class aves: birds 18a
DESCRIPTION
Common Characteristics Covered with feathers Have thin-walled, often hollow bones (these bones are not lighter, but they are denser, stiffer, and stronger) Require enormous amounts of energy Demand lots of oxygen for respiration Are endothermic (warm-blooded) Have high metabolism Have no teeth (durable beak made of keratin is just as efficient but lighter) OviparousTRANSCRIPT
Class Aves: Birds
18A
Common Characteristics• Covered with feathers• Have thin-walled, often hollow bones (these bones are
not lighter, but they are denser, stiffer, and stronger)• Require enormous amounts of energy• Demand lots of oxygen for respiration• Are endothermic (warm-blooded)• Have high metabolism• Have no teeth (durable beak made of keratin is just as
efficient but lighter)• Oviparous
FeathersCare• Gland at base of tail produces oil• Preening- bird applies oil to feathers with its bill while it adjusts and
smoothes its feathers• Oil provides waterproof shield
FeathersFunction• Shape the body to make the bird aerodynamic• Help birds retain heat• Serves as cushion- protecting the skeleton during collisions• Help camouflage the bird or attract and identify a mate
FeathersStructure• Grow from a structure in the skin called a papilla• The feather consists of
– Flat vane which consists of parallel rows of thin barbs with parallel rows of thin barbules that are hooked together
– Rachis- shaft within the vane– Quill- hollow shaft from papilla to vane
FeathersTwo types• Down feathers make up the underlayer providing insulation as and cushion• Contour feathers are the vaned feathers that cover most of the body and give
external shape and color, and also the flight feathers which extend from the wings and tail
Feathers
• Fully developed feathers, likes scales and hairs are dead
• Bird sheds or molts old feathers and replaces them
Appendages• Forelimbs (wings) for flying• Penguins and some other flightless birds use their “wings” to swim• Lower part of the hind limbs are usually thin and covered with scales• Most birds have 3 or 4 clawed toes
Wings• Elliptical- short and wide providing for quick takeoffs and landings, low
speed flight, and maneuverability (sparrows, woodpeckers)• High-speed- thin, long, tapered shape that produces minimum drag
(terns, swifts, sandpipers)• Soaring- long and thin and resemble the wings of a glider; enable the bird
to expend minimal energy in staying aloft but provide little maneuverability (gulls)
• High-lift- wings are large and convex; they give a great amount of lift even at low speeds, allowing birds to carry large prey (hawks, eagles, owls)
Feet• Wading- long, thin, widely spread toes that distribute weight; thin
toes and legs permit movement in water without creating turbulence• Swimming- webbed and serve as paddles• Climbing- two toes in front and two behind to provide grip and
balance• Running- toes are strong and hoof like and support heavy birds as
they run along the ground• Grasping- toes with talons (long curved claws) designed to grasp and
kill prey• Perching- three front toes and one back toe; a locking device closes
toes and remains tightly closed until the bird releases it
Skeleton• A bird’s skeleton has numerous air-filled cavities within the bone• Elongated upper jaw (maxilla) and lower jaw (mandible) are elongated and form the bill• Vertebrae of the tail are free moving and help in guiding flight• The trunk vertebrae, the flat ribs, and the sternum (breastbone) are fused to make the
trunk a rigid framework• central ridge of the breastbone called the keel provides attachment for flight muscles.• Clavicles (collarbones) are enlarge and fused, forming the “wishbone” which also
provides attachment for flight muscles
Bird Systems
Digestion
• Birds need a lot of energy to fly so they have to eat a lot.
• They also have to be able to digest food quickly. They can’t carry heavy food around while flying and they need the energy.
Bill• The type of bill
depends on the bird’s diet
• Spearing fish- long slender
• Probing for insects- long slender
• Cracking and crushing seeds- short and stout
• Tearing prey- hooked pointed bills
• Filtering- bills contain throat pouch
Digestion• Esophagus• Crop- stores food. It is an
enlargement of the esophagus• Proventriculus- first part of the
stomach, produces digestive juices• Gizzard- second part of the stomach,
where grinding of the food (mechanical digestion) occurs. It has thick muscular walls. Birds swallow gravel to help grind the food.
• Intestines- final digestion and absorption
• Cloaca- serves as the common opening for the intestine, kidney duct, and reproductive organs
Respiration• Air Sacs- unique to birds– The lungs are unable to supply all the oxygen the bird needs to
maintain its high metabolism. – As the bird exhales oxygen rich air goes from the air sacs to the
lungs, so the bird has oxygen rich air passing through their lungs as they breathe in and out.
– Also make the bird light because they are located in places where fluids or fat would be in other organisms.
Respiration
• High metabolism produces a lot of heat• Respiration is important because it helps cool
the bird• They can rapidly move air in and of their air
sacs. The exiting air carries heat.
Circulation• 4 chambered heart• Oxygenated and deoxygenated blood completely
separated
Circulation• Relative to its body size birds have the largest hearts of
all vertebrates• 135-570 heart beats per minute (avg human heartrate is
60-100 bpm, could be around 200 bpm during exercise)
Excretion• Pair of dorsal kidneys• Waste empties directly from the kidneys into the
cloaca• Birds do not store urine or feces
Sound
• Syrinx- song box, enlargement of the trachea just above where it divides to enter the lungs
• Syrinx and associated muscles produce sound
Bird Mimicryhttp://www.youtube.com/watch?v=VjE0Kdfos4Y
Sensing• Reptiles, amphibians, and fish rely heavily on smell and taste• Birds rely heavily on hearing and sight• Vision of a hawk is 8 times more acute than that of a human• Owls can see in light 1/10 to 1/100 the brightness required by
man to see• Light receptors in the retina of a bird’s eye are packed from 2-
5 times more tightly than those in humans
Falconhttp://www.youtube.com/watch?v=r7lglchYNewEagle goathttp://www.youtube.com/watch?v=VklTs-Tid_IHawk- iguanahttp://www.youtube.com/watch?v=9vQuqg5hZYMBird of Prey- Snakehttp://www.youtube.com/watch?v=s-sHY1zSA2IBird of Prey- Sealhttp://www.youtube.com/watch?v=Ugxq3yLNk6gBird Ordershttp://www.allaboutbirds.org/guide/search
Behaviors
• Mating rituals
Birds of Paradise mating dancehttp://www.youtube.com/watch?v=L54bxmZy_NEPrairie Chicken mating dancehttp://www.youtube.com/watch?v=s2_wdMmEupQ