Eastern rockhopper penguin on the sub-Antarctic islands of the Indo-Pacific Ocean: Prince Edward, Crozet, Kerguelen, Heard, Macquarie, Campbell, Auckland, and the Antipodes Islands. Eastern rockhopper penguin The eastern rockhopper penguin ("Eudyptes chrysocome filholi") although genetically different is still often considered a subspecies of the southern rockhopper penguin. This species of penguin is also known to be one of the smallest species of penguins they are approximately 45–55 cm in length, and weighing 2.2–4.3 kg. The adult eastern rockhopper penguins feed on small fish, octopus, squid, and krill-like crustaceans. The rockhopper penguin "Eudyptes chrysocome" is sometimes considered two species, northern and southern rockhopper penguin,
What Bird is That? according to their usual habitat. The accompanying text included brief notes on distribution, breeding and behaviour. While initial sales were poor, history tells us that Cayley had accurately discerned a market need and successfully responded to it. During WWII sales accelerated and Cayley’s first collection, reprinted time and time again, eventually became a household name among birdwatchers and the book was recognised as an Australian classic. The original sponsorship of "What Bird is That?" proved a great investment for the Gould League, who benefited from the sale of its numerous reprints and revised editions. By 1960, it was rated the