The Fiordland crested penguin population is largely affected by introduced predators such as the weka (Gallirallus australis), which preys on eggs and chicks and causes up to 38% of egg mortality and 20% of chick mortality on Open Bay Island. Other predators include dogs, cats, stoat, and rats.
All 17 species of penguin are legally protected from hunting and egg collecting. The Antarctic Treaty of 1959 makes it illegal to harm, or in any way interfere with, a penguin or its eggs. Every penguin specimen collected with a permit must be approved by and reported to the Scientific Committee for Antarctic Research (SCAR). Penguins are vulnerable to habitat destruction, overfishing of primary food sources, ecological disasters such as oil spills, pollution such as trash in the ocean, and human encroachment into nesting areas.