Which bear is now described on Wikipedia as a highly efficient hibernator?

The American black bear is now described as a highly efficient hibernator.

This wording reflects a change in how biologists define hibernation. Black bears were once excluded from the category of “true” or “deep” hibernators because their body temperature falls only modestly compared with that of many small mammals. Research showing that bears can remain dormant for months without eating, drinking, urinating, or defecating led many biologists to emphasize metabolic suppression rather than a particular body-temperature threshold.

American black bears enter dens roughly from October or November, though timing varies with latitude, climate, sex, pregnancy, and local food conditions. Before denning, they may add as much as 30 pounds of fat. Hibernation typically lasts three to eight months.

Their physiology is remarkable: heart rate can fall from about 40–50 beats per minute to roughly 8, while metabolic rate may drop to one-quarter of the non-hibernating basal rate. Unlike many inactive mammals, bears retain much of their muscle and bone strength during this long period.