Marine Birds (Subphylum Vertebrata; Class Aves)

• Birds evolved from reptiles (dinosaurs) approximately 150-200 million years ago during the Jurassic period

• Modern birds are characterized by feathers, the laying of hard shelled eggs, and a lightweight, but strong skeleton

• Birds are warm-blooded– Homeothermic and endothermic!– Scaly legs and claws

• Birds have light, hollow bones for efficient flight

• Marine birds, or seabirds, are birds that spend a significant part of their lives at sea and feed on marine organisms

• Most breed in large colonies on land• True seabirds have webbed feet for

swimming

Marine Birds

Marine Birds

• Seabirds require a tremendous amount of food to supply the energy required to maintain their body temperature

• Only ~3% of all birds are marine birds• Marine birds, like reptiles, have salt-excreting

glands to allow salt from their diet to drip out passages on their beaks

Marine Birds• Of all the seabirds, penguins and tubenoses

are the best adapted to the pelagic realm

Penguins• Penguins have completely lost the ability to fly

and have modified their wings into flippers• Fatty insulation keeps penguins warm while

denser bones allows them to maintain neutral buoyancy in the water

• Streamlined bodies; can alternately swim and jump out of the water to reduce drag and increase swimming efficiency

Penguins

• All penguins are found in the Southern Hemisphere

• Believed to consume ~86% of all food taken by birds in the Southern Hemisphere!

Penguins

• Dense, waterproof feathers trap air that, warmed by their body heat, protects against the cold

• The larger penguins (such as Emperor and King) hunt for squid and fish

• Small penguins (such as Adélie) feed primarily on krill

Tubenoses

• The tubenoses comprise a large group of seabirds with distinctive tube-like nostrils and heavy beaks that are usually curved at the tip

• Includes albatross, petrels, and shearwaters• Spend months and often years at sea• Salt glands empty into the nostrils to get rid of

excess salts

Tubenoses

• Tubenoses possess a tubular nasal passage allows them to smell and locate patchily-distributed food at sea, and to help locate their own nests

Southern fulmar

Tubenoses

• Tubenoses are very skillful fliers• Albatross have the largest wingspan

of any bird (up to 11 feet from tip to tip)

Marine Birds