1 / 46

Birds Class: Aves

Birds Class: Aves. Characteristics. Well adapted to marine, freshwater, & terrestrial habitats Bodies adapted for flight Endothermic - body temperature controlled by metabolism ( 40 to 41 degrees Celsius body temperature) ). Evolution. Evolved from reptiles

idalia
Télécharger la présentation

Birds Class: Aves

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. BirdsClass: Aves

  2. Characteristics • Well adapted to marine, freshwater, & terrestrial habitats • Bodies adapted for flight • Endothermic - body temperature controlled by metabolism (40 to 41 degrees Celsius body temperature) )

  3. Evolution • Evolved from reptiles • Few fossils due to lack of preservation of feathers or thin, hollow bones

  4. Characteristics of Birds • Body covered with feathers made of protein called keratin • Thin, hollow bones • Some bones fused for extra strength • Forelimbs modified into wings for  flight • Two hind limbs with claws to support upright body • Scales on legs

  5. Toothless, horny beak • Additional air sacs  with lungs for more oxygen

  6. Amniote egg with calcium carbonate shell • Oviparity with both parents often caring for eggs • Eggs usually incubated within a nest

  7. Feathers!!!

  8. Feathers: • Modified scales • Function to provide lift for flight & help conserve body heat • Five kinds of feathers ----- down, contour, flight, filoplume, & bristles

  9. Down feathers: 1. Soft & fluffy2. Cover the body of nestlings3. Provide an undercoat insulating adult birds

  10. Down feathers

  11. Contour Feathers: 1. Give streamline shape to body2. Provide coloration to adult birds3. Give additional insulation to body

  12. Contour

  13. Flight Feathers: 1. Specialized contour feathers2. Found on wings & tail

  14. Flight feathers

  15. Filoplumes: • 1. Called pin feathers2. Hair like feathers under contour feathers on body

  16. Filoplumes

  17. Parts of a feather • Develop from tiny pits in the skin called follicles • Shaft emerges from the follicle • Two vanes develop on either side of shaft • Barbs branch off of each vane & have projections called barbules • Barbules have microscopic hooks to hold barbules together

  18. Parts of a Flight Feather

  19. Microscopic Hooks on Barbules

  20. Feathers • Birds preen their feathers to clean them & coat them with oil • Preen glands - oil glands located at the base of the tail • Birds shed or molt feathers periodically:1. Molting usually in late summer between breeding & migration2. Flight feathers replaced3. Some birds molt before courtship

  21. Beaks and Feet • Adapted to habitat & feeding • Hawks & eagles have hooked beaks & talons for tearing meat

  22. Swifts have tiny beaks that open wide to catch insects in midair • Flightless birds like ostriches have legs & feet modified for running & walking

  23. Penguins have wings modified into flippers for swimming • Ducks & geese with webbed feet

  24. Legs of some birds such as herons &  egrets turn vivid colors to attract mates

  25. Muscles • Flight muscles called pectorals & are attached to wing & keeled sternum • When large pectorals contract, wings move down • When large pectorals relax & small pectorals contract, wings move upward

  26. Body Temperature • Metabolism generates body heat (endothermic) • Enables birds to survive in warm & cold environments • Rapid breathing & increased air sacs in lungs bring in more oxygen

  27. Ingest large amounts of food for energy • Fluff out feathers to trap air for insulation • Aquatic birds have thin layer of fat for insulation

  28. Digestive System • Fast & efficient digestion • No chewing • Crop for temporary food storage • Two part stomach --- proventriculus & gizzard • Proventriculus is 1st chamber where digestive juices added • Gizzard is 2nd part for crushing food

  29. Pyloric sphincter valve at lower end of gizzard controls food movement into intestines • Duodenum - beginning of small intestine where bile (digests fats) & pancreatic juice are added & digested food is absorbed

  30. Respiration • Fly at high altitudes where there is less oxygen so need efficient respiratory system • High metabolic rate requires large amount of oxygen • Nine air sacs associated with lungs increase oxygen level & decrease density

  31. Air pathway:air enters body through nostrils on beak  trachea (windpipe) syrinx (voice box) 2 primary bronchi 75% of air into two posterior air sacs and 25% of air into lungs air from lungs into other seven air sacs

  32. Circulatory system • Four chambered heart • Right side of heart pumps deoxygenated blood from body cells to lungs • Left side of heart receives oxygenated blood from lungs & pumps it to the body cells • Single aortic arch • Rapid heartbeat (hummingbird 600X/minute & chickadee 1000X/minute) • Less active birds such as ostrich have slower heart rates (70X/minute)

  33. Nervous System • Large brains relative to size of bird • Cerebellum coordinates movement • Cerebrum controls navigation, mating, nest building, & care of young • Optic lobes receive & interpret visual stimuli • Have color vision for locating food

  34. Reproductive System: • Testes in males produces sperm that travels by the vas deferens to cloaca • Females have single ovary that makes eggs • Eggs are fertilized in the oviducts • In mating, male presses cloaca to female to transfer sperm (internal fertilization)

  35. amnioteegg • 1. Embryo suspended in fluid called albumen (white of egg)2. Chalaza - rope like strands suspending embryo in albumen3. Chorion is membrane inside of shell4. Yolk is stored food surrounded by yolk sac

  36. Eggs incubated by one or both parents  • Brood patch - thickened, featherless patch of skin on abdomen of bird used to warm eggs

  37. Yolk sac has blood vessels to carry food to embryo •  Wastes from embryo collect in membrane called allantois • Chorion membrane lines the shell & allows gas exchange

  38. Young birds may be precocial or altricial Precocial young: Altricial young: 1.Lay fewer eggs2. Hatch quickly3. Hatchlings are blind, naked, & helpless4. Depend on parents for warmth & food for several weeks5. Includes songbirds, woodpeckers, hawks, pigeons, doves, raptors • 1. Have longer incubations2. More eggs laid3. Active as soon as hatch4. Nestlings can swim, walk, & feed themselves5. Need some parental care6. Includes ducks, geese, & swans

  39. Behavior: • Longer parental care allows more complex learning (courtship, nesting, migration, etc.) • Territoriality allows males to establish & defend breeding areas

  40. Courtship • behaviors used by males to attract mates:1. Brightly colored feathers2. Flight displays3. Songs

  41. Courtship

  42. Nest building holds eggs, conceals & shelters young birds, may help attract mates • Nests are built in sheltered, well-hidden spots in trees, on the ground, etc. & are made of twigs, mud, grass, feathers...

  43. nests

  44. Migration • triggered by dropping temperatures & dwindling food supplies • Birds use migration clues including:1. Position of sun & stars2. Topographical landmarks3. Magnetic clues4.Air pressure changes5. Low frequency sounds

More Related