POUL 1010 study guide; TEST 1
1. Definition of bird: all feathered animals are birds. They are warm blooded and have
hollow bones
2. Anatomical differences between prehistoric birds and modern birds:
a. Prehistoric
i. Some had no feathers
ii. Some had teeth
b. Today
i. All birds have feathers, but single gene mutation results in nearly featherless
chickens
ii. All are toothless
3. Archaeopteryx: first fossil animal with feathers, found in Bovaria in 1861
a. Reptile with teeth
b. Had flight feathers on forelimbs and long tail
4. Reason for lack of bird fossils
a. Bird bones are hollow and break very easily so they break down over time/under
pressure and no fossil remains
b. Water birds have better fossils because they don’t have hollow bones
c. Some bird fossils are found around volcanoes because ash is soft and doesn’t crush
the bones
5. Evolutionary advantage of feather development
a. Provide insulation (down feathers and filoplumes)
b. To fly
6. Flight birds and flightless birds
a. Advantage of flying
i. Easier to escape predators
ii. Colonize new areas (trees), move longer distances to relieve overcrowding
iii. Find more food
b. Disadvantages
i. Use tons of energy
ii. Lose dexterity of hands b/c of wings
iii. Huge body size restriction (1.5 g-33 lbs is range of modern birds)
1. Swan is one of largest
2. Mammals body size range from mouse to elephant
iv. Low surface area= hard to regulate body temp
1. Hummingbirds must hibernate at night and eat twice body weight
c. Flightless birds
i. Before many predators, this was advantage because used less energy
ii. De-evolved from ancestors who did fly
iii. Found in closed ecosystems like New Zealand and Hawaii
1. Flightless was more successful here until more humans and
predators came
7. Anatomy and physiological adaptations for flight
a. Efficient respiratory and cardiovascular system
b. No bladder
c. No reproductive system until mating season
d. No eye muscles, teeth, little brain
e. Need center of gravity so no tail bone
f. 50-70% of bird head is the eyes
