Researchers have spotted a rare bowhead whale cruising Cape Cod Bay off the coast of Massachusetts, only the second time in history the species has been seen this far south. The bowhead (Balaena mysticetus) was identified by researchers at the Center for Coastal Studie who were an aerial survey of the coast. CCS scientists were responsible for the only other Massachusetts bowhead sighting in 2012, off of Outer Beach in Orleans. Unlike all other large baleen whales -- filter feeders that subsist on plankton and other small crustaceans -- which migrate out of Arctic waters to feed and reproduce, bowheads spend their entire lives in the polar regions. "This is yet another remarkable sighting in what has been a remarkable several years in our studies of Cape Cod Bay," said Dr. Charles "Stormy" Mayo in a press release. Mayo is the director of CCS's Right Whale Research program. The newly arrived bowhead was seen swimming and feeding alongside a group of right whales. "Two years ago we saw our first bowhead, an animal that should be 1,000 miles from Cape Cod," Mayo added. "These observations along with extraordinary number of rare right whales in Cape Cod Bay seem to be pointing to profound changes in the coastal habitat, to which the whales are responding." Bowheads aren't quite as long as some of the world's largest sea mammals, but it's outweighed only by the blue whale. Its bulky, broad frame supports a blubbery body that can tip the scales at up to 110 tons. The bowhead is named for its large, thick skull, which is used to break through Arctic ice when the whale is in need of fresh air. An early whaling target, the bowhead population was dangerously thin before a 1966 moratorium helped the species rebound. They remain protected by the Endangered Species Act and the Marine Mammal Protection Act.