 Seabirds, breeding predominantly on small isolated islands, are vulnerable to predators because they have lost many behaviours associated with defence from predators.Feral cats can take seabirds as large as albatrosses, and many introduced rodents, such as the Pacific rat, take eggs hidden in burrows.Introduced goats, cattle, rabbits and other herbivores can create problems, particularly when species need vegetation to protect or shade their young.