Chong yee ting 6s (3)

1. Classification: birds Chong yee ting 6s (3)

2. Introduction • Class:Aves • Homoiotherm • vertebrates • There are around 10,000 living species • Most birds can fly, walk and run, many can swim and dive • Size of the birds can vary from the tiny flowerpeckers & hummingbirds • have a keen eyesight and good hearing but sense of taste and smell is poor

3. Body structures (diagram)

5. General features • Have feathers covering the body • legs are covered with dry scales • hollow bones • have a beak for feeding • forelimbs have been modified to become wings • have lungs for breathing

6. Wings

7. Different shapes of wings correspond to beneficial characteristics: • speed • low energy use • types of wings: • elliptical wings • high speed wings • high aspect ratio wings • soaring wings with slots.

8. Flight • Hollow bones reduce weight • Bird’s flight muscles work continuously, pushing the air down to produce lift that balances the weight.

9. The actual available power dwindles as the size of the bird increases • large birds : have just enough power to fly near the minimum power speed OR flightless

10. Feathers • Feathers have evolved to serve a variety of functions : • flight • heat conservation • waterproofing • camouflage • displaythree main types • filoplumes (sensory feathers) • contour feathers • down feathers (insulation).

11. Feathers for different functions Examples: • Owls : • velvet-like projections • fly silently • Sand-Grouse: • feathers with highly curled barbs • hold water

12. Reproduction • Sexual,internal fecundation • on land • lay eggs with chalky shells • Males have two testes and females have one ovary

13. Male Female

14. Courtship Examples: • Pairing:|A sequence of behavioural activities • Nest building:One of the pair or both birds construct a nest

15. Respiratory system • do not have a diaphram • push the sternum in and out • 75% of the fresh air into bones and fills them with air. • 25% of the air goes directly • Importance • for flying need high metabolic rate

16. Evolution • birds evolved from theropod dinosaurs • around 150–200 million years ago • Evidence • Bird-like respiratory systems in dinosaurs • hollow bones

17. Evolution--beak • birds' beaks have evolved to suit the ecological niche they fill • diet are varied (e.g fruit,seeds) • On some birds, the tip of the beak is hard, dead tissue • On other birds, (e.g ducks) The beak grows throughout the bird's life.

18. Gannets • Gannets hunt fish by diving from a height into the sea and pursuing their prey underwater. • adaptations which enable them to do this: • they have no external nostrils • they have air sacs in their face and chest under their skin • their eyes are positioned far enough forward on their face

19. Additional information • Chromosome(Z,W) • male:ZZ • female:WZ • Sex determination determined at fertilization determined at temperature • Red blood cells have a nucleus.

20. Sources 1.http://en.wikipedia.org/wiki/Bird 2.http://www.birding.in/ornithology/bird_flight.htm 3. http://www.birding.in/bird_topography.htm 4. http://www.biology-questions-and-answers.com/birds.html 5. http://www.birding.in/birds.htm 6. http://www.thewildclassroom.com/biodiversity/birds.html 7. http://en.wikipedia.org/wiki/File:Bird_Diversity_2011.png End