I'm like a BIRD I wanna fly away I don't know where my home is. Flashcards
what’s probably the ancestor to the bird?
Theropod dinosaur
what are shared characteristics between birds and dinosaur ancestor?
- bipedal - 3 hind toes
- carnivorous
- 4 chambered heart
- similar lungs
- feathered
- hollow bones
- parental care of eggs and juveniles
Characteristics of a archeopetryx
- crow-sized
- feathers
- wings
- teeth
- bony tail
How many species of birds are there?
9600
characteristics of birds
amniotes
characteristics of birds
endoterhmic
characteristics of birds
4 chambered heart
characteristics of birds
completely separate pulmonary and systemic circuits
characteristics of birds
feathers
characteristics of birds
most can fly
characteristics of birds
diverse beaks = diverse diets
thermoregulation definition
body temperature control
Ectotherms
- absorb external heat
- depend on environment
most mammals are
ectothers
Endotherms
generate their own internal heat through metabolic process
How do endotherms generate heat?
Less efficient at transforming energy
metabolic rate is the …
sum of ALL energy expenditures
It was thought that the metabolic rate of lizards would _____ as temperatures increased
increase
In the field, what was the body temperature of a lizard?
the lizard maintained its body temperature at a different temperature than its environment
How does a lizard maintain its body temperature between upper and lower limits?
by moving between hot and cold microhabitats
what are the three types of thermoregulation?
- behavioural
- physiological
- physical
Example of physiological thermoregulation
human thermostat
- if temperature is too high: sweat - evaporative cooling
- temperature is too cold: decrease blood flow to periphery, shivering
Behavioural thermoregulation
orientation relative to heat source - basking, huddling and varying contact with heat surface
- moving locations throughout the day
Physical thermoregulation
- insulation (fur, feathers, fat)
- colour
- ratio of surface area to volume
Flying and endothermy demand large amounts of…
oxygen
Describe the Respiratory system of a bird
- unidirectional flow of air through lungs
ventilation in birds: breath 1
- air is drawn into the posterior air sacs
- air is propelled through the lungs
ventilation in birds: breath 2
- same air is drawn into the anterior air sacs
- same air is propelled out through the nares
how many cycles does it take for any breath of air to go in and come out?
2 cycles
how many times has flight evolved?
4 times
in what organisms did the evolution of flight occur in?
- insects
- pterosaurs
- birds
- BATS (only flying mammal)
Convergent evolution are similarities due to
common environment but not a common ancestor
Adaptations for flight
hollow bones
Adaptations for flight
sternum enlarged and keeled
Adaptations for flight
increases surface area for attachment of large flight muscles
Adaptations for flight
feathers - theropod dinosaurs had feathers for insulation
what is the function of feathers
insulation, flight, sensory structures, lining nests
what are feathers composed of?
keratin - derived from scales
how do wings enable flight?
- object changes air flow pattern and creates lift
- particles must move faster to get over bump - accelerated flow around an airfoil
Chukars
- hatchlings run from danger often up steep inclines
- they flap their wings
- angel of wing flapping created traction rather than lift = “wing-assisted incline running”
- this perhaps then evolved into FLYING
