Each summer, thousands of beluga whales find sanctuary in Hudson Bay's estuaries, where warm, shallow waters provide safety for nursing their calves. Photographer Martin Gregus Jr encountered this pod beneath the tannin-stained waters and found that, despite the limited visibility, they could navigate with astonishing precision as the calves weaved in and out of one another. | National Geographic

Hundreds of manatees gather in the warm waters of Three Sisters Springs, finding a cozy winter refuge in Florida. | AccuWeather

Hundreds of manatees congregated at Three Sisters Springs, a wildlife refuge in Crystal River, Florida, on December 31st, where the waters “remain at a constant 72 degrees year-round,” according to the Southwest Florida Water Management District. The agency recently restored the shoreline around Three Sisters Springs, which it said “will help prevent future erosion,” improve water quality, and make the area safer for visitors. The marine mammals spend each winter in the balmy spot, then return t