Although still fairly abundant, the erect-crested penguin is considered endangered because it is thought to have undergone significant declines of at least 50% over the last 45 years, a pattern that is only expected to continue. Furthermore, the species' very small and restricted breeding range leaves it particularly vulnerable (2). The reasons for this decline are not fully understood, but are believed to be associated with marine factors, as predation on land during the breeding season is unlikely to be significant, since there are no mammalian predators on the Bounty or Antipodes Islands, except for mice on the main Antipodes Island (2) (7).