Northern rockhopper penguin been caused by a vicariant event caused by a shift in the position of the Subtropical Front during the mid-Pleistocene climate transition. Analysis of a part of a mitochondrial control region from a northern rockhopper penguin found on the Kerguelen Islands showed that it may have come from Gough Island, 6,000 km away, and that the southern and northern rockhoppers are genetically separate, though some individuals may disperse from their breeding colonies. Many taxonomists have yet to recognize the split, although some are beginning to do so. More than 99% of northern rockhoppers breed on Tristan da Cunha and Gough
What Bird is That? friends, together with the succinct but compendious descriptive information, will place within easy reach of the bird lover, a most valuable "vade mecum" of bird and bush lore for out of doors as well as a thing of beauty for the library." Cayley’s aim in creating this work was to make available a book that would encourage and help people to learn about and appreciate Australia’s remarkable and unique bird life. He saw and responded to a need for a simple book that was accessible to the non-specialist birdwatcher. Each species was illustrated in colour and the birds were organised