Paths of coexistence: Spatially predicting acceptance of grizzly bears along key movement corridors

Mama Grizzly and the polar bears.

A recent paper on the matrilineal population history of two sister species, Ursus maritimus (polar bears) and Ursus arctos (brown bears), based on mtDNA sequence analysis, reveals a comparatively recent introgression. The authors propose that it represents a signature of environ mental stress in marginal habitats [1]. In a nutshell, it means that all modern polar bears probably belong to a mate...

Trophic cascades from wolves to grizzly bears or changing abundance of bears and alternate foods?

This is a Forum article commenting on: Ripple, W. J., Beschta, R. L., Fortin, J. K., & Robbins, C. T. (2014) Trophic cascades from wolves to grizzly bears in Yellowstone. Journal of Animal Ecology, 83, 223-233. Comparisons Ripple et al. (2014) used to demonstrate increased fruit availability and consumption by grizzly bears post-wolf reintroduction are flawed and tenuous at best. Importantly, a...

Thermodynamic properties of polarized liquid 3He along different isentropic paths

The dependence of some thermodynamic properties of spin-polarized liquid 3He such as velocity of sound, adiabatic index, isentropic compressibility and temperature on the spin polarization has been investigated along different isentropic paths. The Lennard-Jones potential has been used in our calculations. It has been found that for higher values of entropy, the spin polarization has greate...

Den selection by grizzly bears on a managed landscape

Trophic cascades from wolves to grizzly bears in Yellowstone.

We explored multiple linkages among grey wolves (Canis lupus), elk (Cervus elaphus), berry-producing shrubs and grizzly bears (Ursus arctos) in Yellowstone National Park. We hypothesized competition between elk and grizzly bears whereby, in the absence of wolves, increases in elk numbers would increase browsing on berry-producing shrubs and decrease fruit availability to grizzly bears. After wo...