Northern rockhopper penguin truly different, in terms of more than reproductive isolation and some morphological features, was found in the mitochondrial sequences of the three species. It was found "E. c. filholi" and "E. c. chrysocome" were not as different genetically as "E. c. moseleyi" was to the other two subspecies. The level of genetic differentiation was similar to the genetic difference found in other penguin subspecies groups. Another way that scientists were able to differentiate the different subspecies of rockhoppers were in the parasites that fed off each separate rockhopper penguin species. Penguins are parasitised by 15 species of chewing lice in
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