In this talk I will discuss the ecology and conservation of brown bears (Ursus arctos) in the southern Canadian Rocky Mountains where I have been working since 2000. Specifically, I will relate habitats to grizzly bear behaviours (habitat selection), occupancy-abundance, body size (proxy of fitness), and climate change threats. I will emphasize how tradeoffs between top-down processes (human-caused mortality) and bottom-up factors (food supply) relate to patterns in landscape change (forestry and mining) and the importance of bottom-up regulation of bears. Finally, I will explore how landscape factors and forest stand characteristics relate to fruit production in the most abundant shrub, Canada buffaloberry (Sheperdia canadensis), and how this affects spatial-temporal patterns in brown bear habitat use.