zoology notes: birds. what is a bird? basic definition: – warm blooded vertebrates – feathers...
Post on 13-Dec-2015
215 Views
Preview:
TRANSCRIPT
Zoology Notes: BIRDS
What is a bird?
• Basic Definition:– warm blooded vertebrates – feathers– two legs for walking/perching– front limbs modified into wings
Birds, ARE reptilesFeathers and endothermy (warm blooded-ness) are
the main character traits that separates birds from other reptiles
3 F e a t h e r T y p e s3 F e a t h e r T y p e s3 F e a t h e r T y p e s3 F e a t h e r T y p e s• Contour feathers: shape and
maneuvering– Flight feathers:
lift and balance; asymmetrical– General body feathers: often
bright colors, symmetrical.
• Down feathers: soft & fluffy to provide insulation
• Powder feathers: Release a fine white powder that prevents water from penetrating the down feathers – Water birds also have special oil
glands to repel water
• Assymetrical Feathers• Light, “hollow” bones• Respiratory system: air sacs
extended from the lungs into the body cavity
• Digestive System: no urinary bladder
• High metabolism rate
Structural & Structural & Physiological Physiological
adaptations for flightadaptations for flight
Structural & Structural & Physiological Physiological
adaptations for flightadaptations for flight
• Archaeopteryx is Archaeopteryx is defined as the first defined as the first bird on earth. bird on earth.
• This specimen dates This specimen dates back to the Jurassic, back to the Jurassic, 150 million years ago!150 million years ago!
• New specimens of New specimens of early bird or closely early bird or closely related dinosaur are related dinosaur are discovered every year!discovered every year!
• Archaeopteryx is Archaeopteryx is defined as the first defined as the first bird on earth. bird on earth.
• This specimen dates This specimen dates back to the Jurassic, back to the Jurassic, 150 million years ago!150 million years ago!
• New specimens of New specimens of early bird or closely early bird or closely related dinosaur are related dinosaur are discovered every year!discovered every year!
A r c h a e o p t e r y x A r c h a e o p t e r y x
A r c h a e o p t e r y x A r c h a e o p t e r y x
• Birds have high metabolic rates and burn calories to keep warm (endothermic!).
• Crop: enlarged area in the esophagus, where food can be stored and moistened before it enters the stomach. Sometimes stored food is regurgitated to feed young.
• Gizzard: Muscular part of the stomach that contains gravel swallowed by the bird. This then “chews” food, which makes it easier to digest.
F e e d i n g /F e e d i n g /D i g e s t i o nD i g e s t i o nF e e d i n g /F e e d i n g /
D i g e s t i o nD i g e s t i o n
• Air Sacs: enable birds to remove oxygen from the air when they inhale AND when they exhale – VERY efficient respiration! – Air sacs are also found in
some dinosaurs! – Can affect buoyancy in birds
with aquatic ecology.
R e s p i r a t i o nR e s p i r a t i o nR e s p i r a t i o nR e s p i r a t i o n
• Four-chambered heart
I n t e r n a l I n t e r n a l T r a n s p o r tT r a n s p o r tI n t e r n a l I n t e r n a l
T r a n s p o r tT r a n s p o r t
• Urine (uric acid) flows to cloaca where all the water is absorbed leaving uric acid crystals (paste like “bird droppings”)
• Some birds have specialized salt excreting glands near their eyes to eliminate excess salt
E X C R E T I O NE X C R E T I O NE X C R E T I O NE X C R E T I O N
• Well developed eyes - see color very well; see more shades of colors
• Sense of taste and smell not as well developed (with some exception – vultures!)
• Some have acute sense of hearing• Magnetic sense - birds use magnetic poles to navigate
long migration routes.
R e s p o n s e R e s p o n s e R e s p o n s e R e s p o n s e
R e p r o d u c t i v e R e p r o d u c t i v e S t r a t e g y S t r a t e g y
R e p r o d u c t i v e R e p r o d u c t i v e S t r a t e g y S t r a t e g y
Two primary strategies:•A l t r i c i a l - helpless at birth or hatching and require parental care for some time•P r e c o c i a l - able to move about and care for themselves to a considerable extent immediately following birth or hatching
top related