scholarly journals Intraovarian Immunolocalization of Steroidogenic Enzymes in a Hokkaido Brown Bear, Ursus arctos yesoensis during the Mating Season.

1996 ◽  
Vol 58 (8) ◽  
pp. 787-790 ◽  
Author(s):  
Hiroshi ARAKI ◽  
Toshio TSUBOTA ◽  
Naoko MAEDA ◽  
Nobuhiro HARADA ◽  
Shiro KOMINAMI ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Brown Bear ◽  
Mating Season ◽  
Steroidogenic Enzymes

Immunolocalization of Steroidogenic Enzymes, P450scc, 3β-HSD, P450c17, and P450arom in the Hokkaido Brown Bear (Ursus arctos yesoensis) Testis

1993 ◽  
Vol 92 (3) ◽  
pp. 439-444 ◽  
Author(s):  
Toshio Tsubota ◽  
Hiroaki Nitta ◽  
Yoshio Osawa ◽  
J.Ian Mason ◽  
Isao Kita ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Brown Bear ◽  
Steroidogenic Enzymes

scholarly journals Activity patterns in the reintroduced Pyrenean brown bear population

2020 ◽  
Vol 65 (3) ◽  
pp. 435-444
Author(s):  
Aida Parres ◽  
Santiago Palazón ◽  
Ivan Afonso ◽  
Pierre-Yves Quenette ◽  
Antoni Batet ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Activity Patterns ◽  
Age Groups ◽  
Brown Bear ◽  
Adult Males ◽  
Mating Season ◽  
Intraspecific Interactions ◽  
Management Interventions ◽  
Different Types ◽  
Time Selection

Abstract Mammals usually adjust behavioral patterns when exposed to disturbances. Elusiveness and low-risk time selection may reduce their stress in periods of highest risk. In Europe, brown bears (Ursus arctos) coexist with humans in densely populated and modified landscapes and, consequently, are exposed to human-caused disturbances during the daytime hours. Furthermore, intraspecific interactions might also influence their behavioral responses, especially during the mating season. Activity patterns of several large carnivores have been thoroughly studied; however, research is scarce for relocated populations. Here, we report the activity patterns in the reintroduced brown bear population in the Pyrenees. We expected the bears to reduce their activity depending on the type and level of disturbances. We analyzed individual behavior of both sexes (males, solitary females, and females with offspring) and age groups (adults and subadults) using camera-trap surveys under different types of intraspecific and anthropogenic disturbances. In general, bears were more active during the night (2200–0600 h) and avoided peaks of human activity (1000–1800 h). Furthermore, with the increasing nocturnal disturbance of adult males during the mating season, females with offspring and subadults were more active during daylight. This suggests that vulnerable individuals showed high tolerance for human presence. These results contribute to improve our knowledge of how a threatened and relocated bear population behaves in a human-modified landscape of southern Europe. Further research on this population will be crucial to establish optimal management interventions during translocations, and the prevention of human-bear encounters and conflicts.

scholarly journals Infanticide as a male reproductive strategy has a nutritive risk effect in brown bears

2013 ◽  
Vol 9 (5) ◽  
pp. 20130624 ◽  
Author(s):  
S. M. J. G. Steyaert ◽  
C. Reusch ◽  
S. Brunberg ◽  
J. E. Swenson ◽  
K. Hackländer ◽  
...  
Keyword(s):  
Resource Selection ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Mating Season ◽  
Predator Prey ◽  
Risk Effects ◽  
Risk Effect ◽  
Risk Period ◽  
Common Strategy ◽  
Spatio Temporal

Behavioural strategies to reduce predation risk can incur costs, which are often referred to as risk effects. A common strategy to avoid predation is spatio-temporal avoidance of predators, in which prey typically trade optimal resources for safety. Analogous with predator–prey theory, risk effects should also arise in species with sexually selected infanticide (SSI), in which females with dependent offspring avoid infanticidal males. SSI can be common in brown bear ( Ursus arctos ) populations and explains spatio-temporal segregation among reproductive classes. Here, we show that in a population with SSI, females with cubs-of-the-year had lower quality diets than conspecifics during the SSI high-risk period, the mating season. After the mating season, their diets were of similar quality to diets of their conspecifics. Our results suggest a nutritive risk effect of SSI, in which females with cubs-of-the-year alter their resource selection and trade optimal resources for offspring safety. Such risk effects can add to female costs of reproduction and may be widespread among species with SSI.

