MARS2014 Lecture 8: Unit 8 - Seabirds
Unit 8: Seabirds
▪ What are the characteristics of seabirds?
• A bird that spends a significant part of its life at sea
o Forage at sea
o Nest on land
o Webbed feet
• Include 3% of bird species
o Penguins
o Tubenoses
o Pelicans & allies
o Gulls & allies
• All descended from land birds 23-65 MYA
▪ What are seairds’ adaptatios?
• Insulation (are endotherms, warm-blooded)
o Feathers
o Fat reserves/blubber layer
• Water proofing
o Have an oil gland (uropygial gland) above the base of tail
that they use to preen through their feathers
• Salt excretion
o Have salt secretion glands above their eyes and nasal duct
and salt water drips out of them
▪ How do seabirds move?
• Are light and streamlined
• Often have a large wing span for winds/thermals and gliding
• Webbed feet for paddling and diving
▪ How do seabirds reproduce?
• They are long-lived and slow to reach maturity
• They nest on land
• Most seabirds
o Breed in large colonies
o Have mating rituals
o Mate for life
o Nest on land
o Lay large eggs (usually one, but some species lay more)
o Rear their young
o Nest in remote places
▪ How do seabirds feed?
• Spend >80% of life foraging at sea
• Cope with dispersed and cryptic prey
• Forage far and wide
• Usually migrate
• Have sharp and strong beaks
• Diet includes schooling species, juvenile fish, fish forced to the
surface by predators
▪ What are some feeding strategies?
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