle biopsy on brown bear () movement and physiology.

Animal models are a key component of translational medicine, helping transfer scientific findings into practical applications for human health. A fundamental principle of research ethics involves weighing the benefits of the research to society against the burden imposed on the animals used for scientific purposes. The utilisation of wild animals for research requires evaluation of the effects of capture and invasive sampling.

Body mass is associated with hibernation length, body temperature, and heart rate in free-ranging brown bears.

Background: Despite centuries of research, debate remains on the scaling of metabolic rate to mass especially for intraspecific cases. The high variation of body mass within brown bears presents a unique opportunity to study the intraspecific effects of body mass on physiological variables. The amplitude of metabolic rate reduction in hibernators is dependent on body mass of the species.

Immobility-associated thromboprotection is conserved across mammalian species from bear to human.

Venous thromboembolism (VTE) comprising deep venous thrombosis and pulmonary embolism is a major cause of morbidity and mortality. Short-term immobility-related conditions are a major risk factor for the development of VTE. Paradoxically, long-term immobilized free-ranging hibernating brown bears and paralyzed spinal cord injury (SCI) patients are protected from VTE.

Seasonality in Biological Rhythms in Scandinavian brown Bears.

Biological rhythms, such as rhythms in activity and body temperature, are usually highly synchronized and entrained by environmental conditions, such as photoperiod. However, how the expression of these rhythms changes during hibernation, when the perception of environmental cues is limited, has not yet been fully understood for all hibernators, especially in the wild. The brown bear () in Scandinavia lives in a highly seasonal environment and adapts to harsh winter conditions by exhibiting hibernation, characterized by reduced metabolism and activity.

Room without a view-Den excavation in relation to body size in brown bears.

Hibernation is an adaptive strategy to survive harsh winter conditions and food shortage. The use of well-insulated winter dens helps animals minimize energy loss during hibernation. Brown bears () commonly use excavated dens for hibernation.

Regulated hunting re-shapes the life history of brown bears.

Management of large carnivores is among the most controversial topics in natural resource administration. Regulated hunting is a centrepiece of many carnivore management programmes and, although a number of hunting effects on population dynamics, body-size distributions and life history in other wildlife have been observed, its effects on life history and demography of large carnivores remain poorly documented. We report results from a 30-year study of brown bears (Ursus arctos) analysed using an integrated hierarchical approach.

Physiological reactions to capture in hibernating brown bears.

Human disturbance can affect animal life history and even population dynamics. However, the consequences of these disturbances are difficult to measure. This is especially true for hibernating animals, which are highly vulnerable to disturbance, because hibernation is a process of major physiological changes, involving conservation of energy during a resource-depleted time of year.

Den Entry Behavior in Scandinavian Brown Bears: Implications for Preventing Human Injuries.

Encounters between Scandinavian brown bears () and humans that result in human injuries and fatalities typically coincide with den entry in October and November, and commonly occur near a den. Our aim was to determine when bears arrive at their dens, identify potential predictors of this event, document behavior and activity associated with this period, and attempt to explain the increased risk of bear-caused human injuries in this period. We analyzed global positioning system (GPS) location and activity data from brown bears in south-central Sweden, using generalized linear mixed models, statistical process control, and activity analyses.

Factors affecting date of implantation, parturition, and den entry estimated from activity and body temperature in free-ranging brown bears.

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.

Metabolic changes in summer active and anuric hibernating free-ranging brown bears (Ursus arctos).

The brown bear (Ursus arctos) hibernates for 5 to 6 months each winter and during this time ingests no food or water and remains anuric and inactive. Despite these extreme conditions, bears do not develop azotemia and preserve their muscle and bone strength. To date most renal studies have been limited to small numbers of bears, often in captive environments.