Lecture 14: Birds

• Seabirds are endotherms (body temperature dependent on metabolic heat production)
• Feathers are light weight, high strength and useful for flight
• Seabirds have salt glands that spray salt from nasal openings

  Able to turn their salt glands on and off
• Oil glands used to trap air for insulation and buoyancy; also useful in coating feathers to prevent water logging
• Countercurrent heat exchange through rete mirabile: complex of arteries and veins lying very close to one another
• Types of soaring:

  Dynamic (bird glides downward, gaining speed and kinetic energy, then it turns into wind and gains height by converting kinetic energy into potential energy)

  Slope (takes advantage of ascending air on the upwind side of a hill)
• Seabird Reproduction:

  Always returns to land, slow breeding cycles, complex mating behavior
• Shorebirds (waders - spend time in the intertidal)

  • Oystercatchers: long bills for cutting, prying, and crushing
  • Plovers: curved bill to help pry open bivalves
  • Sandpipers
  • Avovets, Silts: longest legs per unit body length
• Herons and egrets as a type of shorebird
• Gulls and Terns:

  • Predators and scavengers
  • Nest in large numbers
• Skuas and Jaegers:

  • Aggressive
  • Carnivores and scavengers
  • Aerial pursiut
• Skimmers fly parallel to the shoreline to create a disturbance that attracts fish for food

  Pupils in a vertical slit (reduces glare) and flexible lower protruding jaw
• Auks, Murres, Puffins as part of Gull relatives
• Pelicans have webbed toes and hooked upper mandible
• Bobbies dive from great heights called "surface plunging"
• Cormorants are pursuit divers
• Fishermen use cormorants to help catch fish
• Frigatebirds do not have any oil glands and never land on water
• Tubenoses (Albatross) have the largest wing span and can stay out to sea for 1-2 years in the Southern Hemisphere
• Storm Petrels are a type fo tubenose that move their feet in the water to attract fish
• Penguins are the most highly adapted to life in the sea
• Seabird Feeding Behavior:

  • Surface plunging (pelicans, boobies)
  • Aerial pursuit (jaegers, frigatebirds)
  • Dipping (gulls)
  • Pursuit diving with wings (diving petrels, penguins)
  • Pattering (storm petrels)
  • Pursuit diving with feet (cormorants)
  • Pursuit plunging (shearwaters)