These nesters include species of albatrosses, petrels, skuas, gulls and terns. The passage hosts whales, dolphins and seabirds including giant petrels, other petrels, albatrosses and penguins. Sea birds reported include petrels and albatrosses. The group that includes modern albatrosses, petrels and storm petrels. The albatrosses and petrels are "amongst the most severely threatened taxa worldwide". Some seabirds, particularly the albatrosses and gulls, are more well-known to humans. These methods increase the bycatch of animals such as albatrosses. The albatrosses in general feed on fish, squid and krill. Many species, including hummingbirds and albatrosses, have two foveas in each eye. Commercial longline fishing is also one of the main threats to albatrosses. Long-ranging birds, like albatrosses, and most commercial aircraft maximize aspect ratio. Many Buller's albatrosses and black-footed albatrosses nest under trees in open forest. They also tend to forage in colder waters further south than other albatrosses. Current thinking divides the albatrosses into four genera. The principal threat to the albatrosses and larger species of procellariids is long-line fishing.