Rockhopper penguin positions and islands became surrounded by subtropical water masses, resulting in a split between Northern and Southern rockhopper penguins. Many advance and retreat cycles of Patagonian icecaps during the late Pleistocene may have created a barrier to gene flow between Southern Pacific and Southern Atlantic populations, causing a split between Southern and Eastern rockhopper populations. Adult Rockhopper penguins have no land-based predators. They are eaten when at sea by leopard seals, fur seals, killer whales and blue sharks. Chicks and eggs are eaten by many birds including giant petrels, skuas, sheathbills and various types of gulls. Although the rockhopper penguin
Free as a Bird Beatles songs, such as "Penny Lane", "Paperback Writer", "A Day in the Life", "Eleanor Rigby", "Helter Skelter", "Piggies", "The Continuing Story of Bungalow Bill", "Strawberry Fields Forever", "Doctor Robert", and "The Fool on The Hill". Between 80 and 100 allusions to the Beatles' story, music and lyrics in the video have been estimated. Although the bird can be heard at the beginning of the video, it is never seen. Neil Aspinall (Apple Records executive at the time) said that this was because no-one could agree on what kind of bird it should be. Pytka had to send his ideas to