Study #6: Test 3: Birds Flashcards
Diapsids
- *Amniote tetrapods
- *2 holes in each side of skull (temporal fenestra)
- *late Carboniferous period (300MillYrsAgo)
- *Descended from archosaurs
Members of Diapsids
Crocodiles Lizards snakes tuatara birds non-avian dinosaurs (theropods)
Theropods
Had feathers for insulation, water repellency, etc.
PREDATED FLIGHT
Archeopteryx-Jurassic
150 mya fossil
- *theropod dino w/ feathers
- *Many modern bird traits:
- clawed fingers to climb trees
- toothed beak
- long reptile-like tail
- hindlimbs for bipedal running
- short, rounded wings for gliding or short flight
Class Aves: Birds
1. Adapted for flight: wings feathers high metabolic rate endothermy vertebral column and bones with air spaces
Class Aves: Birds (cont.)
- Horny bill and no teeth
- Diverse feeding habits with different bills for specific habits.
- Endothermic with countercurrent heat exchange systems in feet
Generalized bill
Raven
Seed cracker
Cardinal
Worm burrow probe
American Avocet
Tears meat
EAgle
Fish spear
arhinga
dip net
pelican
nut cracker
parrot
mud shifter
flamingo
General Traits of Birds
- Feathers: glands secrete oil for water repellency
- Median keel sternum & paired clavicles for flight muscles to attach
- Flight muscles very vascular and a lot of mitochondria.
Anatomy of wing
Humerus with scapular feathers
Ulna with secondary feathers
Hand bones with primary feathers
Anatomy of skull
Sclerotic ring orbit for eye nostril maxilla & mandible quadrate (hinges maxilla & mandible)
Pectoral girdle
Fused clavicle, coracoid connects to sternum with keel, ribs connect to scapula
Pygostyle: end of pectoral girdle
Leg
Femur (thigh bone) Fibula/Tibiotarsus (shin) Heel Fused ankle bone 4 toes
Pelvic Girdle
legs connect into it
Wings
Form airfoil:
thicker anterior margins
convex upper surface
concave lower surface
Air flow around wings
Lowest pressure and most lift when air flows fast over upper surface
Smaller area of high pressure and lift underneath wing
Angle of attack (see slide)
Tail
Balance, steering and braking
Circulation: Heart
large and beats rapidly
Seperate atria & ventricles (res. in seperate pulmonary and atrial circuits) to prevent oxygenated and deoxygenated blood from mixing
Respiratory system
Complex and efficient
Air sacs throughout body that connect to lungs
Breathing
Inspiration and expiration results from expansion and compression of air sacs
- *takes 2 ventilatory cyclesto move air thru Resp. system
- *results in oxygen rich air at all times, very little dead space
Excretion
Similar demands to reptiles
**excrete uric acid
Osmoregulation
Salt glands drain excess salt in marine birds
Glands have lobe and central canal
Nervous system
well devel brain
**lg forebrain due to lg cerebral hemispheres
Vision
most important sense large eyes rel. to body size Double focusing mechanish Mono and binocular vision Both rods and cones
Hearing
well developed
Olfaction
poor
