ArticleFrontiers in zoology2016
Drivers of hibernation in the brown bear.
Article in Frontiers in zoology, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 65 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
65 citing papers in PubMed, 179 citations in OpenAlex.
- Trial
- Active bile acid metabolism could contribute to muscle preservation in hibernating bears via the TGR5 pathway.Pflugers Archiv : European journal of physiology · 2026Article
- The Preservation of Muscle Mitochondrial Machinery During Hypometabolic Hibernation in Scandinavian Brown Bears (Ursus arctos).Acta physiologica (Oxford, England) · 2026Article
- Drosophila melanogaster larvae generate force to counteract external mechanical pressure.The Journal of experimental biology · 2026Article
- Rivers constrain female but not male dispersal and genetic structure in brown bears.Scientific reports · 2026Article
- An Energetic Tradeoff Best Explains Parturition Timing in Grizzly Bears.Ecology and evolution · 2026Article
- Article
- Identifying Conservation and Conflict Zones for Tibetan Brown Bears Under Climate Change Through Integrated Habitat and Prey Modeling on the Qinghai-Tibet Plateau.Ecology and evolution · 2026Article
- One Species Hibernates Shorter, the Other Longer: Rapid but Opposing Responses to Warming Climate in Two Sympatric Bat Species.Global change biology · 2025Article
- Seasonal variations in ventricular repolarization and tachyarrhythmias in hibernating brown bears (Ursus arctos arctos).Physiological reports · 2025Article
- Unpredictable disturbance and its effects on activity behavior and lifespan in Drosophila melanogaster.Biology open · 2025Article
- Acceleration Data Reveal Behavioural Responses to Hunting Risk in Scandinavian Brown Bears.Ecology and evolution · 2025Article
- Climate-Driven Range Shifts and Conservation Challenges for Brown Bears in Türkiye.Ecology and evolution · 2025Article
- Behavioral adaptation to seasonal resource scarcity by Caribou (Journal of mammalogy · 2025Article
- Reduced ATP turnover during hibernation in relaxed skeletal muscle.Nature communications · 2025Article
- Microclimate of Brown Bear (Animals : an open access journal from MDPI · 2024Article
- Sensory integration of food and population density during the diapause exit decision involves insulin-like signaling inProceedings of the National Academy of Sciences of the United States of America · 2024Article
- Optimal sampling interval for characterisation of the circadian rhythm of body temperature in homeothermic animals using periodogram and cosinor analysis.Ecology and evolution · 2024Article
- Sensory integration of food availability and population density during the diapause exit decision involves insulin-like signaling inbioRxiv : the preprint server for biology · 2024Article
- Polar bear energetic and behavioral strategies on land with implications for surviving the ice-free period.Nature communications · 2024Article
5 more citing papers are in PubMed but not listed here.
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 6 institutions in 5 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundHibernation 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, we recorded movement, heart rate (HR), heart rate variability (HRV), body temperature (Tb), physical activity, ambient temperature (TA), and snow depth to identify the drivers of the start and end of hibernation. We used behavioral change point analyses to estimate the start and end of hibernation and convergent cross mapping to identify the causal interactions between the ecological and physiological variables over time.
resultsTo our knowledge, we have built the first chronology of both ecological and physiological events from before the start to the end of hibernation in the field. Activity, HR, and Tb started to drop slowly several weeks before den entry. Bears entered the den when snow arrived and when ambient temperature reached 0 °C. HRV, taken as a proxy of sympathetic nervous system activity, dropped dramatically once the bear entered the den. This indirectly suggests that denning is tightly coupled to metabolic suppression. During arousal, the unexpected early rise in Tb (two months before den exit) was driven by TA, but was independent of HRV. The difference between Tb and TA decreased gradually suggesting that bears were not thermoconforming. HRV increased only three weeks before exit, indicating that late activation of the sympathetic nervous system likely finalized restoration of euthermic metabolism. Interestingly, it was not until TA reached the presumed lower critical temperature, likely indicating that the bears were seeking thermoneutrality, that they exited the den.
conclusionsWe conclude that brown bear hibernation was initiated primarily by environmental cues, but terminated by physiological cues.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.