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
Rockhopper Exploration viable rates. In July 2012, Rockhopper announced that it had entered into a conditional farm out agreement with Premier Oil plc whereby Premier will acquire 60% of Rockhopper's interests in its North Falkland Basin licences in exchange for an upfront cash payment of $231m, a contribution of $722m to Rockhopper's share of the Sea Lion development costs and a net exploration carry of $48m. Rockhopper will be fully funded on its share of the Sea Lion development through the contribution to costs and standby financing provided by Premier. First oil from Sea Lion is expected in 2020. Rockhopper holds interests