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
Featherless bird-riddle Featherless bird-riddle The Featherless bird-riddle is an international riddle type about a snowflake. In the nineteenth century, it attracted considerable scholarly attention because it was seen as a possible reflex of ancient Germanic riddling, arising from magical incantations. But although the language of the riddle is reminiscent of European charms, later work, particularly by Antti Aarne, showed that it occurred widely throughout Europe─particularly central Europe─and that it is therefore an international riddle type. Archer Taylor concluded that 'the equating of a snowflake to a bird and the sun to a maiden without hands is an elementary idea that cannot yield