Northern rockhopper penguin Northern rockhopper penguin Recent studies show the northern rockhopper penguin, Moseley's rockhopper penguin, or Moseley's penguin ("Eudyptes moseleyi") distinct from the southern rockhopper penguin. A study published in 2009 showed that the population of the northern rockhopper had declined by 90% since the 1950s. For this reason, the northern rockhopper penguin is classified as endangered. The rockhopper penguins have been considered to consist of two species, northern and southern rockhopper penguin, since research published in 2006 demonstrated morphological, vocal, and genetic differences between the two populations. Molecular datings suggest that the genetic divergence with the southern rockhopper penguin may have
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