Weights and hematology of wild black bears during hibernation.

Black Bears in the Wild Retain Muscle Strength During Hibernation

Bone formation is not impaired by hibernation (disuse) in black bears Ursus americanus.

Disuse by bed rest, limb immobilization or space flight causes rapid bone loss by arresting bone formation and accelerating bone resorption. This net bone loss increases the risk of fracture upon remobilization. Bone loss also occurs in hibernating ground squirrels, golden hamsters, and little brown bats by arresting bone formation and accelerating bone resorption. There is some histological ev...

Wound healing during hibernation by black bears (Ursus americanus) in the wild: elicitation of reduced scar formation.

Even mildly hypothermic body or limb temperatures can retard healing processes in mammals. Despite this, we observed that hibernating American black bears (Ursus americanus Pallas, 1780) elicit profound abilities in mounting inflammatory responses to infection and/or foreign bodies. In addition, they resolve injuries during hibernation while maintaining mildly hypothermic states (30-35 °C) and ...

Grizzly bears (Ursus arctos horribilis) and black bears (Ursus americanus) prevent trabecular bone loss during disuse (hibernation).

Disuse typically causes an imbalance in bone formation and bone resorption, leading to losses of cortical and trabecular bone. In contrast, bears maintain balanced intracortical remodeling and prevent cortical bone loss during disuse (hibernation). Trabecular bone, however, is more detrimentally affected than cortical bone in other animal models of disuse. Here we investigated the effects of hi...

Bending Properties, Porosity, and Ash Fraction of Cortical Bone from Black Bear (ursusamericanus) Tibias Are Not Compromised with Aging despite Annual Periods of Disuse

Introduction Osteoporosis is a disease characterized by low bone mass and structural deterioration of bone tissue, which leads to bone fragility and increased fracture risk. For prolonged bed rest, immobilization, and space flight, disuse atrophy of bone is prevalent in many animals including humans. However, black bears may not develop osteopenia during long periods of disuse (i.e., hibernatio...