Exam 1 Flashcards
Why are birds so popular?
they sing and dance, they have been serviceable to humans, we’re jealous that they can fly, they are colorful and visible
What have birds use been through time?
canary in the coalmine, carrier pigeons, honeyguide, birds helping Polynesians find islands
Do you believe the ivory billed woodpecker exists? Why or why not?
Yes, because the papers that argue that it does exist have experimental evidence, where the others do not. One paper that argues the woodpecker does exist sites 14 occasions where they identified birds with characteristics of the ivory-billed woodpecker. They also found holes of woodpeckers much larger than the pileated or any other woodpecker would make
What makes a bird a bird?
feathers, pneumatic bones, unique respiratory system, no teeth, digitigrade
Does evolution pose a problem for your faith, why or why not?
No it does not. God created the world, species and us somehow. Why couldn’t that process be evolution?
Why do people believe that birds have a reptilian origin?
Because their skulls have many features that are similar between them:
- lower jaw composed of many bones
- sclerotic ring (bone in eye)
- single middle-ear bone
- single occipital condyle
Theropod or thecodont origin and why?
Theropod. Because we have found several genera with feathers, and they have very similar proteins.
What factors are responsible for current bird distribution?
History (continental drift), ecological tolerances, distribution of habitats, matching species to location
what are the general patterns of molt?
Most birds molt sequentially, one feather on a time on either side of the bird in order to maintain balance. More rarely, large waterbirds will molt all of their feathers at once
what are the types of feathers?
vaned feathers - flight feathers, contour feathers.
Downy feathers - no vein, insulation, semi-plume
Other - bristles, filoplume
What’s the general structure of a feather?
calamus, rachis, barbs, barbules, hooklets
What are the general patterns of plumage?
Birds have pteryla (tracts) - areas where lots of feathers are growing, and apteria - areas where feathers don’t grow (but are still covered by feathers)
What are the mechanics of flight?
Gravity - overcome with lift (air foil shape of wing)
Drag - overcome by thrust (wing flapping)
What are the types of flight?
Thermal / slope soaring - use of thermals, key is uneven heating of the groundd
Dynamic soaring - utilizes differential wind speeds above the ocean
Flapping, hovering, intermittent flight
flap bounding - starts flapping when heading down, quit flapping before hitting apex.
Flap gliding - flapping up to an apex, then soaring down
flight adaptations to avoid stalling?
Alula - bird “thumbs” help smooth the air moving across the top of the wing
Coverts - lift up to prevent stalling when landing
Tail- helps smooth out and prevent turbulance
Explain wing loading vs aspect ratio
Aspect ratio - the lenght of the wing / width of wing
wing loading - body mass of bird / area of the wing
what are the extremes of flight?
Frigate birds and albatross can fly for extremely long periods of time without rest. Hummingbirds are extremely agile, flying backwards, forwards and hovering
Key differences between circulatory and respiratory system
respiratory - small lungs that wrap around the ribs, no diaphragm, air sacs, unidirectional flow of air
circulatory - large heart, high blood pressure, high glucose levels, paired veins + arteries maintain core temp
circulatory and respiratory system adaptations for flight
circulatory - large heart, fast heart beat and high pressure delivers nutrients quickly to muscles, thin capillary walls allow for rapid diffusion of gasses
respiratory - Allows for more efficient breath due to unidirectional flow and no mixing of high- and low-oxygen air
general structures, unique adaptations of birds
air sacs, ribbed lungs, paired arteries/veins, high glucose levels
Endocrine and urogenital systems - differences, unique adaptations, relation to flight, key structures
Endocrine - greatly reducesed, whd or lost. Pineal gland and pituitary gland present, and a few others.
Urogenital - much reduced. One sided. No scrotum, no penis. Male system degenerates when not breeding. Makes birds lighter and more aerodynamic. Both have cloaca and the cloacial kiss
What are uncinate processes and their function?
uncinate processes are projections between the ribs that help create negative pressure
Endocrine and urogenital systems - differences, unique adaptations, relation to flight, key structures
Endocrine - greatly reduced or lost. Pineal gland and pituitary gland present, and a few others.
Urogenital - much reduced. One sided. No scrotum, no penis. Male system degenerates when not breeding. Makes birds lighter and more aerodynamic. Both have cloaca and the cloacial kiss
Key muscles and adaptations
the low, central center of gravity aids in flight. Large muscles, up to 1/3 of total bodyweight.
The pectoralis and the supracoideus work antagonistically to beat the wings in flight.
The AHL, attaching the humerus to the shoulder, was critical in the evolution of flight
