Class Aves 1 Class Aves Feathers No teeth

Class Aves 1

Class Aves • Feathers • No teeth • Flexible long neck – One occipital condyle • • Scales on legs Bones with air spaces Endothermic Four chambered heart 2

Adaptations for Flight • Honey-combed bones – Air cavities – Less weight 3

Light Weight Skeleton • Example: – Frigate bird – 7 foot wing span – 4 ounce skeleton 4

Adaptations for Flight • Enlarged sternum – Flight muscle attachment • Long neck – balance 5

Adaptations for Flight • Wing – lift 6

Adaptations for Flight • Feathers – Light weight – Strong – Downy, Primary, Flight 7

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Adaptations for Flight • Reduce body weight – No teeth – No urinary bladder – Reduced genitals during non-mating season – Hollow bones 9

Migration • Ruby-throated hummingbird • Migrates to Central and South America in October • Returns in May • Follows the blooming flowers 10

Migration • Arctic tern • Migrates 25, 000 miles! 11

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Beak Adaptations • Ripping flesh 13

Beak Adaptations • Eating seeds 14

Beak Adaptations • Sucking nectar from flowers 15

Beak Adaptations • Drilling wood 16

Beak Adaptations • Catching fish 17

Beak Adaptations • Basket-like bill to hold fish caught under water 18

Beak Adaptations • Filtering 19

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Digestive System • Crop – Storage • Proventriculus – Enzymes • Gizzard – Grind food • Cloaca – Waste – Reproduction 22

Vision • Up to 8 times keener than human vision • Each eye moves indendtantly 23

Respiratory System • Nine air sacs – Connect to lungs and centers of bones – Cools the bird • Fresh air always moving – No dead ends as in mammals • Each wing beat moves air – Never run out of air 24

Benefits of Birds to Man • Eat insects, rodents and weeds • Spread seeds for flowers and trees • Food • Sport • Pets • Birdwatching (link to “nature”) 25

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Caudipteryx • Feathered dinosaur • Flightless • Transitional fossil – Dinosaur arms – Dinosaur teeth • Only front of upper jaw – Bird feathers 27

Archaeopteryx • 147 MYA • Transitional fossil – Characteristics of reptiles – Characteristics of birds 28

Archeopteryx • Reptile characteristics – Teeth – Boney tail – Fingers with claws • Bird characteristics – feathers 29

Evolution of Flight Running Hypothesis 30

Microraptor gui 31

Evolution of Flight Gliding Hypothesis 32

The End 33