Amazing drone footage shows feeding blue whales swimming to the surface

Blue whales swim to the surface to feed on krill as it helps them to conserve energy, according to a new study that involved amazing drone footage of the mammals. Experts from Oregon State University found that feeding on the ocean's surface plays an important role in the hunt for food among New Zealand blue whales. Blue whales are the largest mammals on Earth and have to carefully balance the cost of energy they get from food with the cost of energy used in getting the food. Researchers say the marine mammals forage for krill in areas where they are densely packed and found near the surface of the water to cut their dive time. The Oregon team found that the blue whales do this to conserve on the energetic costs of feeding such as diving, holding their breath or opening their mouths.