Brown Bear (Ursus arctos) Habitat Use and Food Resources on Elmendorf Air Force Base, Alaska

2007 ◽  
Author(s):  
Sean D. Farley ◽  
Herman Griese ◽  
Rick Sinnott ◽  
Jessica Coltrane ◽  
Chris Garner ◽  
...  
Keyword(s):  
Habitat Use ◽  
Air Force ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Food Resources ◽  
Air Force Base

scholarly journals Using Landscape Change Analysis and Stakeholder Perspective to Identify Driving Forces of Human–Wildlife Interactions

Land ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 146
Author(s):  
Mihai Mustățea ◽  
Ileana Pătru-Stupariu
Keyword(s):  
Landscape Change ◽  
Ursus Arctos ◽  
Driving Forces ◽  
Brown Bear ◽  
Mountain Range ◽  
Change Analysis ◽  
Local Stakeholders ◽  
Stakeholder Perspective ◽  
Forested Ecosystems ◽  
Forest Habitats

Human–wildlife interactions (HWI) were frequent in the post-socialist period in the mountain range of Central European countries where forest habitats suffered transitions into built-up areas. Such is the case of the Upper Prahova Valley from Romania. In our study, we hypothesized that the increasing number of HWI after 1990 could be a potential consequence of woodland loss. The goal of our study was to analyse the effects of landscape changes on HWI. The study consists of the next steps: (i) applying 450 questionnaires to local stakeholders (both citizens and tourists) in order to collect data regarding HWI temporal occurrences and potential triggering factors; (ii) investigating the relation between the two variables through the Canonical Correspondence Analysis (CCA); (iii) modelling the landscape spatial changes between 1990 and 2018 for identifying areas with forest loss; (iv) overlapping the distribution of both the households affected by HWI and areas with loss of forested ecosystems. The local stakeholders indicate that the problematic species are the brown bear (Ursus arctos), the wild boar (Sus scrofa), the red fox (Vulpes vulpes) and the grey wolf (Canis lupus). The number of animal–human interactions recorded an upward trend between 1990 and 2018, and the most significant driving factors were the regulation of hunting practices, the loss of habitats, and artificial feeding. The landscape change analysis reveals that between 1990 and 2018, the forest habitats were replaced by built-up areas primarily on the outskirts of settlements, these areas coinciding with frequent HWI. The results are valid for both forest ecosystems conservation in the region, wildlife management, and human infrastructures durable spatial planning.

Plasma ochratoxin A in the European brown bear ( Ursus arctos L.) from Croatia

2017 ◽  
Vol 280 ◽  
pp. S198
Author(s):  
Dubravka Rašić ◽  
Maja Lazarus ◽  
Đuro Huber ◽  
Slaven Reljić ◽  
Maja Peraica
Keyword(s):  
Ochratoxin A ◽  
Ursus Arctos ◽  
Brown Bear

scholarly journals Fallot's Tetralogy in a European Brown Bear (Ursus arctos)

2005 ◽  
Vol 41 (4) ◽  
pp. 825-828 ◽  
Author(s):  
Erik Ågren ◽  
Arne Söderberg ◽  
Torsten Mörner
Keyword(s):  
Ursus Arctos ◽  
Brown Bear ◽  
Fallot's Tetralogy ◽  
Fallot’S Tetralogy

scholarly journals Phenological synchronization disrupts trophic interactions between Kodiak brown bears and salmon

2017 ◽  
Vol 114 (39) ◽  
pp. 10432-10437 ◽  
Author(s):  
William W. Deacy ◽  
Jonathan B. Armstrong ◽  
William B. Leacock ◽  
Charles T. Robbins ◽  
David D. Gustine ◽  
...  
Keyword(s):  
Sockeye Salmon ◽  
Ursus Arctos ◽  
Large Body ◽  
Brown Bear ◽  
Switching Behavior ◽  
Air Temperatures ◽  
Trophic Resources ◽  
Energy Flows ◽  
Strength Of Interaction ◽  
Prey Interaction

Climate change is altering the seasonal timing of life cycle events in organisms across the planet, but the magnitude of change often varies among taxa [Thackeray SJ, et al. (2016) Nature 535:241–245]. This can cause the temporal relationships among species to change, altering the strength of interaction. A large body of work has explored what happens when coevolved species shift out of sync, but virtually no studies have documented the effects of climate-induced synchronization, which could remove temporal barriers between species and create novel interactions. We explored how a predator, the Kodiak brown bear (Ursus arctos middendorffi), responded to asymmetric phenological shifts between its primary trophic resources, sockeye salmon (Oncorhynchus nerka) and red elderberry (Sambucus racemosa). In years with anomalously high spring air temperatures, elderberry fruited several weeks earlier and became available during the period when salmon spawned in tributary streams. Bears departed salmon spawning streams, where they typically kill 25–75% of the salmon [Quinn TP, Cunningham CJ, Wirsing AJ (2016) Oecologia 183:415–429], to forage on berries on adjacent hillsides. This prey switching behavior attenuated an iconic predator–prey interaction and likely altered the many ecological functions that result from bears foraging on salmon [Helfield JM, Naiman RJ (2006) Ecosystems 9:167–180]. We document how climate-induced shifts in resource phenology can alter food webs through a mechanism other than trophic mismatch. The current emphasis on singular consumer-resource interactions fails to capture how climate-altered phenologies reschedule resource availability and alter how energy flows through ecosystems.

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