Warmer temperatures and earlier melting of sea ice are causing polar bears to go hungry. The number of undernourished bears has tripled in a 20-year period. Seth Cherry of the University of Alberta, Canada, and colleagues monitored the health of…
Warmer temperatures and earlier melting of sea ice are causing polar bears to go hungry. The number of undernourished bears has tripled in a 20-year period. Seth Cherry of the University of Alberta, Canada, and colleagues monitored the health of…