In this photo taken Wednesday, May 7, 2014, an Arctic tern chases off a gull that approached its Potter Marsh nest in Anchorage, Alaska. Arctic terns spend winters in Antarctica, southern Africa, southern Australia or New Zealand and fly at least 11,000 miles north to breed in Alaska. They fiercely guard their territory and will attack gulls, eagles, people or other intruders who get close to nests.Dan Joling/The Associated Press