122 Marine Microbes
11
MARINE REPTILES AND
BIRDS
Chapter Outline
MARINE REPTILES
Amniotic Egg
Physiological Adaptations
Marine Crocodiles
Sea Turtles
Adaptations to Life at Sea
Behavior
Sea Snakes
Adaptations to Life at Sea
Feeding and Nutrition
Reproduction
Sea Snakes and Humans
SEABIRDS
Oystercatchers
Plovers and Turnstones
Sandpipers and Curlews
Avocets and Stilts
Herons
Gulls and Their Relatives
Gulls
Frigate Birds
Tubenoses
Albatrosses
Petrels
Penguins
KEY CONCEPTS
Chapter Objectives
• Describe the advantage of producing an amniotic egg.
• Identify the physiological adaptations of marine reptiles.
• Explain the basic structure and adaptations of crocodiles.
• Recognize the specific adaptations of sea turtles including structure, physiology,
behavior, feeding and nutrition, and reproduction.
Key Terms
amniotic egg
amnion
carapace
plastron
ecological equivalents
gular pouch
Chapter Summary
1. The evolution of an amniotic egg allowed reptiles to completely sever all ties with
their aquatic environment, giving them a great reproductive advantage. Other
2. Several species of crocodile enter the ocean to feed, but the best-adapted is the Asian
3. Marine turtles have changed very little since they first evolved. Their bodies are
streamlined, and their appendages are modified into flippers. Turtles lack teeth,
4. The only marine lizard is the marine iguana of the Galápagos Islands. This relative of
5. Snakes evolved from the lizard line of reptiles, and several species are found in
6. Instead of a body covering of scales, birds have feathers. Feathers are light,
facilitating flight, and provide good insulation. In addition to feathers, the evolution
7. Shorebirds, or waders, have long legs for wading and thin, sharp bills for finding
8. Gulls are efficient predators and scavengers. Because gulls are found mostly along
9. Pelicans are large-bodied birds that feed by scooping up large amounts of water with
their gular pouch. Boobies, cormorants, and frigate birds are related to pelicans.
10. Birds known as tubenoses are represented by albatrosses and petrels. Albatrosses are
11. Penguins are the birds most adapted to life at sea. Their streamlined bodies and
flippers, instead of wings, make them excellent swimmers. Most penguin species are
found in the Antarctic, where they feed on fish, squid, and krill. In turn, leopard
Chapter Outline
I. Marine Reptiles
A. Amniotic egg.
B. Physiological adaptations.
C. Marine crocodiles.
D. Sea turtles.
1. Adaptations to life at sea.
2. Behavior.
5. Turtle migrations.
6. Sea turtles in danger.
7. Marine biology and the human connection—endangered sea turtles.
E. Marine iguana.
F. Sea snakes.
1. Adaptations to life in the sea.
II. Seabirds
A. Adaptations for flight.
B. Adapting to life in the sea.
C. Shorebirds.
1. Feed in intertidal zone.
D. Gulls and their relatives.
1. Worldwide distribution.
2. Do not stray far offshore but do head inland.
126 Marine Reptiles and Birds
5. Terns.
a. Convergent evolution.
b. Nesting and reproduction.
c. Parental care of the young.
E. Pelicans and their relatives.
1. Most live in tropics and warm temperate regions.
2. Most in coastal areas and sometimes in inland waters.
3. Pelicans.
Suggestions for Presenting the Material
1. Arrange for a coastal field trip to observe shorebirds engaging in their natural
behaviors.
2. Nature centers may have biological materials available for loan to educators, such as
bird skins, stuffed specimens, and bones. Contact your local natural history museum
for more details.
Classroom Discussion Ideas
1. How do marine birds differ from terrestrial birds? Discuss anatomical, physiological, and
behavioral differences.
2. In what ways can our ordinary, everyday actions affect seabirds? List ways that individuals
can reduce their impact on sea life.
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3. How do female sea turtles navigate back to their home beaches after they have spent years
swimming thousands of kilometers across ocean basins? What special senses may be
involved?
4. What are ways that global climate change could affect seabird and sea turtle populations?
Consider how increased sea level and melting of polar ice might affect nesting grounds for
these animals.
Videos, Animations, and Websites
Videos
Adventures in Birdwatching. (DVD, Janson Media, 2004)
This two-disc set tours the country to provide close-up views of wading birds, raptors,
and other avian species.
The Life of Birds. (Set of three DVDs, BBC Video, 2002)
Documentary series hosted by David Attenborough traverses the globe to reveal the
world through the eyes and experiences of birds. Stunning wildlife photography at its
Life in Cold Blood. (five-part series, BBC Video, 2008)
The last in the Nature of Life series hosted by David Attenborough, examining the variety
and adaptations of reptiles and amphibians.
World’s Last Great Places: Galapagos Islands, Land of Dragons. (VHS, National
Geographic, 1998)
Showcases the unique creatures from the remote island group, including seabirds,
iguanas, and penguins.
Websites
National Audubon Society.
One of the nation’s largest conservation organizations working to restore natural
Save the Albatross.
Nonprofit organization providing the latest conservation information and status about
128 Marine Reptiles and Birds
Oceana’s Campaign to Protect Sea Turtles.
Sea turtle conservation organization provides information on species, current legislative
Suggested Answers to End of Chapter Questions
Multiple Choice
1. c. the amniotic egg
2. b. reproduce
Matching
1. c.
Short Answer
1. Describe how marine turtles are adapted to life in the sea.
Adaptations of marine turtles for life in the sea include a streamlined shell with
2. Describe the nesting behavior of sea turtles.
After mating at sea, female turtles migrate back to the beaches where they were
3. Compare marine iguanas with their more terrestrial cousins.
Chapter 11 129
4. Explain how sea snakes that do not lay their eggs on land reproduce.
Like some land snakes, sea snakes have been observed to congregate in large
5. Explain how birds are well adapted for flight.
Birds are adapted for flight with the following features: a light body-covering
6. Describe how seabirds maintain their osmotic balance despite drinking seawater and
eating marine animals.
7. Why are most soaring birds, such as albatrosses, primarily confined to the southern
hemisphere?
Albatrosses are primarily confined to the southern hemisphere because wind
8. Why do the birds known as alcids resemble penguins more than the gulls and terns to
which they are more closely related?
Because alcids in the polar north regions occupy similar niches as penguins in the
9. What human activities are contributing to the decline in sea turtle populations?
Human activities responsible for the decline of sea turtle populations include:
130 Marine Reptiles and Birds
Thinking Critically
1. Why do seabirds that nest in trees or other protected areas tend to lay fewer eggs than
seabirds that nest on the ground?
Most seabirds lay their eggs in a shallow depression in the ground. This behavior
2. Why is it important for marine reptiles and birds to be able to efficiently eliminate salt
from their bodies?
If these vertebrates were unable to excrete salt form their bodies, eventually the
3. Which of the following would you expect to suffer more from predation, albatross
adults or chicks? Why?
Albatross chicks are more vulnerable to predation than are adults, since chicks are
Suggested InfoTrac® Articles
“Sea Turtles as Biological Transporters of Nutrients and Energy from Marine to
Terrestrial Ecosystems.” Bouchard, S.S. and K.A. Bjornadal. Ecology, (2000).