Southern rockhopper penguin penguins which get around obstacles by sliding on their bellies or by awkward climbing using their flipper-like wings as aid, rockhoppers will try to jump over boulders and across cracks. This behaviour is by no means unique to this species however - at least the other "crested" penguins of the genus "Eudyptes" hop around rocks too. But the rockhopper's congeners occur on remote islands in the New Zealand region, whereas the rockhopper penguins are found in places that were visited by explorers and whalers since the Early Modern era. Hence, it is this particular species in which this behaviour was
What Bird is That? kookaburra seated on and within a large red question mark. It contains 36 coloured plates of paintings of Australian birds by the author, as well as several black-and-white photographic plates of habitat. There were numerous reprints and revised editions in various formats produced well into the 1980s. The first edition was sponsored by the Gould League of Bird Lovers of New South Wales of which Cayley was a Council member. In return for its sponsorship, Cayley offered the Gould League four tenths of his 10% book royalty. However, initial sales were slow and in 1935 he sold his entire share