Polar bears’ ‘walking hibernation’ not much of an energy saver
Summertime dips in activity and body temperature may not be enough to protect bears from challenges of climate change
![Polar bear](https://i0.wp.com/www.sciencenews.org/wp-content/uploads/2015/07/sm_polarbear_free.jpg?fit=860%2C460&ssl=1)
BUDGETING ENERGY Polar bears, like this youngster on pack ice over the Arctic Ocean, have to learn to cope with lean times in summer. But their warm-weather energy-saving tactics may not give them much leeway as a changing climate extends hungry times.
Shawn Harper