introduction to Birds outlining evolution, anatomy and reproduction.

1. Birds
Alexandra Fowler

2. Phylum- Chordata
Class- Aves

3. Bird Orders
•27- 29 Orders of birds
•2 exclusively marine- the penguins and albatrosses
•8 contain mixture of coastal and terrestrial

4. • Anseriformes
Waterfowl • 149 species
• Sphenisciformes
Penguins • 17 species- truly marine
• Gaviiformes
Divers • 5 species
• Procellariiformes
Albatrosses • 108 species- truly marine
• Podicipediformes
Grebes • 22 species
Herons/ Egrets • Ciconiiformes
• 119 species
• Pelecaniformes
Pelicans • 65 Species
• Falconiformes
Birds of prey • 307 species
• Charadriiformes
Waders/Gulls/Auks • 343 species
• Coraciiformes
Kingfishers • 191 species

5. Bird evolution

7. • Archaeopteryx-
Cretaceous (first bird-
like fossil), but had:
- Clawed forelimbs
- Teeth
- Long tail with
vertebrae
• Weak flyer
• Their evolution is still
hotly contested among
scientists

8. Small digression-
•Potential that bird ancestors were in fact crocodiles
•New evidence that dinosaurs came after birds in the
evolutionary scale
•Continually new fossil discoveries
•Always open to interpretation and debate
•See here

9. General features
•Scales on legs
•Feathers
•Eggs

11. Flight
A variety of slow motion clips
Sparrow
In Flight
Duck
Dipper underwater

12. • Modern birds have developed a variety of means to enable efficient
flight
• Honeycombed bone structure (reduced weight)
• Absence of some organs (right ovary)
• Toothless (food ground in gizzard)
• Efficient lungs and heart
• Well developed sight (best of all vertebrates)
• Large brains - complex behaviour
• Very muscular pectoral muscles anchored to keel on breastbone
• Fused digits - even airflow
• Wings and feathers

13. Flight- evolution
Three Theories:
• Cursorial - used speed from running to gain
momentum
• Arborial - claws on wings enabled climbing and then
gliding
• Pouncing proavis - ancestors pounced on prey from
trees etc. Developing wings let them steer.

14. Paper aeroplane time!

15. What advantages do birds have over simple paper aeroplanes?

16. Feathers
• Keratin
• Initially functioned as
insulation
• Provide support and wing
shape
• Allow fine control of the
airflow over the wing

17. Types of Feathers

18. http://www.birds.cornell.edu/AllAboutBirds/studying/feathers/feathers

19. Anatomy – digestive system

20. Anatomy and Physiology – gas exchange
• Extremely complex
• Pharynx has a voice box called a syrinx.
• This is located between the trachea and the bronchi.
• Bronchi link to air sacs in the thorax and abdomen and
both lead to the lungs.
• Lungs are made of parabronchi, a series of tubes.

21. Anatomy and Physiology – gas exchange
• There are two ventilatory
cycles to move a volume of
air into and out of the bird.
• This respiratory method is
the most efficient in the
vertebrate classes. Birds
have a high metabolic rate.
• This system also allows
them to fly at high altitudes
– some geese can fly at
over 9000m.

22. Physiology – thermoregulation
• Birds regulate their body temperature between 38 and
45 C. Below the lower range birds become torpid (slow,
sleepy) and eventually die. Above the upper range and
they die of heat exhaustion.
• Heat maintained by fluffing feathers.
• Feet have little musculature or blood supply to prevent
heat loss.

23. Anatomy and Physiology – vision
• Birds have rods and cones in their retinas.
• Birds can double focus – that is, they can focus near and
far.
• Binocular (3D vision) depends on location of eyes.

24. Anatomy and Physiology – hearing
• Birds have sensitive hearing.
• No external ears but adapted feathers to allow sound
through.
• Hearing range 100 – 15000 Hz
• For humans it is 20 – 17000 Hz.

25. Anatomy and Physiology – excretion
• Kidneys are paired and lead to the cloaca.
• Kidneys cannot concentrate salt so bird relies on salt
glands near the nostril.
• Kidneys produce uric acid as opposed to urine.

26. Finding a mate
• Territories established by most male birds.
• Courtship – plumage colours and appendages.
• Different pairing arrangements
• Monogamy
 Usually for the season, sometimes for life (swans,
eagles, etc).
 Happens when resources are present.

27. Anatomy and Physiology – reproduction
• Birds are oviparous
• Have paired gonads
• Usually only the left ovary develops.
• Ovary is enveloped by ostium (funnel) that collects egg.
• Egg is fertilised in oviduct.
• Fertilised egg is passed to shell gland.
• Except for certain waterfowl and ostriches, no penis –
sperm is passed by aligning male cloaca to the female
cloaca.

28. Eggs and nesting

29. Adaptions
• On your handout you will see a variety of
adaption's according to food sources and
habitat.

30. Now to learn some bird names!!