Southern rockhopper penguin the last thirty years. This decline has earned them the classification of a vulnerable species by the IUCN. Threats to their population include commercial fishing and oil spills. With the approval of the European Association of Zoos and Aquaria (EAZA), Drusillas Park in East Sussex holds the studbook for rockhopper penguins in Europe. Zoo manager Sue Woodgate has specialist knowledge of the species, so the zoo is responsible for co-ordinating the movements of penguins within zoos in Europe to take part in breeding programmes and offer their advice and information about the species. Rockhopper penguins are the most familiar of
Bird-of-paradise lek-type mating system. Others, such as the "Cicinnurus" and "Parotia" species, have highly ritualised mating dances. Males are polygamous in the sexually dimorphic species, but monogamous in at least some of the monomorphic species. Hybridisation is frequent in these birds, suggesting the polygamous species of bird of paradise are very closely related despite being in different genera. Many hybrids have been described as new species, and doubt remains regarding whether some forms, such as Rothschild's lobe-billed bird of paradise, are valid. Birds-of-paradise build their nests from soft materials, such as leaves, ferns, and vine tendrils, typically placed in a tree