Northern rockhopper penguin mice ("Mus musculus") have been introduced into their environment by human sea expeditions. The mice have proven to be invasive, and consume northern rockhopper eggs, as well as hunt their young. In order to preserve the birds, a culling of the mice is being considered. The northern rockhopper penguin is classified as endangered because of the decline in numbers over the last three generations (or 30 years). Population Trends by Year and Island On March 16, 2011, the Maltese-registered freighter MS "Oliva" ran aground on Nightingale Island, spilling tons of heavy crude into the ocean. The crew was rescued, but
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