Northern rockhopper penguin two genera, "Austrogoniodes" and the monotypic "Nesiotinus". Within rockhopper penguins, the host-specific louse "Austrogoniodes keleri" is present only on southern rockhoppers; the multi-host "Austrogoniodes concii" parasitises only northern rockhoppers and "Austrogoniodes hamiltoni" parasitises only eastern rockhoppers. Cross contamination of the lice is not possible naturally due to the fact that chewing lice have limited mobility and heavily rely on their host for survival, meaning that the lice can only be transmitted across species by way of close physical contact. The northern rockhopper penguin feeds on krill and other sea life such as crustaceans, squid, octopus and fish. It breeds 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