scholarly journals Long-Term Safety of Intraperitoneal Radio Transmitter Implants in Brown Bears (Ursus arctos)

2018 ◽  
Vol 5 ◽  
Author(s):  
Jon M. Arnemo ◽  
Bjørnar Ytrehus ◽  
Knut Madslien ◽  
Jonas Malmsten ◽  
Sven Brunberg ◽  
...  
Keyword(s):  
Ursus Arctos ◽  
Brown Bears ◽  
Radio Transmitter

scholarly journals Can hunting data be used to estimate unbiased population parameters? A case study on brown bears

2016 ◽  
Vol 12 (6) ◽  
pp. 20160197 ◽  
Author(s):  
Martin Leclerc ◽  
Joanie Van de Walle ◽  
Andreas Zedrosser ◽  
Jon E. Swenson ◽  
Fanie Pelletier
Keyword(s):  
Adult Female ◽  
Ursus Arctos ◽  
Temporal Trends ◽  
Legal Protection ◽  
Brown Bears ◽  
Adult Females ◽  
Fundamental Research ◽  
Management And Conservation

Quantifying temporal changes in harvested populations is critical for applied and fundamental research. Unbiased data are required to detect true changes in phenotypic distribution or population size. Because of the difficulty of collecting detailed individual data from wild populations, data from hunting records are often used. Hunting records, however, may not represent a random sample of a population. We aimed to detect and quantify potential bias in hunting records. We compared data from a long-term monitoring project with hunting records of brown bears ( Ursus arctos ) in Sweden and investigated temporal trends (1996–2013) in the ratio of yearlings to adult females, yearling mass and adult female mass. 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. Although hunting data can be reliable to approximate population abundance in some circumstances, hunting data can represent a biased sample of a population and should be used with caution in management and conservation decisions.

scholarly journals Brown bear communication hubs: patterns and correlates of tree rubbing and pedal marking at a long-term marking site

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e10447
Author(s):  
Eloy Revilla ◽  
Damián Ramos Fernández ◽  
Alberto Fernández-Gil ◽  
Agnieszka Sergiel ◽  
Nuria Selva ◽  
...  
Keyword(s):  
Chemical Communication ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Population Level ◽  
Adult Males ◽  
Communication Behaviors ◽  
Brown Bears ◽  
Low Frequencies ◽  
A Site

Chemical communication is important for many species of mammals. Male brown bears, Ursus arctos, mark trees with a secretion from glands located on their back. The recent discovery of pedal glands and pedal-marking at a site used for tree-rubbing led us to hypothesize that both types of marking form part of a more complex communication system. We describe the patterns of chemical communication used by different age and sex classes, including differences in the roles of these classes as information providers or receivers over four years at a long-term marking site. Using video recordings from a camera trap, we registered a total of 285 bear-visits and 419 behavioral events associated with chemical communication. Bears visited the site more frequently during the mating season, during which communication behaviors were more frequent. A typical visit by male bears consisted of sniffing the depressions where animals pedal mark, performing pedal-marking, sniffing the tree, and, finally, rubbing against the trunk of the tree. Adult males performed most pedal- and tree-marking (95% and 66% of the cases, respectively). Males pedal-marked and tree-rubbed in 81% and 48% of their visits and sniffed the pedal marks and the tree in 23% and 59% of visits, respectively. Adult females never pedal marked, and juveniles did so at very low frequencies. Females rubbed against the tree in just 9% of their visits; they sniffed the tree and the pedal marks in 51% and 21% of their visits, respectively. All sex and age classes performed pedal- and tree-sniffing. There were significant associations between behaviors indicating that different behaviors tended to occur during the same visit and were more likely if another individual had recently visited. These associations leading to repeated marking of the site can promote the establishment of long-term marking sites. Marking sites defined by trees and the trails leading to them seem to act as communication hubs that brown bears use to share and obtain important information at population level.

scholarly journals Competition between apex predators? Brown bears decrease wolf kill rate on two continents

2017 ◽  
Vol 284 (1848) ◽  
pp. 20162368 ◽  
Author(s):  
Aimee Tallian ◽  
Andrés Ordiz ◽  
Matthew C. Metz ◽  
Cyril Milleret ◽  
Camilla Wikenros ◽  
...  
Keyword(s):  
Opposite Effect ◽  
Ursus Arctos ◽  
Brown Bear ◽  
Trophic Levels ◽  
Apex Predators ◽  
Brown Bears ◽  
Common Assumption ◽  
The Common ◽  
Kill Rate

Trophic interactions are a fundamental topic in ecology, but we know little about how competition between apex predators affects predation, the mechanism driving top-down forcing in ecosystems. We used long-term datasets from Scandinavia (Europe) and Yellowstone National Park (North America) to evaluate how grey wolf ( Canis lupus ) kill rate was affected by a sympatric apex predator, the brown bear ( Ursus arctos ). We used kill interval (i.e. the number of days between consecutive ungulate kills) as a proxy of kill rate. Although brown bears can monopolize wolf kills, we found no support in either study system for the common assumption that they cause wolves to kill more often. On the contrary, our results showed the opposite effect. In Scandinavia, wolf packs sympatric with brown bears killed less often than allopatric packs during both spring (after bear den emergence) and summer. Similarly, the presence of bears at wolf-killed ungulates was associated with wolves killing less often during summer in Yellowstone. The consistency in results between the two systems suggests that brown bear presence actually reduces wolf kill rate. Our results suggest that the influence of predation on lower trophic levels may depend on the composition of predator communities.

scholarly journals Quantifying long-term stress in brown bears with the hair cortisol concentration: a biomarker that may be confounded by rapid changes in response to capture and handling

2014 ◽  
Vol 2 (1) ◽  
pp. cou026-cou026 ◽  
Author(s):  
M. Cattet ◽  
B. J. Macbeth ◽  
D. M. Janz ◽  
A. Zedrosser ◽  
J. E. Swenson ◽  
...  
Keyword(s):  
Cortisol Concentration ◽  
Hair Cortisol ◽  
Brown Bears ◽  
Rapid Changes

Molecular identification of Taenia spp. in wolves (Canis lupus), brown bears (Ursus arctos) and cervids from North Europe and Alaska

2011 ◽  
Vol 60 (3) ◽  
pp. 289-295 ◽  
Author(s):  
Antti Lavikainen ◽  
Sauli Laaksonen ◽  
Kimberlee Beckmen ◽  
Antti Oksanen ◽  
Marja Isomursu ◽  
...  
Keyword(s):  
Molecular Identification ◽  
Canis Lupus ◽  
Ursus Arctos ◽  
Brown Bears

Sexing free-ranging brown bears Ursus arctos using hairs found in the field

1993 ◽  
Vol 2 (6) ◽  
pp. 399-403 ◽  
Author(s):  
P. TABERLET ◽  
H. MATTOCK ◽  
C. DUBOIS-PAGANON ◽  
J. BOUVET
Keyword(s):  
Ursus Arctos ◽  
Brown Bears ◽  
Free Ranging
Sign in / Sign up

Export Citation Format

Share Document