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? all-time best seller in Australian natural history and is still in print today. While sales and stature of Cayley’s original collection continued to grow, the prolific artist and ornothologist Cayley was working on a much more ambitious project – his so-called “big bird book”. From about 1918, he was creating illustrations of subspecies, plumage stages and eggs (now lost) of all known Australian birds. The project was incomplete at the time of his death in 1950, although the illustrations were all but finished. The ornithologist Terence Lindsey revived Cayley’s plans in the 1980s, creating the last and most significant revision